Drop a wing or crab

[Admin]

When coming in on final with a bit of crosswind we have two options - to either keep the aircraft straight by dropping a wing or to crab her in. The technique we individually use I think...could be related to the way we are taught i.e. our instructors preference, but what are the pros and cons of either technique?

 

I mean we have seen a lot of landing videos and we see some dropping a wing and landing on one wheel and then we see some crabbing in and then kinking her around to land straight. Is your decision at the time dependent on aircraft type or the wind condition at the time?

 

 

[shafs64]

My instructor taught me the crab. i have not done the drop a wing yet.

 

Paul

 

 

[Matt]

I've never thought much about it until you asked the question, but recalling from experience I've tended to wing down in a high wing aircraft and crab in a low wing aircraft...no idea why, just seems to be what works for me.

 

 

[farri]

Hi Ian,

 

The objective is, we need to hold off Drift.

 

I would say that the method used should be relative to the conditions at the time and the type of aircraft being flown,again the objective is to get on the ground saftely,pilot prefference.

 

farri.

 

 

[Guest brentc]

This one usually raises a bit of a debate.

 

You'll likely find that a combination of both is often required, particularly in higher winds as the rudder for example in strong winds won't have enough effect on certain aircraft.

 

As for which one happens first, the rudder or wing, that's the pilots preference and the end result should be the same.

 

 

[hihosland]

Using either technique during approach at the point of touchdown the upwind wing needs to be down to stop the wind getting under it.

 

.

 

What I aim for is to crab to round out then rudder it aligned with the runway and at the same time plant the up wind wheel.

 

Davidh

 

 

[poteroo]

Considering that crosswind handling is the weakest link in the BFR's that I've done over many years in GA, this should be an interesting thread.

 

I was never able to handle crosswinds as a PPL because I learnt at Archerfield when it was an allover grass paddock in 62/63. We just followed the wind around - too easy!! Twas only later that I learned off my charter Chief Pilots and peers.

 

For the record, I use a crabbed approach and roundout,yawing the aircraft straight, then lowering the upwind wing sufficient to hold it down....landing on the upwind wheel first....then increasing aileron input to keep the upwind wing from lifting. Less flap and more power enables you to counter stronger crosswinds.

 

cheers,

 

 

[Guest pelorus32]

I think the important point here is that at the point of touchdown the aircraft needs to be moving straight down the runway - neither crabbed nor drifting sideways. On a B744 or something you will get away with landing crabbed - in fact I understand that they pretty well straighten themselves out if you touch down crabbed. If we did that we'd either head from the scrub or drag a tyre off a rim.

 

That all means timing for me. I prefer to come down final crabbed and to hold that crab right up to the point of flair. Then I kick straight, lower the upwind wing and expect to touch down right then. I like the aircraft to be pretty well finished flying when I get myself aligned with the wing down so that the flair is a short process with positive touchdown. I don't like long floats. My daughter, who sets herself high standards for gentle touchdowns, thinks that my crosswind touchdowns are too abrupt!

 

I feel that the crab down final is a very stable process where alignment and speed control are easily managed. It just suits me better than a slip.

 

Regards

 

Mike

 

 

[farri]

This one usually raises a bit of a debate.You'll likely find that a combination of both is often required, particularly in higher winds as the rudder for example in strong winds won't have enough effect on certain aircraft.

 

As for which one happens first, the rudder or wing, that's the pilots preference and the end result should be the same.

Brentc,

 

Absolutely.

 

farri.

 

 

[Guest Juliette Lima]

Hi All,

 

One of the most comprehensive and informative books on flying technique I have ever read is 'Takeoffs and Landings' by Leighton Collins ....available from Sporty's USA.

 

Apart from detailed analysis of all of the above options, pros and cons etc. Collins talks about a crosswind landing method used by the oldtimers in a section of his book headed 'Throw the Crosswind a curve' . Basically,final is made at an angle (10-20 degrees) into the crosswind, downwind of the strip with a heading on the opposite side of the strip some 150 metres ahead.....crossing the downwind side of the runway, he'd flair, stick back, and conmmence a curved landing roll gradually to runway heading.

 

I can hear the cries of dissent now....but for my high drag aircraft it works beautifully.....as does his other option of taking off in crosswinds, namely, commencing the takeoff roll on the downwind edge of the runway with a heading 150 metres to the topside of the runway....thus more into wind, and gradually curve to runway heading.

