B-52 doing the crabwalk

[Escuadrilla Azul]

Incredible crosswind landing of a B-52 at RAF Fairford, UK, doing a 'crabwalk'.



Source and more detail in this site:

Watch This B-52 'Crabwalk' Down The Runway In A Heavy Crosswind Like Only It Can

Watch this B-52's unique swiveling landing gear get a full workout during this windy recovery at RAF Fairford.

www.thedrive.com

 

[Wurger]

 

[Escuadrilla Azul]

Awesome! I didn't even know about the swiveling landing gear!

 

[Wurger]

I have known but didn't know it could be swiveled as much.

 

[Escuadrilla Azul]

I have known but didn't know it could be swiveled as much.

That people at Boeing did thought of everything. Unlike nowadays.

 

[special ed]

The kids can do it as well as their grandfathers did in the B-52

 

[buffnut453]

That was almost landing sideways.

The main runway at RAF Alconbury was actually built so that it had a pretty permanent crosswind. This was because it had been designated as a master diversion airfield for B-52s if war had ever broken out with the USSR. The crosswind runway was necessary because a damaged Buff that's lost an engine or two would need extra lift on that side, and the crosswind provided that extra lift. Of course, the crosswind runway presented some operational challenges for other aircraft types, most notably for the U-2/TR-1 when it was based there. Sadly, the runway is now used for truck storage and likely will never reopen as a flying base.

 

[Snautzer01]

Skater dudes go

 

[Gnomey]

Good one!

 

[GrumpyOldCrewChief]

As a former maintainer of that airframe, in its now-retired "G" model, testing that feature required placing the airframe on "greaseplates", which were much like their name. Two large, (~1yd/1m on a side) square steel plates, with a handful - literally - of grease sandwiched between, were placed under each of the four main gear trucks. Nosewheel (actually the two forward trucks) steering was separate from the crab feature, but used the same component on the gear. All four trucks were effectively identical, with some small detail differences, based on the individual locations. Each truck location carried a different safety switch set.

To test the alignment and proper functioning of the steering and crabbing features, the friction of the tires on the runway/taxiway surface had to be reduced. Brakes could not be locked, nor chocks installed. At Loring, this operation was usually only done in our big Arch hanger, where the plane was shielded from wind, and the floor was reeeeally level. Ya don't want the thing to start rolling around...

Watching your airplane taxi in slightly askew, after a flight, was always a bit strange. The flight crew would get roundly called out, if they forgot to straighten out the gear, before engine shutdown. Towing the big bird around, with the gear crabbed, was unsafe, and generally not allowed. To square the gear back up needed either an engine running, or a ground mule, to get enough hydraulic pressure and flow, to do the job. Plus, the plane had to be on the greaseplates...

 

[pbehn]

As a former maintainer of that airframe, in its now-retired "G" model, testing that feature required placing the airframe on "greaseplates", which were much like their name. Two large, (~1yd/1m on a side) square steel plates, with a handful - literally - of grease sandwiched between, were placed under each of the four main gear trucks. Nosewheel (actually the two forward trucks) steering was separate from the crab feature, but used the same component on the gear. All four trucks were effectively identical, with some small detail differences, based on the individual locations. Each truck location carried a different safety switch set.

To test the alignment and proper functioning of the steering and crabbing features, the friction of the tires on the runway/taxiway surface had to be reduced. Brakes could not be locked, nor chocks installed. At Loring, this operation was usually only done in our big Arch hanger, where the plane was shielded from wind, and the floor was reeeeally level. Ya don't want the thing to start rolling around...

Watching your airplane taxi in slightly askew, after a flight, was always a bit strange. The flight crew would get roundly called out, if they forgot to straighten out the gear, before engine shutdown. Towing the big bird around, with the gear crabbed, was unsafe, and generally not allowed. To square the gear back up needed either an engine running, or a ground mule, to get enough hydraulic pressure and flow, to do the job. Plus, the plane had to be on the greaseplates...

View attachment 662968

I was going to ask why large airliners dont have something similar, but I think you just answered that one.

 

[GrumpyOldCrewChief]

Very few aircraft bothered with a "rectangular" landing gear set-up. Most have a three-point, with the nose gear being the only one steerable. And by the way, those greaseplates would be useful under the nose gear, too. Even the modern superheavies, with LOTS of gear trucks, still only have one that is steerable. Geometrically, still a triangle. The modified bicycle (quadracycle) gear of a B-52 was a big rectangle. Tricycle geared birds can crab in crosswinds, but that big rectangle cannot. The crabbing feature is how Boeing got around the physics of the limitations of that gear design.
Formula 1 designs also had four wheel steering, for a while, I think...

 

[bdefen]

I assume that the swiveling landing gear system is automatic, adjusting itself to the angle of the aircraft relative to flight direction, when deployed. Or..............is there a REALLY SKILLFUL crew member who controls it manually?

 

[GrumpyOldCrewChief]

SORT of automatic. There was a large horizontal wheel, at the starboard rear of the center console, between the pilots, that controlled the crab angle. The control wheel inputs went to a BIG metering valve, that actually moved all four of the the gear to the commanded angle. The angle off center number that sticks with me is 23°, but I am also pretty sure that the limit was actually higher than that. The rudder pedals also had inputs to that metering valve, for "regular" steering inputs, for the front trucks only.

It was up to the pilot, or co-pilot, to decide on the correct angle, and set it into that wheel.

Unfortunately, none of the photos of BUFF cockpits I can find show the aft end of the center console, with that control wheel in view.

All "facts" quoted are subject to verification. It has been 3+ decades since my last time sitting in those seats...

 

[bdefen]

Maybe that's where the fire department guys who steer the back end of a hook and ladder truck learned their craft......or the guy who drives the back end of the wind turbine hauler. Thanks for the response.