FL510. First time for me!
Posted by Lazy_Entertainment73@reddit | aviation | View on Reddit | 289 comments
Flying in a Gulfstream V. It was during a Ferry Flight between Guarulhos and Lima.
-Sm00th-0perat0r-@reddit
If a decompression happens, you’ve got 6~9 seconds of useful consciousness at that altitude.
njsullyalex@reddit
Question, how did it work for Concorde passengers who regularly flew above FL600?
-Sm00th-0perat0r-@reddit
Concorde Pressurization System
At 18,300 metres (60,000 ft), Concorde’s cabin altitude pressure was maintained at an equivalent to 1,700 metres (5,500ft), considerably below that of a subsonic aircraft.
Airliner cabins are usually pressurised to 6-8,000 ft (1,800-2,400 m) elevation while the aircraft flies much higher. Concorde’s pressurisation was set to an altitude at the lower end of this range, 6000 feet. Some passengers can have difficulty even with that pressurisation. A sudden reduction in cabin pressure is hazardous to all passengers and crew. Concorde’s maximum cruising altitude was 60,000 ft (18,000 m) (though the typical altitude reached between London and New York was about 56,000 ft (17,000 m)); subsonic airliners typically cruise below 40,000 ft (12,000 m). Above 50,000 ft (15,000 m), the lack of oxygen would limit consciousness in even a conditioned athlete to no more than 10-15 seconds. A cabin breach could even reduce air pressure to below the ambient pressure outside the aircraft due to the Venturi effect, as the air is sucked out through an opening. At Concorde’s altitude, the air density is very low; a breach of cabin integrity would result in a loss of pressure severe enough so that the plastic emergency oxygen masks installed on other passenger jets would not be effective, and passengers would quickly suffer from hypoxia despite quickly donning them. Concorde, therefore, was equipped with smaller windows to reduce the rate of loss in the event of a breach, a reserve air supply system to augment cabin air pressure, and a rapid descent procedure to bring the aircraft to a safe altitude. The FAA enforces minimum emergency descent rates for aircraft and made note of Concorde’s higher operating altitude, concluding that the best response to a loss of pressure would be a rapid descent. Pilots had access to Continuous Positive Airway Pressure which used masks that forced oxygen at higher pressure into the crew’s lungs. Had access to CPAP (Continuous Positive Airway Pressure) which used masks that forced oxygen at higher pressure into the crew’s lungs
Source;
https://www.heritageconcorde.com/concorde-pressurization-system
getting_serious@reddit
The way that I always imagined this was 1) Flight level was limited by decompression limits (blood boiling), I'd imagine they'd have designed the engines to work even higher otherwise, 2) Fast descent is practically limited by speed of sound on all other airliners but Concorde doesn't have that limit.
I am a total layperson, am I on the right track with this? In particular, what does fast descent look like in practice, flap deployment and all?
Lost_Cockroach6702@reddit
That’s only if it’s not a rapid-d. If it’s rapid it’s closer to 3-5. The people who don’t wear masks at that altitude are morons. I know a guy who died in the F-15 from a rapid-d in the 50s because he had his mask down to drink water when it happened.
addicted_to-water@reddit
Can someone explain this to me in basic terms? If I just out of nowhere breathe out and stop inhaling I don’t immediately pass out. Even if completely unprepared, I still have oxygen in my bloodstream from my last breath and I feel like it easily lasts 10-15 seconds or maybe even longer.
Why is that different at such high altitude?
RealPutin@reddit
You won't actually be able to hold your breath. All of a sudden you'd be holding back nearly an entire atmosphere worth of pressure which is well above what your lungs can handle. You'll exhale whether you like it or not. If you manage not to, you will suffer severe injuries.
And then the partial pressure of oxygen in your blood will actually be higher than in the air/your lungs after breathing, so you'll experience rapid deoxygenation with oxygen flowing the "wrong way" into your lungs
KDiggity8@reddit
Thank you for this explanation! I never really understood why you'd lose consciousness so quickly in the event of a rapid decompression, but this makes total sense.
shamberra@reddit
+1 on appreciation of this explanation. I too was thinking "the fk I don't pass out in under 10 seconds after exhaling, there's plenty of oxygen in my blood" and this comment perfectly explained why it's different when there's such a significant difference in pressure.
gefahr@reddit
That all sounds very unpleasant.
Is that similar to what happens to divers who ascend too rapidly? Or I guess that's the opposite?
This is breaking my brain for some reason.
