The Boeing-Vertol BV-347 - Basically a Chinook with wings!
Posted by RonaldMcDnald@reddit | WeirdWings | View on Reddit | 42 comments
Posted by RonaldMcDnald@reddit | WeirdWings | View on Reddit | 42 comments
BrtFrkwr@reddit
Good wiki entry https://en.wikipedia.org/wiki/Boeing_Vertol_BV-347
waldo--pepper@reddit
Never flown ... well golly!
ackermann@reddit
What about this design made it so easy to fly? Do the wings add stability somehow?
MadMike32@reddit
Massive surplus of lift when not loaded, no tail rotor to worry about, and a ton of mass to dampen out wind and whatnot. I had a buddy I used to work with, who was primarily an Apache pilot, but managed to fly damn near every airframe the Army operated. He always raved about how nice the Chinook was to fly.
Mediocre_Dog_8829@reddit
A Chinook and an Apache landed near me recently. I was surprised to see that the Apache is almost as long as the Chinook. Roughly 15 metres vs approx 16 metres, if my memory of what I read in Wikipedia is accurate.
rocket_randall@reddit
Lift, mostly. I have never flown a Chinook, but pilots have said that it's a bit more intuitive than other helicopters since the rotors are synchronized and you can change power without having to engage the pedals to offset yaw. This model also had the automatic flight control system which was incorporated into the D model, which further assisted the pilot.
RCAF_vet71@reddit
If the rotors were not synchronized, they would quickly chew each other to bits on start. I think you mean to say that they are counter rotating and therefore cancel out the torque that a single rotor helicopter experiences, which in turn requires the tail rotor.
aadoqee@reddit
I would say the fly-by-wire system is responsible
rocket_randall@reddit
Vietnam era rotary aviation had its moments.
http://airassault.bizhosting.com/PostRVN.htm
sidneylopsides@reddit
"In a fraction of a second the mast is overloaded and it snaps. In this case the blade pivoted down and sliced through the left side of the cockpit after breaking off. The blade was recovered several hundred meters away. Embossed in the leading edge, in reverse type, was the word "BELL". This matched the raised lettering on the co-pilot's anti-torque foot pedals of the Huey, destroyed when the blade sliced through and struck them."
Wow
rodface@reddit
That is a dark story. I like seeing this sort of writing out there, real history.
Mal-De-Terre@reddit
Sorta begs the question of why they're called pilots, then
Constant-Draw2629@reddit
Im surprised it didnt get more widely adopted
Xav_NZ@reddit
This thing had FLY BY WIRE in 1970 in a HELICOPTER that is insane ! apparently the very first helicopter to have FBW.
CountGrimthorpe@reddit
It's almost the first aircraft period to fly with digital fly-by-wire (analog systems predate it by a lot). There was a NASA F-8 with an Apollo guidance computer that beat it out, but that's assuming the 347 didn't have the FBW system in its first test flights. I did a little looking to see when the prototype had its FBW system installed, but there's not a lot out there.
Xav_NZ@reddit
I was about to mention the Space Shuttle in my original comment but STS1 launched in 1981 so technically this either predates or is roughly at the same time. Pretty insane either way.
Gramerdim@reddit
ok but why and how?
Agitated_Art7@reddit
B
Latentius@reddit
The wings are, of course, the primary weird feature of this aircraft, but just in case that weren't enough, they added an extra blade to each rotor.
Raaka-Kake@reddit
Any idea why they added the extra blade?
Latentius@reddit
I would expect extra lift would be a primary factor, but a quick search says it was also an attempt to reduce noise by splitting the same load across more blades.
WholeLottaBRRRT@reddit
It looks like they’ve took the wings from an F-8 Crusader or A-7 Corsair
Correct_Inspection25@reddit
The USSR Mi series had a number of models that could achieve up to 20% of their crushing lift with wings, this made sense. Guessing the mass of the wing didn’t offset the lift gain.
earl_of_lemonparty@reddit
The Mi-24 produces 28% of it's lift from it's fixed wings:
https://www.globalsecurity.org/military/world/russia/mi-24-design.htm
R-27ET@reddit
The lift gain does offset the mass by quite a lot.
The main problem with the wings on Mi-6/24 is that the rotor wash pushed against them in a hover, reducing max hover takeoff weight.
Little problem for Mi-24, bigger problem for Mi-6.
Mi-6 could even rotate the wings down to stop them stalling during autorotation, which is another weakness.
For Mi-6/24, the benefit was from cruise/climbing/turning from ETL to max speed, actually reducing Retreating blade stall becuase by being position behind the rotor/CG they reduced the need for forward cyclic (which decreases speed of retreating blade stall), and increased pilot comfort and also acted as a stabilizer.
On Mi-35M with shortened wing, one of the main complaints was pilots was it made it less stable at cruise speeds.
dmr11@reddit
BV-347 fixes that problem by rotating the wing to point up during hover, as seen in the third picture of the post.
Correct_Inspection25@reddit
Thank you! I only recently learned about that feature, and wondered why the US didn’t have that featured more prominently. Like i thought the Navy heavies sponsons provided some lift but found out that effect was negligible.
BrtFrkwr@reddit
What the wing does is partially unload the rotors allowing the aircraft to fly faster and more efficiently.
Correct_Inspection25@reddit
Didn't even think of that bonus, longer serviceable rotor lifespan.
Foreign_Athlete_7693@reddit
Now this is the sorta plane I wish someone would add to the FlightGear repository😂
Havoccity@reddit
Looks and is named like something made by Blohm & Voss
Constant-Draw2629@reddit
I wonder why it isn’t more popular
_BMS@reddit
It's kinda hard to visit. It's located at the Army Aviation Museum at Fort Rucker, meaning you need to either have a military ID or get a visitor's pass to get on the installation to visit.
Vast-Return-7197@reddit
Well damn, tilt wings.
CarVac@reddit
Tilt wing but fixed rotor.
brumbarosso@reddit
Chinook be wildin sometimes
bCup83@reddit
Oh god no! Dear god no no! 😱
PlanterDezNuts@reddit
I am a pilot who has also never flown any other type of aircraft
tuckernielson@reddit
I love this sub - I’ve never seen this before. Thanks for sharing.
CapitanianExtinction@reddit
What do the wings do?
RonaldMcDnald@reddit (OP)
They were added to provide extra lift and maneuverability during flight, and even cooler, they could rotate 85 degrees upward to minimize rotor downwash during hovers
Double_Minimum@reddit
Provide lift when moving forwards? Which likely increases fuel capacity, so extra distance, or if that isn’t needed, possibly extra cargo instead of the fuel weight.
One the fastest helicopters in the world has wings (single “post” counter rotating rotors and a pusher prop).
Not having a tail rotor can make a helipad design wild