A technique question for the ages......

[pc12_driver]

Ok, all you jet jocks, help me out here. Crab & Kick or cross control on final/touchdown? Let 'er rip guys...................

 

[pilotyip]

depends upon the airplane.

Ok, all you jet jocks, help me out here. Crab & Kick or cross control on final/touchdown? Let 'er rip guys...................

Depends upon the airplane.

 

[ruhroa]

yup ....depends on the airplane and of course what feels more comfortable ............ some aircraft such as the cl604 you can't afford to let the wing drop. also because the cross section of the cockpit is wide you lose the sense of a slight dip left or right

 

[TurboHonda]

Crab and kick will work for anything you fly (high wing, low wing, swept wing, spoilers, jet, props). Cross control will work for some of the planes you fly.

The choice is yours. Practice the technique for all. Practice the technique for some.

 

[pilotyip]

Of course then there is the B-52, which I understand you do not use either technique. You crap the wheels and land in a crap, no wing down, no kick, just land looking out the side window. Any B-52 drivers care to confirm?

 

[LivestockTony]

I'm not a B-52 pilot, but I thought that monster had steerable mains which permitted that technique.

 

[Coool Hand Luke]

Crab and kick will work for anything you fly (high wing, low wing, swept wing, spoilers, jet, props). Cross control will work for some of the planes you fly.

The choice is yours. Practice the technique for all. Practice the technique for some.

You obviously haven't flown the mighty Embraer Brasilia - EMB-120. Try the crab and kick technique with that plane in a strong cross wind and you'll end up so far centerline you'll think you're on a parallel runway, plus you'll severely side load the mains. There's only one way to land the Bro in a cross wind brother, upwind mains first, downwind mains second.

 

[Waldom]

In an airplane in which there is a choice, the majority of pilots I have flown with use a side-slip technique at touchdown during a cross-wind landing.

As Pilotyip mentioned, there are some airplanes that due to design allow little or no roll deflection from level in that situation. As an example, a "stretch" DC-8 with the CFM-56 engine conversion will drag an outboard nacelle with three degrees of roll in the touchdown attitude. The "crab and kick" method is used with that machine.

Obviously, both techniques work. If you plan to use the "crab and kick" method, I would suggest mentioning that in the before landing brief. It will save the other pilot a moment of suspense just before touchdown.

 

[Hawker800]

Wing down on the King Air 350 but I was tought crab and kick touchdown level on sweep wings.

 

[TurboHonda]

You obviously haven't flown the mighty Embraer Brasilia - EMB-120. Try the crab and kick technique with that plane in a strong cross wind and you'll end up so far centerline you'll think you're on a parallel runway, plus you'll severely side load the mains. There's only one way to land the Bro in a cross wind brother, upwind mains first, downwind mains second.

***************
OK. Let me explain the crab and kick. It is in effect the same as the cross control, only it is employed on very short final and the touchdown is completed before the plane has established a prolonged wing low attitude. It’s like any other landing, in that the plane is positioned over the centerline with the ailerons (or spoilers) and the wheels are lined up with the rudders. These control inputs are maintained and probably increased during rollout. The overall result is that the plane lands with no side load and has the proper control input for crosswind.

It is not an aggressive maneuver; although the short duration, as compared to a cross control on long final, requires some finesse and practice.

I’m sure that there are exceptions, like the B-52 and Ercoupe, but overall it’s simple aerodynamics.

 

[pilotyip]

Da-20

Wing down on the King Air 350 but I was tought crab and kick touchdown level on sweep wings.

Wing down works just fine in the DA-20; it is what I teach. Of course it has wing like a trainer airplane and ailerons the size of most airplanes flaps. In the L-188 and DC-9 we had to crab and kick if we anything above a minor X-wind

 

[cherry20's]

Yeah, the Falcon 20 was a great airplane to cross control or wing low. The Citation X on the other hand, don't even try it in big crosswinds! Works in low to med winds, but not strong crosswinds as you'll drag a wing in a hurry doing it then!

 

[ksu_aviator]

I just hate the use of the word kick. It implies abrupt control movements and I can't imagine why anyone would intentionally do something abrupt. Maybe we can rename it to Crab and Correct.

 

[Colonel Savage]

On narrowbodies (DC-9, 737, etc), maintain the crab until over the threshold then lower the upwind wing to maintain centerline while straightening the nose with the rudder. The flare is done cross-controlled, landing on the upwind wheels first. In a really strong crosswind, you should have close to full aileron into the wind as the downwind wheels touchdown (helps the rudder keep the nose straight). Keep the aileron in during roll out until rudder is no longer used for directional control.

When planning on landing with a strong crosswind, make sure the ground spoilers get armed, and make sure they come up after touchdown. If you don't, you may find the upwind wing coming back up after the downwind wheels touch down even with full aileron into the wind. I know the DC-9 can do it!

 

[pilotyip]

almost like a DC-3

When planning on landing with a strong crosswind, make sure the ground spoilers get armed, and make sure they come up after touchdown. If you don't, you may find the upwind wing coming back up after the downwind wheels touch down even with full aileron into the wind. I know the DC-9 can do it!

Almost like its older brother the DC-3 don't take out the X-wind correction before slowing to a taxi speed But on the 9 don't get that spoiler up before touchdown.

 

[Colonel Savage]

True. The 737 has a bad habit of deploying auto spoilers after small bounces. One learns to guard the handle until settled securely on the runway.