RealPutin@reddit
Yup, it's the exact same thing. You can get decompression sickness, there are recorded examples of this in U2 pilots you can google about
gefahr@reddit
Thanks
Rustyducktape@reddit
What's your age? Just curious
CaptnHector@reddit
50s, as in 50k feet, not 1950s, lol
Rustyducktape@reddit
Im such a jackass! sorry!!
krudhead@reddit
Keep your forked tongue between your teeth next time
Rustyducktape@reddit
A bit harsh, but I hear ya, you've got a point
krudhead@reddit
Lol jk bro I was just making a stupid Lord of the rings quote. No /s so I got downvoted to oblivion
gefahr@reddit
I mean, I read it the same way you did.
HarryTruman@reddit
Bro you are not even part of the convo.
chowl@reddit
chill
yvery@reddit
Modern business jets and I believe the A350/A220 will emergency descent on their own if it senses depressurization.
enfly@reddit
Was there an NTSB report? How did you find out?
Lost_Cockroach6702@reddit
The NTSB doesn’t investigate military accidents, the DOD has their own accident investigation schools and organizations. We don’t publicly release safety investigation board reports.
BeenThereDoneThat65@reddit
IF you are a world class tri-athlete or mountain climber.
Most pilots it will be lights out in 2-3 seconds.
FL470 your TUC goes up to 10-12 seconds. And that’s a realistic time To get your O2 mask on
There is a reason that most jets that can fly at FL510 have a EDM that the plane will do on its own in the event of a Decompression
prophettoloss@reddit
What if you were a skilled free diver? And was aware it was going to happen?
CaptnHector@reddit
Say you try to hold your breath - you wouldn't be able to keep air in your lungs. At 50k feet, you're at 15% sea level air pressure, which is closer to vacuum than it is to normal air. The air in your lungs would be sucked out of your body and you'd be left with the oxygen dissolved in your blood. Maybe you've trained and have more hemoglobin, but you're still going to pass out in seconds.
Think of elite high altitude mountaineers. They still need days/weeks of acclimatization, and can barely function without supplementary oxygen at 29k feet. Now go 21k feet higher... no chance.
RealPutin@reddit
Which would be at a higher partial pressure than the air you're now breathing in, so your blood would actually rapidly deoxygenate back into your lungs, meaning you wouldn't even get to keep that oxygen as long as normal.
prophettoloss@reddit
thank you!
-Sm00th-0perat0r-@reddit
If my grandma had wheels, she would’ve been a bicycle…
Laxboarderchill@reddit
This was my thought as well. Current U-2 pilot….af requires a full pressure suit for any sustained flight above FL500 for this reason as well as the risks of decompression sickness
Jdubya38one@reddit
Wasn't there another U-2 pilot commenting on a "hardest plane to fly" thread the other day? Are there really TWO Dragon Lady pilots hanging around on Reddit?
Not hating or being a dick at all, genuinely curious but also maybe a small bit skeptical lol
donkeyrocket@reddit
It checks out. Because I'm also a U-2 pilot and that's my buddy, a fellow U-2 pilot.
Purplesect0rs@reddit
You too are a U-2 pilot. U 2 are U-2 pilots
hoppertn@reddit
You need some U2 flair in your description
donkeyrocket@reddit
I've already said too much.
hoppertn@reddit
Totally understand wanting to keep a low profile. Not even my wife knows I secretly test the crashed Alien tech we reengineered back in the 50’s. Artemis 2 furthest humans from Earth, LOL. She thinks I’m an accountant. /s
elPatronSuarez@reddit
Be careful! Dude in the cube next to me got divorced and the sick bitch even took the ice cube trays!
hoppertn@reddit
It’s all good, I can keep a secret, well at least the government thinks I can.
Jdubya38one@reddit
You can tell you're being truthful because you said you are!
Jokes aside, that's very cool and a really small bunch right? How many people have flown the U-2 all time?
donkeyrocket@reddit
Jokes aside the best I could find is there's potentially 50 active pilots at a given time. According to this (2020) there's been 1,058 pilots qualified to fly the U2.
ZeroWashu@reddit
I just have to ask, are parts of the flight boring and if so what do pilots typically do in that situation.
Laxboarderchill@reddit
The number you found isn’t necessarily qualified….its the number of people who have solo’d the u-2. It’s a big party!
Laxboarderchill@reddit
That number isn’t far off, my solo number is slightly over 1100
Dropssshot@reddit
Do you think there's a chance I could give you a few bucks to send me one of your U-2 patches? I'm AFE in Germany so I don't see anything cool like that very often.
donkeyrocket@reddit
Sure, here's a spare one of mine
brodie34mills@reddit
Y’all know “Lucky”?
Laxboarderchill@reddit
We’re all aviation nerds at the end of the day! And what better place to hang out than here!
