Side load and drift.

[Flyxaos]

Hi,

I'm curious as to ideas on how to keep the silly airplane straight down the center line. Not in flight but At and After touch down..?

I did a flight review the other day with landings in a pretty direct 10 knot crosswind. I did ok with the wind but I want great, not ok. All is well on approach, nose and aircraft allinged with center, but after touchdown right as it starts to slow and settle the airplane seems to want to get blown across the runway. As with any landing if you have to think of what to do, you are too late. The instructor (young, not that there is wrong with that )was very good at book learning but for that he just said 'Keep it on the center line'. I don't think he knew really what to do to control the airplane.

So, what do you do to not sideload the gear and how do you stop the drift?

 

[Tools]

Can you keep it straight down the runway during takeoff? You know, full crosswind controls modulated to less as they become effective and you use only what you need…

Reverse engineer that.

Best efficiency in learning comes from bracketing. Over do the crosswind controls on the landing. Hold them in AT TOUCHDOWN and add more as you slow down.

 

[Domenick]

You prevent side by using proper crosswind technique.
Maintain your rudder crosswind controls through the rollout. If you are tracking the center line on touchdown, there won't be much side load.

Consider practicing two crosswind landing techniques and choosing the one that works best for you.
1. More or less a stabilized approach where crosswind control corrections are set and maintained throughout final and landing.
2. Kick out the crab. Crab in on short final tracking the center line and kick out the crab just before or as you round out, that is, before the flare. Maintain the corrections throughout the rollout.

 

[schmookeeg]

I find it common lately that pilots are afraid to use full aileron close to the ground for fear of a wingtip strike.

 

[Stewartb]

Rudder steers the plane on the ground. Dragging a little brake is required if the winds are strong enough.

 

[Clip4]

Hi,

I'm curious as to ideas on how to keep the silly airplane straight down the center line. Not in flight but At and After touch down..?

I did a flight review the other day with landings in a pretty direct 10 knot crosswind. I did ok with the wind but I want great, not ok. All is well on approach, nose and aircraft allinged with center, but after touchdown right as it starts to slow and settle the airplane seems to want to get blown across the runway. As with any landing if you have to think of what to do, you are too late. The instructor (young, not that there is wrong with that )was very good at book learning but for that he just said 'Keep it on the center line'. I don't think he knew really what to do to control the airplane.

So, what do you do to not sideload the gear and how do you stop the drift?

The most common x wind landing error I see is the pilot removing the side slip just before touch down. 2nd most common is not increasing the side slip as the plane continues to slow just before touch down.

You should be landing on one wheel with the aileron and rudder still deflected after touch down.

 

[robin ardoin]

Don’t stop flying the plane until you come to a stop.

 

[dmspilot]

after touchdown right as it starts to slow and settle the airplane seems to want to get blown across the runway.

You're not holding the aileron into the wind.

So, what do you do to not sideload the gear and how do you stop the drift?

To not sideload the gear, the airplane has to be moving in the direction it is pointed when it touches down. You do that by aligning the longitudinal axis parallel to the centerline with rudder, and preventing drift. You stop the drift by banking into the wind. If you drift downwind, increase bank. If you drift upwind, decrease the bank. Almost continuous adjustments will be needed.

 

[Dan Thomas]

Adding aileron will not stop drift if both mains are on the ground. You will need a bit of crab to stop it, and the tires will scuff some. The aileron deflection should be increased as the airplane slows, to keep that upwind wing from lifting, not to stop drift across the runway. With no bank, there is no angled lift vector to prevent drift.

 

[dmspilot]

Adding aileron will not stop drift if both mains are on the ground. You will need a bit of crab to stop it, and the tires will scuff some. The aileron deflection should be increased as the airplane slows, to keep that upwind wing from lifting, not to stop drift across the runway. With no bank, there is no angled lift vector to prevent drift.

The ailerons still have an aerodynamic effect on the ground, even though it would not be properly called "lift".

I don't understand why you're trying to make a distinction, you are saying the ailerons won't prevent drift on the ground, then say the point is to prevent the upwind wing from lifting. But that's exactly what causes drift after landing.

