crank
Posts: 1524
Joined: Tue May 22, 2001 11:42 pm

How Do You Land An A/C With A Crosswind?

Tue Aug 21, 2001 4:13 pm

Hi,
I was wondering,
when an A/C lands with a crosswind, its a bit sideways, but how come is it going straight on the runway when it lands and not sideways Confused Confused Confused Confused
 
XFSUgimpLB41X
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Joined: Fri Aug 25, 2000 1:18 am

RE: How Do You Land An A/C With A Crosswind?

Tue Aug 21, 2001 4:30 pm

The basic technique is... dip the upwind wing into the wind, and apply the opposite rudder (i.e. if the wind is coming from your right, dip the right wing and apply the left rudder). This is because: with a wind the plane crabs into it like a weather vane, apply opposite rudder straightens the airplane up. The upwind wing brings a horizontal lift component into the mix which compensates for the wind trying to drift the airplane off course. This correction is usually applied, and should be applied, on very short final or just before flare.
Chicks dig winglets.
 
Guest

RE: How Do You Land An A/C With A Crosswind?

Wed Aug 22, 2001 12:51 am

Crank,

You really should be asking a CFI these type of questions. This is for your own good since many Airliners.net members are Flight Simulator 2000 pilots who don't know a rat's ass about real-world flying.
 
Klaus
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RE: How Do You Land An A/C With A Crosswind?

Wed Aug 22, 2001 1:04 am

I remember someone´s earlier post about the 747 having to land with level wings even under crosswind conditions due to limited engine ground clearance.

If that is true, how exactly does it work?
Are there specific modifications to the main landing gear so it adapts or at least withstands an angled touchdown?
How is the plane "straightened out" to the runway after that?
 
Guest

RE: How Do You Land An A/C With A Crosswind?

Fri Aug 24, 2001 1:50 am

From what I was taught in my flight-training, there are two types of technique for a crosswind landing. The one that was described in detail by the first response to this query is called a 'sideslip' maneuver which works nice with most general aviation aircraft, and for most commercial jets in situations of a light crosswind.

In a more severe crosswind, the bank angle of the plane may indeed become too steep for sufficient engine clearance. The effect is beautifully illustrated in the following pic:


Click for large version
Click here for full size photo!

Photo © Daryl Chapman



An expensive trip to the engine shop Big grin

The alternative is to use a 'crab angle' which means keeping the wings relatively level and 'yawing' the plane into the wind using the rudder. This keeps it on a straight course with the runway, though you are effectively doing your final approach pointed slightly sideways, and unless you are a B-52 bomber, your gear is probably not designed to cope with this. So....right before touchdown, you'll release that rudder pressure and add opposite rudder if required to line the plane up with the runway again. This approach in particular takes quite a bit of practice to get it right!! Landing her partially sideways leads to the following scenario:


Click for large version
Click here for full size photo!

Photo © Samuel lo



very annoyed passengers!!

Some years ago I was sitting in the tail of a QF B767-300 on landing in Perth, Western Australia which is notorious for strong crosswinds. Right before touchdown, the captain must have given an almighty kick on the right rudder, as for a moment my body became one with the cabin wall. Thunk!!!! Ouch!!

I fly mostly light aircraft and I prefer the sideslip maneuver whenever possible. It is a pretty stable approach where the maingear on the lower wing will touch down before the one on the other side. I don't like doing last minute adjustments too much, but for the lads who fly the heavy metal it's all in a day's work  Smile
 
Klaus
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Zbeeblebrox74

Fri Aug 24, 2001 9:07 am

Thanks for the explanations. Interesting.  Smile

I sorta remembered the pictures you quoted.  Wink/being sarcastic

But there was a text somwhere that talked about the 747 being special in that way that it was constructed for better performance at "crabbed" landings. So I wondered what these might be...  Smile
 
b767-400er
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RE: How Do You Land An A/C With A Crosswind?

Fri Aug 24, 2001 9:27 am

According to earlier discussion on this forum, Both 747 and 777(not sure about 767) has the ability to sustain up to 45 degrees of crab landing with no damage to the gear assembly itself.