Jazzlike_Climate4189@reddit
You mean you can suffer DCS from a rapid depressurization at 50k feet? That’s wild
Fourteen_Sticks@reddit
What’s the PSId of a U2? I bet it’s significantly lower than a GV/550
Laxboarderchill@reddit
At 70k+ PA, it’s ~14k cabin altitude ever since a structural modification was made a number of years ago. Previously, pilots would sit at ~30k CA. The pressure suit (minus the face seal) matches the cabin under normal circumstances, but will inflate to keep the pilot ~35k if/when the cabin is breached
weegus@reddit
Shows you how good Concorde was - cruising at Mach 2 at 60,000ft.
limits660@reddit
No problem 😁
Neither-Way-4889@reddit
Just hold your breath!
chokingpacman@reddit
Right? Or does the air get sucked out of your lungs when the outside air pressure is so low
Soronya@reddit
Can you even hold your breath at that altitude
elliptical-wing@reddit
Why isn't it the length of time that a person can go without breathing? I.e. if I hold my breath, I can do that for 30 seconds at least.
OP_Skis_In_Jeans@reddit
That's why masks are mandatory for at least one pilot in the flight deck above FL410. In practice they're somewhat uncomfortable to wear for long periods so compliance varies.
hoppertn@reddit
Just hold your breath for a minute or more. /s
RandomNightmar3@reddit
6-9 seconds if you're in your 20 with an athletic body.
Anything other than that, less than half, that's why at least one should wear an oxygen mask.
movemetal17@reddit
Nice
CardinalOfNYC@reddit
Challenger astronauts were up around this height, 60k at the peak of the crew cabin's arc. It's the data that supports our hope that all the astronauts were unconscious when they hit the water.
UnreasoningOptimism@reddit
"We don't have any passengers on board so we decided to have a little fun and come on up here."
No-Sell-3064@reddit
Wasn't that the story of guys who lost their engines and endup crashing?
Cow_Launcher@reddit
Yep - it was this one.
Squawk_7777@reddit
Been up there. Once. Not as high as you though. Then startes reading up on higher atmosphere radiation. Don't want to spoil your excitement making it to FL510, but get yourself one of these:
Geiger Counter
Study your manual. How much protection from the airframe, windshield etc. you get. You might want to thank yourself in 20 years or so.
hughk@reddit
Concorde cruised at FL60 for transatlantic crossings, and they had a dosimeter (cumulative radiation over time) at the Flight Engineer's station.
Squawk_7777@reddit
FL600. AFAIK, the only commercial aircraft that had one.
WSI (app we use) also has an option for space weather aka radiation.
hughk@reddit
Space weather is also interesting for long distance comms. HF and Sat Comm can be affected as well as GPS.
Wack-waving-arms@reddit
The beauty of piloting a private jet 👍. What’s the curvature like up there?
jcla@reddit
I love that the true airspeed is 439 knots versus the indicated airspeed of 189 on the HUD, the air gets thin up there...
iechicago@reddit
That's the most notable thing here for me. Illustrates how IAS "works" very clearly for PPL students...
BugHistorical3@reddit
So basically what you're saying is that we should start using Gulfstreams for training instead of Cessna 172s
SmokeMidKids@reddit
Fuck sign me up too, I might have to go and get my ppl again then... ;)
Atomic_Priesthood@reddit
Dammit - I'm in!!
Zintoatree@reddit
Me too, anyone have any idea where I can find a Gulfstream for 160/hr wet.
fighterace00@reddit
That'll cover about 3 seconds
Bmil@reddit
You paying 160 wet on a 172?!
Boxerocks08@reddit
$150 wet at my local fbo for the ones with a six pack and a gns430/530. $140 for the one with no gps. Even the ones with more modern avionics and autopilot are in the $160-170 range.
Atomic_Priesthood@reddit
When I got my ticket, it was half that.
Zintoatree@reddit
Nope, that's just what I remembered from when I was giving flying a serious look. Just asked Google and it looks like it's 190+ now wet.
HotRecommendation283@reddit
You can get one for 160/min for sure!
RealPutin@reddit
That's actually still not quite enough to charter some Gulfstream models lol
Adviderisj@reddit
Operational costs won't break 9,600. Chartering can cost way more, due to the pilot, etx. Being an expense
Zintoatree@reddit
Close enough.
TraderJ1@reddit
Air Force used to use the T1 (basically a Beech 400) for the guys learning heavies which you would go to after 35ish hours flying a DA20.
CaptainSnacks@reddit
When I was in college at Texas A&M I used to love those little red tail bugs flying around all day from Lackland. Fun lil goobers
vissor4@reddit
Unless you were XPW you never flew the T-1 without ~100+ hours in the T-6 first.
NoDoze-@reddit
That would be awesome!
RedditVirumCurialem@reddit
What might the stall speed be up there for that thing? I expected it to be indicated on the speed strip...
DecelerationTrauma@reddit
If that isn't Coffin Corner, it's definitely on that block.
Some1-Somewhere@reddit
0.02 below target mach suggests they're a bit short on thrust too., which you'd expect.
wayofaway@reddit
They don't indicate on older avionics, I think it's because they were afraid of giving incorrect data.
