747 Cross-wind landings

[oncemorealoft]

Admiring the performance of those landing this morning on 27L at LHR in a fair amount of cross-wind, I thought I recalled reading something about the 747's main landing gear trucks being able to be turned to make cross-wind landings easier.

Am I imagining this or can someone tell me the correct technical details?

Many Thanks

[Otterman]

hello,
No the Boeing 747, does not have that feature. Coming up on 10,000 hours on this beautiful machine. It is a lovely predictable aircraft in a x-wind. We are taught to de-crab during the flare and counteract drift with airleron input. But we were also told during type-rating that the aircraft is certified with no decrab, at its maximum x-wind limit. This will jar your fillings out though.
Another Boeing the B-52 does have it. But it sits a lot closer to the ground and has a huge wing that could easily make contact if a more normal x-wind technique is used.

[Notso Fantastic]

It's all very well having a fancy crabbing main landing gear. It lets you set the anticipated drift on landing. But can you imagine the embarrassment if the wind has suddenly changed or it is blustery, and the drift is different? When you touch down, you are likely to suddenly shoot sideways. You can see if 5 degrees expected drift becomes 5 degrees the other way at touchdown......you will be a Pprune star! Better to do the way the Wright brothers planned.......the old fashioned way without any fancy sophistication that could cost you your pension.

[phnuff]

What is the crosswind limit of a 747 ? (not that this will ever be anything more than useless info to me in my little spamcan)

[Notso Fantastic]

Landing Dry 36kts, Wet 32, Contaminated 15, Autoland 25
Takeoff Dry 40, Wet 25, Contaminated 15
(These are big boys toys)

[phnuff]

Appreciated - (and sure are big boys toys)!

[Dan Winterland]

Those limits are for the -400. The Classics are a bit less at 30 knots dry and 25 Knots wet for both takeoff and landing.

The C5 Galaxy also has rotating trucks.

[ETOPS]

The Lockheed C-5 Galaxy also has this feature. The gear is aligned by the ILS signal (clever eh?) so the amount of crab angle is always allowed for even if the wind changes late in the approach.......

[411A]

Clever...yes, it is a LOCKHEED aeroplane.:D

I even liked flying the 1649A, (never mind the TriStar)...superb:D :D

Altho the 1649A did not, some of the Connies had a walking gear...interesting to watch in a crosswind.:eek:

[australiancalou]

Hi guys

Just a little precision concerning the cross wind limits.
They don't take the burst into consideration:rolleyes:
These are only steady wind limits.
So landing still remain a "big boy" decision.

[galaxy flyer]

Not so fast on the C5!! The crosswind gear was never installed on the B-models and was removed from the A's about 10 years ago. It didn't align with the ILS signal either. The engineer went into a rather daunting chart and determined a crosswind gear setting. The co-pilot had a knob to set in the correct gear setting. It was graphically shown on a gauge that Lockheed no doubt charged a small fortune for. All five gear rotated to the set crab angle.

Has been done wrong once or twice, setting it in as a drift angle instead of a crab angle. Wasn't there, but V. exciting. Lockheed came to the rescue after the dust settled.

I never felt comfortable using it and the maintenance effort brought about the gear changeover. It was frightfully expensive to maintain and would occaisionally go duck-footed for no reason. A very quick halt!!

[manuel ortiz]

Beech 18´s ( Beautifull taildrager to fly ) had the cross wind system option.

Flew a D-18 one day and the gear did not retract , left wheel had gone full deflected just after lift off and got stuck that way.

Made some touch and goes trying to get it straight with no luck.
Managed to land OK that way and eliminated the system.
Never liked it anyway...