azeem
Posts: 132
Joined: Mon Jul 03, 2000 8:17 pm

Crosswind Landings

Mon Jul 03, 2000 8:37 pm

Anyone of you know other method of performing crosswind landings. Other than 'crab-n-slip' method. PIA pilots use it.
 
J32driver
Posts: 385
Joined: Fri May 05, 2000 2:55 am

RE: Crosswind Landings

Tue Jul 04, 2000 4:57 am

Some airplanes are designed to be landed in a crab. I might be mistaken, but I think the main gear of a 737 can caster up to 10 degrees so it doesn't have to slip to land in a crosswind. Keeps it from smacking an engine pod on the runway. It also makes it taxi goofy and crooked.  
 
victech
Posts: 541
Joined: Sun Jun 11, 2000 9:46 am

RE: Crosswind Landings

Tue Jul 04, 2000 6:33 am

If I remember correctly, the Boeing 777 also has "crabbable" wheelsets - you certainly wouldn't want a GE90 smacking the ground...they might make you pay for it!
 
dnalor
Posts: 346
Joined: Fri Mar 10, 2000 7:58 pm

RE: Crosswind Landings

Tue Jul 04, 2000 4:26 pm

From quality information I have received here, I beleive the 777 has a steerable third axle to reduce drag when taxying thru tight turns, some better semi trailers here have the same deal when fitted with a triaxle down the rear.

Also thru here I have read that a 747 can land at 45 degrees to the runway, as it cant tip a wing into the wind very far b4 an engine strike happens.
 
cdfmxtech
Posts: 1319
Joined: Wed Jul 05, 2000 11:37 am

RE: Crosswind Landings

Tue Jul 18, 2000 8:19 pm

The B777 and B747 are the only two aircraft (I only work on Boeing) that I know are truly equipped crosswind landings because the each have Body gear (747), Main gear (777) steering actuators. The 777 even minimizes the amount of the slip duyring crosswind APP thru the AP.
 
Mriya225
Posts: 77
Joined: Wed Nov 30, 2011 10:43 pm

RE: Crosswind Landings

Fri Jul 21, 2000 7:50 am

Do you still have the option of slightly lowering your upwind wing and applying opposite rudder, so that you track straight down the runway? Theoretically, you should kiss the runway on the upwind wheels first, followed by the downwind wheels and nose. Would that work? Maybe you could even enhace your control with this kind of technique if you retracted your flaps on the kiss to really grab the runway. It seems logical enough - maybe some of you pilots out there can tell me if that would work or not.

     
 
dnalor
Posts: 346
Joined: Fri Mar 10, 2000 7:58 pm

RE: Mriay225

Fri Jul 21, 2000 4:46 pm

From what I have read the ability to lower a wing into the x wind on a 747 is quite limited, the forward energy will quickly line up the AC onto the runway heading.

As for quickly retracting the flaps, well most of the landing roll on large aircraft would be complete by the time that was done, thats the purpose of the spoilers that are able to be activated quickly and in alot of cases automatically on larger aircraft. Spoil lift and create drag, just watch a 737 squat down on it's gear when the spoilers deploy!

In light aircraft some pilots chose to quickly retract the flaps to decrease lift on touchdown as its just like a park brake lever, how ever this may not be a great idea on retractable landing gear AC's as you might grab the wrong lever! We are usually taught that cross wind landings should be definitely firm, well I was anyway, to avoid skidding sideways

Conversely some pilots at MTOW on Piper PA28's do the take off roll with no flap, accelerate to 66knots, then pull on one stage of flap b4 rotating this somewhat increases lift without the penalty of drag on the TO roll.

Hope this helps.

Cheers
 
dnalor
Posts: 346
Joined: Fri Mar 10, 2000 7:58 pm

RE: Crosswind Landings

Fri Jul 21, 2000 5:01 pm

Also in regard to earlier posts, I believe the 747's body gear steering is disabled during take off and landing as its merely for taxying, not sure about the 777's third axle though!
 
Mriya225
Posts: 77
Joined: Wed Nov 30, 2011 10:43 pm

RE: Crosswind Landings

Fri Jul 21, 2000 5:10 pm

Dnalor,
Thanks for your response, and yes, it does help. The more I thought about it, after I'd posted the message, it seemed a little too simplistic. The touchdown of a large jet happens so fast - and their landing support systems are so much more complex than that. But that prompts me to ask another question: is the spoiler deployment (like the brake actuators) on some sort of a squat switch also?

 
 
dnalor
Posts: 346
Joined: Fri Mar 10, 2000 7:58 pm

RE: Crosswind Landings

Fri Jul 21, 2000 5:39 pm

Mriya yes I believe if the spoilers are auto armed for landing they are activated by a combination of squat switches on the gear as well as safety features that override that, such as flap position and throttle position, a heavy jet pilot would have much more accurate info on this for us.

I didnt consider your question simplistic at all 
 
Guest

Mriya225

Sat Jul 22, 2000 6:43 am

The recommended crosswind landing technique on a L-1011 was the sideslidp method;you could track the runway better and the bank angle was -amazingly-very slight (the order was in the vicinity of 3 degrees for a 20 kt crosswind component).The AP did the same.
Tried it on the A-320 but the electrons did'nt want to know!
On a windy/gusty/low vis conditions,I know some colleagues of mine who don't bother de-crabbing.That technique is approved by AI.
Cheers
 
Mriya225
Posts: 77
Joined: Wed Nov 30, 2011 10:43 pm

RE: Crosswind Landings

Sat Jul 22, 2000 9:16 am

Okay,
This is the part where I get to look like a fool (but I'm not a pilot so I guess I can stomach it) but....
What is Crabbing?

 
 
Guest

RE: Crosswind Landings

Sat Jul 22, 2000 9:40 pm

Mriya225 the word crabbing describes the the condition when an aircrafts longitudinal axis is not aligned with the flight path (relative to the ground). You may have seen aircraft landing with a headig correction into wind to maintain centre line tracking. This is crabbing.

The side slip is the one where you lower one wing to correct for wind drift, they serve the same purpose. i.e. crosswind landings.

Hope it helped.

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