is there a rule of thumb for crosswind landings?

[florismulock]

Hi all i was wondering if there is some kind of rule so that you know how much rudder you have to apply for different cross winds?

[emerydc8]

Whatever it takes.

I use the de-crab-during-flare method, where you crab all the way down into the flare and as you approach about 10-20 feet in the flare you start to apply rudder to align the nose of the aircraft with the runway and add aileron into the wind to keep the wings level (this is the de-crab). The downwind rudder application causes the upwind wing to rise as that wing accelerates, so you use whatever aileron it takes to keep the wings level. If you time it right, the nose will just be aligning with the runway heading as you touch down with both gear (left and right). You will touch down with cross controls -- again whatever aileron it takes to keep the wings level on the rollout and whatever rudder it takes to keep the nose on centerline.

If you de-crab too soon, you will get blown downwind of the centerline. If you de-crab too late, you will land in a crab, which usually doesn't result in a nice landing; although the aircraft is certified to land in a crab up to the landing crosswind guideline speeds.

I don't know of anyone who is good enough to duplicate the sideslip (wing low) method used by the autoland, especially if the conditions are gusty (and they usually are). This technique is a combination of the crab and slip where you land slightly wing low on the upwind gear first. I wouldn't bother practicing this. Go with the de-crab technique.

There is no set rule-of-thumb. Just practice. PSX is great for this!

Jon

[Jeroen Hoppenbrouwers]

Just to re-iterate:

1. The best way to screw up a nice approach is to use the rudder during the approach.
2. Don't use the rudder.
3. Keep your feet on the floor.
4. Except just before touchdown in a crosswind (see previous post).
5. And if you suffer an engine failure, stamp on the good engine full rudder immediately to stop the swing, then moderate back to keep the wings level and the ball centered with rudder. Do not apply ailerons -- they will extend spoilers on the high wing and this costs you way too much lift. Use the barn door at the tail to keep yourself straight.


Hoppie
Not a pilot
Just an engineer
Ohne gewähr
Objects in the mirror are closer than they appear

[emerydc8]

Good summary. I think it's better to focus on whatever rudder is needed to keep the airplane flying straight rather than the mechanical approach of identifying a good engine and thinking about applying rudder on that side. Once you have control of the airplane you can always look over and see what you've got as far as engines.

[Jeroen Hoppenbrouwers]

Good summary. I think it's better to focus on whatever rudder is needed to keep the airplane flying straight rather than the mechanical approach of identifying a good engine and thinking about applying rudder on that side. Once you have control of the airplane you can always look over and see what you've got as far as engines.

Sure, but me not being a pilot, I read that often your instruments yell at you which engine is faltering before you really notice the deviation. Hence first stomp onto the pedal, then start flying. But then, last time I had an engine failure on climbout (in a real sim) was, what, 10 years ago. Gnnnnn. Need to get more sim time.


Hoppie

[emerydc8]

I'm not good enough to look at the upper EICAS during a V1 cut to determine which rudder I need to apply, based on which engine has failed, and still keep the airplane on the centerline. Maybe some pilots can do it, but my experience is that you will know the engine has failed because you can feel it going off the centerline, you can see the engine gauges in your peripheral vision too, and the PNF calls out the engine failure (remember that caution is inhibited on the ground).

Your job is to apply whatever rudder is necessary to keep it tracking straight, lock that rudder in like your foot is glued to the floor, and rotate to about 12 degrees. This will put you in the ball park as far as the amount of rudder needed. If you're still moving the rudder during rotation, there's a good chance you're going to strike a pod. On at least one of our V1 cuts, the visibility will be 500 RVR and there is usually a 15-knot crosswind coming from the direction of the failed engine, so there is not a lot of room for error. If you take your eyes off the centerline for a fraction of a second after a V1 cut you are probably screwed.

I thought this was a good summary of some of the aerodynamic considerations during a V1 cut.

