During the test flight of a Boeing 717 over the Pacific, off of the coast of California, the plane flipped upside during an intentional stall.The skilled pilots managed to recover and land safely.
Posted by Twitter_2006@reddit | aviation | View on Reddit | 561 comments
CarrotWaxer69@reddit
What was the altitude? Before and after. How well can you predict how an aircraft will behave at syall?
Loud-Aioli-9465@reddit
It's my understanding they were at 15,000 feet when the manuever started. Pretty not ideal.
this_shit@reddit
you can see the elevation go from five digits to four while their dive is still vertical đŹ
BabyBubblezs@reddit
Jesus imagine what was running thru there minds
icarusbird@reddit
With as many hours as it takes to be a commercial pilot, I guarantee they were 100% locked in on regaining control authority and leveling the aircraft. Not hitting the ground was priority 3. Anything beyond that was bandwidth they couldn't afford to spend.
DingDangDongulus@reddit
The PIC in this video is Bear Smith. He was a Blue Angel before he came to McDonnell-Douglas as a flight test pilot. Because he was a BA, he knew it was best to roll all the way through, rather than fight the roll & try to roll back. I knew Bear well & flew many MD-11 & 717 flights with him. Odd coincidence: his parents & my parents lived across the street from each other in a Hemet mobile home retirement community. Great people all around. The co-pilot in the video was Tim Dineen, also a pro of the pros when it comes to test flying .
OEMregEng@reddit
Both are gone now.
DingDangDongulus@reddit
Indeed it was. I spent many flights with him testing auto flight systems. I'm still in contact with him on LinkedIn. He's up in NorCal.
BabyBubblezs@reddit
Well im glad they have such strict requirements !
stephen1547@reddit
Literally nothing but the task at hand.
Nicker@reddit
You can make it out in the top right video,
Started at 20,100 stabilized at ~2500..
big yikes.
Xianxia@reddit
It's 15.1k to 5700.
flagrananante@reddit
*puckering intensifies* Eeeeek!
well-that-was-fast@reddit
They may have needed to test a stall / wing performance at a certain air pressure which required being at that altitude?
So, testing at this altitude might have been unavoidable and considered low risk if engineers had no hint at whatever caused this was going to happen.
Still a but shocking to hear the "altitude . . . altitude" warning with the horizon showing 80% earth and the stick shaker going. Yikes.
VillageIdiotsAgent@reddit
The âaltitudeâ alert just means they are off of their selected altitude.
Itâs the âwhoop whoop pull upâ that is the scary one
mysteryofthefieryeye@reddit
Stupid question but what detector causes the "pull up" and does it work if the plane is upside down? Like, does the sensor know the ground is above the plane?
jkrejcha3@reddit
It depends, but the Honeywell EGPWSes uses various different altitude sources, including GPS altitude, radio altitude, and pressure altitude into what they call "geometric altitude" (reference, p. 6) combined with a database of terrain and obstacle features.
For SINK RATE/PULL UP (mode 1), it's based on the descent rate and height above terrain (the margin between the alert (SINK RATE) and warning (PULL UP) is a bit higher at higher altitudes.
For TERRAIN TERRAIN/PULL UP (mode 2), it's based on the rate of terrain closure.
(EGPWS has other modes too such as those for altitude loss during takeoff (DONT SINK), too close to terrain (TOO LOW TERRAIN), altitude callouts (which ones are enabled depends on configuration of the system itself), and windshear alerts)
BabyBubblezs@reddit
Not ideal is an understatement haha
Clementine-TeX@reddit
jesus . . just proves that that manâs amazing at his work
Phraoz007@reddit
You can see in the video (kinda) 15,000 -> 5,0000 10k feet
deleted_by_reddit@reddit
[removed]
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DudleyAndStephens@reddit
If the story I read was true this behavior was unanticipated and only happened in one test aircraft.
I'm going on memory here and can't cite a source, but what I read was that only one of the planes used in testing did this. They couldn't recreate it or figure out why that one airframe had the issue so they ended up scrapping it. Could be BS, I can't vouch for the story's reliability.
thisisinput@reddit
Started at FL150, and it seems they recovered at FL65ish.
Whimsy69@reddit
Thatâs not how flight levels work
theArcticChiller@reddit
Tell me you have no idea of ICAO without saying you have no idea of ICAO
Whimsy69@reddit
Explain to me how that applies to airspace off the coast of California
discard1198@reddit
In Europe it can be. Us Americans start at fl180 but it's not the same across the worldÂ
Whimsy69@reddit
Video clearly states off the coast of California. Thatâs not how flight levels work
discard1198@reddit
I'm just saying that some people may refer to it that way and not realize that's not how they work in the states, since it could be correct in other counties.
khando@reddit
Flight Level starts being used at the transition altitude, so you would just write that as 15,000 feet and 6,500 feet.
theArcticChiller@reddit
The ICAO recommendation for transition altitude is 3000ft. Doesn't make much sense. But still, FL 150 and FL 65 is correct in aviation terms
No-Engineering-1449@reddit
ICAO yes, USA no
Illustrious-Peak3822@reddit
Simulation.
IRideZs@reddit
Whole lot of people didnât understand what you were getting at
Illustrious-Peak3822@reddit
Indeed. People here perhaps donât work in design and engineering?
pulse7@reddit
They think you're talking about this video and mistakingly telling you it's not a sim
HG-Beutler@reddit
you wouldn't be able to do that right now either.
Illustrious-Peak3822@reddit
Depends, with a GPU farm and Airbus/Boeing budget, it should be possible but probably not warranted. Straight up turbulence will be a bigger noise factor than all the rivets.
HG-Beutler@reddit
I was recently at a conference where someone from Airbus gave a plenary talk about their simulation chain, and as far as I remember, the âfull modelâ (the complete airplane) was ridiculously coarse by todayâs simulation standards. They definitely didnât resolve any rivets.
Illustrious-Peak3822@reddit
Interesting! But again, the plane isnât flying into a stagnant and even chunk of air mass in real life, which would be a bigger component to factor in than rivers.
deltaforce5000@reddit
Nope
Fluffy_Ideal_3959@reddit
Why shouldn't simulation be able to predict stall?
scottydg@reddit
You can literally see the sun casting shadows a they rotate.
thabc@reddit
The question was
What do shadows have to do with this? I think you misread the above comment, thinking it meant this video is fake. They meant that "simulation" is used in aerospace engineering.
Illustrious-Peak3822@reddit
Finally someone with reading comprehension. I took the liberty to inline the original question.
kursneldmisk@reddit
Because simulations never have shadows, right
Illustrious-Peak3822@reddit
Sure, but the question was how you can predict it, i.e. without testing it for real. You simulate it.
Centaurtaur69@reddit
Sims don't predict stalls on aircraft very well.
The closest we can get is through aerodynamic simulators that simulate air tunnels. But even then you can't fully predict everything (for example: changes in center of gravity and how that will affect handling)
Illustrious-Peak3822@reddit
Thatâs one way to simulate without actual air flight.
Yahit69@reddit
They were in a slight right bank and probably slowed to stahl speed. All predictable
TheTopButton@reddit
And here I'm panicking when I get to the kitchen in the morning and realize I'm outta coffee....
av8geek@reddit
Stabilize... Stabilize... Stabilize...
Desert_Trader@reddit
I'm out of coffee too.
Worst part, I forgot to get more again today
TheTopButton@reddit
đąđąđą
NoIdenty0000@reddit
Are there ppl inside????
th3orist@reddit
Happy to see this because i was under the impression that the frame of a commercial airliner could not take this kind of stress.
FZ_Milkshake@reddit
Up to 2.5g is not a problem at all, around 3.5 is what most are designed to handle without massive issues and there are instances of much higher forces.
Sposedtolose@reddit
Iâd like to hear some instances please
BlackadderIA@reddit
TWA814 had an asymmetric slat deployment in cruise flight that send the B727 into an uncontrolled spiral dive.
The max rate of descent peaked at 76000 feet per minute and witnesses on the ground heard a sonic boom as the aircraft allegedly went supersonic in the dive.
The crew deployed the landing gear in a last ditch attempt to save the aircraft, ripping off all the gear doors and twisting one of the main gear through 90 degrees. They then pulled 6g in the recovery.
They landed safely, presumably then buying new pants and buying lottery tickets.
darkenthedoorway@reddit
Dont you mean 7600 ft per minute?
BlackadderIA@reddit
Nope. They apparently averaged 35000fpm with a brief peak of 76000fpm. The aircraft did at least two full 360 rolls eventually pointing straight down at cruise power. Peak Mach number was calculated at 0.96 which is utterly bonkers for an airliner and means that parts of the airframe would have almost certainly seen supersonic airflow.
Pulled 5.5G in the first 360 and 6.0G in the second. Incidentally, the report mentions some passengers were actually stood in the cabin during this and âsustained some bruisingâ when forced to the floor.
Lowering the gear helped reduce the speed but the offending slat tearing off is what allowed them to regain control.
I believe the crew were actually vilified by the FAA. Their suspicion was they accidentally extended the slats while trying to add a tiny bit of flap during the cruise for some odd performance reason. The slats all extended together when the flap lever was moved too far, were quickly retracted again, but the number 7 slat jammed and this caused the asymmetry.
FZ_Milkshake@reddit
727 Crews sometimes did that at high altitudes. They'd pull the circuit breaker for the slats and go to the first notch of flaps. Initially the flaps just extend without deflecting this increases wing area and give a bit better high alt performance.
Chairboy@reddit
I think they meant exactly what they typed, that is basically VNE straight down.
darkenthedoorway@reddit
When you use the 'peaked' at 76000ft pm it implies the aircraft held this rate for a minute, which isnt possible. Sorry for the confusion I misread.
Chairboy@reddit
It doesnât, though? In aviation we refer to fpm ascent/descents because we have a gauge that reflects our vertical speed that way. There is no requirement for it to be sustained for a full minute.
darkenthedoorway@reddit
I understand, which is why I said I misread.
NumbersRLife@reddit
Im sorry but that plane did not go 51,000 mph otw down lol.
7,600 fpm is a ton though.
Chairboy@reddit
I think you might have done your math wrong, did you calculate 76,000 ft./s instead of per minute?
NumbersRLife@reddit
34,000 ft / 1.05 minutes = 32,381 fpm
How is that wrong?
Chairboy@reddit
You wrote:
This is 76,000 feet per second
From the post you responded to (emphasis mine):
Above you wrote:
This presumes that the plane dropped at the same velocity from the moment it began its descent until it leveled out. The text is very clear that the rate of descent peaked at 76,000fpm which is in line with a plane that experiences a descent that begins slowly, ramps up to a maximum descent rate, then begins to level out. The averaged descent is 'just' 32,000 fpm but the maximum rate of descent was measured at 76,000 fpm.
NumbersRLife@reddit
I see. So I did the math correctly for average, but it would make sense there was a faster period and a slower period of descent in there. Makes sense! Incredible they were able to pilot the plane in those conditions and that the airplane stayed together. Maybe the best save of all time? Except for that movie Flight of course ;)
Chairboy@reddit
Agreed, there are some pretty amazing pilots out there, I could only hope I'd survive the same situation!
