Jet Crosswind Landing Technique
 

Transitioning from Piston Engines to Jets,

On a Crosswind Landing we used the de-crab method and applied aileron into wind just prior touchdown on a piston-engine aircraft like a Cessna 172.

However in a Jet, The aileron into wind might cause a wing-tip strike and undesirable loss of lift due to spoiler deployment. Is it therefore advisable to land with a slight crab in a Jet in a strong cross wind condition? For Example in the A-320.

Cheers, Mav.

You will have an idea of the crosswind in the flare from the latest wind given to you, and the aparent drift. You should learn with a bit of experience roughly how much aileron to apply as you gently push off (not 'kick off'!) drift. There is no risk of touching a wingtip, you fly the plane rather than kick it off and hope for the best! Some types are encouraged to apply bank and sideslip. I have never applied or learnt this technique- I never needed it on the 747 and the 737 doesn't need it, though some seem to swear by it. I think it must be harder, flying a sideslip on short final. I am sure even a 757 will quite happily fly the crab technique.

Sometimes I think I must have missed something along the way ... provided that the crosswind is not excessive for the Type, the pilot is not ham-fisted, and the Type doesn't have some strange characteristic to preclude this, it seemed to me that it was a case of doing the same sort of thing regardless of power units on transport Types.

If the crosswind is excessive and there is no reasonable alternative in an emergency situation, then it is a matter of judging where you want the likely hurt to the aircraft to occur .... generally, the concern is the outboard flap or pod engine rather than wingtip for a slipping touchdown ... or the legs if you land with drift ... acknowledging that some Types appear to be quite happy landing with some drift still on. The AFM remains the pilot's reference on preferred technique.

Main thing is to fly the bird onto the ground and through the rollout until the wind has little capability to cause you angst .. very much a matter of the pilot having to call the shots .. else the bird certainly will have a penchant to bite you.

While others whose skills far exceed mine are able to pirouette in the flare, I was never comfortable with that on a sweptwing aircraft, far preferring to transition to a stable slip for the last 50-150 feet of the approach depending on the magnitude of the crosswind. Strangely, I was quite happy to do the ballet thing on lighties .. probably something to do with the difference in inertias ?

In general, I think it is a reasonable position to suggest that the straightwind piston aircraft can be transitioned from the approach drift angle a bit later than the swept wing jet.

Another thing to consider is that this Industry lives on OWT and crosswind landing techniques are not immune from that fact. The AFM, training guides, etc., form the guidance suite for the pilot.

One related OWT which caused me anxiety was the roll on landing technique beloved in some quarters of the Industry. My first jet (727-200) had this technique pushed hard by the particular operator ... after some considerable time spent semi-destroying the fleet .. I gave up and tried landing it like a 172 ... just about all of my problems disappeared overnight and I even started seeing a return to the greasers of prop days

... isn't this a wonderful Industry ... ?

The MOST important thing in a heavy jet is to have your velocity vector straight down the runway at touchdown. Then inertia will tend to keep you tracking straight as you use the controls to keep the wings level. The 747 will align itself on touchdown if landed in a crab. For a slip, the max bank angle before a pod strike is about 8 degrees, so any more than 5 deg of bank is asking for trouble.

I use a crab until just before the flare. Then I start feeding in rudder and aileron to reduce the crab angle at touchdown and "preprogram" the ailerons into the wind. After that, fly the airplane until it's stopped.

Me too.
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Follow the flight manual. In the 707, 757, 767, and 747, I align the nose of the aircraft with the runway crossing the overrun. Rudder as necesary to align the nose. Aileron as necessary to hold the wings level. The 747 may be landed in a crab on a wet runway, but I don't recommend it. It's just as easy to not abuse the airplane by putting unnecessary side loads on the land gear.

Same here (CRJ200). One factor we have is that the airplane will scream "Bank Angle" if banked more than 10deg in landing config, but rarely is that much bank needed.

I had the privilege of flying the Mighty Tri-Motor for a number of years and it was one of my all time favorite flying machines. It could, however, bite if one misjudged the flare. Over the years during the merger-mania and with various bankruptcies, I flew with a pilots who had flown the Seven-Two with other carriers prior to coming to 'my house'. The different techniques for landing were very interesting.

Some used the grand swoop where there was nothing until the last second and then it was a huge pull to arrest the descent and if it worked (for many it did), the result was an eye watering arrival but nice landing.

Others have perfected the gentle-push where they came into the flare and just before touchdown released back pressure on the yoke and some even pushed. Again, done right, it would squeeze the light out from under the tires.