 

[Jakebud]

Its been some years since I've flown the mighty Buff, but yes, it is rather unique in how it deals with a cross wind. The airplane has a huge knob at the aft end of the center pedestal. With said knob, you simply dialed in the correct amount of crab angle for the main gear. You then simply landed in a crab, with the main gear at the set angle off centerline. OK, it was a bit weird the first few times you tried it, and for some guys, it was never pretty!

SPIKE

 

[dojetdriver]

Of course then there is the B-52, which I understand you do not use either technique. You crap the wheels and land in a crap, no wing down, no kick, just land looking out the side window. Any B-52 drivers care to confirm?

If you don't use the right technique, you probably will crap the wheels as well as land in crap.

At which point, you will be screaming CRAP!!!!!!!!!!!!!!!!

 

[Waldom]

The airplane has a huge knob at the aft end of the center pedestal. With said knob, you simply dialed in the correct amount of crab angle for the main gear. You then simply landed in a crab, with the main gear at the set angle off centerline.

SPIKE

Jakebud, Murphy's Law being what it is, I've always wondered if, after a very long mission, someone ever dialed the correction in the wrong direction. I imagine that would lead to a sporty ride on touchdown.

 

[thunderworm]

from boeing:
Slideslip/zero crab is not allowed when X-wind/flaps
15kts/15 flaps
18kts/30
21kts/40

 

[Colonel Savage]

Why does the x-wind limit increase with the flap setting?

 

[tomgoodman]

x-wind/flap relationship

Why does the x-wind limit increase with the flap setting?

Increased flap settings allow landing at a lower pitch attitude. This can improve ground clearance in a bank. Some airplanes also provide increased aileron authority at lower speeds/higher flap settings.

 

[Colonel Savage]

Understand to first point. The second point, do any civilian types have the extra aileron authority, or is that just military types?

 

[Fly91]

Of course then there is the B-52, which I understand you do not use either technique. You crap the wheels and land in a crap, no wing down, no kick, just land looking out the side window. Any B-52 drivers care to confirm?

B-52 has rotating wheels, you crab the plane and the wheels are pointed straight down the centerline.

BUT......The T-38 Talon, which I flew 4 times (incentive rides in AF ROTC)......is truly a plane that you don't crab or cross control..
You come in, wings level, regardless of the crab angle..and slam it on. Yup, they go through alot of tires. I'm no expert on the t-38, but our pre-flight briefing and pre-landing verbal briefing by the instructor pilots on final approach was....."do not touch the rudders on landing, feet flat on the floor."

 

[Fly91]

Increased flap settings allow landing at a lower pitch attitude. This can improve ground clearance in a bank. Some airplanes also provide increased aileron authority at lower speeds/higher flap settings.

I see you flew the T-38.

What is it called on the Talon that doesn't let you use rudder on landing. It was back in 1992 when I got a few rides but I can;t remember what they called it. I assume its like other aircraft where you just get too much deflection.

?

 

[Colonel Savage]

"What is it called on the Talon that doesn't let you use rudder on landing?"

Rudder limiter? But sounds like the T-38 is opposite from most jets I'm familiar with, as most systems limit the rudder travel at higher speeds (such as after flap retraction), not lower.

 

[LR25]

Done both on 747, seems to work out whether you crab or cross control. If strong wind, you can cross control, but have to watch lowering the wing too much, but thats seems normal on most airplanes.

 

[tomgoodman]

T-38 & rudder

Col Savage & Fly 91,

It's been a long time since I flew it, and you can probably get a better answer from an active T-38 IP in the Military section of the forum.
The only use I made of the rudder was to keep the airplane tracking straight down the runway during takeoff or landing roll. (A button on the stick engaged nosewheel steering, but that was much too sensitive for anything above taxi speed.) The "crab-only" technique was used for crosswind landings. One reason was that inflight rudder application would give you a substantial roll (360-degree rudder rolls were demonstrated at altitude), so students were indeed told to "keep their feet on the floor" until rollout. Sideloads from touching down in a crab were moderate, perhaps because the T-38's tire footprint was small.

 

[Fly91]

"What is it called on the Talon that doesn't let you use rudder on landing?"

Rudder limiter? But sounds like the T-38 is opposite from most jets I'm familiar with, as most systems limit the rudder travel at higher speeds (such as after flap retraction), not lower.

Thats the weird part. There is no "rudder limiter", you get full deflection at slow speeds...thats where the problem happens if you use rudder during landing. When I flew the 747 it was a high-speed issue with a system failure. That had a rudder limiter above 300 kts IIRC, so rudder travel would be limited.

The T-38 was strange because it was a low speed issue.

 

[Fly91]

Col Savage & Fly 91,

It's been a long time since I flew it, and you can probably get a better answer from an active T-38 IP in the Military section of the forum.
The only use I made of the rudder was to keep the airplane tracking straight down the runway during takeoff or landing roll. (A button on the stick engaged nosewheel steering, but that was much too sensitive for anything above taxi speed.) The "crab-only" technique was used for crosswind landings. One reason was that inflight rudder application would give you a substantial roll (360-degree rudder rolls were demonstrated at altitude), so students were indeed told to "keep their feet on the floor" until rollout. Sideloads from touching down in a crab were moderate, perhaps because the T-38's tire footprint was small.

Yeah, I probably did about 10 landings total and thats what I remember the most. The instructor pilots would keep saying it all the way to touchdown...so it must have been a pretty important procedure. And yes, it was just a "slam it on" for crosswind landings no matter how much the angle was. It would hit solid as a rock and straighten right out.

We were allowed to take the controls as soon as we were at 500 feet on climb out and literally fly the entire time till about 500 feet on final....then it was sit there like a statue and don't touch anything.