The only reason to write what you did would be if you were referring to a slippery runway, but you didn't say you were and there is no reason to expect that a student pilot learning to land in the summer is practicing on a runway covered in ice, snow, or slush.

 

[Clip4]

Adding aileron will not stop drift if both mains are on the ground. You will need a bit of crab to stop it, and the tires will scuff some. The aileron deflection should be increased as the airplane slows, to keep that upwind wing from lifting, not to stop drift across the runway. With no bank, there is no angled lift vector to prevent drift.

If the plane is in a crab, the Longitudinal Axis of the plane is not aligned with direction of travel. This is the also the condition called side loading during landing.

The Longitudinal Axis of the aircraft should be aligned with the direction of travel at and after touch down of the plane. Directional control immediately after touch down is maintained primarily with rudder and secondarily with steerable nose wheel in most tricycle gear aircraft. A properly performed cross wind landing does require any crab shortly before or after touch down and does not scuff the tires from being in a crab.

 

[PaulS]

When I was having trouble with this a long time ago, I found I was decreasing aileron on flare, the exact wrong thing to do. As you slow you need more aileron and you need to keep it in until touch down. Once firmly on the ground I just go to full aileron. You should be slow enough that the wing won't lift. If it does, just back off enough so it does not become too much. Hold full aileron until you turn off the runway, then use proper input. Once on the ground the rudder is main control to keep you on centerline. Full aileron into the wind makes the rudder work much better, minimizes weathervaning and keeps you in control.

 

[Stewartb]

Makes the rudder work better? How’s that?

All I fly is taildraggers. The crossing winds I’m used to are gusty and/or rolling over tall trees. My normal strip is very narrow, like 8’ wider than my gear. When new guys use that strip in wind they make a very common error. They use less flaps and too much speed, because that’s what new pilots are taught. I use full flaps to fly the final leg steeper and slower and the wind is much easier to manage, and the slower speed touch down makes the roll-out short. I also dump flaps at the moment the tires touch to kill lift so I can get on the brakes. This technique works at big, wide airports, too.

 

[Clip4]

I don't understand why you're trying to make a distinction, you are saying the ailerons won't prevent drift on the ground, then say the point is to prevent the upwind wing from lifting. But that's exactly what causes drift after landing.

The only reason to write what you did would be if you were referring to a slippery runway, but you didn't say you were and there is no reason to expect that a student pilot learning to land in the summer is practicing on a runway covered in ice, snow, or slush.

Actually it is lift because the down aileron on downwind wing is increasing lift causing a rotational force on the Longitudinal Axis and providing a downward force on the upwind wheel.

 

[Stewartb]

What??? If the pilot is heavy and the passenger light does that make the plane turn to the left? Mine doesn’t. Weight on the wheel? Only on the internet.

 

[flyingron]

The ailerons still have an aerodynamic effect on the ground, even though it would not be properly called "lift".

Eh? The wings are still producing lift even if it's not enough to lift the plane. This is why you need to weigh the plane indoors (or at least on a calm day). In fact, you probably aren't even stalled if the wheels are on the ground.

 

[PaulS]

Makes the rudder work better? How’s that?

All I fly is taildraggers. The crossing winds I’m used to are gusty and/or rolling over tall trees. My normal strip is very narrow, like 8’ wider than my gear. When new guys use that strip in wind they make a very common error. They use too much speed. Fly the final leg steeper and slower and the wind is easier to manage, and the slower speed touch down make the roll-out short. I also dump flaps at the moment the tires touch so I can get on the brakes. This technique works at big, wide airports, too.

The rudder part is talking about on the ground while rolling, not in the air. Aileron input helps keep the airplane from weathervaning into the wind. Very effective in the airplanes I fly, (Cirrus, castoring nosewheel). Not having to use the rudder to counter weathervaning makes it easier to make the airplane turn when and where you want rather than struggling to keep it straight. I'm surprised you don't use aileron input while taxiing in a taildragger.

 

[Clip4]

Makes the rudder work better? How’s that?