SoylentVerdigris@reddit
That would be the average rate of descent, not max.
Sposedtolose@reddit
Rate of decent was 76,000? B727 isnât even supposed to reach Mach speeds right? Thatâs absolutely insane!
NumbersRLife@reddit
TWA 841*
MoreTeaMrsNesbitt@reddit
Itâs impossible to know exactly, but AA175 experienced an insane amount of stress before it struck the south tower on 9/11. Sustained power dive 24000ft in 5 minutes and banking hard. Many passengers vomiting
mig82au@reddit
-4800 fpm is nothing special. It's not even an emergency descent, which is a mandatory tested maneuver.
FZ_Milkshake@reddit
China Airlines 006 a pretty similar incident to this in a 747 but the pilots were not as prepared and the aircraft full of passengers so the forces went up to 5.1g. Aircraft landed safely.
Sposedtolose@reddit
Next time I fly Iâll have to ask the pilot to give me a demonstration of this sort! Iâm imagining some sort of unmanned commercial jet acrobatics, like whatâs possible beyond the human limit
NotCook59@reddit
That would be a story to tell the grandkids! Theyâd be like, âRight, Papa, like that really happened.â
capt_jack994@reddit
By buddy, a retired AF colonel said a guy from his squadron had a flight control issue in a F15 at night over the pacific. He ended up in a dive at mach 1.4 and pulled 13Gs in order to not hit the water. He was able to fly the jet back home but in the process the airframe sustained irreparable damage, including shearing the engine mounting bolts and the engines were flopping around loose in the airframe.
XxRAM97xX@reddit
How many gs can a fighter jet handle ?
FZ_Milkshake@reddit
Usually between 8 and 9g regularly.
Mean_Magician6347@reddit
Thatâs how many the human body can handle.
The plane can handle more.
Jetfuelmakesmewet@reddit
Thatâs not true.
Firstly, itâs airframe dependent. Most jets that fly in the world canât handle 9G without structural damage.
Of the 9G capable jets, they have been specâd to 9Gâs and have a high chance of damage above that.
There are designs that are capable of exceeding 9Gs but those designs arenât typically manufactured due to cost of materials and human capabilities as well for manned aviation.
IHeartData_@reddit
And to add it's pointless, as adding enough strength to exceed 9+ regularly will increase weight, hurting the rest of the performance envelope where dogfights mostly occur. Dogfights aren't spent primarily at 9g because of the energy losses.
Arthree@reddit
Dogfights aren't really a thing at all, anymore. If you end up merged with someone, you already screwed up.
But also, dogfighting isn't really about energy anymore either. Modern fighters with FBW, thrust vectoring, and all-aspect, high off-boresight heat seekers enable them to point their nose and hit the other plane long before energy allows them to get around the circle.
Theory89@reddit
Uh, I'm pretty sure I saw some 5th generation fighter jets having dogfights in the documentary "Top Gun: Maverick"
CrunchingTackle3000@reddit
I was waiting for someone to start spitting straight scientific facts to educate these pleebs. Thanks man.
ASDFzxcvTaken@reddit
Anytime, Ice (chomp) man.
PresentationJumpy101@reddit
lol if f/a 18 hornet 2.0 taught me anything, is that battles are won from 30 miles away, with an amraamâŚand target view padlockâŚand like 25 seconds of blinking at the enemy mig-23âŚ.wait for itâŚâŚâŚ.waaaaait for it
Gwthrowaway80@reddit
Modern maneuvering has become focused on breaking away after deploying countermeasures.
PorschephileGT3@reddit
Which sort of doesnât matter anyway when youâre shooting from 200nm away.
But watching thrust vectoring at low speed in action is worth all the needless expenditure, imo.
decollimate28@reddit
2D vectoring on the F22 actually has a lot of utility outside of dogfighting. Makes supersonic / high altitude maneuvering significantly more efficient.
mr_potatoface@reddit
This was the original purpose of the F-14. To never engage in dogfights. Powerful radar, long fucking range missiles. Fly in, dump the missiles, get out, no dogfighting.
But then it became sort of useless because its radar lacked adequate Friend/Foe identification and couldn't be used in any type of combined arms scenario beyond visual range like in the Gulf.
Nicedudeyesdude@reddit
Yes and no. We still very much train to dogfighting. When everyone is stealth, you just end up at merges a lot more actuallyâŚ
tempskawt@reddit
Nope
Fibonacci_1357@reddit
You know he flies F-35s for a living right?
Acoustic-Regard-69@reddit
Yes you may not pull 9+ during a dogfight anymore but you sure as fuck will when your controller tells you there are 3 missiles flying at you as he speaks.
god34zilla@reddit
Link?
--Dirty_Diner--@reddit
It was a simple search on YouTube, but here ya go, lazy redditor
SU-34 evading Patriots over Ukraine
SilentSpr@reddit
Thatâs not a real source thatâs military-sim game larping as combat footageâŚâŚ.
--Dirty_Diner--@reddit
They are more than welcome to do their own search.
SilentSpr@reddit
The burden of proof is on the one making the claim. They do have to do anything, they can just not believe what youâre saying if you donât back it up with something valid. A simulation is not valid evidence of something in real life
Oh_ffs_seriously@reddit
To be fair, the author of the video used the audio-only recording that he then linked in the description.
theaviationhistorian@reddit
Most of the arguments above might qualify if we didn't have an ongoing war where engagements and countermeasure maneuvers are far closer and more common than the BVR launches many believe is the future.
Nicedudeyesdude@reddit
I can assure you no controller is telling me when there are any missiles flying at me hahahaha. You also canât just make the jet pull more than 9Gs. The FCS will limit you to 9.
SilentSpr@reddit
Or the F16 pilot evading 6 missiles during desert storm with a defective countermeasure system.
Terrh@reddit
I know reddit really thinks this, - but every recent incident involving fighter jets (ukraine war, israel, India/Pakistan battles, etc) shows that dogfighting and high energy manoeuvring are still very much a thing.
There's a reason why every nation on earth that has fighter jets spends the majority of their training money on WVR tactics, and it's not because it isn't really a thing anymore.
Candymanshook@reddit
Everyone who says things like what you quoted sounds like the panphlet for long-distance air to air interceptors.
Nicedudeyesdude@reddit
We do not spend most of our training on WVR. But it is certainly important, and youâre pretty on the money with the fact that most of it comes down to it when all the fancy stuff stops working.
irregular_caffeine@reddit
Every incident involving F-35 (Israel in Iran) had the opposing fighters literally bombed on the ground
Terrh@reddit
And what happens when it's not F35 vs 3rd gen fighters, but is instead F35 vs J-20 or F-16s vs J-10/11/16/35s?
irregular_caffeine@reddit
Probably something like India-Pakistan this year when there were ~110 planes in the air, whole battle was BVR, and a Rafale was downed at 200km
https://www.reuters.com/business/aerospace-defense/how-pakistan-shot-down-indias-cutting-edge-fighter-using-chinese-gear-2025-08-02/
Arthree@reddit
The recent incidents you're talking about are mostly fighter -> drone kills and involve cold-war era fighters and missiles.
And also, training for BVR is a lot easier to do in a simulator or a classroom. It's not surprising that it's cheaper to train for that.
Distinct-Nectarine-9@reddit
Well commercial freighters have 9G bulkheads and nets aft of flight deck, to help with sudden stoppages and freight/igloo shifting.
Galf2@reddit
fighter jets rated to 9G can take MUCH more than that, it's just that 9G (clean) is the rated maximum for decades of service life without flying a banana in 2 years.
If you are in a combat situation that limit goes out of the window, coming back alive is much more important, which is why there's easy to reach temporary overrides that allow to pull much more than that without actual critical damage to the plane, it will still fly just fine, you're just destroying its service life drastically, but better than catching a missile.
tempskawt@reddit
[citation needed]
NotCook59@reddit
I get your point, and I agree, but part of âcoming back aliveâ usually depends on the wings not coming off. Or even just one coming off. Just sayin.
Galf2@reddit
my point is that they're not coming off, they're going to bend
NotCook59@reddit
Well, the could come off, too. I suppose spars could just bend, and might make it interesting to fly, but thereâs a real possibility that they would break.
DODGE_WRENCH@reddit
Of course they could, the whole plane could also come apart in forward flight and that has happened before.
The point is aircraft (and most other things designed by engineers) are almost always derated below their actual capabilities. Engineers had to set a limit somewhere but they still know that the limit will be broken regardless of what it is.
Galf2@reddit
they're not derated, it's that the G limit is built with decades of service in mind, that's all - it's why the plane will come back, but the maintenance crew will rip you a new one with all the work that will be necessary to check if the plane is still straight lol
DODGE_WRENCH@reddit
You just described derating, the limit is set lower than the actual point of critical stress so the plane can have a usable service life.
Galf2@reddit
the point is they won't unless you pull like 25G lol (random number here, but as I said: the pilot would immediately pass out long before any G loading capable of breaking the plane)
joshTheGoods@reddit
Yea, standard safety factor is 1.5x, and so a 9G airframe like the F-35A was definitely tested to 13.5G which would be considered the ultimate load. Hit that and the airframe is basically guaranteed full write off.
ZugerPL@reddit
There are videos online of F-14B HUD with G-meter maxed out at over 10G - and the thing was rated for only 6.5G during normal operations. Above that these were 20-years old airframes. Also, some pilots managed to break Tomcat's G-meters pulling roughly 12-13G and besides that nothing bad really happend to jet.
Galf2@reddit
yup, with wings swept in if you don't put load on them the body of the plane acts like a wing with huuuuge load capacity
JudiciousSasquatch@reddit
Reminds me of US submarine operational depth maximums versus Russian.
merlin_34@reddit
Look up the difference between limit load and ultimate load.
TheTense@reddit
Watch in cockpit view of red bull air races. They have the G meter as the primary instrument. Youâll see it flash red when the tickle above 9G
theforbinprojects@reddit
You're not kidding, I had to look this up
AboveAverage1988@reddit
And these guys do it without G-suits. For a lot shorter periods admittedly, but still, any normal person would be out cold in fractions of a second at 10G+ without a suit. Oh, and, I have no idea what sort of capabilities the human body has in these conditions, but competition aerobatic planes are generally rated +-12G, i.e. from a structural point of view they can pull -10G or more too. Highly doubt anyone can do that for more than a tiny fraction of a second though.
elwiscomeback@reddit
And that's because exceeding 10/12G means disqualification. They were certified to 12G, with simulations showing that they can handle up to 20G.
I miss the races.
Individual_Tie_9740@reddit
SO THAT'S WHY IN TOPGUN 2 THEY WERE GETTING ON MAVERICK FOR POSSIBLY DESTROYING THE FIGHTER WORTH MILLIONS BECAUSE OF THIS BRASH AIR COMBAT DRILL TRAINING FLYING....
4rch1t3ct@reddit
Maybe for older fighters. Most modern fighter frames are rated for like 12G.
They are rated for higher because 9G is a regularly used turn in a fighter. If you were pushing it that close to structural damage all the time the frames wouldn't last very long. They still have built in margins.
That was true for aircraft who were structurally limited like the F-4 or F-14.
Likos02@reddit
Code 3 due to over-G. Fun days.