 

Apart from this little gem, the book is simply brilliant and a must for those safety inclined 'still learning' pilots like me.

 

Cheers

 

JL

 

 

[Guest TOSGcentral]

The basic controlling factor should be aircraft design. You may HAVE to crab low wing aircraft, especially those with longer wing spans, as you may not be able to get the wing down far enough in some conditions without risking grounding the wing tip.

 

 

Another point made in a post above is rudder power. The aircraft has a stated cross wind component limit in the POH and has been demonstrated. If you are operating within the cross wind limits of the aircraft then you will have sufficient rudder power. However these parameters were set via physical demonstration by a test pilot – so pilot proficiency in everyday circumstances may become an issue.

 

 

In training I far prefer the wing down method. Everything stays lined up and does not interfere with glide slope and directional control so is easier for the student to come to grips with and get more valid stick time in conditions that are marginal for their current ability level.

 

 

In strong cross winds (maybe when you are forced to land outside normal limit as you have no option). With the wing down technique you do everything as normal but do it with a wing down and on one wheel. This can tame something even as savage as a Thruster and make it relatively easy.

 

 

In comparison the crab technique is fine and easy – until you get to the kicking off drift bit! The timing has to be exact or you will land somewhat sideways. Meantime a big boot full of rudder enthusiastically induces secondary effect of rudder that has you rolling away from the wind and encourages you to use a big handful of aileron and aileron drag then yaws you away from what you want to happen and you are very keen to have both the nose and direction of travel going in a less than heart pumping direction!

 

 

While this is going on you are still attempting to do a basic landing and all that entails (a bit of a balloon in the middle of all this is wonderful fun – very stimulating) that I am sure students reading this will agree can be taxing enough!

 

 

Just some thoughts

 

 

Tony

 

 

[antzx6r]

I think a lot of instructors seem to teach the crap approach hence most newer flyers crab without thinking too much of it. (ie is there any other way) On thinking about it tho, it stands to reason that you would want to fly in balance for as long as possible. For comfort as well as performance. And as mentioned earlier, its a little easier to line up and get the approach line consistant in a crab. adjust power as necessary and kick a little rudder in if you're high. The only reason I can think of that you might slip in from higher on final is if you're not sure about how much crosswind you have to deal with and if your rig can take it.

 

Is there more to it, am I missing any advantages of a slip approach? Other than wanting to lose height in the approach...

 

Ant.

 

 

[Guest TOSGcentral]

Good one JL - I taught the 'diagonal landing' as a matter of course and it is a most worthwhile option if you have the space.

 

At Watts we have a runway and taxiways 130 metres wide and you can roll from one to the other so you have a huge dimension of angle which takes a lot of sting out of beyond the limit cross winds. This has enabled me to get down without drama after returning from cross country and finding the situation had changed somewhat from what was confidently forecast by the met office!

 

Using the diagonal landing also has the psychological advantage of breaking the mind set that everything has to be in neat 'squares' relative to the ground - when the reality is that you can use available space to your advantage.

 

Another good hint that I taught standard was using the wind to compensate against engine effects. When faced with a 90 degree cross wind you have an equal choice of landing directions on a single strip airfield.

 

If your aircraft (for example) will naturally swing left on landing then land with the wind on your right and the weathercock stability of the cross wind will take the sting out of the natural swing tendency

 

Tony

 

 

[skybum]

Good thread. From my limited exerience, was taught to crab or lay off on finals and at the point of flare cross control to upwind wing down. Now this little maneuver caused me some consternation and my attemt to get into the upwind wing down position at late finals at about 100ft , so I could get this sucker worked out. rudder to keep the aeroplane aligned with the strip and aileron to keep tracking for the runway, taught me a very real lesson about sideslipping close to the ground. You see, that is what we do when we go upwind wing down. We enter a sideslip. My beautifully crafted approach literally fell apart, increased rate of descent made me undershoot that quick it caught me out....lesson learned. Now, even after many years away from it, the action is mechanical. lay off drift then cross control to align with the runway. You know you have got it when you start co-ordinating smoothly to adjust for gusty conditions. It is truely one of those alien moments when you start to learn it!