All I fly is taildraggers. The crossing winds I’m used to are gusty and/or rolling over tall trees. My normal strip is very narrow, like 8’ wider than my gear. When new guys use that strip in wind they make a very common error. They use too much speed. Fly the final leg steeper and slower and the wind is easier to manage, and the slower speed touch down make the roll-out short. I also dump flaps at the moment the tires touch so I can get on the brakes. This technique works at big, wide airports, too.

Maybe for gusty winds the “new guys” are using FAA guidance.

“For landing in turbulent conditions, the pilot should use a power-on approach at an airspeed slightly above the normal approach speed. This provides for more positive control of the airplane when strong horizontal wind gusts, or up and down drafts, are experienced. Like other power-on approaches, a coordinated combination of both pitch and power adjustments is usually required. The proper approach attitude and airspeed require a minimum round out and should result in little or no floating during the landing.

To maintain control during an approach in turbulent air with gusty crosswind, the pilot should use partial wing flaps. With less than full flaps, the airplane is in a higher pitch attitude. Thus, it requires less of a pitch change to establish the landing attitude and touchdown at a higher airspeed to ensure more positive control.

Pilots often use the normal approach speed plus one-half of the wind gust factors in turbulent conditions. If the normal speed is 70 knots, and the wind gusts are 15 knots, an increase of airspeed to 77 knots is appropriate. In any case, the airspeed and the flap setting should conform to airplane manufacturer's recommendations in the AFM/POH.”

I do fully agree with your steeper approach.

 

[Stewartb]

the reason ailerons are deflected is to prevent the upwind wing from lifting when wind speed produces lift. Without that all they’re adding on roll-out is drag, and deflection up or down wouldn’t matter.

In my planes in flight at MCA I use rudder to lift a wing. Aileron use will promote a stall. I use aileron for ground ops into and with the wind for the reason described above. I steer with rudder and if necessary, brakes.

 

[Clip4]

The rudder part is talking about on the ground while rolling, not in the air. Aileron input helps keep the airplane from weathervaning into the wind. Very effective in the airplanes I fly, (Cirrus, castoring nosewheel). Not having to use the rudder to counter weathervaning makes it easier to make the airplane turn when and where you want rather than struggling to keep it straight. I'm surprised you don't use aileron input while taxiing in a taildragger.

Aileron does not prevent weathervaning even in a Cirrus. Weathervaning is rotation on the vertical axis and the ailerons do not control yaw.

 

[PaulS]

Aileron does not prevent weathervaning even in a Cirrus. Weathervaning is rotation on the vertical axis and the ailerons do not control yaw.

Ah, ok. A lot of Cirrus landing accidents are in crosswinds departing the runway, most likely from improper controls after landing. What do yo propose?

 

[RoscoeT]

Aileron does not prevent weathervaning even in a Cirrus. Weathervaning is rotation on the vertical axis and the ailerons do not control yaw.

Yep, they help slightly in taildraggers when rolling in a 3pt attitude due to AOA and adverse yaw but not so much in the level attitude of trikes.

 

[Stewartb]

At critical AOA the rudder is what saves us from loss of control, not aileron. In fact aileron increases the stall and wing drop potential. I’ve never flown a Cirrus but I suspect the same rule applies.

 

[Capt. Geoffrey Thorpe]

All I fly is taildraggers. [...] I can get on the brakes.

OMG! YOU ARE GOING TO DIE! DON'T YOU KNOW THAT THE INTERNET EXPERTS SAY TO NEVER USE THE BRAKES ON A TAILDRAGGER????????
(the "experts" say a lot of strange things...)
(My Matco's aren't strong enough to put it over on the nose, so I STAND on them when doing stop and go's )


But, as far as not being on the centerline is concerned, I consider it a public service to distribute the wear evenly across the whole width of a runway. (also )

 

[Clip4]

Ah, ok. A lot of Cirrus landing accidents are in crosswinds departing the runway, most likely from improper controls after landing. What do yo propose?

1st, use some risk management. Obtain and maintain proficiency with crosswind landings in make and model, set a personal maximum for xwind component and a personal minimum for runway width (75 ft) would eliminate most those accidents.

