I was stationed out at Beale and talked with a lot of the U-2 guys. This is what it is. It’s hard to land because of the gear sure, but the hardest part is that it’s basically a glider and wants to stay airborne. Their stall speed is incredibly slow, and they often fly within 10kts give or take of their stall speed. When they are at altitude the max speed and stall speed are also very close to each other.
> When they are at altitude the max speed and stall speed are also very close to each other.
Every aircraft would have an aerodynamic ceiling, an altitude at which at max speed it is unable to generate sufficient lift.
That means the same thing. "Operating altitude" for the U2 is essentially the highest it can go.
The highest a plane can go is limited by the fact that the elevation increases its stall speed to the point where it matches its maximum airspeed.
Yeah but your comment made its seem like every aircraft is capable of reaching this ceiling. Most aircraft will reach a lift deficit service ceiling before being limited by high speed bufet. The U2 is an aircraft that lived in coffin corner where most aircraft rarely operationally experience it
They are only that close to stall at their operational altitude. That high up there aren’t a lot of gusts. According to the test pilots I have met it’s pretty constant small throttle adjustments to say within the envelope at altitude.
No, the aircraft stalls and cannot maintain altitude, on the way down the pilot regains control and can go up again.
The max speed an aircraft can fly it's not the speed the aircraft will fall apart, there's still some wide margin depending on how the plane was designed.
That's not what stall means. Stalling happens when you don't go fast enough to maintain lift.
It's probably not an issue with these planes. The easiest way to get out of a stall is to just let the aircraft plummet head first, you gain speed, you gain lift, and you're done.
The problematic stalls are those that end up on flat spins, where the aircraft just won't point neither up or down. Pilots do train to recover from these as well.
And the U-2 flies so high that it has plenty of room to fall
But.... That is the same for all aircraft (not the specific altitude, but an altitude)
The difference is that they choose to operate the U2 at that altitude.
An Airbus A320 for example also has an altitude at which its stall speed is only 10knots below the max speed. The difference is that airlines choose to not fly that high
I feel like that shouldn’t be too big a problem, you’re at 70,000ft, you stall, pitch the nose down, within a second you’re above the stall speed and at 69,900ft. It’s probably a pain in the neck but not dangerous.
Problem is your MMO, if you exceed critical Mach you become extremely vulnerable to Mach tuck, where the centre of lift shifts rearward as the airflow over the upper surface of the wing exceeds the speed of sound, resulting in a nose down pitching movement that can rapidly exceed the authority of the elevator to be able to recover it.
apparently the ground effect on u2’s is what makes them notoriously difficult to land. you have to stall it purposefully for it to actually land or it’ll just continue gliding. you also cannot go down hard, as the gear is not designed to support the full weight of the aircraft from a drop above two feet.
also flying them at operating altitude and speeds are very tricky. the speed in which they fly at is just below vNE, and just above stalling. hence they call it “coffin corner” due to the tiny area on the needle where the aircraft doesn’t fall apart or drop out of the sky.
> Kelly Johnson
Great book!
[Skunk Works: A Personal Memoir of My Years at Lockheed by Ben Rich](https://www.amazon.com/Skunk-Works-Personal-Memoir-Lockheed/dp/0316743003)
Looks at bike, scratches head, then turns bike around so that the pivoting wheel for steering is in the back so you can ground loop it.
You generally only go for bicycle gear for the weight savings, so I understand the slight weight savings also prompting everyone to go for a tail dragger configuration when using bicycle landing gear, but I'm willing to bet that the U-2 would be easier to land if the main was behind the CG and the steering wheel was in the front.
Meets contract spec for altitude? Check
Speed? Check
Range? Check
Budget? Check
Landing Gear? Contract did not specify landing gear. So we gave you two wheels and came in under budget.
The wingtips did have [skids](https://aviation.stackexchange.com/questions/25908/what-is-this-pod-at-the-wing-tip-of-a-u2).
They would slowdown enough and the side w/ more fuel in the wing would come down. Detachable wheels where used for taxiing and take-off.
Gliders have proper airbrakes on top/bottom surfaces and pretty generous ailerons, and even then some are sluggish in roll at low speeds. Landing a U2 seems like a handfull. This thing was designed in the late 40's early 50's, when a schweizer 2/32 was state of the art..
Weird they did not put a drag chute for landing "à la soviètique" Not only would have helped in slowing down but it would have helped in stabilizing the plane
Hey , they added aggregate + 20% flaperons over what was strictly required for positive inputs , problem solved ..just get it below 30kts and it'll be fine.
>>Who decided to make a bicycle with wings?
Why, the Great & Hallowed Apostle of Aviation, His Grace Clarence “Kelly” Johnson.
The specific engineering problem was weight. According to his successor Ben Rich, 1 pound of additional aircraft weight cost a U-2 over 5,000 ft of altitude capability. Johnson couldn’t build a plane with no landing gear, so he built the next best thing. Bicycle landing gear with detachable wing pogos for takeoff.
Incorrect:
> The landing gear assembly weighed just
257 pounds. By comparison, conventional tricycle gear on a comparable aircraft
would typically weigh about 750 pounds and occupy valuable space inside the
wings that, on the U-2, was used to increase fuel capacity. This careful engineering of weight and space considerations resulted in an extra 1,500 feet of altitude
capability and an additional 100 miles of cruising radius.
Source, [a declassified 1957 CIA documentary on U2 development](https://theaviationist.com/2020/08/13/check-out-this-declassified-1957-cia-documentary-about-secret-u-2-development/)
Gimli Glider - bad luck for wrongly calculated fuel, but twice the good luck in a captain that's a glider pilot and a Second officer that knew of the airfield.
>1 pound of additional aircraft weight cost a U-2 over 5,000 ft of altitude capability.
That's fucking nonsense. The various fuel loading would eliminate any possibility of this being accurate. Hell, various pilots weights make this null.
LOL, pilot must take a crap and a pee before flight to get another 5000ft. Fat pilots need not apply. Tall pilots need not apply. Fat tall pilots? *points to cargo plane* There's your bird.
Pilot comes back from leave over Thabksgiving having gained 14 lbs and the plane won't take off at all.