 

As for landing the big machines, understand that there is very little clearance to the bottom of outboard engine nacelles to the ground in 747s and the like to cross control into wind. The method apears to be a rudder kick at exactly the right time to result in a touchdown, wings level before the cross wind starts moving you sideways again.

 

 

[Guest TOSGcentral]

Antzx6r. You have not quite got the reasoning correct mate.

 

There is a difference between a crab approach, a wing down approach and a side slip approach.

 

This is basically in a scenario where the cross wind is coming from the right, in the crab the nose will be pointing to the right of direction of ground track. In a sideslip the nose will be pointing to the left of direction of ground travel.

 

In the wing down techniques (while you are basically side slipping, but this is quite a mild slip as opposed to a deliberate slip to lose height) the nose is held firmly on the runway centre line and bank is used to counter drift. That is what makes it so easy.

 

I disagree with you that it is easier to establish direction of travel in either the side slip or the crab (and especially if you have an aircraft with parallax challenges) as compared with keeping the nose on the extended runway centre line

 

Tony

 

 

[Yenn]

The common situation with a lot of pilots is to carry a bit more speed in crosswind situations, that is going to make either method harder to handle. If you get the speed right down and are a few inches off the runway so you stall it on you will have good tyre contact whichever method you use. In my case I seem to use a bit of both but drop it on firmly.

 

 

[antzx6r]

Tony,

 

I see what you mean about the ease factor of the wing down approach. In my crosswind stage of training I was getting quite frustrated with the crab approach. I couldn't get my head around the hold off, rudder, aileron, power off, wing down, all at seemingly the same time. I asked my instructor if there was anything wrong with lining up the runway with rudder earlier on finals just because it seemed too much to deal with. Little did I know I was instingtively wanting to use a wing down approach. I nailed it in the end tho. I might play around a bit with wing down the next windy day and think more about personal preference rather than my instructors. (Love these forums!)

 

Ant

 

 

[Guest J430]

I fly the crab approach, but do not kick a boot full of rudder in during the flair. I use rudder input and wings level as I round out and then flair normally while I now have the a/c under control.

 

As the airspeed decays, adding more and more input in all 3 fight controls.

 

Now having said that.........thats how it is meant to happen, can't say I get it all perfectly sorted more than 3 or 4 times out of 10:blush:

 

J

 

 

[Guest J430]

Pelorus32

 

As for a B744.....45 knots of x-wind, crab it in, bit of rudder to help her square up, the u/c takes a pounding.

 

Most typical x-winds they just crab it on the undercarriage is designed to take it.

 

No wing dropping.......pod strikes are not appreciated!:hittinghead:

 

 

[Ultralights]

i vary my method depending on wind strength, 0 to 5 kts cross. then crab in and kick it straight, anything over, ill use the wing down method. and there is a lot more satisfaction in nailing a smooth landing with 15 kts crosswind, and feeling the upwind wheel touch first, followed a few seconds later by the downwind wheel, and letting the nose settle on the centerline....

 

 

[Flyer]

I had to think about this for a minute. I use the crab approach method and just before flare I swing the aircraft straight with the rudder and stop it sliding across the runway with wing down.

 

I can and have used the wing down method the whole way down final but find that it a bit more difficult to co ordinate.

 

A side slip is more uncomfortable on the passengers....

 

Regards

 

Phil

 

 

[Guest Teenie2]

I do a bit of both, crab and wing low at the same time.If you just crab in until the flare then kick her straight and lower the wing,there is sometimes a large amount of yaw just at a fairly important phase of flight.Wing low the whole way down feels horrible,and takes a lot of effort to get the correct approach angle.So I do both at the same time,slight wing low and slight crab.Try it next time you are landing in a cross wind.

 

 

[icebob]

Hi Guys,

 

i use the crab method, slightly higher approach speed, no flaps and on landing,wind side aileron fully up all the way to engine shut down.

 

Bob.

 

 

[spacesage]

I was taught the wing-down method from the very beginning. I was even criticized for using it by one of my later instructors. I think it comes down to the type of aircraft and the robustness of the u\c.

 

The wing down method uses ailerons which keeps this control in mind for the post-landing roll out. Bearing in mind the need to compensate for crosswind during the rollout with ailerons.

 

I have flown predominantly at airfields where there is always a x-wind component. I have always found this method, although more technically demanding to be the most effective and smoothest.

 

p.s. I always refered to these methods as "wing Down" and "Kick Straight"