BatmaniaRanger@reddit
The pressure diff must've been insane...
twilighttwister@reddit
How is the true airspeed measured?
jcla@reddit
The indicated airspeed is measured by a pitot static system that compares the air pressure moving forward with the air pressure in the air mass around you.
As you go higher, the air pressure around the aircraft drops dramatically (there are less air molecules higher in the atmosphere and the temperature is significantly colder) which gives inaccurate speed readings, as the system is calibrated to work at sea level pressure and temperatures.
This isn't a big issue at lower altitudes, but at airline crusing altitude (or even higher,like the 51,000' here) there is a significant error.
Now the error is pretty predictable at slower speeds, so pilots or the flight system can use a calculator (an E-6B or whiz wheel, is a mechanical one that's been used for decades, for example: https://en.wikipedia.org/wiki/E6B) to convert the indicated airspeed to true airspeed.
At higher speed (above 300 knots) you get compressibility effects due to the shock wave of the aircraft, so the calculations are more tricky and are typically converted to Mach numbers (percentage of the speed of sound) and done automatically by the flight system with some complex calculations that account for the compression.
Now with GPS systems onboard the nav system can get both the true airspeed and the ground speed from the GPS system, which is what is likely feeding the numbers in the bottom left in the picture here.
Jango214@reddit
How can the GPS get the true airspeed when you need an actual instrument to measure the air speed?
twilighttwister@reddit
True airspeed is relative to the ground, it's an equivalent airspeed at sea level (or at whatever the system is configured to).
Indicated airspeed is the airspeed the plane "feels". It's the pressure of air going into pitot tubes at the front of the aircraft, and also the pressure of the air on the wings, which gives lift.
As the air density goes down with altitude, the plane must travel faster relative to the ground (true airspeed) to maintain the same air pressure and lift (indicated airspeed). This is overly simplified, but hopefully you get the idea.
GPS measures speed relative to the ground, and is more accurate than the true airspeed calculated from the indicated airspeed.
prof_r_impossible@reddit
this shot is showing TAS, not GS; GPS not involved
RCAF_vet71@reddit
I hear that Iced Tea is a Pretty Cool Drink…..
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSlvjQQjWIdiu-WvC_2OnZBtTeOxryZ9JxRKA&s
Jazzlike_Climate4189@reddit
https://letmegooglethat.com/?q=how+is+true+airspeed+measured
allaboutthosevibes@reddit
How does it still fly with IAS of 189…? I thought that’s a bit low, don’t most jets cruise around 200-250?
oshawaguy@reddit
Thank you! I was just intelligent enough to wonder why the knots and Mach were so different.
twilighttwister@reddit
Yes, the speed of sound goes down with increase in altitude (I think it's actually temperature, but for flight altitudes they correlate). You also have the stall speed rising, as their is less air to generate lift.
The best part is coffin corner, the edge of the flight envelope where the stall speed and the speed of sound meet. It's maybe a bit higher than this, but the U2 spy plane has issues banking at altitude - the inside wing tip is going slower than the outside, so the inside wing stalls while the outside wing goes supersonic.
DifficultyAwareCloud@reddit
The U-2 has no issues banking at altitude. There is no significant difference in wingtip speeds, one going supersonic is nonsense
velociraptorfarmer@reddit
Correct. Speed of sound is surprisingly only dependent on fluid temperature, all else being equal.
Temperature in the atmosphere nominally decreases as altitude increases in the troposphere (lower level of the atmosphere), then actually begins increasing with altitude through the stratosphere.
TbonerT@reddit
It isn’t surprising at all that a multi-variable value changes based on one variable when you set the rest equal.
WaitForItTheMongols@reddit
Am I missing something or is this a tautology? Of course it's only dependent on one thing if all else is equal.
peteroh9@reddit
It's mostly altitude, because it's due to air pressure, but temperature obviously has a correlation with that, too.
CA_LAO@reddit
Stall and Vmo. Not sound :)
twilighttwister@reddit
Fair play. But how far apart are they up there?
CA_LAO@reddit
The spread from Vmo t m1.0 can vary significantly by aircraft, if that's what you are asking. The margin between Vmo and where the wing stops working as needed is also variable, and the most critical factor. .
twice_paramount832@reddit
Where is TAS indicated?
jcla@reddit
You can see it on the partial display on the bottom left corner of the picture
kyoshiro_y@reddit
Check the bottom-right part of the left PFD. It shows both TAS and GS.
Seacabbage@reddit
I had no idea ias would go that low at cruise from turbines. Knew it would drop down and there would be a large delta between ias and true but wow
Mission-Wasabi-7682@reddit
So you say if I take my Arrow high enough my 189kts equal 0.81 Mach? That’s amazing! /s
jetdriver13@reddit
Impressive, no red at all at the bottom of the speed tape! Congrats!