Sleep_adict@reddit
Hence pressurized flight suits
Galf2@reddit
they're not pressurized they're only meant to tighten around you to help you sustain G loads, but they're far from pressurized, those are actual almost space suits used by really specialized planes like the SR-71 due to how high they went, so you need these suits to ensure survivability. Pic related, this is a pressurized suit.
NotCook59@reddit
Youâre referring to a G suit, not a pressurized suit. A pressurized suit is not a G suit.
Tiny-Character-1252@reddit
But G suits do use pressure to achieve their goal right?
Galf2@reddit
yes but it's just constraining your blood flow so you don't black out. Blood wants to pool up when you pull G's, either in your legs (blackout) or in your head (redout)
G suits tighten when you pull G's to slow down the blood so you can handle a bit more G's.
fun fact there's also a biological reason I forgot but women handle G's slightly better
Jaded_Turtle@reddit
Men maybe more naturally vascular to deliver blood to higher musculature in the body.
Tiny-Character-1252@reddit
You are misunderstanding the definition of pressure.
The atmospheric pressure was normal today.
The pressure on my legs helps keep blood in my head so I can pilot.
They hydraulic line operates at 100 pounds of pressure per square inch.
PieMan2k@reddit
That has nothing to do with the g limitations of aircraft
Tiny-Character-1252@reddit
Did anyone mention drones or AI aircraft? Or are you thinking they are drop testing the airframe?
What is the context where an unconscious pilot from g forces is not a limitation?
Jaded_Turtle@reddit
There is really no use case for high G escape maneuvers in unmanned aerial vehicles (UAV). Unless youâre talking small interceptor aircraft.
brennons@reddit
You can bend the frame of any fighter by over Gâing it. The F-18 only can take 7.5 at 9.0 it WILL bend the frame and condemn the aircraft.
B1G_D11CK_R111CK_69@reddit
20 g plus for a short period of time.
LickNipMcSkip@reddit
maintenance crew chiefs hate this man
NinthTide@reddit
But what the enemy doesnât know is your limits. I intend to find them. Push beyond. Today weâll start with what you only think you know.
MasklinGNU@reddit
Confidently incorrect, classic Reddit. Most fighter jets arenât rated for much above 8 or 9 gâs, actually, itâs not just pilot fragility that limits them
Bad_Idea_Hat@reddit
You'll bend an F-14 at around 6.5-7.5 I believe.
Hopeful-Addition-248@reddit
Not true. Many jets need extra inspection after an excess of 7.5 G's.
Especially older airframes and planes that take a lot of G's (like the F-16N's) often just do not hold up over time.
With any ordnance it very quickly goes down to 4G's max.
Onsett is also extremely important. A very fast onesett of G can cause damage while a gradual one is way nice to the airframe.
Not to mention that if there is roll in the pull it very quickly can warp/destroy the airframe.
TheCraftyWombat@reddit
You don't know what you're talking about đ
hegykc@reddit
Not really.
Fighter planes are electronically limited to 7-8-9 G's. There's a lever on the flight stick that a pilot can pull in case of emergencies, that allows them to go beyond that. But if they do, the plane has to go through all out maintenance procedure and will probably get scrapped due to safety concerns over possible structural damage.
Aiderona@reddit
Heard that button on the stick will make you pass out. F22 i think maybe.
hegykc@reddit
It might and probably will, that's why it's emergency only. But pulling out of a dive and passing out is better then just slamming into the ground :)
NotCook59@reddit
I hate it when that happens.
Uncle_Bobby_B_@reddit
No thatâs completely false
VerStannen@reddit
Do fighter have a âG meterâ (or whatever itâs called) that measures G forces?
FZ_Milkshake@reddit
Yes they do have accelerometers (that is what they are called) and modern jets have software limits so the pilots don't exceed the rated go force. Modern airliners have them as well, but I don't know if the pilots can see the value directly or if it's just recorded in the background.
Alternative_Past_480@reddit
I'm on an atr 72 600 and you can see the max airborne and landing g after it's happened, I'm sure every plane is different.
VerStannen@reddit
Sweet thanks!
UniqueIndividual3579@reddit
Yes and it got a student busted at AF pilot training. He was solo in a T-38 and over G forced the jet. He reset his g meter after landing. But the back cockpit also had a g meter. He was out.
VerStannen@reddit
Oh dang he got booted from the program?
Iâd imagine lying and then trying to cover it up was his downfall. Wonder what wouldâve happened if he was just honest and admitted his mistake. It couldnât have been the first time an airframe got over gâd during training.
UniqueIndividual3579@reddit
Trying to cover it up was the problem. If he had admitted it, he would have gotten a lecture and that would be the end of it.
VerStannen@reddit
Yep for sure!
Like I said, it couldnât have been the first time itâs happened at probably wasnât the last, but lying and the attempted cover up is NOT a good look haha.
UniqueIndividual3579@reddit
You had "the student shield", students were expected to screw up. Some actually crashed and stayed in the program. After an over g, the jet needs to be checked out. A structural flaw could have gotten another student killed. It could even be a few years later.
There was another student, before my time. His first ride in a T-38. The wing came off. The student and the instructor ejected. The instructor looked at the student and he had a streamer, the shrouds were over the top of his parachute. The student was casually floating on his back and flicking the cords off one by one until the chute opened. The student was a former Army paratrooper.
VerStannen@reddit
Wow that dude was cool as ice đ§
UniqueIndividual3579@reddit
Air Force parachute training was a lot more basic. They hooked you up to a rope on a pick-up in a big field and as you started to run two others were holding a chute open. You got up to about 100 feet and disconnected the rope and landed. The other trainer was a swing trainer, over a gravel pit. Various heights and you learned how to land. Had this old Sergent who would say in a deep southern voice "it's self correcting". I go off the high one, about 10 feet, and forget to hunker down my head. It bounces off the gravel. I'm laying there dazed in my helmet. The Sergent walks over, looks down at me and says "It's self correcting."
And the gravel pit drops were on a Friday, it was hard to walk Saturday.
VerStannen@reddit
What I say you boy, itâs self correcting!
lol great stories man!
Anon387562@reddit
Pilot is the limiting factor, jet can handle more.
77going2heaven@reddit
Not true. The top aerobatic pilots pull from what I know up to +12Gz and some even push that much negative.
Most airplanes lose their wings we'll before that.Â
Anon387562@reddit
Yeah for a few seconds. When you crash your car you may survive 50Gz, but Iâm talking about the standard for jet pilots. Also still pilot remains the limiting factor. You will pass out before breaking the aircraft if itâs not a batshit crazy stick yoinkđ
77going2heaven@reddit
In a car crash you usually don't experience acceleration in the Z axis. It's the same reason astronauts are basicly lying on their back when launching to space.
G tolerance is trained and has to be maintained. If you or I were to now strap into an aerobatic plane and push f.i. -6G we'd probably both die on the spot. In the summer when I fly a lot, I might be able to take it without too much trouble.
Anon387562@reddit
Okay, but that still doesnât explain, why the pilot isnât the limiting factor in a fighter jet, as you said. The fighter jet will withstand way more than 9gs, but not the pilot, because itâs not an airrace where the pilots pull for a few seconds, but ment in the context of air to air combat. Maybe some highly trained can pull 9,5-10g for a short period.
Sure you could yank the controls (in an older aircraft, new fly by wire systems will stop you from destroying it, or at least try their best) and pull a high Gs for a brief moment, which will damage the aircraft, but is to short for killing you, but thatâs just bs.
BabyBubblezs@reddit
Thats insane to me.
Zkenny13@reddit
These levels would also make a normal person even not normal people pass out. Pilots for fighter jets are a different breed.Â
hdhddf@reddit
no that's the pilots the planes can often handle more
TheCraftyWombat@reddit
r/confidentlyincorrect
XxRAM97xX@reddit
Wow
platour220@reddit
At 14g the tail of the f 16 is known to snap off. The f 35 is limited by computer to 9. (Who knows what it could actually do)
Nicedudeyesdude@reddit
I fly F-35s. The A model is -3 to 9 Gs. B model and C model that the marines and Navy fly are 7.5 pretty sure. When I flew F-16s, that was also 9. The issue comes when you starting adding things to the wings, it then changes your G limits. So if you put bombs on, itâs 5.5 based on there now being a 2k pound bomb on the wing. Clean is when youâd have the full up G regime.
HighHokie@reddit
Can you expand on the negative gâs being a lower threshold in laymanâs terms? Iâm sure I could google it but always appreciate learning from someone that knows their shit.Â
beanbody1@reddit
For one, the human body canât take negative g as well as positive g. 2-3 negative g is really the limit, and that is only briefly. Unlike positive g which is causing blood to pool in your lower extremities (and why a g-suit contracts around the legs and midsection), negative g causes blood to pool in the head. The body canât take that and a pilot will redout rather quickly. Since the human body canât take it, no reason to design the airplane to take it either.
Nicedudeyesdude@reddit
Yup. Also because of the fact our bodies canât handle it well, negative Gs are the worst. Truly.
Galf2@reddit
fundamentally they're almost G-unlimited, meaning the pilot will probably pass out before a catastrophic G limit failure occurs. You could pull 14G and come back to land in an F/A-18C
The thing is, now your jet is a banana, and written off.
Generally speaking military jet fighters are built aiming at 9G unloaded. The moment you add external load that limit comes down fast and the computer stops you from pulling harder than that in most modern fighter jets. A fully loaded F-16 with triple tanks for ferrying may even be limited to 6G, I don't remember exactly but you get the gist of it
on older high performance jets like the F-14 you had no computer to stop you from blowing it up, but fun fact, the wings were G-limited, the body itself is virtually g-unlimited.
Pulling slightly over G limits is possible with manual overrides, that are to be used only in emergencies, and once you come back (if) the plane needs to undergo a deep check to see if it's written off or only needs a few fixes. In general fighter jets live a hard life and older ones will be all a bit bent due to repeat G forces.
TheCraftyWombat@reddit
You are so, so wrong
Galf2@reddit
Feel free to prove me wrong, I hate to tell you but replying to a well researched post with "lol no u" makes you look like an ass.
So I'm open to learning, go ahead
TheCraftyWombat@reddit
Okay sure:
Well researched? Cite your sources then, you chimp. There's never been an instance where a manned fighter can pull 14 Gs and be fine.
You are the one making spurious claims. Cite your sources.
Vessbot@reddit
It also didn't appear in the post you're attacking.
Galf2@reddit
How about a Grumman test pilot, mr. "I'm a reddit pilot"?
https://youtu.be/YolnXZnw2cY?t=3312
Or how about that time an F-4 pilot pulled 12.5G and landed back home?
https://theaviationgeekclub.com/usaf-phantom-ii-fighter-pilot-recalls-when-he-over-gd-his-f-4-pulling-12-5-instantaneous-g/
Glad I could help.
If you really think a pilot could overcome the G limitations of the airframe, meaning the plane would break a wing before the pilot would pass out, I think that's just absurd.
TheCraftyWombat@reddit
You didn't answer to the claims you made about the F-18 or F-15.
You just referred to an abnormal over-G, which happens all the time.