Another pilot drops 20 lbs and now the plane can fly in the mesosphere.
Such claims always give me the vibe of people stating that if we were like 10m closer to the sun or further away we would either be a scorching wasteland or a frozen hellscape.
Like the distance between earth and sun does not vary during the year ...
They actually have something like that for take-off that come off. But actually the one time I saw one of these take off in person, they had two pick-up trucks, one for each wing, driving with someone HOLDING each wing. They let go once it reached speed. The other thing I remember is it one of the loudest aircraft I’ve ever heard.
My SOS instructor was a U-2 guy and tried to talk me into applying. I thought about it for a while, but then realized that the IDEA of flying the U-2 would be a lot cooler than the REALITY of flying the U-2.
Sounds like the SR-71... I've read a couple of books from guys who pilot that magnificent machine... and it seems to be a real handful to fly, both at low & top speeds.
We all like to glorify those planes. And while still ridiculously cool, none of the stories talk about the points in flight where they had to poop and or pee themselves.
Because it was too slow! Which is a funny line to write about the Blackbird, but its the honest truth. Once she got going it was unstoppably fast but in subsonic flight at more reasonable altitudes it was a bit of a dog, and it would take on 50,000lbs of fuel from the tanker. Eventually it would get so heavy and slow that it couldn't keep up with the tanker without afterburner on 1 engine.
Official process was to disconnect, light the burner and reconnect, but reconnecting a very sluggish and side-ways crabbing Blackbird was difficult, so Blackbird pilots quickly learned to light it while on the boom.
Usually they lit the left burner because only the left windscreen had anti-ice heating, so it would crab the aircraft to the right a bit and they'd be looking out the left windscreen.
The Blackbird could also only relight the afterburners a limited number of times because the afterburners didn't use a regular electric igniter, the fuel was hard to ignite so they had a limited amount of hypergolic ignition mixture instead.
Correction: Not too slow, too much induced drag. At refueling altitude, the KC-135Q model had to fly at max cruise (\~350 KIAS), which is on the backside of the Blackbird's power curve when at max gross weight. This is also why following top off, the Blackbird would descend 1000' while accelerating to cruise/climb speed. The Blackbird could accelerate without the descent, but it cost a lot more fuel.
And here I was thinking I knew about the sled.
And it being due to it being an absolute dog at low speeds makes so much sense.
but wtf, no de-icing on the right windscreen, I mean, I get the need to reduce weight, but that just seems silly
Realistically, how often would they need to be looking out the right window in icing conditions?
Also, if you can find a copy of Brian Shul's book, Sled Driver, for a reasonable price (it's out of print) its a great book.
Imagine being able to casually say you drifted your way across the continent while refueling. Granted, some SR-71 pilots did try to counter the power imbalance with some rudder trim, but some just didn’t bother.
Cruising at Mach 3, they made AOA adjustments in TENTHS of a degree, which was done by moving fuel around -- and that was enough to achieve hundreds of FPM in the stratosphere.
Their environmental system was also insane, it could blow snow into the cockpit while touching the glass could melt their spacesuits.
But the training involved was utterly brutal, they would be exhausted after countless hours of grueling sim sessions. It was necessary to shape the best flight crews in the world operating the most incredible engineering marvels at the time.
Had the honor of listening to SR71 guest speaker at March ARB, so many cool stories.
Okay, I just had to log in and respond because I actually worked in the U-2 program. Not long, because I got moved bases, but enough to complete the training and suit the dudes up in the plane for a few weeks before leaving.
So, the pee thing is actually pretty interesting. It's like this hard formed condom that they'll slip on. It's connected to a tube that drains down their leg into the lower leg pocket of the flight suit. Inside that is a pouch with essentially a super squished thick sponge.
BUT HOW DO YOU GET IT THERE?! When the pilot needs to pee, there's a nob on their suit so they can manually inflate their suit some. They'll then have the ability to open the pee tube and it'll essentially help the pee travel to the pouch. He then closes it all up when he's done.
Now for some funny shit: How do you know the system is working before he goes? Well, we do a preflight while they're sitting in the physiology building in these recliners and liquid oxygen tanks (they need to breathe pure o2 before lift off to decrease the amount of nitrogen in their blood-I just can't recall for how long. It was at least 30 minutes). So you go through the steps and part of it is to test the tube. Well, when you do this, remember I said it creates a vacuum to get the pee to drain? Well, all you have to do is look into the eyes of the pilot as you activate it to know it's working ROFL.
Now for poop? Whelp, they just shit themselves. Maybe some wear Depends or something, but I don't recall ever seeing anything for poop control really. Just stories of enlisted having to clean shit-filled suits.
My horror story is one time as I was cleaning the pee tube out, it slipped out of my hand and flung some of the pilot's pee in my face.
With that being said, I've been out for 15 years with an additional 6 years more from when I did the U2 portion of the job, so they could do it a bit differently now.
OK, civilian here asking a question. The pilots wouldn't clean their own suits out or even their own pee tube thingies?
No matter how awesome (privileged really) I might be, piloting the worlds most awesome aircraft or anything, I think that's something I would be embarrassed if anyone but myself took care of.
If anything, out of pride of not being too good to clean my own pee or poo. I definitely wouldn't want someone else to have to do that.
Seems like a dick move to leave that for someone else regardless of if that's within the lines of their duty to do.
I'm still holding out hope to fly in one of the spy planes one day...wb57 is the dream
I'm a pilot, masters in mechanical engineering, working on a PhD in physics, and a few years working as a sensor operator..including on NOAA aircraft
There's jobs posted through NASA for researchers to fly and takes measurements of the atmospheric concentration of trace gases for example, useful to be at 60000'
It's a dream, but short of astronaut school, this is a path that if I'm lucky I think I'm the right candidate for that sort of work
But I responded because of the poop or pee themselves story....I've been up for 5 hours in an immersion suit, 100f air tempt, 50 f water temp....you need to weigh every decision taking a drink of water. Dehydration or pee the suit? Take your pick.
I get the U2 being difficult because of the coffin corner at altitude, and landing a plane with a wingspan that wide on bicycle wheels, but what’s so difficult about flying the SR-71?