I’m seeing a lot of comments about radiation. Is it really that different between 410 and 510? I’m in the 40s all the time.
Impressive_Jury_2211@reddit
What’s the time of useful consciousness around that altitude?
Katana_DV20@reddit
With the nightmare of a rapid decompression at that altitude its about 4 to 5 seconds.
Theres a reason why the pilots have "quick don" masks. They have to come on real quick or its lights out.
Impressive_Jury_2211@reddit
Idk man 4-5 seconds is not a lot of time. When I was in the army and we did simulated gas attacks no way we got the mask on under 10 seconds
Katana_DV20@reddit
An airline pilot buddy on the A320 who used to fly the big Gulfstreams said its about 5 sec up there in the 50s for a really bad scenario, windscreen blowout maybe like the Chinese Airbus incident where FO almost got sucked out.
This demo shows a pilot putting on the mask. About 6 sec from reaching for it to sealed on face.
https://www.youtube.com/watch?v=mgLSTimJ868&pp=ygUccXVpY2sgZG9uIG1hc2sgYWlybGluZSBwaWxvdA%3D%3D
brom5ter@reddit
Clint Eastwood reflexes on the oxygen mask.
Swimming_Way_7372@reddit
So impressive. Even at 510 there isn't a coffin corner.
Texas_Kimchi@reddit
I believe thats the max altitude.
Swimming_Way_7372@reddit
It sure is, but most airliners would have a very distinct coffin corner when they get up near the 40s and in this picture you can see there isn't even a hint of color on the bottom section of the airspeed tape.
joesnopes@reddit
I've logged a reasonable amount of time at FL450/M.86 in an SP over the Pacific. It wasn't seriously near coffin corner. Have hand flown it and not over touchy. That was our height limit.
Fourteen_Sticks@reddit
Modern corporate jets are limited by time to descent to 10,000. Hard to find one that has a true coffin corner.
UpDog17@reddit
Really? That's interesting I didn't know that. So need to reach 10 000 in a certain time?
Fourteen_Sticks@reddit
Sorry. Not necessarily 10,000’.
14 CFR 25.841 outlines what’s necessary to be certified with a pressurized cabin. It’s a multi-faceted regulation that implies you’ve got to be able to descend to a survivable altitude in a certain amount of time.
It specifically mentions 15,000 feet, which is, unironically, the altitude to which the emergency descent mode in a modern Gulfstream is programmed to descend to.
toshibathezombie@reddit
It might be flight level capped by cabin differential pressure rathert han Coffin corner
BeenThereDoneThat65@reddit
Oh yes there is a coffin corner
Very few will actually operate a GV at FL510. Hell I don’t like cruising it at FL490
RealPutin@reddit
I don't remember the GV offhand, but generally for this class of bizjets the envelope spot where the true U2-style coffin corner would be doesn't hit until about 5k-10k above the service ceiling.
You're still in a pretty touchy zone in terms of margins, excess thrust, etc but it's relatively safe
Perfect_Big_5907@reddit
Sweet. Only made it 470 in a Lear once. Super smooth, quiet and we had a quartering 180 knot headwind.
Lazy_Entertainment73@reddit (OP)
I also fly the Learjet 60, but in that only reach FL430. Pretty close to the coffin corner, and if you have turbulence there, it's not a pleasant experience.
bigbel100@reddit
Can you explain why the turbulence isn’t as pleasant up that high? Because the air is less dense so less control around the airfoils? Wind strength?
Mr_Muckle@reddit
How much fuel on board? I fly a 550 and 600 and haven't been above 470.
Lazy_Entertainment73@reddit (OP)
Around 8000 pounds. Just 2 pilots, no pax, no bags. We ascend to 510 at the last hour only.
BreakfastBurrito@reddit
Clearly way too much, whoever planned you needs lessons, get that EFOB down to the 3s baby
Wings_Of_Power@reddit
Was it a smooth flight since you were well above most of the weather?
BreakfastBurrito@reddit
Wonder if they're kind enough to give a LGT CHOP somewhere for the Delta guys
therealjerseytom@reddit
Probably didn't hit any birds up there
allaboutthosevibes@reddit
Gotta watch out for superman, though!
joyurifan132@reddit
no landings in the Hudson for sure
mz_groups@reddit
Hell, at that altitude, they could probably GLIDE to the Hudson from Lima, Peru if they had to.
ImNot6Four@reddit
Surely Down to Acapulco Bay
Die-youngg@reddit
erm actually 🤓☝️
mz_groups@reddit
Hyperbole, my friend. Hyperbole.
Die-youngg@reddit
jk jk
donkeyrocket@reddit
Never tell me the odds, kid.
Evanescence fades in
hoppertn@reddit
Still got to keep your eyes out for balloons.