I never contest the thought that planned could handle more, but I'll absolutely contest that an F-18 pulled 14 Gs and was fine.
You are cherry picking misaligned data to support indirect claims you made. You were no test pilot.
Galf2@reddit
I'm not entertaining this further if you think an F-15 is worse built than an F-4. Have fun. I don't believe you're a real pilot, all your posting history is childish remarks.
Good day.
TheCraftyWombat@reddit
You still can't back up your claims
Galf2@reddit
There's a literal Grumman pilot in the video and another example, you just discounted those and went back crying. I'm not in the mood for that, so I will just block you, it's fine!
No-Marsupial-1753@reddit
The F-15 can pull 15G. Once. They literally write off the airframe if it does it.
massunderestmated@reddit
What about the meat inside the plane?
gromm93@reddit
The wording here, because I don't think any military aircraft are even insurable.
I'm sure you meant "scrap" though.
No-Marsupial-1753@reddit
I never said anything about insurance.
gromm93@reddit
"written off" is a term insurance companies use when the cost to repair exceeds the book cost of something.
XxRAM97xX@reddit
https://youtu.be/XEL65gywwHQ
Kramer fro, Seinfeld âthey just write it off â
MechEGoneNuclear@reddit
The instance term youâre thinking of is âtotal lossâ. Â Written off is just accounting speak for value now equals zero. Â Cue the schittâs creek scene about write offs.
KS_Gaming@reddit
It's also used in accounting, or at least they did 10+ years ago during these few accounting/audit lectures i went to before dropping out..
No-Marsupial-1753@reddit
As per Merriam-Webster:
Written off
1: to eliminate (an asset) from the books : enter as a loss or expense
2: to regard or concede to be lost
holl0918@reddit
Just for funsies, common aerobatic competition and red bull raceplanes are spec'd for between +/-12 and +/-14 Gs.
DOOM_INTENSIFIES@reddit
While the airframe can take it, i don't think anyone is walking away from -14g.
_HIST@reddit
"g" is a weird metric, because it doesn't paint you a full picture. It's an equation of force and time. During a crash people experience even higher g forces but for a split second
SugarBeefs@reddit
Theyâre making a joke about negative G.
-14 would probably kill you dead
dingman58@reddit
Yes without a measurement of time over which the g force exists it's basically meaningless. For example when you drop something the G can be in the thousands for milliseconds
NotCook59@reddit
I donât like to break, personally.
airfryerfuntime@reddit
When they were developing the Extra 300, they were so concerned with the wing box and spars that they neglected the engine mount. They were almost shearing the engine clean off the airframe each time they pushed it to 10+gs.
holl0918@reddit
𤣠Yeah, that sounds about right for an engineering problem!
DoesntMatterEh@reddit
More than the pilots in some cases
-Badger3-@reddit
More than the pilot lol
_HIST@reddit
The issue is always how many gs can the pilot handle. They're the weakest link in maneuverability. This is why countries are developing pilotless jets
Significant_Quit_674@reddit
Yes and no
For sustained Gs, you're correct, but for a brief moment the pilot can stay concious at Gs most airframes can't handle.
Also there is a range where you lose vision entirely but not yet your entire consciousness.
I've been there once in an emergency and I do not want to go there again, it is realy unnerving to not see where you're going, but knowing you're approaching the nearby ground rapidly.
Thick_Comedian_6707@reddit
F18 gets overstress caution at 7.5. It generally handles itâŚ
EchoOneFour@reddit
9G.. they can hold over that as well but you will permanently damage the plane
syzygialchaos@reddit
Well, some airframes can take it. Itâs typically the human that limits the Gs on fighters.
BrainDamage2029@reddit
Very few airframes can actually take over 9G as a course of service and overwhelming most are G-limited to 7.5 or 8. For example the F-15E was "rated" to 9, can take up to 11G before things seriously brake....but they're service limited to 7.5 fleet wide. Meaning if you go over 7.5G you're getting a talking to as the plane gets ripped apart to inspect the wing roots.
TOPGUN for the Navy bought the F-16N as a high performance, stripped down dog fighting F-16 variant with a bunch of sensors for aggressor training. They wanted to match the rather crazy maneuverability of the Mig-29 and their old F-5's were 15 years old and getting issues. They rather famously decided to "ride them hard and put them away wet" so to speak with the new F-16N's and regularly hit 9G's. And they basically trashed all 22 air-frames they just bought in less than 5 years and all were retired before the F-5 Tigersharks they were meant to replace were fully phased out.
EchoOneFour@reddit
They can take it but they won't be safe to fly after... or at least in my country they won't be allowed to fly... After 10G you bend the actual airframe.. even if it doesn't catastrophically fail it's still not good to fly again as if it was fine
Helmett-13@reddit
The old English Electric Lightnings were like that by the end of their careers.
Creaky and couldnât flex em like when they were younger.
ThermosphericRah@reddit
I know the feeling
Helmett-13@reddit
Yeah, I'm gonna be 55 in January and I have to PLAN how I get on the floor to play with the dogs and get back up again, now.
I picked up a buffet furniture...thing...for my wife and when I looked out of the tailgate I realized I wasn't gonna jump down out of the truck bed anymore.
I CAREFULLY used the fender and bumper steps!
NotCook59@reddit
Amen! So, itâs not just me. Good to know.
jakeod27@reddit
Just fly it the other direction and itâll buff right out
this_is_bs@reddit
Like, in reverse?
IndoorPool@reddit
Inverted 10G
gromm93@reddit
Haha. Good luck getting a pilot to survive that.
NotCook59@reddit
Yes, for example. Also, like driving my cousins old Chevy in high school, if you make up for several miles, it winds the miles back off the odometer. True facts.
Sonar_pulse@reddit
This made me smile
XxRAM97xX@reddit
đđ
TheGoalkeeper@reddit
I thought 9g for the pilot, and a bit more (12/15) for the plane?
_HIST@reddit
Correct
FFJosty@reddit
I learned this from TopGun Maverick
XxRAM97xX@reddit
Wow
atomcurt@reddit
The confidently incorrect crowd here is just wild.
I was a structural engineer in the development of a fourth gen fighter, mostly working on fwd fuselage.
Not going to ever comment on real performance metrics, but just consider that aluminum doesnât have an endurance limit, thus every single flight will âdamageâ the aircraft as some of you believe that x Gs would yield. Depending on flight envelope some individuals will be scrapped sooner that othersâŚdonât look too hard on those load limits, itâs a combination of many other parameters.
HarambeSixActual@reddit
Most fighters are limited by the pilot or by whatâs on the airframe (bombs, pods, fuel tanks) rather than the airframe itself. Not always true but generally speaking.
surfsnower@reddit
For fighters, the unloaded and no external fuel tanks F-16 with under a certain level of gas isn't G limited. Most others have a limit, usually posted publicly because at a point it drives higher quality of inspections.
PXLShoot3r@reddit
Way more than any human
HandiCAPEable@reddit
If you go over 9g you're probably bending the frame, but it's possible to get home still.
TheCraftyWombat@reddit
haha "unclass figures"
there's not a "classified" higher G
merlin_34@reddit
Depends on the model. The highest airframe limit load rating is about 9g. But even on a 9g jet like the F-16, the actual limit could be lower depending on the gross weight and what weapons or sensors you're carrying.
BigBlueMountainStar@reddit
Itâs not just about the Gs though, you got to consider the weight as well. A fully loaded aircraft at 2g is probably worse loading than an empty aircraft at 3g.
mkosmo@reddit
The certification requirements are all at max gross.
BigBlueMountainStar@reddit
Wasnât talking about certification, I was comparing a full aircraft at 2g compared to an empty one at 3g.
mkosmo@reddit
A full aircraft at 2G is well below certification limits, let alone failure tests. Nothing to be concerned about whatsoever.
BigBlueMountainStar@reddit
Fuck me; thatâs not what Iâm saying, read my comments. Iâm saying g forces are not the full story, the mass of the aircraft also needs to be accounted for.
mkosmo@reddit
No, it doesnât. Itâs already accounted for in the certified flight envelope. Anything that would be unsafe isnât an allowed point in the envelope.
BigBlueMountainStar@reddit
Fuck me, Iâm not even saying itâs unsafe, or not certified, thatâs not what the discussion is about, itâs about the relative differences between 2 sets of manoeuvres.
FZ_Milkshake@reddit
Depends where the weight is, fuel in the wings actually decreases the load on the wing root.
BigBlueMountainStar@reddit
Pulling out of a dive it doesnât.
mkosmo@reddit
Yes it does. Theres a reason some airframes have prescribed requirements to burn out of fuselage tanks before wings. Itâs about specific wing root loading.
Interesting-Yak6962@reddit
It still should be avoided, when youâre flying around with the weight of a swimming pool of fuel in your tanks, itâs not a good idea to triple its weight.
twolf59@reddit
3.5g and there's usually a factor of safety around 1.5 on top of that
_Makaveli_@reddit
Not true
twolf59@reddit
What a low effort comment. Don't believe me, Go read up on Vn diagrams, limit vs ultimate loads in structures
_Makaveli_@reddit
Ok let me rephrase, look up CS25 design specifications
twolf59@reddit
CS-25 requires the structure to withstand: Limit loads â the maximum loads expected in service Ultimate loads â limit loads Ă safety factor (typically 1.5)
No permanent deformation at limit load. No failure at ultimate load. This is enforced by European Union Aviation Safety Agency (EASA), and CS-25 is harmonized closely with FAA 14 CFR Part 25
mig82au@reddit
Exactly, you were wrong. It's 2.5 and it's not "usually". The ultimate factor is non negotiable.
_Makaveli_@reddit
Exactly what I was referring to lol
RankBrain@reddit
Thanks chat gpt
twolf59@reddit
Actually Claude after I fed in the entire 600pg CS25 handbook
Terrh@reddit
The real answer here is the maximum allowable G depends entirely on how heavy you are.
Any airframe that can withstand 3.5G full of fuel can deal with much more when it's light.
mkosmo@reddit
+2.5 is a certification requirement for transport category aircraft... with a minimum safety factor of 1.5.
deleted_by_reddit@reddit
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Sir_Sir_ExcuseMe_Sir@reddit
I'm sorry, did you not see Flight, with Denzel Washington?
userlivewire@reddit
Have you seen that video of them bending the wing until it breaks?
th3orist@reddit
have not, would you be so kind to link it?
userlivewire@reddit
Hereâs one of the older ones. https://youtu.be/Ai2HmvAXcU0?si=LOCPdyXLCIqJyb03
Malcolm2theRescue@reddit
Hell, China Airlines did this in a 747. The 5 g pull up damaged the tail. It was back flying in a couple of months and flew for years after that.
BadassBlondeMILF@reddit
A Grissom KC-135 had an autopilot malfunction in the mid 80s rolled, and dived. They exceeded Mach 1 in the dive. It was bent, but repairable. The incident was known as "Mach 1 Over Michigan" and I the airplane ended up with nose art later that reflected the event. One of the pilots (Greg) ended up flying U-2s later.
Down_Blunder@reddit
From memory it did a bit more than that. I believe the horizontal stabilisers were permanently bent slightly upwards after that incident.