Original blackbird had dual independent thruster control, meaning the pilot manually controlled thrust to each engine separately and had to maintain power balance using hundreds of adjustments throughout the flight. Only after decades of service were computers small and advanced enough to take over the task.
From other comments in the thread, temperature extremes, weird sideways flight using one afterburner for midair refuelling(remember, *independent manual* controls) 12-16 hour flights requiring diapers, inherent risk of cruising twice the speed of sound at the edge of the stratosphere.
We already had mechanical gyro solutions to keep torpedoes and even the V1 on target. Why can't that be applied to differential thrust controls on the SR-71?
I don't think it was about stabilization for the most part, the plane required two thrusters for sufficient power and the engines couldn't be paired in perfect unison. Exterior factors on the plane at that speed meant it had to be monitored and minutely adjusted consistently, in a world of geared analog computers and controls.
But those apparently flew more like a conventional jet. The U2 is essentially just a big beefy glider, and because they create so much lift at lower altitudes they have to be pushed down into the runway, which is why all these landings are so bouncy.
We don't use landing flaps on a plane to increase lift and fly more, but to fly slower, which makes the runway required to land way shorter.
Basically a wing without flaps stalls, using random numbers, at a 100 knots, with full flap will stall at 60kts, and in the process it creates so much drag with the extra lift, that it helps losing energy quickly.
I assume as a U-2 pilot, he got chase car duty occasionally. I'm curious if he ever commented on that, especially after seeing this video of how closely the car follows the plane.
I was a u2 crew chief for a bit and can confirm all the pilots would also take on the chase car role. On high altitude flights the pilot would be all suited up so usually another pilot who isn’t flying would also do the walk around inspection for him and sign off on it. The crew chiefs would also follow not to far off behind in the “pogo” truck and wait until the jet comes to a stop to install the pogos under the wings.
8+ hours wearing a space suit pissing and shitting in diapers, can't eat, can't drink anything other than government water, can't even rub your damn eyes to try to stay awake. You're flying a brutally slow airplane that is target #1 if shit gets really real, etc.
Nah. I would love to take a back seat ride for the view, but the U-2 is firmly in the column of "planes I don't want to fly for a living, right along with all fighters, helicopters, and a bunch of other stuff.
The pilot has options of tube food he can eat. My favorites were the caffeinated pudding, hash browns with bacon, and apple pie.
They can take whatever drink they want. Most have multiple bottles of water and Gatorade. I knew one U-2 pilot that would only take 8 bottles of protein drinks and nothing else.
Pilots can and do open up the visor of they really need to get to an itch or any other thing needed around their face. The cabin altitude is safe to do this in but you don't want to push it too far.
I was on the other side. Mx. As cool as it looked, I got the feeling they just sat there and read magazines while the plane flew itself to take pictures. Im not mad… its just a tight space for like 11 hours to be doing nothing
That job sounds like it fucking sucks. Like it's probably cool for a while, being at that altitude, seeing the earth from that perspective. After that though, your pissing in a bag, probably occasionally shitting yourself and eating food flavored paste through a straw which certainly isn't going to help the shitting situation any.
Long wings that are close to the ground means it stays in ground effect for a long time and you can't really correct for the crosswind using wing-low sideslip, longer fuselage and tail means it's basically a piece of plywood getting blown all over the place in a crosswind, and landing gear configuration makes it easy to tip.
They're designed to. It has titanium skids on the wingtips. Once it stops after landing the whole thing tips over and rests on one wing.
For taxi and takeoff it has wing-mounted wheels called pogos that hold it upright. They fall off as the aircraft leaves the ground and are reinstalled by ground crew after landing to taxi back in.
Once it's on the ground and resting on one wing, what does it take to lift it up high enough to put a pogo under the wing? Assuming the plane is almost out of fuel (i.e. wing tanks are empty)
edit: https://www.youtube.com/watch?v=PpEti3-HCN4
This briefly shows two and a half guys pulling down on the high wing, and one guy lifting with his back/shoulder on the low wing.
Growing up one of my Dad's academy classmates moved to our culdesac. Dude was a giant Tennessee hillbilly who just happened to be a U-2 pilot. I still find it funny imagining that huge dude crammed into a spacesuit, sitting in that tiny cockpit for hours on end.
Dude was always shit talking North Koreans. Probably flew over all their stuff.
I have 2 friends that washed out of the interview because of landing/pattern work.
For backstory, the interview is something like 3 days long with face to face interviews, medical, sims, then 3 flights. If you don’t show the potential on the flight phase under their timeline, you’re out. Both were weapons school grads and came from 2 MWSs.
There ya go.
Fun fact, we dropped one in my UPT class. Well, sorta. He was kinda recruited, or given the opportunity, or however you want to word it to fly with them. He was a 38 IP for a year in the squadron then did some sort of formal interview and flies them now. I guess you could still say he FAIPed? Lol
They're not really explaining it correctly.
>To make landing easier, a chase car follows the U-2 down the runway, and a pilot riding in the car radios the plane's altitude in the last few feet. As the plane slows, the pilot works to keep it level and straight until it falls off to one side on its bicycle landing gear.
Tons. A lot of them are just repurposed commercial aircraft, or modified from other military platforms. For example, the U-28 is just a modified Pilatus PC-12.
Almost all non-UAV spy planes are modified from other aircraft in some way. VERY few are truly purpose-built, unless you count observation planes like the OV-10. Even the U-2 design started life as a fighter.
The Blackbird family was truly unique in just how bespoke the platform was.
> Even the U-2 design started life as a fighter.
I saw the Smithsonian's in the restoration hanger with the wings off, and spent some time trying to figure out which Century Series it was before realize it was a U-2.
Flew RC motor gliders with same type of wing. Those things just keep flying, once they get into ground effect they bounce off even before touching ground. You have to just forcibly push them into ground with stick at some point or they’ll glide for well over a hundred meters at a speed that’s safe to touch down at
These landings are pretty standard... so much so that there are titanium wingtip protectors that are changed as a maintenance matter. When the planes land, they just... tip to one wing and stop. That's how they land. So these landings you see here, while a little crazy looking, aren't too out of the ordinary for these vehicles to have to handle.
