J32driver From United States of America, joined May 2000, 399 posts, RR: 1 Reply 1, posted (13 years 5 months 1 week 5 days 9 hours ago) and read 1419 times:
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.
Dnalor From Australia, joined Mar 2000, 369 posts, RR: 0 Reply 3, posted (13 years 5 months 1 week 4 days 22 hours ago) and read 1366 times:
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 From United States of America, joined Jul 2000, 1338 posts, RR: 28 Reply 4, posted (13 years 4 months 3 weeks 6 days 18 hours ago) and read 1268 times:
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 From French Polynesia, joined Nov 2011, 0 posts, RR: 0 Reply 5, posted (13 years 4 months 3 weeks 4 days 6 hours ago) and read 1225 times:
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 From Australia, joined Mar 2000, 369 posts, RR: 0 Reply 6, posted (13 years 4 months 3 weeks 3 days 21 hours ago) and read 1208 times:
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.
Mriya225 From French Polynesia, joined Nov 2011, 0 posts, RR: 0 Reply 8, posted (13 years 4 months 3 weeks 3 days 21 hours ago) and read 1208 times:
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 From Australia, joined Mar 2000, 369 posts, RR: 0 Reply 9, posted (13 years 4 months 3 weeks 3 days 21 hours ago) and read 1206 times:
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.
Skyhooked From , joined Dec 1969, posts, RR: Reply 10, posted (13 years 4 months 3 weeks 3 days 7 hours ago) and read 1192 times:
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.
Line_up_29R From , joined Dec 1969, posts, RR: Reply 12, posted (13 years 4 months 3 weeks 2 days 17 hours ago) and read 1170 times:
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.