Malcolm2theRescue@reddit
Hell, China Airlines Flt 006 did this in a 747. The 5 g pull up damaged the tail. It was back flying in a couple of months and flew for years after that.
Hereâs a good picture of it. If I were younger and computer savvy I could sharpen it up and make it color.
Malcolm2theRescue@reddit
Hmm, I hadnât heard that but Iâm not an expert on the subject. They kept on flying it. Must have been within limits I guess.
tarmacjd@reddit
Fuck me
Malcolm2theRescue@reddit
Please. We hardly know each other!
kosherhalfsourpickle@reddit
China Airlines Flt 006. Here is the wiki on it: https://en.wikipedia.org/wiki/China_Airlines_Flight_006
kipperzdog@reddit
Wild, basically just terrible decisions by the pilot
SubarcticFarmer@reddit
That's the 747SP left derelict in Guadalajara I believe.
Malcolm2theRescue@reddit
I just looked it up. Itâs in Tijuana.
SubarcticFarmer@reddit
That's the one. Sorry, was still waking up
Malcolm2theRescue@reddit
Not to worry. I do stuff like that when Iâm fully awake! I was doing a flight east out of Denver and put in GDL instead of GLD (Goodland, KS) Imagine my surprise when the magenta line went due South for 1200 miles.
Malcolm2theRescue@reddit
Hmm. Are there any other airliners stored there?
elightened-n-lost@reddit
I have an old VHS of my family member rolling a 747 over the Atlantic Ocean. Airplanes are way more capable than they have any right being with the way they look.
roehnin@reddit
You have got to post this for us
elightened-n-lost@reddit
I'll see if I can find it and convert it to digital. I'll also have to check and make sure there isn't some kind of trouble he could get in. He used to find it funny to do 1g rolls in a g2 as well and got a kick out of passengers not noticing unless they looked out the window.
Specialist_Reality96@reddit
As it is a stall it's all likely a 1g it would only be the recovery from the dive that might get to 2. You can see them throttle back once they get the wings flying again.
I'm guessing the wing with the slightly higher angle of attack stalled first causing the initial inversion, but it rolling the opposite way to the turn is a bit of an interesting handling trait. I guess why stick shakers bitching betty and stall warnings all exist, they really don't want people to stall swept back wings.
immaZebrah@reddit
Keep in mind the aircraft here is probably minimally loaded, under a full load at those g's it could very well break apart
CrawlingBigfoot@reddit
Rather infamously a Fedex DC-10 had to roll inverted and nearly broke the speed of sound in a dive while the flight crew fought off a hijacker. Flight 705 to be specific. The aircraft returned to service afterward and flew until the end of 2022. So even the big boys are pretty durable.
mikeblas@reddit
Tex Johnston rolled a 707 (before there were 707s) at SeaFair in 1955.
https://theaviationgeekclub.com/the-story-of-when-tex-johnston-barrel-rolled-the-boeing-367-80-the-boeing-707-prototype-200-feet-over-lake-washington/
Easy-Natural1419@reddit
Thereâs a vid out there where they flex the stripped frame in the factory and the wings can bend nearly straight up
flagrananante@reddit
That exact video is what made me relax about flying quite a bit. I now recommend it to other people who are trying to get over a fear of flying because it made things click in my brain that just hadn't until I saw it.
Fabulous-Suspect-72@reddit
Wasn't there a case where s China Airlines 747 pulled something ridiculous like 5gs because they were in a similar dive for some reason?
LudasGhost@reddit
Yes, Mentour Pilot did a video on that one. I watched it so long ago I donât remember the reason. May have been spatial disorientation.
th3orist@reddit
As someone with a fear of flying and a long two leg flight coming up i do not want to even begin to imagine that đĽšđ
halcyon_aporia@reddit
It should be reassuring, everyone made it!
But yeah, terrifying in the moment.
doomiestdoomeddoomer@reddit
One Fifty Four
PiperArrow@reddit
One Fifty Four!
imadave@reddit
One Fifty Four!
EggsceIlent@reddit
The only thing getting stressed that much are the seat cushions as I'm betting someone's butt is puckered so hard it's starting to consume the cushion itself.
savageotter@reddit
"I think I'm going to try to do a barrel roll, and if that goes good, I'm just gonna go nose down and call it a night."Â
Pickleparty187@reddit
RIP sky king
Maelstrom_Witch@reddit
The sim instructor was pretty impressed too.
blueb0g@reddit
It's not a sim
Maelstrom_Witch@reddit
The video? Yes. Itâs a real flight. I was referring to my comment about my dad in a sim many years ago.
Noobs_Man3@reddit
yeah played enough war thunder to know the wings would rip off
die_liebe@reddit
I am a bit late, but what were they testing? Did the plane pass the test?
Exact-Magician1387@reddit
Since it is day time, the pilots had two different horizon levels. One is the instrument and another is physical horizon reference, if it is in night time, it would be very difficult if they don't trust the instruments while the aircraft is running on autopilot with no moon day.
Extension_Pie2602@reddit
Denzel Washington would like a word
fivespeed@reddit
When I watched this I heard him say "I have control"
PureBogosity@reddit
Former US Navy civil service flight test engineer (35 years in the business) here, who has participated in and led this kind of testing, on a 707 airframe in one case. This is really not THAT big a deal, folks. Yes, certainly "whoops," in the sense that the amount of wing drop was certainly more than expected. But any stall testing like this is always approached as very high risk, and a lot of thought goes into what MIGHT happen, and if it does, how to deal with it. Tests that might not be recoverable if it DOES go wrong simply won't be attempted, unless there's a really serious need. In this case, there was already a known problem with roll during stall, so they were not really caught off guard - only by how much.
And that's why they sound calm: because they are. There's no real surprise or panic, because they'd done their homework.
I'm sure they knocked off the testing due to the overspeed on recovery, and went back home for a careful overstress inspection. But just like almost every test flight, they walked away healthy with a solid airplane, because of all that risk-mitigation up-front planning.
I'm certain the pilots could have easily recovered faster if there was a need due to low altitude. But the first thing to do is get back enough speed that the aircraft can be maneuvered without reentering a stall.
Here are some more details about this event. https://avgeekery.com/time-boeing-717-went-inverted-testing/
Vessbot@reddit
The big deal is not that the initial upset happened, but rather the recovery - in their disorientation they did every possible wrong thing:
PureBogosity@reddit
Well, I have to disagree with you.
I've watched the video a bunch of times with my 35-year flying qualities flight test expertise at full ready. I have plenty of personal stall testing experience (from the control room, not the cockpit) and I've ridden through (and personally flown some of) hundreds of stall tests in the seat of numerous Level D full flight simulators. I've done deep data analysis, and I have hundreds of data plots that I've produced from such stall tests on my hard drive.
It looks to me like they did everything appropriately. The pilot centers the controls immediately upon departure at 0:09 (step 1 in every stall checklist, especially during stall test flights), pushes over the nose at 0:11 to allow the airplane to accelerate well above stall speed, starts to pull a bit at 0:13 to avoid excessive acceleration, THEN at 0:20 finally begins to apply roll control towards the nearest horizon (unlike you stated above), then begins to pull. I don't see ANY rolling pullout at all, anywhere in the maneuver. He looks like he's very careful to avoid an RPO, in fact, not pulling at all until he's wings-level.
This is textbook departure recovery.
The only possible critique might be that they didn't pull power back off until 0:20, about 11 seconds into the recovery. That could have been done sooner, but it's a tradeoff between primary controls handling to get the right attitude, and focusing anywhere else. And you don't pull power until you're absolutely certain that you have enough airspeed to recover. Entering a secondary departure is a real concern, and could be fatal if you're already quite nose-low and it delays your recovery further. So I really have no solid critique there. I think it was a reasonable choice.
The extreme nose-low condition is simply a result of the extreme roll at departure; there's nothing they could have done about it. And that's exactly why you start with plenty of altitude for exactly this possibility. Also, at slower speeds, the ailerons are usually ineffective, and can lead to yawing departure due to adverse yaw; you really don't want to trigger a spin that way. So there's no good way to stop the roll initially, which is why centering the controls is so important.
Vessbot@reddit
Thanks for the reply, and after careful rewatch, I agree with you on some of the points, but not the major ones. My background comes from a past life of years teaching acro and unusual attitude recoveries in light pistons through light jets. (These days, I accept flight plan datalinks into the FMS and click TOGA for a living.) And my biggest lasting impression is the difficulty of breaking people away from their gut response to instinctively pull on the elevator any time stress and/or unusual situations are encountered, ranging from acro upsets to normal flight low speed events.
First points of agreement are that
- this (initial) upset is very expected from stalling at high sideslip
- their correct initial response to center everything, along with pushing slightly to reduce AOA, and avoiding aileron until clearly out of the stall
- and then to pull the thrust to idle after they've taken a breath and evaluated the face full of ground in front
(However you note that they then pulled slightly (0:13) to avoid excessive acceleration, which, being inverted, would pitch them into the ground and increase acceleration. I think it's likelier they were just pitching to stop the visual attitude rate and get a stable platform from which to continue.)
After that comes the first biggie, the roll direction: at "easy roll to the horizon" (0:15) the nearest horizon is clearly to the left, and the airplane rolled *away* from that to the right, toward inverted. And unlike what I remember from past watching, and unlike what you said, this didn't seem to be from yoke input at this low speed, which stayed centered (plus and minus some transients.) So it's probably from residual sideslip.
Next, the pull. Here, I partially retract that they did a rolling pullout. The yoke is centered, and from the PFD it's hard to tell. It shows a right roll, but from a clean pull, it could still falsely show roll as they pass through the bottom near (but not exactly through) the nadir. (The animation to the right is worthless for this without knowing the camera origin point and other geometry factors.) I was prepared to fully retract my statement, if it wasn't for them seemingly showing intent to roll with the hard to make out "easy right... easy right turn there."Â
Stepping away from this event, as a generality we know that for nose low inverted upsets, we need to roll upright and then pull out. But also, if the pitch attitude is close to vertical, let's say 70 degrees nose down inverted, it would be quicker in time (and in less airspeed built) to pitch 40 degrees through the bottom to 70 degrees nose down upright, than it would be to roll 180 degrees to the same attitude. And this is indeed the typical scenario (and recovery) from a half turn spin in a GA trainer.
Back to this video, at initial stabilization they were at a moderate 20 degrees pitch down, from which I would have absolutely rolled in any circumstance. But not having done it in an airliner, I entertained the possible explanation that there were particular factors I hadn't considered, and that they had planned and intended to pitch through in such a scenario all along. OK. But this is squarely contradicted by "easy roll to the horizon" and "easy right turn there," so I'm back to no explanation, and defaulting to my original explanation: that they planned to roll (the conventional response), were a few seconds behind in processing and began this roll after the airplane had already rolled itself (from residual beta) through inverted and was quickly pitching itself (from the trim) through 45 degrees, and at the point they began the roll the nearest horizon was to the right, toward which they rolled with a timid and invisibly small input (which, at these speeds, would be effective) simultaneous with pitching.
I hate to come off like I'm tarnishing other pilots' actions. I recognize that I have the benefit of watching this from a chair, and can only hope that my hundreds or thousands of times of doing this planned would result in a correct response if I ever encounter it unplanned. But in the end physical facts are physical facts, and if someone asks me about this video with respect to what they should do in that situation, I can only point to it as an example of what to avoid.