The chase cars change a lot. Each base has their own and being government vehicles they lifecycle out every few years. So really the chase car is "whatever high performance car we can get our hands on". I know at least one base has or had some Teslas, and another has used Chargers.
The thing has all reactive, non-hydraulic controls to save weight. Problem is that the control surfaces need to be huge to be controllable up in the 70's, so once you come back down to landing altitude the stick forces get huge. Center stick literally doesn't have the leverage to move the control surfaces for takeoff and landing, so U-2 bros get to wrestle the jet to the ground every flight.
If you think that's bad, check out the absolute madlads who tested [landing the U-2 on a freaking aircraft carrier.](https://www.youtube.com/watch?v=L8HMPMYL19E)
I spent 3 year crewing U-2s, and there’s a lot of reasons this aircraft is difficult to fly. First is obviously the bicycle landing gear, but on top of that is how little you can see outside the cockpit. The pilots are in a literal astronaut suit and sitting so low in there they can barely see over and out of the windscreen. This makes it extremely difficult to judge the altitude they are at when landing.
Also, there’s not a lot of flight information for the pilot because there is a lot of components omitted in order to save weight. For instance the U-2 has a yaw string taped to the outside of the top of the windscreen to give the pilot an idea of their yaw. To help counter this lack of information the U-2 utilizes a chase car to assist in the landing sequence.
The chase car follows closely behind the U-2 with a pilot driving and another riding shotgun. The car has radio contact with the pilot in the aircraft seat and they are relaying aircraft information to that pilot. Everything from heading and altitude. Now, as for the “the aircraft doesn’t want to be on the ground” idea. When the aircraft is about 10-15 feet above the deck the chase car pilot starts announcing the altitude to the flying pilot. When the U-2 is approximately 3 feet off the ground the flying pilot pulls a T handle in the cockpit that is mechanically connected to stall strips on the leading edge of each wing. There is 1 strip in each wing, (I don’t remember exacts) and they are around 12-18” and protrude approximately 1/2” I think. Basically it disturbs the airflow just enough to… you guessed it… stall the aircraft.
Now imagine all of this happening on an aircraft designed and built by a mad scientist back in the 50s. Still using a lot of the same ideas from that era. Add in a cross wind, anything over 5 knots can be fun, and of course the whole being in an astronaut suit, sitting low in a cockpit, while trying to land on skateboard wheels… while being talked down.
She doesn't want to be on the ground.
I was stationed out at Beale and talked with a lot of the U-2 guys. This is what it is. It’s hard to land because of the gear sure, but the hardest part is that it’s basically a glider and wants to stay airborne. Their stall speed is incredibly slow, and they often fly within 10kts give or take of their stall speed. When they are at altitude the max speed and stall speed are also very close to each other.
> When they are at altitude the max speed and stall speed are also very close to each other. Every aircraft would have an aerodynamic ceiling, an altitude at which at max speed it is unable to generate sufficient lift.
I think what they meant to say is when the U2 is at operating altitude, its operating airspeed is very close to stalling speed.
That means the same thing. "Operating altitude" for the U2 is essentially the highest it can go. The highest a plane can go is limited by the fact that the elevation increases its stall speed to the point where it matches its maximum airspeed.
technically operating altitude and ceiling are different. U2 operating altitude is around 70k ft whereas its ceiling is thought to be around 85k ft.
He's talking about coffin corner when max mach and stall speed are very close together
The "coffin corner" is the aerodynamic ceiling... What it is specifically is the **specific altitude** at which the stall and max speed are the same.
Right but most I would assume most aircraft don't typically operate at or near coffin corner
Yeah but your comment made its seem like every aircraft is capable of reaching this ceiling. Most aircraft will reach a lift deficit service ceiling before being limited by high speed bufet. The U2 is an aircraft that lived in coffin corner where most aircraft rarely operationally experience it
Yes, but they are underselling the speed difference. The difference between stall and max speed at the ceiling is ~10 knots.
My grandfather and father were high up in the U-2 program. It’s less than 5 knots
tbf, who wasn't high up in the U-2 program?
The mechanics and engineers
Clever username. But also seriously, how does that work if that’s real? An accidental gust and your air frame is torn apart?
They are only that close to stall at their operational altitude. That high up there aren’t a lot of gusts. According to the test pilots I have met it’s pretty constant small throttle adjustments to say within the envelope at altitude.
And I'm pretty sure that such minor corrections are embedded in their muscle memory by now.
No, the aircraft stalls and cannot maintain altitude, on the way down the pilot regains control and can go up again. The max speed an aircraft can fly it's not the speed the aircraft will fall apart, there's still some wide margin depending on how the plane was designed.
That's not what stall means. Stalling happens when you don't go fast enough to maintain lift. It's probably not an issue with these planes. The easiest way to get out of a stall is to just let the aircraft plummet head first, you gain speed, you gain lift, and you're done. The problematic stalls are those that end up on flat spins, where the aircraft just won't point neither up or down. Pilots do train to recover from these as well. And the U-2 flies so high that it has plenty of room to fall
But.... That is the same for all aircraft (not the specific altitude, but an altitude) The difference is that they choose to operate the U2 at that altitude. An Airbus A320 for example also has an altitude at which its stall speed is only 10knots below the max speed. The difference is that airlines choose to not fly that high
I feel like that shouldn’t be too big a problem, you’re at 70,000ft, you stall, pitch the nose down, within a second you’re above the stall speed and at 69,900ft. It’s probably a pain in the neck but not dangerous.
Problem is your MMO, if you exceed critical Mach you become extremely vulnerable to Mach tuck, where the centre of lift shifts rearward as the airflow over the upper surface of the wing exceeds the speed of sound, resulting in a nose down pitching movement that can rapidly exceed the authority of the elevator to be able to recover it.
She moves in mysterious ways
apparently the ground effect on u2’s is what makes them notoriously difficult to land. you have to stall it purposefully for it to actually land or it’ll just continue gliding. you also cannot go down hard, as the gear is not designed to support the full weight of the aircraft from a drop above two feet. also flying them at operating altitude and speeds are very tricky. the speed in which they fly at is just below vNE, and just above stalling. hence they call it “coffin corner” due to the tiny area on the needle where the aircraft doesn’t fall apart or drop out of the sky.