Check out these links:

http://www.airliners.net/discussions/tech_ops/read.main/8540/4/

http://www.aviationpics.de/app/app.htm

Also, more info when you search "crab angle", make sure you select it to list all posts, not just last 2 weeks.

Tony,
B767-400er
 
Guest

B767-400er

Fri Aug 24, 2001 6:00 pm

Hey Tony!

WOW! Those were some good sequences of pics. I've seen some of these pics individually on airliners.net, but never in their proper sequence. Tells a lot about the unbelievably robust construction of the 747.

Just wondering about the comments from the MAS captain who thought he'd carried out a 'reasonably normal landing' (I do suppose that any landing you can walk away from is a good one!). Where did he go to flight school?? That thing was rolling all over the place Big grin (no critique to MAS though, I've had some very pleasant flights with them  Smile )
 
Klaus
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RE: How Do You Land An A/C With A Crosswind?

Fri Aug 24, 2001 6:59 pm

Thank you both for the info.

It seems its all down to a strengthened MLG.
For the A380 there was mention of one of the bogeys being (partially) steerable; But that was probably thought for tight taxiway turns.
 
XFSUgimpLB41X
Posts: 3961
Joined: Fri Aug 25, 2000 1:18 am

RE: How Do You Land An A/C With A Crosswind?

Fri Aug 24, 2001 11:58 pm

THe 747 and 777 also have steerable main gear... but that is not for crosswind stuff like the B-52... that is jsut for making tight turns.

My explaination was for aircraft that dont have the wing dip restriction in effect, btw.
Chicks dig winglets.
 
musang
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RE: How Do You Land An A/C With A Crosswind?

Sat Aug 25, 2001 12:27 am

On the B-52 a gear crab angle is calculated and dialled in from the flight deck.

Do any other aircraft have this capability?

Many large transports are routinely landed in x-winds with the logitudinal axis not aligned withe runway, i.e. crabbed, which they can of course withstand. Once in contact, they would be yawed around with rudder to maintain the centreline.

A variation on this is to aim the trajectory (not the nose) a little upwind of the centreline, and rudder it straight just before touchdown. It starts to drift downwind immediately of course, but will land in a second or two so won't drift far.

Bear in mind that in the wing down method, the "cross-controls" you have in place to hold the slip must not be released on touchdown, but usually increased, as more control input is needed as the aircraft slows. One might reach the runway exit with full aileron deflection into wind and almost full rudder downwind, in strong x-winds.

A turboprop may require aileron inputs identical to those used on light aircraft in strong winds, even while taxiing under nosewheel steering.

Regards - Musang
 
flymia
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RE: How Do You Land An A/C With A Crosswind?

Wed Mar 30, 2005 12:55 pm

There are alot of videos of crosswind landings at flightlevel350.com
B767-400er has not posted in more than two years. This topic is from August 2001! What is wrong here. How did it let me respond to this topic?

[Edited 2005-03-30 05:03:45]
"It was just four of us on the flight deck, trying to do our job" (Captain Al Haynes)
 
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HAWK21M
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RE: How Do You Land An A/C With A Crosswind?

Wed Mar 30, 2005 8:29 pm

I've heard that [Maldives] Male Airport Runway is subjected to +20 kts crosswinds at all times.Is it true.
Any Experiences.
regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
AR1300
Posts: 1686
Joined: Mon Feb 07, 2005 1:22 pm

RE: How Do You Land An A/C With A Crosswind?

Thu Mar 31, 2005 2:29 am

Side wind wing down and opposite rudder.I remember my first crosswind landing.Helluva experience.

Mike
You are now free to move about the cabin
 
stealthpilot
Posts: 502
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RE: How Do You Land An A/C With A Crosswind?

Sat Apr 02, 2005 12:46 pm

Prob not true, heres the current METAR for MLE
METAR: 020100Z 29015KT 8000 FEW017TCU BKN130 29/25 Q1007

its morning there Mel ..... winds less than 15  Smile
-Nikhil
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