PerfectPercentage69@reddit
~~balloons~~ UFOs
SourcedLewk@reddit
Yeah but then you start hitting low flying aliens
BreakfastBurrito@reddit
Up there with the damn weather balloons I'm barely seeing NOTAMs for
Metallifan33@reddit
-78 SAT!
BreakfastBurrito@reddit
Beach day
Voodoo_One@reddit
So a sweatshirt is a must if you open the window?
sodium_hydride@reddit
And flip flops.
CycleComfortable3028@reddit
Wow that’s awesome
aviatorcowboy@reddit
I was expecting the TAS to be a bit higher, considering the very high FL. Maybe I'm missing something, need to get back to the ATPL books!
Zeeuk@reddit
GVs are great. Mostly what I work on. Weird seeing one without synthetic vision
BeenThereDoneThat65@reddit
I don’t know of a single Classic V with Synthetic vision. That was introduced on the 350/450/550
Zeeuk@reddit
I think the ASC is 183B. That ASC takes the DUs from 880s to 885s. When combined with the PEAF mod, it makes it possible. I don’t have the documentation in front of me currently but I’ve done a few installs for synthetic vision on both GIVs and GVs
enfly@reddit
What does synthetic vision look like?
Zeeuk@reddit
It simulates what the environment and terrain looks like around the aircraft and displays that on DUs 1 and 6. I can tell right away this aircraft doesn’t have it due to not seeing the enable switch next to the LPV enable switch.
ecnehls@reddit
Been there… many times.
DependentEchidna87@reddit
Show us the horizon out the window bro !!
Poopy_sPaSmS@reddit
Fkng seriously! I need to see it!
AnArmChairAnalyst@reddit
A pic of the horizon would of added 1,000 more comments to this post. IYKYK
old_righty@reddit
(See cliffs around Antarctica then end of the flat earth) “Uh, my bad, nothing to see here”
mokupilot@reddit
Where are the stars?
Digger_Pine@reddit
Where are the stars for you?
mokupilot@reddit
Usually up, unless (crosses hands) we were inverted.
Digger_Pine@reddit
Yeah, they were all yellow
NoDoze-@reddit
Totally! Where's the pics!?!
Express-Way9295@reddit
Was an O2 mask required to be used at that altitude?
Neither-Way-4889@reddit
Legally yes (required above FL410), but in real life its not so common.
Mountain_Fig_9253@reddit
So what’s the plan if you de-pressurize rapidly? Just die?
Neither-Way-4889@reddit
A rapid or explosive depressurization above FL410 is extremely unlikely. TUC is measured in seconds at those altitudes, but the masks are designed to be donned + delivering O2 in 5 seconds.
If anything I would be more worried about a gradual depressurization. If it goes unnoticed (which it wouldn't because there are many safety systems in place), the gradual loss of pressure would be far more insidious. You could be unconscious before you even realize what happened.
gsmitheidw1@reddit
You're not really selling me FL510 here. Good old ~36k with a bit of turbulence chop is sounding a lot nicer!
RandomNightmar3@reddit
100%! And less cosmic radiation too!!
gsmitheidw1@reddit
Now there's a question, are people less shielded in composite fuselage aircraft than traditional aluminium ones?
How many 787 flights Vs 777 is the same radiation given same altitude and constant atmosphere density etc
RandomNightmar3@reddit
I asked Gemini. Apparently composite are better at NOT generating secondary radiation and absorbing primary radiation, but the rate of absorption of primare radiation is negligible anyway.
I also asked the average radiation dose at mid latitudes at 390 and 510: 5.50 µSv/h vs 11.0 µSv/h.
So yeah, 510 is not a very healthy choice on multiple factors. And thank god I don't do polars anymore!
Dropssshot@reddit
We're really asking AI
f1racer328@reddit
And it’s wrong. Shocker.
Source: I bought a spectrometer and have measured the radiation levels all the way up to 410.
RandomNightmar3@reddit
And shocker. You used the wrong tool.
f1racer328@reddit
Tell me how a scintillation spectrometer isn’t the correct tool.
RandomNightmar3@reddit
Because apparently they are practically blind to fast neutrons, so you are measuring radiation only in the gamma rays, which makes your data/measurements very much incomplete.
RandomNightmar3@reddit
I don't have any friend in nuclear engineering. And definitely don't have a siever dosimeter at hand.
The relation between those numbers still stands even if those numbers are wrong: twice the radiation at 510.
f1racer328@reddit
Those numbers for 390 are wrong from what I’ve measured. I have a spectrometer and have measured between .9 and 1.2 µSv/h.
RandomNightmar3@reddit
And shocker. You used the wrong tool.
