HiI read somewhere that the U-2 Dragon Lady steers using its tailwheel. The thing is, it only steers 6 degrees in either direction. Why is that? To avoid putting too much stress on the pogos? To make the U-2 pilot's life harder? Why not make the tailwheel turn 180 degrees instead? It only widens the U-2's already large turning radius.

That doesn't sound right, the U-2 wouldn't be able to turn from the TWY onto the RWY. Perhaps the 6º limit applies once the tailwheel is "locked" for Take-off? (Just guessing...)Cheers,- jahman.

Interesting. I found a U-2S pirep that says this on taxiingPreflight checks completed andengine started, we taxied to Beale's 12,000-foot-long runway. The singlemain landing gear is not steerable, differential braking is unavailable,and the dual tailwheels move only 6 degrees in each direction, so ittakes a lot of concrete to maneuver on the ground. Turn radius is 189feet, and I had to lead with full rudder in anticipation of all turns.I can confirm this with an article from Avweb.com about the U-2, written by a former U-2 pilotIt was a unique arrangement, that demanded you fly the thing to a stop, and even after stopping, you could still fly the wings with 10 knots of wind. And taxiing, well, that's another story! A 200-foot turn radius with a tailwheel that only steers six degrees requires a lot of room ... and some unique methods of weight distribution to ensure wingtip clearance.My guess is that that is the farthest the tailwheel can turn. Would turning much further wear out the bearings and/or linkages? It IS a pretty tiny wheel... Plus, these are two pictures of U-2 taxiinghttp://www.sky-flash...magepage29.html http://www.sky-flash...magepage62.htmlThe first one is the U-2 on landing. The tailwheel IS swivelled left, it might be hard to see.THe second one is the U-2 taxiing. It's shot from an angle, so it's hard to tell if the tailwheel is turning. The pilot is using what looks like full right rudder, so I would guess that the U-2 is turning right.If the pilot in the article "had to lead with full rudder in anticipation of all turns", then what turns the tailwheel? A tiller? Rudder control?

Anybody have an answer yet?

Anybody have an answer yet?

The answer seems to be above.

The answer seems to be above.

I was asking why, not how.

I was asking why, not how.

Because if they gave that tailwheel a greater degree of movement while keeping it linked to the rudder, it would likely cause you to ground loop on takeoff and landing. On a tailwheel aircraft during takeoff and landing rolls, you will often find yourself sawing the rudders back and forth almost stop to stop, and if the tailwheel moved a large amount back and forth, you would probably lose control and ground loop. On most tailwheel aircraft, the tailwheel as steered through the rudder pedals only have a small degree of movement, with the ability to disengage from the steering and caster freely for tight taxi turns achieved with differential braking/power.

I've had the pleasure of seeing these take off and land real world, from my time spent in the Air Force. These planes are extraordinarily loud! I would imagine that the limit on steering is due to the fact that wingspan is so great the plane may wing-strike the ground at any time if you're not careful.

...Plus, these are two pictures of U-2 taxiinghttp://www.sky-flash...magepage29.html

Notice that the speedbrake negative dihedral causes a nose-down moment on deployment!

Because if they gave that tailwheel a greater degree of movement while keeping it linked to the rudder, it would likely cause you to ground loop on takeoff and landing. On a tailwheel aircraft during takeoff and landing rolls, you will often find yourself sawing the rudders back and forth almost stop to stop, and if the tailwheel moved a large amount back and forth, you would probably lose control and ground loop. On most tailwheel aircraft, the tailwheel as steered through the rudder pedals only have a small degree of movement, with the ability to disengage from the steering and caster freely for tight taxi turns achieved with differential braking/power.

Why didn't they use a tail wheel lock plus a separate "tiller" lever for ground sterring? Heck, I could have even designed that! (And not much more than that). :-)Makes me wonder how she handled takeoffs and landings in a crosswind with little steering available from that shopping-cart for a tail wheel bith barely any weight on it and no differential steering to talk about. Any differential spoilers that could help?Cheers,- jahman.

Why didn't they use a tail wheel lock plus a separate "tiller" lever for ground sterring? Heck, I could have even designed that! (And not much more than that). :-)Makes me wonder how she handled takeoffs and landings in a crosswind with little steering available from that shopping-cart for a tail wheel bith barely any weight on it and no differential steering to talk about. Any differential spoilers that could help?Cheers,- jahman.

Not that I know anything more about the U-2 than the next guy, but if you think about it, why should they? The purpose of that plane is to grab as much altitude as it can, not for ease of operation. I imagine anything that adds even an ounce of weight and is not directly related to maximising altitude and range performance for its primary mission would have been nixed.U-2 operations are probably subject to strict crosswind limits, given its long span and bicycle gear design, even if it did have a fully steerable tailwheel.

Doing the the mid 60s ,all the u-2s I ever seen were towed to and from the runway..

Because if they gave that tailwheel a greater degree of movement while keeping it linked to the rudder, it would likely cause you to ground loop on takeoff and landing. On a tailwheel aircraft during takeoff and landing rolls, you will often find yourself sawing the rudders back and forth almost stop to stop, and if the tailwheel moved a large amount back and forth, you would probably lose control and ground loop. On most tailwheel aircraft, the tailwheel as steered through the rudder pedals only have a small degree of movement, with the ability to disengage from the steering and caster freely for tight taxi turns achieved with differential braking/power.

Interesting. Apparently when taxiing the P-51 Mustang, neutral stick also gives you 6 degrees of tailwheel control for S-turning. Couldn't making tailwheel control proportional to rudder deflection make more sense? As in, if you press left rudder all the way to the floor while taxiing, the tailwheel would turn 90 degrees left and you'll be able to turn 180 degrees on the taxiway for those really tight turns. On the subject of full-stop rudder deflection during landing, couldn't you just lock the tailwheel until you're safely on the ground?

Interesting. Apparently when taxiing the P-51 Mustang, neutral stick also gives you 6 degrees of tailwheel control for S-turning. Couldn't making tailwheel control proportional to rudder deflection make more sense? As in, if you press left rudder all the way to the floor while taxiing, the tailwheel would turn 90 degrees left and you'll be able to turn 180 degrees on the taxiway for those really tight turns. On the subject of full-stop rudder deflection during landing, couldn't you just lock the tailwheel until you're safely on the ground?

Haha I couldn't imagine a fully proportional tail wheel. It is already bad enough with a couple degrees. In gusty situations and you are all over the place it would make it very difficult to keep the airplane straight.

Haha I couldn't imagine a fully proportional tail wheel. It is already bad enough with a couple degrees. In gusty situations and you are all over the place it would make it very difficult to keep the airplane straight.

Well as I said above, couldn't you just lock the tailwheel in that case? That would allow you to do all the full-stop rudder deflection you want but still keep going straight down the runway.