Crosswind Landing Question!

[centralhome]

I had a question for anyone that will chime in.
As a student you are taught to keep the airplane coordinated(ball in center). But one technique for crosswind landings is to come in with cross-controls(wing down into the wind, and opposite rudder).

How do you tell the student this is O.K.
Do you tell him as long as he keeps up the speed it is O.K., just don't use cross controls when you are slow?
I would appreciate any responses.

Thanks,
Joey

 

[meritflyer]

I had a question for anyone that will chime in.
As a student you are taught to keep the airplane coordinated(ball in center). But one technique for crosswind landings is to come in with cross-controls(wing down into the wind, and opposite rudder).

How do you tell the student this is O.K.
Do you tell him as long as he keeps up the speed it is O.K., just don't use cross controls when you are slow?
I would appreciate any responses.

Thanks,
Joey

The wing low method of crosswind landings is where the aileron is held into the wind while the rudder aligns the longitudinal axis of the airplane with the extended centerline. Most likely the student has had the it burned into his head that cross controlled situations ultimately result in spins. I have several students that were taught the same by their previous instructor. One thing I'd suggest is taking the student up to altitude and demonstrating flying the airplane in a cross controlled fashion. I often demonstrate cross controlled stalls as well. This eases the fear of student or rather allows them to gain a better understanding of what is occuring when the airplane is in a cross controlled configuration.

As for landing with the wing low method, the student must ensure the airspeed is adequate. I find that with the cross controlled situation the form drag of the airplane is increased dramatically hence the tendency is to fly much to slow for comfort. Teach the student to call out their airspeeds. I do this often just to keep their ASI in their scan. Regardless of whether you fly the plane in a crosswind with the wing low method or the crab method, at one point or another the airplane must be cross controlled.

A little altitude demonstration should really put things in perspective for the student.

 

[fish314]

Well, not exactly. By very nature of it being a landing, you are going to be "slow".

Basically, I would go about it by telling him that there are only 2 ways to fly the airplane down the runway in a cross wind scenario. He can either crab into the wind all the way down until he lands (i.e. using NO cross-wind controls) or he can cross-control.

If he crabs, then the airplane will land with the tires not lined up on the runway, and it will be violently obvious that it isn't right. As the wheels begin to skid the airplane will shudder violently left and right, and the result may cause left and right banking tendencies as the shudders change the airflow over the wings, but not in a symmetric way. The only airplanes that should land in a crab are ones that can turn the landing gear to align with the runway (like a B-52).

So your only other option is to use the rudder to align the tires with the runway (by aligning the NOSE with the runway), but if you do that you will begin to drift down wind for 2 reasons. First you will be yawing downwind, and second, you will have take out the crab that was keeping you flying down center line.

So now, if you touch down (proper rudder, but no wing low) you will have the same problem as if you were crabbing on touchdown. Now, the wheels are aligned with runway centerline, but the airplane isn't FLYING down runway centerline. The airplane is flying forward and sideways. So when the wheels hit the pavement, they are still going to be skidding along, and you will still get that violent and unpredictable left and right shuddering reaction.

To land the airplane well, the airplane must be flying parallel to the runway centerline, and the wheels must be parallel to the runway centerline. This is accomplished by rudder to align the nose, and wing low to kill the drift.

We as pilots worry about yaw for a couple of reasons. The biggest is because STALL + YAW = SPIN. Now on final as he's putting in his cross-wind controls he should have no worries about spinning, because there is no stall--PROVIDED HE'S ON SPEED (or even a few knots fast). So this emphasizes the importance of not getting slow on final, because he HAS to put in that yaw if he wants to land in a cross. But as long as he's on speed-no problems.

I'll teach guys that their window on final is 0 knots slow to 5 knots fast.

 

[fish314]

Ah Merit, looks like you type faster than I do! But yeah exactly.

 

[Andrew_VT]

I tell my students not to think that hard, they're just confusing themselves.

Hold a contant approach speed untill flare, then ailerons are for drifting side to side of the centerline and rudders are for keeping the nose pointed straight ahead. If they're eyes are focused down at the end of the runway it'll all come together. Even if they do stall (and its uncoordinated) they shouldnt be more than 5 feet up anyway and it'll just land.

Dont let them overthink things.

 

[centralhome]

Thanks for all the responses.

 

[CoffeeIcePapers]

I tell my students not to think that hard, they're just confusing themselves.

Hold a contant approach speed untill flare, then ailerons are for drifting side to side of the centerline and rudders are for keeping the nose pointed straight ahead. If they're eyes are focused down at the end of the runway it'll all come together. Even if they do stall (and its uncoordinated) they shouldnt be more than 5 feet up anyway and it'll just land.

Dont let them overthink things.

That is what I teach as well. Basically, I have them crab until we get close to the runway, and explain it exactly the way you explained it. Some guys teach the wing low method, and that is perfectly fine as well. It is all preference.

 

[MidlifeFlyer]

I had a question for anyone that will chime in.
As a student you are taught to keep the airplane coordinated(ball in center). But one technique for crosswind landings is to come in with cross-controls(wing down into the wind, and opposite rudder).

How do you tell the student this is O.K.

There's nothing inherently evil about being uncoordinated. Except for some specific situations along the edges of performance - stalling when uncoordinated, skidding in a turn - it's not even particularly dangerous. Mostly, it's inefficient (try an uncoordinated climb out in a 172 at a high density altitude airport) in and uncomfortable (especially for people who are sitting behind the G rather than more or less on top of it, like us).