Personally, I just tried to keep the picture the same and had a fair amount of success. I never dropped the masks however I did plunk a few on.

The ONE thing you didn't do in the 727 or the -80 was to try to arrest that sinking feeling was pull back and you certainly didn't do it in a bounce. One merely added a few fist fulls of power and kept adding power until it got stabilized.

As for crosswinds, the -320 commands a roll rate and not x amount of aileron. So, you can't cross control the -320 like other machines. It requires a deft foot to align in the flare and done right, no big deal. The -321 seemed the easiest of the bunch (319,320,321) to land.

As for the most difficult to land in a strong crosswind, that goes to my 1946 Swift. Every landing is a challenge....

Leave it to Lockheed to get it right...and easier
 

The Lockheed TriStar can be landed either way...

Sideslip, wing down
De-crab at the last moment, ala B707

In fact, the automatic approach/land accomplishes the landing using the wing down method...and quite precisely too, as any 'ole Lockheed tri-motor driver (including this one) will tell you.

In fact, some of the biggest laughs I've had is watching a new TriStar guy try the Boeing push...hmmm, sure is good that Lochkeed bolted the wings on reallytight at Palmdale...:D :E

Maybe too tight! I hear that a senior occifer in the RAF managed to put the gear through the wings on one.

Yes he did, but they thought they were doing an autoland:hmm:

John, I am interested to know exactly how you go about this! Thanks for any help.

Yes, I wondered if that term describes a technique I used to use on medium weight turbo props.
Using a wing down technique often needed a turn while on one wheel to align with the centerline. It sounds horrible, but was totally stable and rather dainty.

Some of the severe weather cross-wind landing on youtube had me on the edge of my seat. Into-wind wing high, while tracking down wind. Just a total @$^^ up from the onset.

I always made a point of knowing just how far I could roll/rotate/flare etc...event to the point of asking the guys in the tower to watch during training. What totally #@$ me off was the new world of SOPs telling me that I couldn't use a lower flap setting--when I had so much concrete that I could have built a small township beyond the touchdown point. Far greater bank potential, and much better ground handling in gusty conditions, but a rule that said that I could no longer do it.

It's a strange time this transition period -- between the old timers and the computer chips that will eventually do everything.

At the other end of the flight...
I am always frightened by colleagues who, at Vr, remove all crosswind inputs. Luckily enough, none have come to grief yet but it's painful feeling the aircraft begin to roll over about the downwind main wheel.
I've tried to explain how the inputs required to keep the aircraft straight down the runway are the same as the inputs required to keep it straight until the whole aircraft is completely airbourne. Once airbourne the controls can be returned to balanced flight and eureka! the aircraft has just applied exactly the wind correction angle it needs to track straight along the centreline.

This is what real pilots do.

I always employed the crab technique that gets squeezed out in the flare. As the crab gets squeezed out, some mild bank get's placed into the mix to control last second drift as the upwind main gear touches down followed by the downwind main gear and an active nosewheel fly down with increasing aileron input into the wind.

One true benefit of this teqnique is better recognition of changing conditions like windshear as the aircraft is flying "straight", aerodynamically speaking (normal thrust and control inputs all the way down to the flare). And for transition to larger equipment, no big jump in landing technique is needed.

I first started using it in my CE-402 days and it served me well in commuter, corporate and 727/737/MD-80 jets. It takes a small while to master the timing but it is a very effective technique used by most of the pilots I've flown with.

One potential disadvantage to using a basic sideslip technique in turbojet aircraft (besides striking a pod in a wing mounted airplane) is the potential to stall the inlet flow into the engines and create potential engine issues. You would have to be really agressive in sideslip to do this in modern aircraft but some crosswinds may require agressive corrections that may not feel aggressive to the flying pilot when in the heat of the battle.

The autoland programs I've seen (B-737 300/400/700/900 and MD-83) fly the aircraft in a manner that squeezes out the crab late in the round out and then uses a "modified and mild" slip technique for the last second or two. Essentially it looked a lot like a basic crab technique but autoland programs I personally have worked with also had lower crosswind limits available to cope with conditions we might see in a hand flown gusty landing when you can't sit out the mandatory portion of the flight.

What a thoroughly enjoyable and jolly thread - well written by everybody. Yet despite the cross-wind landing being one of the more tricky pieces of pure flying skill it is rare to find a simulator instructor who will devote time to allowing his brood to practice crosswind landings. I don't mean just one landing - but four five or six approaches from 1500 feet raw data and no automatics - dry and slippery runway

Very rare also, to see pilots practicing in the simulator the slippery runway crosswind landing where the aircraft starts to slide sideways under the influence of reverse thrust vector which drags the tail around, necessitating swift reversion to reverse idle, rudder and judicious use of brakes then back to application of full reverse when straight down the centreline. Phew!...I sweated that landing....