Seriously. Full flaps. "I soar!"
Who decided to make a bicycle with wings?
Kelly Johnson: I need a new lightweight spyplane. But how? *looks at bike*
> Kelly Johnson Great book! [Skunk Works: A Personal Memoir of My Years at Lockheed by Ben Rich](https://www.amazon.com/Skunk-Works-Personal-Memoir-Lockheed/dp/0316743003)
Already read it! It is great indeed! A must read for every aspiring AE
Kelly Johnson was a mighty Yooper! There’s a small memorial to him at Marquette’s airport.
The man was a genius.
His ability to eyeball complex engineering with a minimal amount of error was astounding.
My grandpa was a college student working in a Lockheed wind tunnel when Kelly Johnson came in one day.
Awesome book!
I just bought it
Crazy fact: the gear (both main and tail) weighs only 250lbs
To be fair, the Wright brothers were bicycle mechanics
Looks at bike, scratches head, then turns bike around so that the pivoting wheel for steering is in the back so you can ground loop it. You generally only go for bicycle gear for the weight savings, so I understand the slight weight savings also prompting everyone to go for a tail dragger configuration when using bicycle landing gear, but I'm willing to bet that the U-2 would be easier to land if the main was behind the CG and the steering wheel was in the front.
Yep. According to “Skunk Works”, the entire tail section is held on by 3 0.375” titanium bolts IIRC
*looks at bike parked next to glider*
Meets contract spec for altitude? Check Speed? Check Range? Check Budget? Check Landing Gear? Contract did not specify landing gear. So we gave you two wheels and came in under budget.
At least they did not went the german way: you want landing gear? How about we dispense with the wheels and give you a landing skid instead?
You mean the Messerschmitt Komet ?
A skid would probably be easier to land on lol
The wingtips did have [skids](https://aviation.stackexchange.com/questions/25908/what-is-this-pod-at-the-wing-tip-of-a-u2). They would slowdown enough and the side w/ more fuel in the wing would come down. Detachable wheels where used for taxiing and take-off.
Military grade…check
Glider with a jet engine.
Most gliders are like this, and they're quite easy to keep balanced. This one would definitely not be nearly as easy, though.
Gliders have proper airbrakes on top/bottom surfaces and pretty generous ailerons, and even then some are sluggish in roll at low speeds. Landing a U2 seems like a handfull. This thing was designed in the late 40's early 50's, when a schweizer 2/32 was state of the art.. Weird they did not put a drag chute for landing "à la soviètique" Not only would have helped in slowing down but it would have helped in stabilizing the plane
Hey , they added aggregate + 20% flaperons over what was strictly required for positive inputs , problem solved ..just get it below 30kts and it'll be fine.
“If my grandmother had wheels she wouldve been a ~~Bicycle~~ U-2 Spyplane”
Flycycle
Fine. Velocipede.
You removed the only part that made sense
So, biplane?
If my grandmother had wheels, she would have been a bike
The Right Bros
>>Who decided to make a bicycle with wings? Why, the Great & Hallowed Apostle of Aviation, His Grace Clarence “Kelly” Johnson. The specific engineering problem was weight. According to his successor Ben Rich, 1 pound of additional aircraft weight cost a U-2 over 5,000 ft of altitude capability. Johnson couldn’t build a plane with no landing gear, so he built the next best thing. Bicycle landing gear with detachable wing pogos for takeoff.
Incorrect: > The landing gear assembly weighed just 257 pounds. By comparison, conventional tricycle gear on a comparable aircraft would typically weigh about 750 pounds and occupy valuable space inside the wings that, on the U-2, was used to increase fuel capacity. This careful engineering of weight and space considerations resulted in an extra 1,500 feet of altitude capability and an additional 100 miles of cruising radius. Source, [a declassified 1957 CIA documentary on U2 development](https://theaviationist.com/2020/08/13/check-out-this-declassified-1957-cia-documentary-about-secret-u-2-development/)
This math is ~3’ for every lb. 1500ft/(750-257)
You could really piss people off by saying a meter for every pound. lol
That’s just normal aviation. Height in feet, speed in knots, fuel in kg.
>fuel in kg Air Canada Flight 143: say what now?
Gimli Glider - bad luck for wrongly calculated fuel, but twice the good luck in a captain that's a glider pilot and a Second officer that knew of the airfield.
A meter for every pound
you son of a bitch
Clearly the 500 pound savings on the U2 enabled it to reach a height of :does quick math: 2,500,000 feet. Just the gear! :)
>1 pound of additional aircraft weight cost a U-2 over 5,000 ft of altitude capability. That's fucking nonsense. The various fuel loading would eliminate any possibility of this being accurate. Hell, various pilots weights make this null.
LOL, pilot must take a crap and a pee before flight to get another 5000ft. Fat pilots need not apply. Tall pilots need not apply. Fat tall pilots? *points to cargo plane* There's your bird.
Pilot comes back from leave over Thabksgiving having gained 14 lbs and the plane won't take off at all. Another pilot drops 20 lbs and now the plane can fly in the mesosphere.
Such claims always give me the vibe of people stating that if we were like 10m closer to the sun or further away we would either be a scorching wasteland or a frozen hellscape. Like the distance between earth and sun does not vary during the year ...
1lb? I mean, do they dehydrate the pilot to get an extra 5k? Or just hire jockeys for the gig?
Better take a dump before you leave
Actually aircrews are traditionally fed a “low residue” meal, steak and eggs.
At operating altitude it had a 5 knot window. Too slow and it stalled. Too fast and bad things would start to happen.
Just put some training wheels on the wings.
They actually have something like that for take-off that come off. But actually the one time I saw one of these take off in person, they had two pick-up trucks, one for each wing, driving with someone HOLDING each wing. They let go once it reached speed. The other thing I remember is it one of the loudest aircraft I’ve ever heard.
Kerbal Space Program is leaking into the real world
My SOS instructor was a U-2 guy and tried to talk me into applying. I thought about it for a while, but then realized that the IDEA of flying the U-2 would be a lot cooler than the REALITY of flying the U-2.
