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-   -   x-wind landings on big jets (https://www.airlinepilotforums.com/technical/36441-x-wind-landings-big-jets.html)

captscott26 03-17-2009 04:07 PM


Originally Posted by Airhoss (Post 579878)
The A-320 is the first and only airplane I've ever flown where I've hit the control stops with the stick in all four directions on one landing within 50 feet of the ground. Not the norm mind you but until you get accustomed to it the 320 can be a bit disconcerting in a strong gusty crosswind.

It's also the only airplane I have ever flown that you run out of aileron way before you run out of rudder in a strong x-wind. Its pretty interesting the first few crosswind landings, but you get the hang of it. Since you are dealing with flight control laws, the aircraft will not allow a sideslip above 50 ft RA. Below 50 ft the computers essentially give the pilot "normal" control, or what you would be used to in any other aircraft. So basically, kick it and stick it! ;)

KC10 FATboy 03-17-2009 05:48 PM


Originally Posted by captscott26 (Post 580054)
It's also the only airplane I have ever flown that you run out of aileron way before you run out of rudder in a strong x-wind. Its pretty interesting the first few crosswind landings, but you get the hang of it. Since you are dealing with flight control laws, the aircraft will not allow a sideslip above 50 ft RA. Below 50 ft the computers essentially give the pilot "normal" control, or what you would be used to in any other aircraft. So basically, kick it and stick it! ;)

I was landing in Boston last week on Runway 27. A jetBlue was in front of us. We had extremely high wind gusts and crosswinds. The jetBlue had to go around. At the time we thought perhaps they weren't worthy pilots. But, after seeing what you just posted about the Airbus, I'm glad they did go around if it got ugly on them.

-Fatty

Pilotpip 03-17-2009 05:53 PM


Originally Posted by KC10 FATboy (Post 579926)
In the DC-10, if you crab into the wind and then kick the rudder in the flare, you better be add simultaneous aileron into the wind. Otherwise, you will get a pronounced rolling moment in the direction of the wind which will cause you to strike a wing, pod, or go off the runway. I have also found that once the main gear touch down and the spoilers kick up, you will need even more aileron into the wind to keep that up-wind wing down.

We had a KC-10 go off the runway and one of the contributing factors was "relaxing" of the crosswind controls. They didn't take them out completely, they just let some out. Given other factors in the accident, that was enough to send them off the runway.

I haven't flown a ton of swept-wing aircraft, but the roll is there for everything down to a 152. There's a limitation for the 170 as well (something like 17 degrees bank) but I can't recall if it's for the engine or the wingtip. Either way, I don't want to find out the hard way.

It's interesting to hear about the other types of aircraft out there. I had a mainline guy in the jumpseat one day and asked why the 737 in front of me looked like it was taxiing sideways. I got to learn that the mains castor a bit to help avoid dragging an engine by allowing to land in a crab. Any other types have something like this?

hindsight2020 03-17-2009 08:21 PM


Originally Posted by Pilotpip (Post 580125)
I haven't flown a ton of swept-wing aircraft, but the roll is there for everything down to a 152. There's a limitation for the 170 as well (something like 17 degrees bank) but I can't recall if it's for the engine or the wingtip. Either way, I don't want to find out the hard way.

It's interesting to hear about the other types of aircraft out there. I had a mainline guy in the jumpseat one day and asked why the 737 in front of me looked like it was taxiing sideways. I got to learn that the mains castor a bit to help avoid dragging an engine by allowing to land in a crab. Any other types have something like this?

Hell yeah, the mighty B-52. Our crosswind crab system is sick. We're wider than we're long, therefore no wing low method on that old bastard. 20 degree maximum gear prepositioning from centerline...which gives a max demonstrated x-wind component of 42KTS. :cool:

It messes with your head the first couple of times, trying to effectively land a crane, visualizing crab angles that put the aft gear that's 80 feet behind you effectively several dozen feet to the left or right of your seating position; having to force yourself to shoot for a cockpit position so many widths left or right of centerline to effect an overall centered landing position in the runway. If the crab is pronounced enough (in the high teens) to warrant having to see through the other pilot's nugget, most pilots elect to allow the pilot downind of the crab to land the crane, er, the airplane. Taxiing crabbed down the runway is another gem....and correcting for any drift you allowed while over the threshold on the flare while adequately compensating for the aforementioned geometry considerations is a little puzzling at first, to say the least.

Other than that, the 8 different assymetries of individual engines, flap retractions that resemble closing stadium roofs, ridiculous aerodynamic effects during air refueling due to having longer wings than the tanker, helicopter-style cockpit sight picture during lightweight pattern work due to built-in 8 degrees positive angle of incidence on the wing root (that's right, a whole lot nose down on the ADI gives you level flight) and an artificial feel control system designed to resemble control pressures of a B-36 because the hydraulic assist was making the old dudes over-G it back in the day (i.e. they incorporated unnecessarily fatiguing control forces to fly it manually for hours, for the benefit of people crossflowing in from the old big momma bomber), it flies just like your run of the mill airplane, pull-push houses get smaller get bigger type stuff....:rolleyes::D It's a vintage experience, so it's all good.

Pilotpip 03-17-2009 09:20 PM

Good stuff. I've seen pictures of the BUFF doing those crabbed landings. Amazing that three generations have flown that jet, and over 50 years of technology have yet to replace it. What a magnificent beast.

On a sidenote, does the guy endoing the second mountain bike in your avatar have any significance or is it just a funny pic?

KC10 FATboy 03-17-2009 10:36 PM


Originally Posted by Pilotpip (Post 580125)
I haven't flown a ton of swept-wing aircraft, but the roll is there for everything down to a 152. There's a limitation for the 170 as well (something like 17 degrees bank) but I can't recall if it's for the engine or the wingtip. Either way, I don't want to find out the hard way.

It's interesting to hear about the other types of aircraft out there. I had a mainline guy in the jumpseat one day and asked why the 737 in front of me looked like it was taxiing sideways. I got to learn that the mains castor a bit to help avoid dragging an engine by allowing to land in a crab. Any other types have something like this?

On big airplanes, you also have a very large body force, that is the wind blowing up against the fuselage. That also will push you to the downwind side and help with the rolling moment if you don't apply crosswind controls.

Avg Joe 03-18-2009 07:53 AM

Strong X-wind Landing Video
 
After seeing this video I have great respect for just how strong these gear are and the amount of side-loading they can withstand. :eek:

YouTube - Cross wind landings boeing 777


Joe


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