In order to simulate this it is sometimes necessary to whack in a strong crosswind of 30 knots plus in order to get the aircraft sliding sideways on the simulated slippery runway.

Of course one could argue one would not normally accept such strong crosswinds on slippery runways in real life so what is the point of practicing to such extremes in the simulator. And that is true. But if the aircraft manufacturer's have determined that sideways vector of reverse thrust has in the past caused a directional problem on slippery runways, and thus the technique is worthy of publication in the FCTM, then it is surely wise to observe this phenomenom and to practice counter measures - and what safer place than in the simulator? Beats the hell out of LOFT's on full automatics in real time A to B.:D

Mmmm...hopping island to island -- with the weather closing at each approach comes to mind. Running on vapor, the only viable runway has 45 kts x-wind in rain. Now it's time for some handling practice.

It does happen. Maybe only once a year where I live, but once is enough.

anhedral??
 

i've seen some russian built aircraft with some extreme anhedral which must force them to use the last minute de-crab in a strong crosswind landing.

just sitting on the ramp, the wing tips are close to the ground. perhaps they bend a lot with lift on them.

and while i'm here anyone know the advantages/disadvantages of the dihedral/anhedral choice. it appears all western countries favour the dihedral, but there had to be a reason for the russians to use anhedral other than a simple desire to be different. and considering the proximity to the ground, those advantages must be significant.

Don’t forget that once on the runway the object is to stay on it. This usually means applying more rudder as speed reduces; in some types this then requires compensating roll control. There are few aircraft which require immediate use of nosewheel steering. I have seen pilots rush for the NWS, disregarding the effectiveness of aerodynamic controls which results in a short term loss of control. We must not forget that the aircraft is still aerodynamically capable immediately after touchdown and that any wind gust can overpower NWS, thus continue to fly the aircraft when on the runway.

I found some interesting observations and recommendation on crosswind from a safety report in support of ALAR:

.. John, I am interested to know exactly how you go about this! Thanks for any help ..

Fireflybob .. not entirely sure to what your question refers .. ?

Acknowledging the vast number of pilots with manipulative skills superior to mine and emphasising that the AFM/FCM/etc guidance is persuasive ..

.. the points which appeared important to me ..

(a) 727/737 (which were the toys with which I was permitted to play) were not comfortable aligning with the runway during the flare (.. crosswinds to around 10 kt were not a problem) .. SuperCub, at the other extreme, one could do anything with .. horses for courses, perhaps ?

(b) one needed to know what bank angles were acceptable cf the wind conditions of the day .. as it turned out I was never put in the position of having a silly situation arise .. max crosswind I can recall in airline operations was around 30-35 kts or so and that never presented any major problems.

(c) I aligned the aircraft with centreline around 50-100 ft for moderate crosswind .. increasing to 100-200 ft (or higher) for strong winds. My aim was to have the aircraft very much under tracking control prior to entering the flare. An uncomfortable feeling with the slipping approach but it worked fine. One point which appeared to catch some folk .. one needed to ease the body angle up a degree or two to allow for the bank during the final part of the approach into the flare .. lest the wee beastie fall from the heavens and smite itself upon the runway. Then it was just a matter of modulating the controls to keep the fuse pointing down the centreline and the aircraft locked to the desired approach angle .. and then likewise fly the craft onto and along the runway until the wind ceased to be a problem. On a few occasions the palms of the hands became a tad humid but that is part and parcel of the game in my view ..

I have a feeling that many pilots are a bit "uncomfortable" in crosswind conditions .. I had the benefit of flying quite a few hundred hours (SuperCub, Callair, and Pawnee) in glider towing ops as a youngster and having to cope with plenty of limiting (and worse) crosswinds on landing following launch (with a glider glued to the tail .. which kept the tug straight). More than once did we chaps have to put the bird down obliquely (or such) to the strip ..

If the conditions are outside the box ...

(a) go someplace else

(b) if (a) is not available, then the situation becomes an emergency. Faced with this, I suspect my technique (considering AFM/FCM guidance) would be

(i) flare normally but minimally

(ii) roll the nose down and bank off simultaneously as the aircraft comes onto the ground to minimise time in the flare and risk of flap/pod strike .. also minimises time available for the wind to get the aircraft moving downwind

(iii) anticipate very sweaty palms ...

John, many thanks for your excellent advice!