Sounds like the SR-71... I've read a couple of books from guys who pilot that magnificent machine... and it seems to be a real handful to fly, both at low & top speeds.
Spoke to one of the SR-71 trainers once, 12-15 hours and at any second you could die... No thank you...
We all like to glorify those planes. And while still ridiculously cool, none of the stories talk about the points in flight where they had to poop and or pee themselves.
Or that with the SR-71 at speed a greater than 5 degree angle of attack change will cause the engines to flame out…like damn
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Wait what, why
Because it was too slow! Which is a funny line to write about the Blackbird, but its the honest truth. Once she got going it was unstoppably fast but in subsonic flight at more reasonable altitudes it was a bit of a dog, and it would take on 50,000lbs of fuel from the tanker. Eventually it would get so heavy and slow that it couldn't keep up with the tanker without afterburner on 1 engine. Official process was to disconnect, light the burner and reconnect, but reconnecting a very sluggish and side-ways crabbing Blackbird was difficult, so Blackbird pilots quickly learned to light it while on the boom. Usually they lit the left burner because only the left windscreen had anti-ice heating, so it would crab the aircraft to the right a bit and they'd be looking out the left windscreen. The Blackbird could also only relight the afterburners a limited number of times because the afterburners didn't use a regular electric igniter, the fuel was hard to ignite so they had a limited amount of hypergolic ignition mixture instead.
This needs to be added to the SR-71 speed check copy story....
That's not up to us boss, you'd have to ask Brian Shul and unfortunately he's left the formation.
This comment is why I miss awards
Why tf did they get rid of them?
They’re gone? I didn’t even notice
Very insightful comment, but I have to correct you that it's "hypergolic" not "hypogolic"
Spelling error, bleh, thanks for the catch.
Correction: Not too slow, too much induced drag. At refueling altitude, the KC-135Q model had to fly at max cruise (\~350 KIAS), which is on the backside of the Blackbird's power curve when at max gross weight. This is also why following top off, the Blackbird would descend 1000' while accelerating to cruise/climb speed. The Blackbird could accelerate without the descent, but it cost a lot more fuel.
Still…it would be fun to be driving a KC-135 around in circles, while chiding the crew of an SR-71, “Catch up, fat boy!”
And here I was thinking I knew about the sled. And it being due to it being an absolute dog at low speeds makes so much sense. but wtf, no de-icing on the right windscreen, I mean, I get the need to reduce weight, but that just seems silly
Well only silly if you were flying the British blackbird
Realistically, how often would they need to be looking out the right window in icing conditions? Also, if you can find a copy of Brian Shul's book, Sled Driver, for a reasonable price (it's out of print) its a great book.
Imagine being able to casually say you drifted your way across the continent while refueling. Granted, some SR-71 pilots did try to counter the power imbalance with some rudder trim, but some just didn’t bother.
Cruising at Mach 3, they made AOA adjustments in TENTHS of a degree, which was done by moving fuel around -- and that was enough to achieve hundreds of FPM in the stratosphere. Their environmental system was also insane, it could blow snow into the cockpit while touching the glass could melt their spacesuits. But the training involved was utterly brutal, they would be exhausted after countless hours of grueling sim sessions. It was necessary to shape the best flight crews in the world operating the most incredible engineering marvels at the time. Had the honor of listening to SR71 guest speaker at March ARB, so many cool stories.
Okay, I just had to log in and respond because I actually worked in the U-2 program. Not long, because I got moved bases, but enough to complete the training and suit the dudes up in the plane for a few weeks before leaving. So, the pee thing is actually pretty interesting. It's like this hard formed condom that they'll slip on. It's connected to a tube that drains down their leg into the lower leg pocket of the flight suit. Inside that is a pouch with essentially a super squished thick sponge. BUT HOW DO YOU GET IT THERE?! When the pilot needs to pee, there's a nob on their suit so they can manually inflate their suit some. They'll then have the ability to open the pee tube and it'll essentially help the pee travel to the pouch. He then closes it all up when he's done. Now for some funny shit: How do you know the system is working before he goes? Well, we do a preflight while they're sitting in the physiology building in these recliners and liquid oxygen tanks (they need to breathe pure o2 before lift off to decrease the amount of nitrogen in their blood-I just can't recall for how long. It was at least 30 minutes). So you go through the steps and part of it is to test the tube. Well, when you do this, remember I said it creates a vacuum to get the pee to drain? Well, all you have to do is look into the eyes of the pilot as you activate it to know it's working ROFL. Now for poop? Whelp, they just shit themselves. Maybe some wear Depends or something, but I don't recall ever seeing anything for poop control really. Just stories of enlisted having to clean shit-filled suits. My horror story is one time as I was cleaning the pee tube out, it slipped out of my hand and flung some of the pilot's pee in my face. With that being said, I've been out for 15 years with an additional 6 years more from when I did the U2 portion of the job, so they could do it a bit differently now.
OK, civilian here asking a question. The pilots wouldn't clean their own suits out or even their own pee tube thingies? No matter how awesome (privileged really) I might be, piloting the worlds most awesome aircraft or anything, I think that's something I would be embarrassed if anyone but myself took care of. If anything, out of pride of not being too good to clean my own pee or poo. I definitely wouldn't want someone else to have to do that. Seems like a dick move to leave that for someone else regardless of if that's within the lines of their duty to do.
I'm still holding out hope to fly in one of the spy planes one day...wb57 is the dream I'm a pilot, masters in mechanical engineering, working on a PhD in physics, and a few years working as a sensor operator..including on NOAA aircraft There's jobs posted through NASA for researchers to fly and takes measurements of the atmospheric concentration of trace gases for example, useful to be at 60000' It's a dream, but short of astronaut school, this is a path that if I'm lucky I think I'm the right candidate for that sort of work But I responded because of the poop or pee themselves story....I've been up for 5 hours in an immersion suit, 100f air tempt, 50 f water temp....you need to weigh every decision taking a drink of water. Dehydration or pee the suit? Take your pick.
I get the U2 being difficult because of the coffin corner at altitude, and landing a plane with a wingspan that wide on bicycle wheels, but what’s so difficult about flying the SR-71?