 Yaw: After a yaw movement occurs due to engine failure, the intent is to keep at least parallel to the centerline. Over-rudder will induce a roll in the direction of the over-rudder. Once the correct rudder pressure is established, attempt to lock the rudder pressure and maintain it throughout the rotation phase. Full rudder may be necessary for full TO thrust takeoffs and an outboard engine failure occurs. Once the correct rudder control is locked, occasionally check the PFD for correct roll control to maintain wings level. If full rudder does not maintain centerline, forward nosewheel pressure should be increased. If the aircraft has drifted to the edge of the runway, a correction should be made towards the centerline prior to rotation if possible.
 Pitch: With the nosewheel on the ground, both nosewheel and rudder authority control yaw performance. A slight nose down yoke pressure will assist in steering performance until Vr is called out. If full rudder does not maintain centerline, forward nosewheel pressure should be increased. Excessive nose wheel pressure may mask the true rudder pressure necessary when the nosewheel becomes airborne.
 Roll: Keep the wings level throughout the rotation and climb. Do not remove aileron inputs for wings level until the autopilot is engaged. When close to V1 and above, the wings begin to flex. When this occurs, there is a greater potential for crosswind roll effect.

[acannata]

An interesting reading about crosswind landings:
https://flightsafety.org/wp-content/uploads/2016/09/alar_bn8-7-crosswind.pdf.

Anyway, I apply the following rule: 10kts crosswind, 4° of crab angle; 20kts crosswind, 8° of crab angle.

Aldo (not a pilot)

[florismulock]

Whatever it takes.

I use the de-crab-during-flare method, where you crab all the way down into the flare and as you approach about 10-20 feet in the flare you start to apply rudder to align the nose of the aircraft with the runway and add aileron into the wind to keep the wings level (this is the de-crab). The downwind rudder application causes the upwind wing to rise as that wing accelerates, so you use whatever aileron it takes to keep the wings level. If you time it right, the nose will just be aligning with the runway heading as you touch down with both gear (left and right). You will touch down with cross controls -- again whatever aileron it takes to keep the wings level on the rollout and whatever rudder it takes to keep the nose on centerline.

If you de-crab too soon, you will get blown downwind of the centerline. If you de-crab too late, you will land in a crab, which usually doesn't result in a nice landing; although the aircraft is certified to land in a crab up to the landing crosswind guideline speeds.

I don't know of anyone who is good enough to duplicate the sideslip (wing low) method used by the autoland, especially if the conditions are gusty (and they usually are). This technique is a combination of the crab and slip where you land slightly wing low on the upwind gear first. I wouldn't bother practicing this. Go with the de-crab technique.

There is no set rule-of-thumb. Just practice. PSX is great for this!

Jon

sorry do not fully understand. when do you begin your crab? earlier post said dont crab at all only at the last moment (whcih i doubt is the best way). there really is no rule of thumb?

or perhaps this sim has an slip indicator?  (which indicates that your approach is straight to the runway? (so your slip/crab is right) that way you dont have to rely on your "feeling".

[florismulock]

An interesting reading about crosswind landings:
https://flightsafety.org/wp-content/uploads/2016/09/alar_bn8-7-crosswind.pdf.

Anyway, I apply the following rule: 10kts crosswind, 4° of crab angle; 20kts crosswind, 8° of crab angle.

Aldo (not a pilot)

ah and how do you know the crab angle? you read it from the nav display? or the PFD?   or are you using an other instrument?

[Britjet]

Just with regard to the engine failure sub-thread. Try my video here..
https://youtu.be/4idnKt_yxOI

Also, I think that the crosswind landing technique is ably demonstrated here...http://youtu.be/OkeC56ZRwDA
(but I agree with Jon's comments anyway).

There is only one place the handling pilot should be looking on take-off - the far end of the runway.
In the older 747-100 you could hear an engine reading change because the digital counters made quite a racket as they changed quickly - not so in the glass cockpit of course - progress eh?

The only useful function of the THR switch as far as I am concerned is that if you ask a pilot what it does and he knows, then he is probably far too clever to be a pilot, and should be monitored carefully at all times ....

Peter

[florismulock]

thr switch?  why would you use that with the cross landing?  manually using your power is much better to keep good 800ft descent

lol funny video.

so as far i understand  read the pfd for the angle you using (which is hard not a very precise instrument (for 1, 2, or 3 degrees ) and your feeling.  with that and practice!