Personally my technique after touch down in a Cirrus is to stay off the brakes and use aerodynamic braking to slow the plane while maintaining direction control with rudder until the airplane has slowed a lot.

If you are flying a G2 with the aileron rudder interconnect, I suspect aileron may be luring you into improper use of rudder during landings.

 

[midlifeflyer]

The Number 1 crosswind landing error I see - regardless of type or general crab-kick or slip technique preference - is neutralizing ailerons at touchdown and not transitioning from crosswind landing to crosswind taxi by going to full deflection. It's as if they think crosswind taxi technique doesn't apply on the runway.

 

[midlifeflyer]

If you are flying a G2 with the aileron rudder interconnect, I suspect aileron may be luring you into improper use of rudder during landings.

You are probably right. My first crosswind landing with interconnected rudder was during a Bonanza checkout and it surprised the heck out of me. I had my instructor complete the landing.

 

[Stewartb]

Cessnas and Cubs have rudder assist, too. Not a problem for anyone of average size and strength.

 

[dmspilot]

Actually it is lift because the down aileron on downwind wing is increasing lift causing a rotational force on the Longitudinal Axis and providing a downward force on the upwind wheel.

Agree...normally Dan Thomas is a beacon of wisdom but he isn't making sense this time.

The Number 1 crosswind landing error I see - regardless of type or general crab-kick or slip technique preference - is neutralizing ailerons at touchdown and not transitioning from crosswind landing to crosswind taxi by going to full deflection. It's as if they think crosswind taxi technique doesn't apply on the runway.

Agree.

 

[RyanShort1]

Hi,

I'm curious as to ideas on how to keep the silly airplane straight down the center line. Not in flight but At and After touch down..?

I did a flight review the other day with landings in a pretty direct 10 knot crosswind. I did ok with the wind but I want great, not ok. All is well on approach, nose and aircraft allinged with center, but after touchdown right as it starts to slow and settle the airplane seems to want to get blown across the runway. As with any landing if you have to think of what to do, you are too late. The instructor (young, not that there is wrong with that )was very good at book learning but for that he just said 'Keep it on the center line'. I don't think he knew really what to do to control the airplane.

So, what do you do to not sideload the gear and how do you stop the drift?

Most of the previous advice in this thread is about control technique. If you were my student, we would go to the narrowest runway I could take you to and practice there for 10+ landings. Also, it sounds like maybe you don’t know what to look at. Usually looking at the centerline is unhelpful. You need to look at the end of the runway as far out as possible and use your peripheral vision to keep the plane in the middle. Let your eyes tell you where to take the plane with the controls, be smooth, and make small corrections.

 

[midlifeflyer]

Agree.

One of my great days as a CFI was when my very first student showed up one day and said, "I want you to see what I added to my checklist."

He added

Rollout...FULL CROSSWIND TAXI CORRECTION​

to his before landing checklist as a reminder.

It was after a lesson where we landed in a rear quartering crosswind. Light enough to be workable; strong enough to require the reversal of the controls.

 

[Stewartb]

Reversal of what controls? A crosswind drift is coming from the side whether biased toward nose or tail.

 

[PaulS]

1st, use some risk management. Obtain and maintain proficiency with crosswind landings in make and model, set a personal maximum for xwind component and a personal minimum for runway width (75 ft) would eliminate most those accidents.

Personally my technique after touch down in a Cirrus is to stay off the brakes and use aerodynamic braking to slow the plane while maintaining direction control with rudder until the airplane has slowed a lot.

If you are flying a G2 with the aileron rudder interconnect, I suspect aileron may be luring you into improper use of rudder during landings.

I’m proficient, and I’m telling you, if you land or take off in a Cirrus with no crosswind correction on a stiff crosswind day (let’s say above 10 knots), the nose will turn into the wind in the roll. Proper technique will take care of it. Above 15 the wing can lift if you leave the ailerons neutral. The interconnect has nothing to do with it. I’m flying g6 now, but it was the same with the trainers I used to fly.

 

[midlifeflyer]

Reversal of what controls? A crosswind drift is coming from the side whether biased toward nose or tail.