Octavus@reddit
Aircraft skins are much too thin to provide any shielding.
ptmiguel@reddit
Thats actually a great question, to which i have no idea of the answer
Zinger21@reddit
I love flying a plane that can rather easily make FL470, but our O2 masks are only certified to FL400… I thought we had the wrong masks or something, but nope. That’s literally how Cessna spec’d it. Haha
Swimming_Way_7372@reddit
You guys don't take the 680 above FL400 ?
Zinger21@reddit
Oh we do, FL430 is our sweet spot with the winglet mod. When I asked about the FL400 cert on the masks the reason they gave was for prolonged use they are only certified up to 400, in the event of a rapid decompression they will get you down to a safe altitude assuming you start a decent in a timely manner.
Swimming_Way_7372@reddit
I see. My favorite 680 variant is the +. I like the look of the wing against the classic fuselage diameter. Im in the 680A and its a dog to be honest.
Zinger21@reddit
I agree. Sovereign’s are definitely the better looking versions. That + wing fits it really well. Our winglets are huge and they look a little disproportionate.
I’d be curious to see if your masks are also certified only to FL400, Cessna likes to reuse as much as they can.
RandomNightmar3@reddit
A window blowing out wouldn't be fatal at all at 410.
Margins depends by a multitude of factors, and on Airbuses are generally way better than Boeing.
Why would you need thrust at 410 anyway? Plenty of time to glide at an appropriate speed.
Neither-Way-4889@reddit
Neither Airbus nor Boeing are routinely cruising above FL410.
RandomNightmar3@reddit
You're confidently wrong. 410 is very common for airbus's wide bodies. Boeings always fly lower (good for them).
sodium_hydride@reddit
Turning on the 410 altitude filter on FR24 instantly shows a few. Admittedly not that many airliners beyond 410. It's mostly business jets at 420 and above.
Squawk1000@reddit
A350s regularly go up to 430.
Baarhyn@reddit
410 is common for both newer airbuses or boeings, 430 sometimes and i've never seen either at 450 or abv.
Am a high level enroute controller, I frequently have 25-30 big jets on my frequencies.
AlexisFR@reddit
Just don't hit anything and trust your mechanics!
thetiredtypist@reddit
You eventually get down to safe altitude again... Eventually...
MTX-Prez@reddit
My pilots never wore a mask above FL41 in our Bravo. We would get to 44k a few times a year going from PHX to SDF or back. The last trip in that plane we were at FL39 and it got really loud / alarms went off as the main door seal failed. We landed in Dallas where I was reassured it was just ice build up. Got back on that plane to PHX and put it for sale that week. For anyone wondering what it is like at FL44 in a Bravo… the nose is noticeably pitched up during level flight and the chips bags go pop every now and then.
Tom-Nook-98@reddit
Sorry for hijacking the thread but I have a related question. In Airport (1970) the pilot remaining in the cockpit hat to put on his oxygen mask when the other pilot left the cockpit. Is this also done in real life? (at "normal" flight levels for passenger flights). Or was it standard procedure when the movie was made?
Neither-Way-4889@reddit
Above FL350 if one pilot leaves the cockpit the other must put their mask on. This does happen because its just a short time so no big deal. Cruising above FL410 with a mask on the whole time is a major drag.
Swimming_Way_7372@reddit
You don't see that in the corporate pilot world.
Imaginary_Amoeba3461@reddit
With 121 it’s above 410. 350 might be a 91/135 thing, no idea.
-Sm00th-0perat0r-@reddit
Where did you get that info?
Tom-Nook-98@reddit
Cool, thank you!
Express-Way9295@reddit
Cool!
the_other_paul@reddit
Bro, you joined the 510 club!
MD-80-87@reddit
CRTs ;)
JazznBlues_lover@reddit
How's the view up there?
All kidding aside, I've flown in commercial planes around 20K, but never 50K. That's pretty cool. Did you get to see the curvature of the Earth or anything else that was noteworthy?
PromiscuousLover4me@reddit
A few more feet and you’d have been astronauts lol
Ouchthathurtsbjj@reddit
In a classic V!!! I see you’re monitoring the ECS page 😆. I would be too, that pressurization system is fighting for its life!
Minority_Carrier@reddit
I thought this is somebody taking a MSFS screenshot using their phone
A_LittleBitHigh@reddit
That's really high
ContributionEasy6513@reddit
Very impressive
Instarainz@reddit
Project Farm Approved!!!!
moon__lander@reddit
We're gonna test that.
Isme1@reddit
I here the voice
Trematode@reddit
Let's see Paul Allen's flight level.
Foxhound_Ocelot@reddit
peteroh9@reddit
Well that's not very high.
conspiracylover@reddit
-Badger3-@reddit
My god…it’s AGL
Dasgerman1984@reddit
His even has a water mark
Lazy_Entertainment73@reddit (OP)
Jesus. Dorsia? On a Friday night?