[acannata]

Example:

Runway heading 090°
Wind from 000° (ie from left side) @ 10kts
In order to keep aircraft track aligned to the runway, I need to maintain 86° heading (on NAV display).

Hope this helps

Aldo

[florismulock]

ok thanks so there is no slip indicator, but this will do nicely aswell!

[Hardy Heinlin]

There is a slip indicator.

Slip and crab is not the same.

Slip is not an angle. Slip is a force, a force induced by yaw motion and/or by gravity (when banking). Slip is indicated on the attitude indicator (by that moving rectangle under the attitude pointer).

Crab is an angle. It's the angle between heading and track. Crab is indicated on the PFD and ND compasses.

[emerydc8]

There is only one place the handling pilot should be looking on take-off - the far end of the runway.
In the older 747-100 you could hear an engine reading change because the digital counters made quite a racket as they changed quickly - not so in the glass cockpit of course - progress eh?

Peter

In some of the older sims, you could hear a distinct button pop when the engine failed so, like you said, if you focused on the far end of the runway (or whatever centerline lights you could see if the visibility was bad), the takeoff was manageable. Years ago, on the classic, V2 cuts were all the rage. I guess the check airmen were bored with V1 cuts. I always felt that V2 cuts were harder because you have no visual reference when the engine fails.

Peter, do they do V2 cuts at BA? Fortunately, I haven't seen any of these for a long time. I don't think it was part of their training curriculum -- maybe just sadistic check airmen?

That's funny about the THR switch, but you're probably right.

so as far i understand  read the pfd for the angle you using (which is hard not a very precise instrument (for 1, 2, or 3 degrees ) and your feeling.  with that and practice!

There is no elixir that can be applied for crosswind landings -- just practice. Once you understand the de-crab technique, it really becomes a question of flying skills. Forget about landing in a crab or using the sideslip technique. Leave that for the A/P.

Crosswind Landing Techniques
Three methods of performing crosswind landings are presented. They are the de-crab technique (with removal of crab in flare), touchdown in a crab, and the sideslip technique. Whenever a crab is maintained during a crosswind approach, offset the flight deck on the upwind side of centerline so that the main gear touches
down in the center of the runway.

De-Crab During Flare
The objective of this technique is to maintain wings level throughout the approach, flare, and touchdown. On final approach, a crab angle is established with wings level to maintain the desired track. Just prior to touchdown while flaring the airplane, downwind rudder is applied to eliminate the crab and align the airplane with the runway centerline.

As rudder is applied, the upwind wing sweeps forward developing roll. Hold wings level with simultaneous application of aileron control into the wind. The touchdown is made with cross controls and both gear touching down simultaneously. Throughout the touchdown phase upwind aileron application is utilized to keep the wings level.

[the mad hatter]

i guess there is no place anymore for old fashioned stick and rudder skills .. shame

[emerydc8]

i guess there is no place anymore for old fashioned stick and rudder skills .. shame

Crosswind landings in the 744 still require stick and rudder skills. There is no magic formula here -- it's pretty much all hand-eye coordination. Set up a 30-knot crosswind in PSX and practice. When you have that down, set in some gusts or turbulence. It is challenging.

Don't let all the automation fool you. Not only does the 744 require stick and rudder skills, I can assure you that those skills are well beyond the level of skill required to fly small airplanes, so you can't get away with any general aviation slop, like not crossing the numbers on-speed, floating, or landing 75 feet off centerline. The approach speeds and descent rates are much higher, you have a swept wing, and you have the possibility of hitting the tail or an engine. 

PSX is an excellent tool for practicing x-wind landings.

[the mad hatter]

C172   push fwd nose down B747 push fwd nose down Space Shuttle push fwd nose down ... .. centre line temains centreline only differences are weights and rates is my point .by way example a particular well respected carrier goes from zero to hero ...all time in sim including check ride are there stick skills there? dont answer am being flippant so back to topic 😆

[Britjet]

Jon, V2 failures would be a training item only, and might be practised depending on airline. The EASA regulations are for a failure after V1 and before V2, I think, and at light weight as you know V1 and Vr will be coincident, which is where the engine is normally failed.
Peter.

[frumpy]

Here is an example of the de-crab method with the 737:
https://youtu.be/HcDomEhZu6U?t=2m30s