PureBogosity@reddit
Very thoughtful response, and I see what you're saying. It's easy to armchair a mishap or near-mishap or even non-mishap-but-highly-dynamic video like this. From having done some stalls and spins in a T-34C and a Citabria, I can testify that wild rides like this really do cage your inner ear gyros pretty quickly, and if you're not well-accustomed to getting thrown around like that (which I wasn't) it can be quite hard to keep a solid sense of orientation - even with a full set of flight instruments right in front of you. The brain is a funny thing, and the unexpected can narrow your attention down to just one or two facts, ignoring a ton of other relevant data.
Years ago I went thru a US Navy Test Pilot School flying short course, hence the T-34 flights. A good friend of mine was the stall/spin instructor (Gerald "Gerry" Gallagher - brother of the famous comedian Gallagher - the smashing watermelons guy), and he made a point of showing how deceptive the spin direction is. Your brain can completely misinterpret all the data flowing in, and it becomes surprisingly easy to misapply the anti-spin controls because of that failure to read the instruments right. Even looking out the window at the rotating horizon will often provide a very overwhelming sense of a certain yaw rate, which is actually the complete opposite sign from the true numerical rate. So good reaction to a dynamic departure like we see in this video is not trivial.
And the failure to read the situation correctly, and to get disoriented, is exactly why pilots do so much training. And in particular to this case, it's why I am a strong advocate of stall/spin training in light aircraft for airline pilots. If you spend your entire life basically in an easy chair, always below 1.5g and 45 deg AOB and within 15 degrees of zero pitch, getting unexpectedly thrown upside down pointing straight at the ground is a real shock to the system. And even a test pilot of a large commercial class is subject to that limitation, if not properly trained in a real stall/spin situation.
In the end, it all worked out for these guys, and I assume that the overspeed didn't result in any damage. So it's probably not worth being TOO critical of the job they did.
Thanks for a fascinating discussion!
Original_Emphasis942@reddit
But why the roll input on a stall test? Aren't you kind of setting yourself up for a wing drop?
We did a 1500 rpm, 15 degrees flaps stall in a C152 when I was on my first examination for a ppl. And I was taught to keep the wings level by using rudder, not aileron.... needles to say, the 152 has a nasty habit of flipping in such case..... which I wasn't taught during training, so I just expected a normal stall. We flipped, I recovered, I nearly flew into Germany..... but made the nicest "engine-out" landings..... got my license, with a stern warning to take care not getting lost again.... never did before, and never did since.
Enough with the story.
PureBogosity@reddit
My understanding from the various stories about this event was that there was a known asymmetric issue with that particular airframe, and the test point was specifically stalling in a turn. That's not uncommon for stall testing, by the way; in a turn you have yaw rate, which means one wing is at a slightly higher airspeed than the other, thus the two wings will have different moments of stall. And any roll rate changes the AOA between the two wings. So it's normal to test variations of roll and turn during a stall evaluation.
nicoled985@reddit
Thank you for your service and explanation! Very interesting!
duketoma@reddit
Had a bit of coal bin in his rectum he'd have a nice diamond to remember that day.
Automatic_Tea_2550@reddit
I get the feeling test pilots enjoy this sort of thing.
Malcolm2theRescue@reddit
Yes, Adrenalin junkies!
Sarpool@reddit
Aerobatic flying exists!
Able_Exam_1403@reddit
McDonell Douglas MD-95!
Icy_Huckleberry_8049@reddit
well, they are TEST pilots
snowboardmonk@reddit
I feel like you become so acceptant of the potential of death it began to not feel real anymore. Thatâs why these guys remain so calm. My grandfather was a p51 fighter pilot in WWII. Calmest man I ever knew
v1rotatev2@reddit
From your description it reads that they were surprised by this.
They exactly knew what they were doing
BrewCityChaserV2@reddit
If you read the report on this test flight, they actually were quite surprised by the violent response of the aircraft to a power-on stall as this is the first time they tried this in a 717 in real flight conditions. The PF just happened to respond in the way a well-trained test pilot would (with the coaching of the PM in the right seat).
saml01@reddit
Pilot flying had full right aileron he was full expecting a violent wing drop.Â
cheetuzz@reddit
it rolled to the left though
vghouse@reddit
Thats how wing drops work. When you roll to the right, your right aileron goes up and your left aileron goes down. The side with the downgoing aileron should stall first due to the increased camber and angle of attack it causes.
If the left side stalls, and the right side is still producing lift, if will roll the airplane to the left like in the video. Thatâs why itâs important to keep your ailerons neutral using stalls and especially during stall recovery.
cheetuzz@reddit
wow, thanks for that knowledge. Counterintuitive though!
Ok-Question6527@reddit
I wasn't aware until reading this comment that a wing could individually stall.
phaederus@reddit
Even individual parts of a wing can stall at separate moments, see root stalls.
pjakma@reddit
Pretty rare for each wing to be exactly identical, and the airflow to be exactly identical over each wing. So... one wing will stall before the other. Pretty much the norm.
_Wily-Wizard_@reddit
You may be even more surprise that a helicopter's individual blades can stall in sections of the rotation cycle. Which is in fact the limiting factor in forward airspeed for helicopters... The blade retreating + relative airspeed makes the blade stall and the helicopter will start rolling to either side depending on rotational direction. Two rotor designs are essentially attempts at increasing top speed in helicopters because you can push past retreating blade stall a bit and go faster.
TowMater66@reddit
Yes the âapproach turn stallâ is a general aviation killer and should be part of training.
vghouse@reddit
It actually causes a fair amount of crashes in small 2-4 seat prop planes. Pilots will accidentally stall one wing at low altitude and spin into the ground.
Run_it_up_boys@reddit
Yep, right wing down aileron will usually cause the left wing to stall first in a high AOA scenario. The right wing was still flying and flipped the jet over.
BrewCityChaserV2@reddit
They were expecting a roll, just not 100 degrees of it.
cozywolf1332@reddit
Turning stall left wing lost lift first due to higher AOA hence left roll.(dont crucify me if im wrong)
DontLookUp21@reddit
No this was unintended.
Source: I was a flight test engineer on the 717.
ResortMain780@reddit
Im surprised they recovered by doing an Immelmann. That would seem so much more risky to overspeed and overstress the airframe than just rolling out and pulling out.
FZ_Milkshake@reddit
They were absolutely surprised by the severity of the wing drop but as test pilots they were also prepared. A split S is absolutely not an approved maneuver for a 717.
-LordDarkHelmet-@reddit
Errrr⌠no that looked like the proper recovery technique. Roll to right side up, then level. You donât pull through the long way to level the wings.
phaederus@reddit
It was certainly a split S, report stated as much.
-LordDarkHelmet-@reddit
Yes I agree. To clarify my comment above is saying that a split S is the proper recovery technique for that unusual attitude
phaederus@reddit
Apologies, misunderstood your comment.
YmFsbHMucmVkZGl0QGdt@reddit
They were stalling the plane intentionally. They didnât know it would flip the plane upside down.
Also, the pilot stated later that he shouldnât have performed the split S to recover
Soft_Walrus_3605@reddit
Don't suppose you have a link to the source on that?
DudleyAndStephens@reddit
Do you have a source for that? I've read so many things about this incident but it's almost always second or third hand. I'd love to read the official take on it.
Substantial_Elk_5779@reddit
They were inverted, what choice did they have besides a split S?
TenderfootGungi@reddit
I had to look up a Split S: https://en.wikipedia.org/wiki/Split_S
Simple, but likely cost a lot of altitude.
Few-Dance-7157@reddit
Split S in a 717 is wild. What a legend!!
tarrasque@reddit
Yup. This was an intentionally uncoordinated stall. Whether the roll was expected or not I donât know.
The_Ashamed_Boys@reddit
What makes you think they knew exactly what they were doing and were not surprised? Do you have special insider knowledge or industry knowledge or something that the rest of us don't have?
flightwatcher45@reddit
They are test pilots. The brief that morning covers the risk of the stall testing, including aircraft upset and loss of control. The brief also covers exactly how to safety recover from a stall, one axis at a time. They new it was possible but didn't expect it. Clean recovery!
runway31@reddit
They werenât expecting that much wing drop
Bigbearcanada@reddit
Disagree. Look at the bank angle. It was held in a right bank to ensure the left wing stalled first and rolled them over.
Loud-Aioli-9465@reddit
Yes they were calling out the bank angle of the plane during the manuever (27...28...30...hold). They absolutely wanted to hold the 30 degrees of bank at stall to see what the plane would do. That doesn't mean they planned for it to completely roll onto its back in 1.5 seconds.
Centaurtaur69@reddit
Yeah there's no commercial airline manufacturer that actually wants their aircraft to roll that hard in a banked stall.
They try to design aircraft in ways to prevent that
runway31@reddit
No itâs a fact lol, This test is discussed in my place of work from time to time, in flight test, with people who knew the crew. It was intentional stall testing, but they factually were not expecting the wing drop and incipient spinÂ
SortAccomplished7102@reddit
The plane just wanted a belly rub.
randomtask733@reddit
I have watched this video over and over for years. His "whoops" is so casual like it has happened to him so many times it is not a big deal.
Malcolm2theRescue@reddit
Iâve rewatched this also. One of the things that impressed me was the âhuman controlled G limiterâ. The right seat guyâs hand comes cautiously over to guard the yoke so that the guy flying doesnât overstress the wings on the pull out. The Captain did it perfectly though so no intervention was required. Pulling out of a maneuver like this is where the wings are going to come off. The snap-roll is very low G.
Maelstrom_Witch@reddit
âSilly me!â
dublingamer44@reddit
thats a realy weird test
speedpug@reddit
Any idea how many feet they dropped before regaining control?
BadassBlondeMILF@reddit
Wrong description. This is either steady heading sideslip tor wings level sideslip testing. Both test pilots (Bear and John) were prior Blues Angels pilots. Will was the FTE. Ironically, the crew had elected to raise the altitude during the prebrief. They ended-up needing that altitude to recover.
Scooney92@reddit
Legend is they had to cut the cockpit open afterwards due to the size of their balls đ đ
Zealousideal-Pop4426@reddit
Meh, Denzel did this in the movie Flight, 2012
đ¨ââď¸
wrongwayup@reddit
Deep stalls on rear-engined T-tails are no joke.
blueb0g@reddit
There's no deep/blanketed stall here
Charlie3PO@reddit
Correct, not sure why you are being down voted though.
dbcooper4@reddit
They ended up pointing straight at the ground. Iâd call that a deep stall.
Charlie3PO@reddit
In aviation, a deep stall is specific aerodynamic condition.
It's a condition where the angle of attack of the aircraft gets so high that the natural nose up pitching moment of the airframe will exceed the nose down pitching moment that the elevator is able to generate. This means that even with full nose down elevator, the nose will not drop enough to un-stall the wing, causing the plane to essentially get 'stuck' in a stall. The aircraft will typically descend at a rapid rate, but in a relatively flat attitude. Not what we see in this video.