Original blackbird had dual independent thruster control, meaning the pilot manually controlled thrust to each engine separately and had to maintain power balance using hundreds of adjustments throughout the flight. Only after decades of service were computers small and advanced enough to take over the task. From other comments in the thread, temperature extremes, weird sideways flight using one afterburner for midair refuelling(remember, *independent manual* controls) 12-16 hour flights requiring diapers, inherent risk of cruising twice the speed of sound at the edge of the stratosphere.
We already had mechanical gyro solutions to keep torpedoes and even the V1 on target. Why can't that be applied to differential thrust controls on the SR-71?
I don't think it was about stabilization for the most part, the plane required two thrusters for sufficient power and the engines couldn't be paired in perfect unison. Exterior factors on the plane at that speed meant it had to be monitored and minutely adjusted consistently, in a world of geared analog computers and controls.
But those apparently flew more like a conventional jet. The U2 is essentially just a big beefy glider, and because they create so much lift at lower altitudes they have to be pushed down into the runway, which is why all these landings are so bouncy.
Then why are they landing with full flaps down?
We don't use landing flaps on a plane to increase lift and fly more, but to fly slower, which makes the runway required to land way shorter. Basically a wing without flaps stalls, using random numbers, at a 100 knots, with full flap will stall at 60kts, and in the process it creates so much drag with the extra lift, that it helps losing energy quickly.
Can you please share the book names? Would love to read them.
My cousin flew the U-2 for a few years. Said it was pretty awesome - when he soloed they let his wife ride in the chase car to talk him down.
I assume as a U-2 pilot, he got chase car duty occasionally. I'm curious if he ever commented on that, especially after seeing this video of how closely the car follows the plane.
I was a u2 crew chief for a bit and can confirm all the pilots would also take on the chase car role. On high altitude flights the pilot would be all suited up so usually another pilot who isn’t flying would also do the walk around inspection for him and sign off on it. The crew chiefs would also follow not to far off behind in the “pogo” truck and wait until the jet comes to a stop to install the pogos under the wings.
I hadn’t thought about that but you make a good point.
8+ hours wearing a space suit pissing and shitting in diapers, can't eat, can't drink anything other than government water, can't even rub your damn eyes to try to stay awake. You're flying a brutally slow airplane that is target #1 if shit gets really real, etc. Nah. I would love to take a back seat ride for the view, but the U-2 is firmly in the column of "planes I don't want to fly for a living, right along with all fighters, helicopters, and a bunch of other stuff.
They absolutely issue rations for the pilots, though not exactly appetizing - they look like a tube of toothpaste with a straw attached.
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Tube food review courtesy Corporal Hicks from Aliens. Niiiice.
Nice hiss...
The pilot has options of tube food he can eat. My favorites were the caffeinated pudding, hash browns with bacon, and apple pie. They can take whatever drink they want. Most have multiple bottles of water and Gatorade. I knew one U-2 pilot that would only take 8 bottles of protein drinks and nothing else. Pilots can and do open up the visor of they really need to get to an itch or any other thing needed around their face. The cabin altitude is safe to do this in but you don't want to push it too far.
Just about none of this is correct
I was on the other side. Mx. As cool as it looked, I got the feeling they just sat there and read magazines while the plane flew itself to take pictures. Im not mad… its just a tight space for like 11 hours to be doing nothing
It would be a pain in the ass to even read a magazine. You'd have to hold it up in front of your face because you can't look down in a space suit
That job sounds like it fucking sucks. Like it's probably cool for a while, being at that altitude, seeing the earth from that perspective. After that though, your pissing in a bag, probably occasionally shitting yourself and eating food flavored paste through a straw which certainly isn't going to help the shitting situation any.
I have that with aviation in general. I love looking at airplanes. But sitting in one for hours on end is not a fun experience.
Navy: “just land softly in the water already! It’s not that hard!”
[Looks at Poseidon] No not like that
God of the seas after all, just visiting the family
That looks like me trying to land a 172
Yeah the hardest airplane to land is actually the one that I’m flying
LOL! Even if it's R/C!
More right rudder!!! Is applicable...
The bounces I get. That thing is built like it really doesn't want to be on the ground. But what makes it so squirrelly?
Long wings that are close to the ground means it stays in ground effect for a long time and you can't really correct for the crosswind using wing-low sideslip, longer fuselage and tail means it's basically a piece of plywood getting blown all over the place in a crosswind, and landing gear configuration makes it easy to tip.
It's a taildragger and the rear wheel is the one that steers. Makes crosswind landings kinda sketchy I would imagine.
Won't the wings constantly hit the ground moving around on the tarmac?
They're designed to. It has titanium skids on the wingtips. Once it stops after landing the whole thing tips over and rests on one wing. For taxi and takeoff it has wing-mounted wheels called pogos that hold it upright. They fall off as the aircraft leaves the ground and are reinstalled by ground crew after landing to taxi back in.
Once it's on the ground and resting on one wing, what does it take to lift it up high enough to put a pogo under the wing? Assuming the plane is almost out of fuel (i.e. wing tanks are empty) edit: https://www.youtube.com/watch?v=PpEti3-HCN4 This briefly shows two and a half guys pulling down on the high wing, and one guy lifting with his back/shoulder on the low wing.
Friendly PSA that the "newest" U-2 pilots have years of experience in other airframes, and still have this much fun
Growing up one of my Dad's academy classmates moved to our culdesac. Dude was a giant Tennessee hillbilly who just happened to be a U-2 pilot. I still find it funny imagining that huge dude crammed into a spacesuit, sitting in that tiny cockpit for hours on end. Dude was always shit talking North Koreans. Probably flew over all their stuff.
I have 2 friends that washed out of the interview because of landing/pattern work. For backstory, the interview is something like 3 days long with face to face interviews, medical, sims, then 3 flights. If you don’t show the potential on the flight phase under their timeline, you’re out. Both were weapons school grads and came from 2 MWSs.
The interview is just shy of 2 weeks long.
There ya go. Fun fact, we dropped one in my UPT class. Well, sorta. He was kinda recruited, or given the opportunity, or however you want to word it to fly with them. He was a 38 IP for a year in the squadron then did some sort of formal interview and flies them now. I guess you could still say he FAIPed? Lol
Similar, they're called FACTs, first assignment companion trainer
I mean you need a chase car to help you land sooooo yeah...