Rilex1@reddit
Nice. Did you glow in the dark after all that cosmic radiation?
f1racer328@reddit
Right? I don’t even like going up to 410 unless there’s a good reason.
RealPutin@reddit
Not even hitting 410 hurts the performance of these birds but there are multiple Gulfstream customers (by customers I mean the richy rich owners) that explicitly avoid going much above that because of radiation and health concerns
eaglingandyj8se7@reddit
Getting a free chest X-ray on the company dime.
zerbey@reddit
Dude you are so high right now.
Austerlitz2310@reddit
Lucky, I'm sitting on a max of FL430 in a slowtation
Digger_Pine@reddit
Cool! My 1st car was a Datsun 510
jseasbiscuit@reddit
Welcome to the club from a fellow FL510 bro
GameonSilver@reddit
Congrats my good sir/madam
Murky-Resident-3082@reddit
Ok
ThisIsMyBigAccount@reddit
Air so thin you’ll live an extra 4 years. Congrats!
Smooth_Load_4833@reddit
Don't forget to land!
PlaneShenaniganz@reddit
Mach Powerrrrr
njsullyalex@reddit
I imagine packs are begging for mercy
Great_Specialist_267@reddit
Pray you don’t have a catastrophic pressurisation failure. At maximum rate of descent you will lose consciousness before sufficient air pressure is restored for the emergency oxygen system to work. That’s why airliners don’t operate above 40,000 ft and fighter pilots wear pressure suits.
TrueNorth_360@reddit
The Mach 0.81 versus 189 IAS is kind of mind blowing 🤯
Electrical_Report458@reddit
What was your cabin pressure up there?
No_Excitement455@reddit
👏
wearsAtrenchcoat@reddit
Nice! What a/c?
Easy-Trouble7885@reddit
Bro it's says right there in the post
wearsAtrenchcoat@reddit
Argh! I only read the title, sorry
Metallifan33@reddit
It's very easy to miss the one liner below the image. No reason to downvote you.
YamComprehensive7186@reddit
Above the high 30's cosmic radiation starts going off the charts.
domyates@reddit
Doffs cap to you!! Well done sir.
FL450 was the best I ever got to.
flyingforfun3@reddit
Welcome to the club! I made it on a winter day in a Lear 75. Took forever.
Crystal-kim@reddit
Beautiful aircraft to fly lucky you 😊👍😉
DCS_Sport@reddit
In a Classic V nonetheless!! Nothing like taking a 30 year old airframe to the limit!
Excellent_Dot_3000@reddit
Impressive, now a window photo please
somewhat-random@reddit
Very impressive! OP can you post a photo of the outside view?
kruzzik@reddit
Welcome to the club!
rdirkk@reddit
How many kms would that be?
15-16?
Lazy_Entertainment73@reddit (OP)
Yes. 15.5km
CarminSanDiego@reddit
Are you seeing that much more fuel efficiency that high up vs high 30s/low 40s?
viniciosxs@reddit
I'm always impressed how jet engines works even in such high altitude
Muted_Fuel7549@reddit
Sunscreen lotion on or did ya cover the windows
RandomNightmar3@reddit
And I don't like to go above 390 due to cosmic radiation..
Inondator@reddit
Glass is opaque to UV rays.
LuuDinhUSA@reddit
Whoa!
hercdriver4665@reddit
I remember a wizzwheel exercise in flight school where they gave us a ~180kt IAS, the OAT, and FL850. The Mach number was 2.5+ I think.
Yeah, IAS gets weird up there.
olddoglearnsnewtrick@reddit
Per aspera ad astra
KurttGoBang@reddit
I get real uncomfortable above .40AOA .52 making me real nervous 😂
Which_Material_3100@reddit
Nice! Above the fray of us peasants scrounging around at FL400 and below
Able-Negotiation-234@reddit
Lear jet used to send you, and I have mine lol gold pins 510 pins if you sent them a picture of the instruments, and crew and passenger list was a nice touch, should see if they do it for the GWIZZ
juani20138@reddit
Nooo
dave-rooney-ca@reddit
Don't open the door 😀
peak82@reddit
Let him try if he wants
No_Mango7658@reddit
It's a fucking video game...
GoobScoob@reddit
Was the earth still flat?
johnbobk@reddit
It's always been flat.
bananasforeyes@reddit
Show picture out window.
ceelodan@reddit
Neat!
Landoof-Ladig@reddit
Sky is black already?
Strenue@reddit
nice! most Ive seen in the jet I fly in is FL390 - SOG gets wild up there due to jet stream.
Triumph807@reddit
Nice! You’re 60 feet high though
/s
Unhappy-Finance7535@reddit
Congrats on the career benchmark. Did you get the stratospheric "trucker tan"?
Things_In_Austin@reddit
Pinnacle Airlines Flight 3701
aviation-ModTeam@reddit
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