In this video, the left wing stalled, the plane rolled inverted and once inverted the stall was over. From that point onwards, it was no longer in a stall, but a large amount of altitude was needed to recover because the nose dropped considerably while inverted (i.e. this aircraft was incapable of sustaining inverted flight)
dbcooper4@reddit
If Iâm pointing straight down at the ground in an airliner Iâm going to go ahead and call that a deep stall. He didnât just take it into the stick shaker and then initiate a recovery.
Charlie3PO@reddit
But that's not what a deep stall is, or at least what most people mean when they say deep stall. This plane was completely un-stalled while pointing at the ground. The actual stall only lasted a few seconds and was not a deep stall. The nose drop came after the stall because the plane was left in an inverted state after the stall was over.
dbcooper4@reddit
I would honestly call taking any swept wing airliner past the shaker a deep stall but Iâll let you keep being pedantic if you insist.
blueb0g@reddit
Well that just isn't what a deep stall is.
https://skybrary.aero/articles/deep-stall
dbcooper4@reddit
Another acktually guy shows up in the replies. Nice.
blueb0g@reddit
In fact I was the original replyer. But you were too busy publicly shitting yourself to notice
Strong_Quarter_9349@reddit
Nice of you to let others correct you. Great to see.
dbcooper4@reddit
Glad to provide the âacktuallyâ crowd with some purpose on a Saturday.
8CYLINDERS117@reddit
It's not about 'acktually' you're just legit misusing a term that has specific meaning. Deep Stalls are a defined term in the aerodynamics / flight test world. This was not a Deep Stall.
dbcooper4@reddit
Thanks acktually guy #3. Glad I could provide some purpose for you on a Saturday.
8CYLINDERS117@reddit
Are you just incapable of admitting you were wrong or something?
dbcooper4@reddit
Are you incapable of being an annoying acktually guy?
8CYLINDERS117@reddit
Haha I take that as a yes then
dbcooper4@reddit
Same with you lol.
Turbulent_Cod_9333@reddit
What causes the abrupt snap to the left?
Tomica333@reddit
Basically.. one wing stalls more than the other, therefore the wing with lift keeps lifting sending the plane over.
Turbulent_Cod_9333@reddit
Is it usually as abrupt as that? That thing snapped down in like 1 second.
Tomica333@reddit
Im only in small planes at the moment, but yes .. once the wing stalls when out of balance yes its abrupt.
Huge_Animal5996@reddit
Does anyone know if/how much they went over speed while recovering?
Aboriginal_landlord@reddit
No overspeed at all, they went into a stall at 80 or so knots, no chance they accelerate to VNE during that recovery.Â
toony042004@reddit
You got ears?
EatSleepFlyGuy@reddit
No chance? Not sure where you get that confident assumption. They were pointing straight at the ground like a lawn dart and did over speed considerably. If you watch the full video you can hear the over speed warning continue even after they are climbing in the recovery and the airspeed tape is reducing.
mongooseme@reddit
Yeah I was much more worried about the overspeed than the g loading.
Too bad this wasn't an airbus yelling "Retard! Retard!" at the pilots.
Choice_Mission_5634@reddit
It's significantly better to over speed than it is to over G.
Loud-Aioli-9465@reddit
Judging by the warning sounds and being able to see a bit of the airspeed indicator. I'd say about 30-40 knots?
ModishShrink@reddit
Test pilots are just next level. My father was a USAF test pilot, and was offered a position in NASA's astronaut training program. He turned it down because he thought it'd be too boring.
Absolute fucking madmen.
Perfect_Jury5632@reddit
In the longer version they shake hands when they pull out of the dive.
unicynicist@reddit
The longer version.
awful_source@reddit
This was like 20 seconds longer than OPs video, why even cut it shorter?
blastcat4@reddit
At least it wasn't the version cropped into portrait and edited with a death metal song.
CubemonkeyNYC@reddit
It's like 50 seconds longer, friendo.
p3rseusxy@reddit
I think the guy on the jumpseat shat his pants a little. Just had to run to the toilet when they were stable again :-D
Porkyrogue@reddit
Ty
botany_bae@reddit
The one my wife prefers.
Fuckthegopers@reddit
Not a single handshake in that video.Â
chefdudehere@reddit
Thanks for posting this link!
SignoreOscur0@reddit
Nicely done Greg. Signature pat on the shoulder after an inverted vertical dive on a commercial airliner.
mistiqflower@reddit
Shaking hands is such a composed reaction after what could've been a disaster. Mad respect for staying cool
mrvarmint@reddit
If you watch the full video (linked on this same thread), itâs a pat on the back from captain to FO, itâs even more ânice one dudeâ than a handshake
BabyBubblezs@reddit
Yea i would have been jumping up and down like a kid lol
StagedC0mbustion@reddit
Little chance of disaster here
The_Autarch@reddit
in situations like these, you wait to completely freak the fuck out until after you've landed
bigtallbiscuit@reddit
Dude I would kiss him.
BabyBubblezs@reddit
Rightfully so.
LostInDinosaurWorld@reddit
Hey captain, take your sweaty hands off me!
Porkyrogue@reddit
Where is the longer version
phyyas@reddit
It took me about a minute or two to realise that you have to put the nose down in this condition to rise the nose up, i guess i am not cut out to be a pilot hehe
Maelstrom_Witch@reddit
My dad swears he got a 767 to do a barrel roll in a simulator when they had some time to kill.
ResortMain780@reddit
I wouldnt read much in to that; commercial simulators arent really designed to simulate aerobatic manoeuvres, I would be very surprised if you couldnt fly inverted in one (for a while at least, I suppose airliner dont have enough elevator authority to keep the nose up inverted). I dont recommend trying it for real.
But the question if a modern airliner could do a loop, without exceeding VNE or G load limits is one I am curious about. Purely guessing, Id say yes if its mostly empty and most likely no if its near MTOW.
tubbleman@reddit
That one guy several years back stole a plane and did a surprisingly successful loop. Not a 747 by any means, but it looks pretty big to be doing a loop.
https://youtu.be/_IYaPWyokIA
ResortMain780@reddit
I dont see a loop. I see a botched barrel roll and some steep banking. A barrel roll, if done correctly, is a 1G manoeuvre, perfectly safe with any aircraft: https://www.youtube.com/watch?v=Ra_khhzuFlE
Of course this guy doesnt do it correctly and will have exceeded 1G by quite some margin, but its still not close to a looping.
friendIdiglove@reddit
Given it was his first time, and, ya know, everything else, I wonât cr
Actual-Lingonberry58@reddit
Is that the one where he stole it and flew for like an hour or two and crashed it
Maelstrom_Witch@reddit
He was within limits, he was a very by-the-book pilot. I wish I could remember the details but it was quite a while ago. Late 90s I would say. They had finished the actual work they needed to do so he asked the instructor if they could give it a try. The instructor was really interested to see it too. It took a lot of coordination with the thrust to get it to go over and it wasnât pretty but it went.
He has a bunch of good stories like that from his years in the cockpit. Always an adventure.
ResortMain780@reddit
its not the "going over" I would question; its the dive recovery. Those planes are fairly aerodynamic, they will pick up speed and being able to come out of the loop below 2.5Gs without exceeding VNE will be challenging I think. I know I cant do it in a modern glider with higher wingloading, while you can do \~2.5-3G loops all day long in much older less aerodynamic and lighter ones.
And I repeat I wouldnt read much in to the sim (especially one from 30 years ago) allowing this to happen. They dont have fancy damage models, they are not meant or created to simulate flight conditions for which there is no data (and no training requirement).
FlatwormNo3937@reddit
Airlines have upset recovery as part of their training. They practice recovering the aircraft from stalls or full rolls in the simulators
Maelstrom_Witch@reddit
Iâll bet youâre super fun at parties.
Kundera42@reddit
I love this topic. I am a simulator engineer and can tell you pilots love to pull a stunt in the sim if they can. Especially during pre qualification checks. So your dad is probably right!
I once went up with an experienced captain, ex fighter pilot, who wanted to always do this circuit challenge in Sydney, fly below the bridge and land, shortest amount of time... A330, direct law. Funny enough I beat him :D, though have to admit he did the trimming and callouts for me đ
We also did testing in the sim with the Airbus Flight Test team for stall model verification. These pilots did the stall testing on a330 cert program. We did some extreme upset events starting with a bank of 120 degrees. They were incredible in their recovery, sometimes doing a full barrel roll without leaving the flight validated envelopes and no buffets felt, let alone stall or structure damage.Â
I think simulators are quite capable in simulating a scenario like in this movie posted by OP. As long as you manage the same g loading throughout, being inverted doesn't really matter. The simulator will tell you if you are in flight validated territory, wind tunnel validated or engineering. Where the last one of not too reliable but the first one is quite close.
Motion cueing will be crap, but buffeting pretty accurate as well.
Anyway, brought back some memories.
Maelstrom_Witch@reddit
Thank you, that was really cool!
My dad has been retired about a decade and a half ago. Flying was all he ever wanted to do, other than putter around the house and get under momâs feet. Heâs got some great stories from 30 years with an airline.
FlatwormNo3937@reddit
Iâve done the same thing in a 777 simulator. Surprisingly easy to recover
Elven_Groceries@reddit
7*7 barrel-rolls are for noobs. Standard proc for short distance flights, to make it more fun.
Maelstrom_Witch@reddit
It would be more interesting for sure
ear2theshell@reddit
u got this denzel!
FlyByPC@reddit
Just another day at the office. Wow.
chewychee@reddit
I think I heard the do not exceed chirp at him during the dive portion of the exercise.
ufos1111@reddit
Never fly boeing.
Snallygaster1234@reddit
The plane came through fine, but the seat covers were ruined!
LMcVann44@reddit
I imagine pants were shat.
It flipped over pretty quick by the looks.
Ok_Reindeer_9769@reddit
would it still be possible to do this including the weight/unbalance of people, suitcases/cargo etc? I feel as though a commercial aircraft couldn't handle that.
This-Fruit-8368@reddit
Anyone know if they had data from previous test flights or modeling so they knew going inverted was a possibility during a stall?
E2TheCustodian@reddit
From the avgeekery article referenced elsewhere in thread: "The aircraft had previously experienced some unusual stall characteristics. This test was an attempt to determine why so that engineers could solve the issue." Given that, it sounds like they were trying to produce 'unusual characteristics' in the stall, in which case I'd expect they would absolutely be considering unusual roll behavior.
8pin-dip@reddit
The sound, sounds like a game from an 80s Commodore 64.
KingSurfz@reddit
they better pay those guys 13 katrillion dollars a year!
Kindly_Steak5156@reddit
Is the FO touching the captainâs arm? Like, to communicate that he has flaps/throttle etc.?
AvailableCondition79@reddit
Don't stop flying.
TectonicTechnomancer@reddit
I dont think the wings would survive that, not a pilot btw.
Tinosdoggydaddy@reddit
Iâd be running for the exit with my parachute
cbowers@reddit
Bewildered that they pulled through it rather than just continuing the roll to upright and then a more gentle ease up to level without all the nose down speed increase.
Key_Slide_7302@reddit
Why is he continuing to pull back after the stall? Completing the bottom half of a loop to stop the dive? Or poor stall recovery technique?