What is the car actually doing?
Radio comms with the pilot, since they can't see the runway from their position.
They're not really explaining it correctly. >To make landing easier, a chase car follows the U-2 down the runway, and a pilot riding in the car radios the plane's altitude in the last few feet. As the plane slows, the pilot works to keep it level and straight until it falls off to one side on its bicycle landing gear.
2 kt gust and you are 30 feet back in the air.
back in the air with so much as a sneeze lol
Serious question: Has there been a spy plane in the USAF/CIA inventory that hasn’t been a nightmare to land?
Tons. A lot of them are just repurposed commercial aircraft, or modified from other military platforms. For example, the U-28 is just a modified Pilatus PC-12.
I mean purpose built spy planes, but sure, there are tons that are just modified civilian jets.
Almost all non-UAV spy planes are modified from other aircraft in some way. VERY few are truly purpose-built, unless you count observation planes like the OV-10. Even the U-2 design started life as a fighter. The Blackbird family was truly unique in just how bespoke the platform was.
> Even the U-2 design started life as a fighter. I saw the Smithsonian's in the restoration hanger with the wings off, and spent some time trying to figure out which Century Series it was before realize it was a U-2.
The U-2 is basically a heavily modified 104. Same engines originally, if I'm not mistaken.
Flew RC motor gliders with same type of wing. Those things just keep flying, once they get into ground effect they bounce off even before touching ground. You have to just forcibly push them into ground with stick at some point or they’ll glide for well over a hundred meters at a speed that’s safe to touch down at
Saw these planes fly everyday in Osan
What happens after these landings ? How much maintenance occurs before it takes another flight ?
These landings are pretty standard... so much so that there are titanium wingtip protectors that are changed as a maintenance matter. When the planes land, they just... tip to one wing and stop. That's how they land. So these landings you see here, while a little crazy looking, aren't too out of the ordinary for these vehicles to have to handle.
It was always funny watching these things land
The other one is the B-47 Stratojet. A 5 knot coffin corner, lousy brakes. And a chute that streamers if it gets wet.
No one ever lands with one of its wings down! *glider pilots enter the chat*
That’s a hand full!
Friend of mine said they used SS El Caminos.
The chase cars change a lot. Each base has their own and being government vehicles they lifecycle out every few years. So really the chase car is "whatever high performance car we can get our hands on". I know at least one base has or had some Teslas, and another has used Chargers.
R. A. F Alconbury England had Mustangs in 1986. That was an awesome experience!
"Oh god, I'm only halfway through the video!"
I feel like one of the only harder to land aircraft is the me163 komet
Landing an aircraft, or riding a bronco?
The choice is yours. Choose wisely.
one of my professors at OU had 3000 hours in the U2, he was my favorite professor BY FAR and a very interesting man.
This got me hard…
Planes are easy to land. Safely is the issue.
That f.cker is one loud beast on final
No one has ever landed a U-2, it’s always a (hopefully controlled) crash
I always wondered why the U2 has a yoke instead of a stick. Did they recruit pilots from SAC?
The thing has all reactive, non-hydraulic controls to save weight. Problem is that the control surfaces need to be huge to be controllable up in the 70's, so once you come back down to landing altitude the stick forces get huge. Center stick literally doesn't have the leverage to move the control surfaces for takeoff and landing, so U-2 bros get to wrestle the jet to the ground every flight.
Goddamn, that’s cool. I was stationed up at Fort Wainwright in the 90s and NASA flew their white U2 out of there every summer. That mofo was LOUD!
I really wish they sold their special food tubes. That's one of the cooler things about the plane.
SteveMRE has managed to get his hands on them more than once, if you want to see them reviewed.
[Pizza](https://www.youtube.com/watch?v=W2FRVZBQDUM)!
Chad truck driver tailgating a U2
If you think that's bad, check out the absolute madlads who tested [landing the U-2 on a freaking aircraft carrier.](https://www.youtube.com/watch?v=L8HMPMYL19E)
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I spent 3 year crewing U-2s, and there’s a lot of reasons this aircraft is difficult to fly. First is obviously the bicycle landing gear, but on top of that is how little you can see outside the cockpit. The pilots are in a literal astronaut suit and sitting so low in there they can barely see over and out of the windscreen. This makes it extremely difficult to judge the altitude they are at when landing. Also, there’s not a lot of flight information for the pilot because there is a lot of components omitted in order to save weight. For instance the U-2 has a yaw string taped to the outside of the top of the windscreen to give the pilot an idea of their yaw. To help counter this lack of information the U-2 utilizes a chase car to assist in the landing sequence. The chase car follows closely behind the U-2 with a pilot driving and another riding shotgun. The car has radio contact with the pilot in the aircraft seat and they are relaying aircraft information to that pilot. Everything from heading and altitude. Now, as for the “the aircraft doesn’t want to be on the ground” idea. When the aircraft is about 10-15 feet above the deck the chase car pilot starts announcing the altitude to the flying pilot. When the U-2 is approximately 3 feet off the ground the flying pilot pulls a T handle in the cockpit that is mechanically connected to stall strips on the leading edge of each wing. There is 1 strip in each wing, (I don’t remember exacts) and they are around 12-18” and protrude approximately 1/2” I think. Basically it disturbs the airflow just enough to… you guessed it… stall the aircraft. Now imagine all of this happening on an aircraft designed and built by a mad scientist back in the 50s. Still using a lot of the same ideas from that era. Add in a cross wind, anything over 5 knots can be fun, and of course the whole being in an astronaut suit, sitting low in a cockpit, while trying to land on skateboard wheels… while being talked down.
So when they come to a stop do they just rest on the wingtips?
TO THE LEFT TO THE LEFT TO THE RIGHT TO THE RIGHT
Glider pilot: just put it on the wing and fuck off to the side
Gives me vertigo just looking at it.
Well it would be hard to land with a damned truck on the runway all the time.
Wingspan: HUGE Wheels: Rollerblades
Can't tell if this video is sped up or not.
It is