Coordination is about knowing how to control yaw and knowing when to remove it and when to use it. An intentional slip is one of those maneuvers where we use it.

 

[tgrayson]

How do you tell the student this is O.K.

Slips are OK, skids are bad. The cross-controlled situation in a crosswind landing is a slip. If you stall, the wings will roll level.

And it's a bit harder to stall anyway in a slip, anyway, because the fuselage is at an angle of attack to the relative wind and supports some of the weight of the aircraft.

 

[SmitteyB]

Slips are OK

While I agree, I think that some instructors teach it too often.

Why not just crab? You will NOT slip larger aircraft.

When a student learns the slip to landing in a crosswind- they seem to think that approaching the runway high is acceptable because "I can just slip it in".

Slips are fine...when they are necessary.

Oh well- I'm a new instructor and I'm still learning.

 

[tgrayson]

While I agree, I think that some instructors teach it too often.

Define "too often."

Why not just crab? You will NOT slip larger aircraft.

You have wing tip clearance problems on some airplanes and engine pod clearance on others, but you can slip *some*. Regardless, little airplanes should not be flown the same as big airplanes.

<<When a student learns the slip to landing in a crosswind- they seem to think that approaching the runway high is acceptable because "I can just slip it in". >>

I thought the topic was crosswind landings, "side slips", not "forward slips"?

<<Oh well- I'm a new instructor and I'm still learning.>>

Hopefully that will continue as an old instructor.

 

[SmitteyB]

Define "too often."



You have wing tip clearance problems on some airplanes and engine pod clearance on others, but you can slip *some*. Regardless, little airplanes should not be flown the same as big airplanes.

<<When a student learns the slip to landing in a crosswind- they seem to think that approaching the runway high is acceptable because "I can just slip it in". >>

I thought the topic was crosswind landings, "side slips", not "forward slips"?

<<Oh well- I'm a new instructor and I'm still learning.>>

Hopefully that will continue as an old instructor.

I just got owned. Whooo!

Too often as in they encourage it too often. I have an older student who constantly wants to slip the airplane in any condition.

 

[tgrayson]

Too often as in they encourage it too often. I have an older student who constantly wants to slip the airplane in any condition.

Yes, they will do that. I view it as a stage that students go through as they explore this tool. I feel this is ok for a while, because it increases their comfort level with a flight maneuver that frightens many people. But in the end, as you say, they should be encouraged to fly good enough approaches where it's unnecessary.

 

[seagull]

Why not just crab? You will NOT slip larger aircraft.

What gave you that idea? Every transport aircraft built can be put into a side-slip for crosswind correction right through touchdown at its max demonstrated crosswind. It's a certification requirement. Many of them do it automatically when autolanding as you pass through about 150'.

 

[CoffeeIcePapers]

What gave you that idea? Every transport aircraft built can be put into a side-slip for crosswind correction right through touchdown at its max demonstrated crosswind. It's a certification requirement. Many of them do it automatically when autolanding as you pass through about 150'.

I think he is referring to the wing low method, or side slip method, where you just hold the slip all the way down on final. You are referring to the crab and kick method, where you just crab into the wind, until a certain point above the runway, then dip the wing and use opposite rudder to hold the longitudinal axis on center line.

 

[staplegun]

I think he is referring to the wing low method, or side slip method, where you just hold the slip all the way down on final. You are referring to the crab and kick method, where you just crab into the wind, until a certain point above the runway, then dip the wing and use opposite rudder to hold the longitudinal axis on center line.

I assure you that either method can and is used to land the B-767 in a cross wind.

Kevin

 

[seagull]

I think he is referring to the wing low method, or side slip method, where you just hold the slip all the way down on final. You are referring to the crab and kick method, where you just crab into the wind, until a certain point above the runway, then dip the wing and use opposite rudder to hold the longitudinal axis on center line.

No, I am referring to starting the side slip at some point well prior to touchdown, like 300' or higher. It is recommended to do it earlier to ensure you are stabilized with it prior to getting close to the ground, actually.

 

[CoffeeIcePapers]

No, I am referring to starting the side slip at some point well prior to touchdown, like 300' or higher. It is recommended to do it earlier to ensure you are stabilized with it prior to getting close to the ground, actually.

Recommended by who? I have no knowledge of landing a large transport jet, so I am just speaking of my single engine knowledge, and either method is fine for landing.

I have no doubt that a 767 can be landed either way. At some point, they pretty much become the same type of landing. You are either going to slip it all the way down, or before you touchdown, but it will be slipped either way.

 

[seagull]

Recommended by who?

The manufacturers. Either way is "legal", but if you mess up when not following the manufacturer's recommendations, your time at that long table with a glass of water will be considerably less pleasant....

Destabilizing is a much greater issue for large aircraft, and they make recommendations based on flight test and what they consider to be safer for the "average" pilot. However, it is noteable that the autopilots in most of the newer aircraft also land it that way.

 

[derg]

Even in Boeing's Flight Crew Training Manual, you don't necessarily always want to decrab the aircraft in high crosswinds. I'd whip it out (OMG! ) but I'm too lazy to walk over to my flight kit and... wait... it's right here by the desk:

Sideslip only (zero crab) landings are not recommended in crosswinds in excess of 28 knots (757-200). The recommendation ensures adequate ground clearance and is based on maintaining adequate control margin...

767-200 - 767-400

...Sideslip only (zero crab) landings are not recommended in crosswinds in excess of 26 knots. This recommendation ensures adequate ground clearance and is based on maintaining adequate control margin..."