Which makes me wonder if the heavy amount of right aileron just before the full break was intentional too?
PlayerOfGamez@reddit
Why did he go for a half loop instead of just rolling back up?
daegojoe@reddit
Denzel in flight movie
oldschoolisdead@reddit
Those were real pilots. Today almost the entire flight is flown on autopilot. You canât compare the flying skills of pilots 30,40 + years ago to those of todayâs pilots. Thatâs reality!
silentstorm2008@reddit
Keep the blue side up
POGsarehatedbyGod@reddit
Balls. Of. Steel.
LostDefinition4810@reddit
Probably aluminum to save weight.
BoringBob84@reddit
Probably titanium to take the heat.
Tricareatopss@reddit
Definitely nickel to endure the tension
Actual-Lingonberry58@reddit
Gold. Golden nuts!
PM_YOUR__BUBBLE_BUTT@reddit
Still not enough saved weight to make room for OPâs mom on the plane though.
LostDefinition4810@reddit
Unsecured load
JJAsond@reddit
No balls, just their job. Shit happens sometimes.
B4rberblacksheep@reddit
From the outside looking in test pilots seem to be built different. And by built different I mean actually fucking insane
POGsarehatedbyGod@reddit
Correkt
BoringBob84@reddit
I have been on test flights before (but nothing this dramatic). Those pilots make no effort to be gentle on the airframe or on the test engineers. The only warning we got was, "You guys might want to strap in. This is going to get rough" over the intercom.
These experiences make me comfortable on commercial flights, even in the most intense turbulence.
Objective-Eagle-676@reddit
Balls Balls Balls Balls Balls of steeeel
Maruan-007@reddit
Steel ? Iâd say Titanium
POGsarehatedbyGod@reddit
Unobtanium
Elven_Groceries@reddit
Virginium :(
ParticularLook@reddit
I would have dropped my lucky brick.
POGsarehatedbyGod@reddit
Wait, yours is lucky??
CrazyKarlHeinz@reddit
So what recovery steps did the pilot initiate? Power to idle it seems. Speed brakes? I would have expected him to push the yoke forward more aggressively but it seems that was not necessary?
StinkyMcgee51@reddit
Denzel did this with some vodka and orange juice. Iâm not impressed
bombom_meow@reddit
Why not continue the barrel type roll to recover rather than risk a loop?
maveric00@reddit
It was caused by a stall, which means that the airspeed was too low to fly.
A barrel roll would not have solved that.
DOOM_INTENSIFIES@reddit
And then, just a few years later, for different reasons, a MD 83 ended on a similar position with zero chance of recovery. This video barely gives an idea of what alaska 261 might have been.
Andrescoo@reddit
So the procedure in this cases is to nose dive and then do the flip and pull up again?
Guess itâs to regain air flow on the wings, and then pull up. Itâs not adviced to flip when youâre downwards since the airflow trough the winds is not optimal. Right?
pattern_altitude@reddit
Wings level, nose to the horizon.
dbcooper4@reddit
A normal stall recovery youâd lose maybe a 2-3k ft. They lost 10k feet of altitude. I donât know what the correct technique is in this scenario (roll inverted) but I donât think this is it.
pattern_altitude@reddit
Well an incipient spin/inversion isn't a "normal stall recovery."
Would love to see how you would've done better than the professional test pilots.
dbcooper4@reddit
Itâs not a spin. The wings rolled inverted. People are saying that the pilots later admitted they didnât respond correctly. They ended up 5k feet above the ground which is way too close for comfort.
No_Train_728@reddit
This is not a normal departure recovery or unusual attitude recovery procedure. You would not see a line crew doing this. Whether the test crew planned for this and prepared in advance, I don't know, but 121 pilot would fail a check doing this maneuver.
SubarcticFarmer@reddit
It's an older test, but looks pretty similar to "push, roll, power, stabilize" which is a common recovery mantra these days.
chuckop@reddit
Remembering my upset training, it felt to me that the PF was late getting the power out.
Puzzleheaded_You2985@reddit
Stupid question: I wondered why he cut power at all. Wouldnât more airspeed, quicker be better in that situation? Only cutting power after they had enough airspeed to correct?
tarrasque@reddit
No. First thing to do in most stall-spin scenarios is power to idle.
Gravity will give you plenty of airspeed when youâre pointed down. Quicker - when youâre headed to the ground - is not better.
Also, pushing the plane only perpetuates the spin because it keeps the upper wing in lift.
Puzzleheaded_You2985@reddit
Thanks for that explanation.Â
vctrmldrw@reddit
You can hear the overspeed alarm just before. As tends to happen when the nose is pointed straight down with power applied, it accelerated startlingly quickly.
collinsl02@reddit
https://www.reddit.com/r/aviation/s/Jfwb6pmFkD
maybesami@reddit
When you do that kind of training do you pack extra underwear?
chuckop@reddit
Nope. The Pucker Factor ensured nothing gets out.
hammer166@reddit
This is great. And true. It's after the adrenaline fades that one needs to visit the john.
maybesami@reddit
Thanks for the info đ
Feedback_Original@reddit
I watched Denzel do this drunk
dubstylerz123@reddit
Sounds like the old video game River Raid
exhaustedhuman1981@reddit
I wonder what their max air speed was
deleted_by_reddit@reddit
[removed]
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Competitive_Dance211@reddit
Uh, no thank you! Those pilots donât get paid enough lol
pornborn@reddit
Donât worry. Weâre just gonna trade some altitude for airspeed.
ZappBrannigansLaw@reddit
Code brown
1mz99@reddit
Aren't there risks that this could end up in an unrecoverable deep stall due to T tail?
jack_harbor@reddit
How is the plane able to carry the enormous weight of their balls?
fiittzzyy@reddit
Blue side up means sky guys, not sea!
Wr3ckless13@reddit
Damn. My dad knew a guy who purposely rolled a 757, guess how he got caught? All the blue water in the lav.
MalaysiaTeacher@reddit
Damn with the 3d render and âtest flightIâ I watched this thinking it was a flight sim. Incredible calmness in the face of death.
deathbyvegemite@reddit
https://youtu.be/L2CsO-Vu7oc?si=AG4buZ0B6ovhRC7a
Here is a longer clip with the celebratory ending slapping.
generalcoopta@reddit
Incredible
becoming_keri@reddit
Dr. Mantis Toboggan at the controls
JJdoom@reddit
sounds like the intro to Jasmine by Jai Paul
Obi_Won_Jabroni_@reddit
Whoops, Ok here we go.
Immediate acceptance of the situation lolÂ
ADeerBoy@reddit
Bet this would look scary af from the ground
Miserable-Anxiety229@reddit
Insanity. 0 panic from the pilot and he immediately knew what to do. Takes a different kind of brain from the rest of us to fly, and fly well
suprPHREAK@reddit
When they do these test flights, do they add ballast to the rear of the plane, to balance the weight of the test pilots' big brass balls?
Because holy shit. I did this in a 172, can't imagine in an airliner...
BelowAboveAvg@reddit
Yeah, they do... https://youtu.be/36D4ne2gqus
ChocolateChingus@reddit
Seeing the attitude indicator be all brown wouldve made my seat the same.
Boundish91@reddit
Its wild to stall it on purpose, but i guess it has to be done for certification purposes?
Objective-Eagle-676@reddit
Gotta figure out what it will do in real life at those conditions.
vctrmldrw@reddit
And, in this case, what it did was rather alarming.
Boundish91@reddit
Makes perfect sense that.
Grouchy-Ad778@reddit
Iâm not a pilot so please excuse the super-amateur question!
What do they adjust at 0:15? To my untrained eye it looks like it might be throttle but it seems that theyâre reducing power which seems counter to what I feel youâd need to doâŚ
Objective-Eagle-676@reddit
Nose pointed directly at the center of the earth is the worst time imaginable to be actively accelerating the plane.
Grouchy-Ad778@reddit
Thanks! Yeh I guess I thought itâd help with getting more airflow over the wings/powering out at the bottom end of the loop
tarrasque@reddit
Gravity will get you plenty of airflow over the wings at 9.8m/s^2 :-)
railker@reddit
Throttle and then I believe speedbrake handle. When you're diving towards the ground, having enough speed is the last of your worries and you can hear the plane call out 'Overspeed' in the last second of the video as they blow over the speed limit.
Even once they had speed, they needed good airflow over the wings and tail and then smooth recovery, can't just yoink the nose level like an F-18 unless you want to snap in half. Power would have come back on as they recovered and their speed got back in range, someone else posted the longer video higher up.
Grouchy-Ad778@reddit
Ah see thatâs another part of my ignorance - I hadnât considered the forces that just pulling the nose up would create at that point.
Thanks for explaining
SubarcticFarmer@reddit
Pointing down like that you are picking up airspeed incredibly fast, you want power at idle. T
Grouchy-Ad778@reddit
Ah got it. In my head I thought the power would be helpful for getting more airflow over the wings but yeh pointing downward is probably doing that for you
tokyoxplant@reddit
Good recovery, Mav!
NoResult486@reddit
Brown power down
e4evie@reddit
The absolute balls on these boys..
kohtuullinen-ajatus@reddit
Panic pull in practice. Continue to roll would have been a lot safer way to recover
AdAdministrative5330@reddit
Seems like forever before he pulled the thrust back and deployed speed brakes
timihendri@reddit
Code brown!
EmptyWish2138@reddit
The drink cart is going to bring it down
_-Cleon-_@reddit
My condolences to whoever had to clean the seats.
collinsl02@reddit
They seemed nice ald calm to me, I doubt cleanup was required.
MaxwellHoot@reddit
r/videosthatendtoosoon
ambreenh1210@reddit
Would this be possible with the weight of passengers, fuel, and luggage?
SubarcticFarmer@reddit
During testing they have water bladders they fill and adjust to give various weights and center of gravity configurations.
Malcolm2theRescue@reddit
They look amazingly calm. Nerves of steel for sure.
fontimus@reddit
Holy crap that makes my stomach turn. The balls on these guys.
JunglePygmy@reddit
The amount of composure pilots have just blows my fuckin mind
Strange-Spinach-9725@reddit
Squad.
Particular-Can1298@reddit
Do these test flights take place at cruise altitude? Iâm guessing yes as they need to take the aircraft through its paces in its natural habitat
Loud-Aioli-9465@reddit
Test started at 15,000 feet. It makes sense to test stall characteristics at lower altitudes. Stalls at cruise are extremely rare barring control issues that likely would doom the plane anyway.
RedditVirumCurialem@reddit
Surely this couldn't have been a surprise? The MD-80 and DC-9 must've gone through the same testing regimen. Is the 717 design really that different?
Samtulp6@reddit
My previous job got two factory new P2006Tâs. Serial number difference of 2. One will stall like it is trying to get you into a spin, whilst the other had very docile stall behaviour.
The Boeing 717/MD-95 is an entirely different fuselage, new wing configuration, new engines. Of course itâs going to have very different stall characteristics.
kingtacticool@reddit
Sketchball city.
REDDITCEOSUXDICK@reddit
why only post part of the video? đ¤Ą
PestoBolloElemento@reddit
That's mad and Amazing
KRino19@reddit
Ooops