My post was talking about

Rollout...FULL CROSSWIND TAXI CORRECTION

IOW, transition to taxi (actually, the whole thread is about that). Yes, in the air, a wind from the right is going to require a crab or wing low to the right, whether front or back. But once on the ground slowing to taxi speed, what's the aileron correction for a rear quartering wind?

 

[bflynn]

Breaking it down mechanically.

Start with your feet and keep the nose straight down the runway. No matter what happens, keep the nose straight. It needs to be automatic to do this.

Next, use ailerons to counteract the drift and stay on the centerline. You will be flying in a forward slip. As you adjust ailerons, you’ll need to keep the nose straight by reflex.

Flare as normal, but realize the upwind main gear will touch down first. Don‘t try to force it down, just keep flying, the downwind main gear will settle soon. Be patient.

As speed slows, control surface effectiveness will decrease and you’ll need more input. Keep flying the airplane.

This is one place where it just takes skill and repetition to learn it.

 

[midlifeflyer]

Breaking it down mechanically.

Start with your feet and keep the nose straight down the runway. No matter what happens, keep the nose straight. It needs to be automatic to do this.

Next, use ailerons to counteract the drift and stay on the centerline. You will be flying in a forward slip. As you adjust ailerons, you’ll need to keep the nose straight by reflex.

Flare as normal, but realize the upwind main gear will touch down first. Don‘t try to force it down, just keep flying, the downwind main gear will settle soon. Be patient.

As speed slows, control surface effectiveness will decrease and you’ll need more input. Keep flying the airplane.

This is one place where it just takes skill and repetition to learn it.

Great explanation.

 

[RyanShort1]

Breaking it down mechanically.

Start with your feet and keep the nose straight down the runway. No matter what happens, keep the nose straight. It needs to be automatic to do this.

Next, use ailerons to counteract the drift and stay on the centerline. You will be flying in a forward slip. As you adjust ailerons, you’ll need to keep the nose straight by reflex.

Flare as normal, but realize the upwind main gear will touch down first. Don‘t try to force it down, just keep flying, the downwind main gear will settle soon. Be patient.

As speed slows, control surface effectiveness will decrease and you’ll need more input. Keep flying the airplane.

This is one place where it just takes skill and repetition to learn it.

All this is correct, but if you aren't looking where you need to look, you'll still mess up. By the time you are in the flare, you need to be looking at the end of the runway, eyes outside the cockpit if you want to keep 'er straight.

 

[Dan Thomas]

Agree...normally Dan Thomas is a beacon of wisdom but he isn't making sense this time.

So. On the highway, in your car in a high crosswind, where is your steering wheel? Is it in the usual position as when there is no wind? No. It is aimed a bit into the wind. That crosswind is pushing the car sideways, and if you just hold the wheel straight, you are in for an unpleasant excursion.

My first car was a Volkswagen Beetle. In a strong crosswind one day, I could hear the tires squealing as I fought the drift. When there was a gust, I'd have to steer more into the wind, and those tires would howl even more.

On the runway, where you cannot bank the airplane to angle the lift vector into the wind as you did in the slip on approach, your only control against drifting off the side of the runway is to steer a little bit into the wind (or let it weathercock a little). If there is another way, please show me, and show me the mechanics of it. Full aileron into the wind does not counter that drift. It cannot generate any side forces. The wind against the fuselage has the effect of pushing the airplane off the runway, and how else are you going to deal with it?

 

[Tools]

Devils advocate… adverse yaw? Ever try it in a champ? Classic, scoot down the runway on the mains, slowly put the ailerons left, you head right!

 

[Flyxaos]

OP here...

Thank you for all of your thoughts.

A couple takeaways for me.

I'm pretty sure I was relaxing the aileron correction after touchdown when it needs to be more of it as it slows.

Keep my eyes farther down the runway.

And I suspect that too much of the cross wind rudder was left in after the nose touched down. (Steerable nose wheel plane.) The dynamics of that are a bit confusing.

I just bought a tailwheel so I can't afford to make mistakes with that. I will get a lot of training before I want to be cut loose in that though.

Thank you!