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Buff crosswind crab taxi

https://www.facebook.com/reel/1654590408286431?fs=e&s=TIeQ9V&mibextid=0NULKw

I can never quite get my head around this. I get the landing itself; you don't kick off the drift and let the undercarriage do its stuff, but what happens next? Once you're travelling sideways at a low enough speed for the aerodynamics not to be in charge, what control inputs do you apply to straighten out?

You dial out the corrective crab angle of the landing gear.
https://www.aopa.org/-/media/Images/...5p_b52_006.jpg

Better video here:

So what bit of the airframe needs to be on the centreline? Not the flightdeck I guess.... that might be the challenge in landing like this.

https://www.airandspaceforces.com/ai...-52-crab-riat/

Air Force Investigates After B-52 ‘Crabbing’ at Airshow Appears to Knock Out Runway Lights

The Air Force is investigating an incident involving a B-52H Stratofortress that took place at RAF Fairford, United Kingdom, during the Royal International Air Tattoo on July 16.

Video footage that circulated on social media appears to show the B-52’s wheel-tip landing gear knocking out runway lights as it taxied at Fairford. The public affairs office for the 307th Bomb Wing, to which the B-52 belongs, declined to provide more details, citing the ongoing probe.

“The incident is under investigation at this time,” a spokesperson told Air & Space Forces Magazine. “While the investigation is ongoing we can’t speculate as to what happened.”

Still, many social media commenters were intrigued by the way the bomber appeared to move nearly sideways down the runway. The technique is called ‘crabbing’ and it helps B-52 crews negotiate narrow taxiways.

Unlike many other planes, the B-52 has wingtip landing gear near the ends of its 185-foot wingspan. Those wheels keep the wings, which can flex down 10 or 12 feet depending on how much gas is stored in the wing fuel tanks, from dragging on the ground. The wingtip landing gear is particularly helpful while taxiing and during takeoff, but it can create problems when the runway is too narrow for both wingtip wheels to set down.

“Other aircraft, their wings can hang out over the grass no problem,” Dave Prakash, a former B-52 pilot, told Air & Space Forces Magazine. “But we have tip gear that need runway to touch down on.”

To solve this and other problems, the B-52’s landing gear was designed to rotate up to 20 degrees to the right or left, which helps the large jet land in a crosswind. The swivel wheels can also help the jet move sideways down a narrow runway. In those circumstances, B-52 crews can also move gas from one wing to another, so that the loaded wing’s landing gear is on the ground while the unloaded wing gear is hanging in the air.

“You’re changing the width of the aircraft when you make it tilt to one side and crab to one side,” Prakash said. “Now you’ve reduced your necessary runway [width] by half, because the one wing is now 10 feet in the air so it can hang out over the grass.”

Unfortunately in the video, the loaded wing’s landing gear appears to have still made contact with some of the lights, which can happen now and then, said Prakash—who flew the B-52 at RIAT in 2009, though he did not recall having to crab there. Pilots typically know the runway dimensions in advance so that they can plan accordingly, he said. Often, a crew member gets out and guides the aircraft down the runway to make sure there are no collisions with the lights.While crabbing is a big help for fitting down narrow runways,

it is also essential for B-52s landing at airfields afflicted by crosswinds. Normally, when pilots of other aircraft are about to land on a runway with crosswind, Prakash explained, they fly into the wind until the last moment, at which point they dip a wing down a bit and apply rudder so that they can land with their wheels and nose pointed straight down the runway.

The B-52 can’t play that game due to its large and very flexible wingspan. Dipping those wings at the wrong moment could scrape a wingtip or, at worst, cause a catastrophic cartwheel, Prakash said. So instead of using the rudder and a wing dip to straighten out at the last moment, the B-52’s swivel wheels allow the pilot to keep the aircraft crabbing into the wind while the gear itself points straight down the runway.

“In the B-52, you can be in such a crab angle that the pilot is looking out one of the side windows, because the side window is what’s lined up with the direction of the runway,” Prakash said. “It makes it easier to land because now you don’t have to worry about finessing your rudder or anything like that.”
Instead, B-52s can maintain their crab position all the way down the runway, then stop and reset the wheels to straight-ahead. After that, it’s just a matter of avoiding the runways lights.

RIAT 2023 Sunday

Quote:

Originally Posted by havoc (Post 11496096)

https://www.facebook.com/reel/1654590408286431?fs=e&s=TIeQ9V&mibextid=0NULKw

Amazing, these machines are about 70 years old ±. Guesses are they will reach 100.... Wish Boeing were the company it was.

How long does it take to re-pack the parachute and who does it?

Or do they have spares to swap in?

Quote:

Originally Posted by pasta (Post 11496102)

If you’re kicking off the drift in any aircraft you’re doing it wrong, the word is push

Quote:

Originally Posted by stilton (Post 11496267)

If you’re kicking off the drift in any aircraft you’re doing it wrong, the word is push

Does that make you a pedal pedant?

Does the B52 have a calculated Vr or do they just levitate?
The certainly don't appear to rotate on lift-off

To plagiarise from another world:-

They don’t get airborne, they are repelled by the earth.

Don’t have to rotate, the wings are already orientated upwards in a raised position - hence the nose down attitude in level flight. A design decision to eliminate the possibility of a tail strike on take-off.

https://cimg6.ibsrv.net/gimg/pprune....c386872c8.jpeg

I went for a trip in a B-52G from Barksdale during GIANT VOICE '79. Very interesting, but give me a Vulcan any day!

The AC let me fly a PAR; by some fluke it went on rails and the aircraft was very pleasant to fly even with handful of 8 throttles.

The 'crab gear' check whilst taxying was very interesting - it seemed so weird to be travelling sideways along the RW!

Quote:

Originally Posted by stilton (Post 11496267)

If you’re kicking off the drift in any aircraft you’re doing it wrong, the word is push

https://cimg6.ibsrv.net/gimg/pprune....469832ff43.jpg

Quote:

Originally Posted by BEagle (Post 11496410)

Might be tough to find you an airworthy Vulcan as it hasn’t passed the test of time like the Buff has.

I’m an old BUFF driver from the ‘70’s. In that time frame we were restricted to airfield with 300 ft. width runways. The crosswind crab system was never contemplated as an aid to turning sharp corners, or taxiway maneuvering, but permitted us to land in 45kt direct crosswinds. The crab setting is precomputed and applied when aligned for takeoff, and removed when slowed to taxi speed after rollout. I had a copilot apply the setting in the wrong direction once. He saw his error, and cranked it all the way the other way while we were rolling. A thrilling low speed rudder dance ensued, similar to the video.

I was stationed at Lakenheath AFB back in the late 1960s and was fortunate enough to see a Vulcan practicing approaches one afternoon. That was the only time I ever saw one in flight, but it looked magnificent!

Quote:

Does the B52 have a calculated Vr or do they just levitate?
The certainly don't appear to rotate on lift-off

Flight manual says they have a pre calculated unstick speed and rotation is begun five to ten knots prior to that speed, forward wheels lift off first, rotation tending to be about the rear gear