captive apple

The quick proof is all the YouTube extreme cross wind landings. But yeah I guess it depends on the plane.

Adlerdriver

I obviously can't speak to all transport category aircraft but the answer is yes for the one's I've flown. They all have air/ground sensing that disables NW steering until nose gear is on the ground. That way you don't have the nose wheel trying to follow rudder commands when it's retracted. When the aircraft is on the ground, the rudder pedals only allow a limited amount of nose wheel travel compared to the tiller which provides full steering capability.
777 pedals only allow 7 degrees of NW steer / Tiller provides 70 degrees
MD-11/MD-10: 10 degrees/ 70 w/ tiller
757/767: says "limited" w/ rudder / 65 w/ tiller (I would guess actual rudder # is 6-7 degrees similar to 777)

So, obviously the engineers were smart enough to figure out we may need full rudder capability during landing and initial roll-out, but don't want to waste brain cells worrying about what the nosewheel steering is doing.

MysteriousMrX

I’ve heard the airbus (a-319/20/21, at least) requires no cross-wind correction. True?
what about CRJs and 737/47/57/67/77? Do you guys put in x-wind correction on takeoff and landing?

Adlerdriver

It's been about 18 years since I flew the A320 family. That said, I know for a fact there isn't some kind of auto-crosswind flight control system. Crosswind controls are required just like any other aircraft. From what I remember, the rudder is analog with hydraulic servos controlled via direct connection to the rudder pedals like any other aircraft. The unique issues of the fly-by-wire (FBW) pitch and roll controls make a cross-wind landing different than most other aircraft. If you put in rudder to align the fuselage with the runway, opposite aileron inputs into the wind to keep the wings level or drop the wing to kill the drift induce a constant roll. That's because the FBW logic responds to any lateral (aileron) stick deflection by commanding a roll rate. The more the stick is deflected, the faster the roll rate and the roll continues as long as the stick is deflected. So, when the pilot puts the aileron into the wind, if he keeps the stick deflected the aircraft will roll past the angle of bank necessary to kill the drift. As a result, I found I had to kind of "pulse" the stick into the wind and then allow it to return to neutral to set the bank angle I wanted. The other option which I preferred on all the transport category aircraft I've flown is to avoid trying to use a forward slip well out on final to counter the crosswind and wait until into the flare to kick the crab out and just bring the wings level for touchdown.

As far as these aircraft: 737/47/57/67/77
Yes, they all require crosswind control inputs on takeoff and landing. 747 is an educated guess as I've never flown it, but it's a Boeing like all the rest and they seem to fly about the same. I don't understand how any aircraft being hand flown through a crosswind takeoff or landing would not require the pilot to provide appropriate flight control inputs to counter the wind. Do you know of such an aircraft?

1wife2airlines

You say you are flying the 767. When does the nose gear decide to follow the rudder when that gear touches the ground when landing? For all the aircraft you flew was the air ground sensing mechanical or electronically? I will give you that most aircraft might only allow 6 degrees of nosewheel steering by the rudder and touching down with rudder input and a nosewheel giving a slight yaw because the rudder position might not even be noticed. We all just fly the aircraft as required.

Adlerdriver

I "say" I'm flying the 767? So am I a poser now?

The 767 (and 757) have tilt sensors located on each main landing gear that signal various systems electronically of the transition from air operations to ground operations (thrust reversers, spoilers and landing gear retraction lever lock, as examples). There are also nose gear strut compression sensors that signal other systems of the air/ground shift (stall warning and portions of the caution/warning system). I can't say for certain if either set of sensors are considered mechanical or electronic. My guess is basic analog binary switches (electronic?) signalling ground or air based on the tilt sensors and nose strut extension.

The 757/767 nose wheel follows the rudder commands to a limited degree when the main gear tilt sensor signals ground transition.

The MD-11/10 relied totally on a mechanical rod behind the nose gear that extends as the nose gear comes off the ground during rotation and extends.

777 uses only sensors on the main gear.


Regardless of how it occurs, the slight degree of nose wheel steering via rudder provided to any of these aircraft during a cross-wind landing is inconsequential. If anything, on initial touchdown of the nose gear while still at high post-touchdown speeds, the slight nose wheel steering input opposite from the cross-wind is only going to help the aircraft track the center-line. At that point there are still significant aerodynamic forces attempting to weather-vane the aircraft into the wind. Centering rudder inputs out of concern over nose wheel steering inputs from a system designed to allow proper cross-wind control application during landing is incorrect procedure, IMO. As you said, you apply the flight controls and fly the aircraft as required.

pangolin

CRJ certainly requires it.

AboveMins

747 requires it. I don't like using more than 2.5 to 3 units since that will deploy the roll spoilers. As far as landing, you can land the 74 in a crab, and she'll walk herself straight, but it's ugly, uncomfortable, and puts a lot of stress on the gear. What I like to do is slowly start de-crabbing when the RA calls 30', straight by about 5', holding the ailerons in to keep wings level, and just enough rudder to keep it straight. Need to pay extra attention in the -8, since those inboard engines don't have much ground clearance. Touching down with more than 5° of bank will strike one of those inboard pods, if I remember correctly... Someone please correct me if that number is wrong. Worked great last week in NRT with those hellacious gusty crosswinds, and I haven't struck a pod... Yet.

rickair7777

They do require it, you're just not supposed to hold bank correction because it will deploy spoilerons which you don't want hanging out in the flare (or T/O roll). You can quickly bump the ailerons, that won't give the spoilerons time to pop out, or at least they won't be up for long.

I don't like it, it's sketchy. Maybe airbuses overseas customer just land the thing in a crab and buy a lot of tires.


CRJ and 737 use normal (for a jet) XW technique. I like those better than bus because they just give you the aileron you command, without a computer in the middle.

aeroengineer

So given the lighter loads frequently flying lately, I know climb performance has improved. How has that affected crosswind landing handling?