Autoland crosswind survey
 

Ladies and gentlemen;
My Airbus manual gives an autoland crosswind limit of 20kts. My company however stipulates no more than 10kts. Seems like a waste of capability to me. I'm curious about other operators and hence this informal survey. I'd appreciate knowing the limitation of other operators. Anybody...?

The two I know of:

FDX 727: 10 kts

Gemini MD11: 15 kts.

No idea what the "factory" limits were, but pretty sure those companies just adopt the official number.

BTW, this was my logic for always hand-flying the landings. I don't want to develop my "feel" for the aircraft when the crosswind is higher than the above numbers!

B 737-300

15 kts which I think is the flight manual figure

The company dictated crosswind limitations for autoland on our 767s are 25 knots except for CAT II and Cat III which are 15 knots. I have seen an autoland with right about a 15 knot crosswind. The jet is working hard...quite a show. It can done more smoothly hand flying it.

Autoland crosswind survey
 

Air New Zealand Boeing 747-400 limits are as follows 25 Kts Headwind 15 Kts Tailwind and 25 Kts Crosswind, these limits reduce to 25 Kts Headwind 10 Kts Tailwind and 10 Kts Crosswind for CAT II/III. I suppose to get the conditions for CAT II/III there would be little wind anyway.
I hope this helps?

Airbus 330: Crosswind landing limit = 20 kt

Tried it in VMC and the aeroplane did a marvelous job! :ok:

Beware of the combination of autoland/crosswind/slippery runway…..on all autoland aircraft I am aware of, once on the ground the only (auto) compensation for aligning to centerline is nosewheel steering. Any crab may/will then be exaggerated.

All the normal (hand flown) tools in this situation (cross control, differential braking, etc.) are not used.

And speaking of differential braking…..I’m on my first aircraft with brake temperature indicators. It is amazing how different brake temperatures are after a crosswind landing. I didn’t think I (and all the other folks I fly with) used much differential braking on a normal crosswind landing, but…..

The Avro RJ series of aircraft have crosswind limits of about 15 kts; however the manufacturer demonstrated considerably higher; I recall 30 kts being quoted. The Flight Manual limitations represent the statistical probabilities in having to maintain a very high level of safety in Cat 3 conditions; possibly higher than for manual landing? The Avro has a super soft autoland without sacrificing head or tailwind limits imposed by the requirement to land in the official touchdown box.

(B777) 40kts landing x-wind limit wet or dry. Autoland limit the same for Cat I or better, 25kts for Cat II or III (15kts in the USA - think this is an FAA thing because I've had this on previous types too...).

Very rare to get big winds in vis. requiring autoland (can happen), and this aeroplane (like the 757 & 767) does actually apply cross-controls when it goes into "runway alignment" mode prior to what is usually an embarassingly good landing. Can't say I'd be too keen to test it in 40-across conditions, though I'm sure some brave soul has to get it published in the manual.

On FKR 100 conversion courses we used the simulator to demonstrate autolands with a 35kt cross-wind...on one engine.

The only problem most folk had was applying even wheel braking, that's when they remembered because they were often totally in awe.

Magic aeroplane!!!

MP;)

UK Charter A321 200 CFM:

Cat 3 Autoland:
H/w: 30kts
T/w: 10kts
X/w: 20kts - (10kts with Rvr less than 100m)

Cheers
mcdhu

Shore guy,

For info the 757/767 uses the rudder for runway alignment after landing. The nose wheels follow via a mechanical linkage.

In our company we have the following limits H/X/T wind autoland:

737-300 22/17/10
737-400 35/20/10
737-800 25/20/10
737-900 25/20/10

I am now for 18 months in this division and have seen 3-4 autolands of which 1 was less then perfect. Probably because of decreasing X-wind component.

LL

I suspect the 10kt limit could have something to do with the requirement that any instrument approach with the RVR less than 4000 or 3/4 mile requires that the X Wind be less than 10KTS . Unless the regs have changed

Regards
VPTAA

Thanks for all the replies. Seems our limits are at the low(more restrictive) end of the pack.
433 mentioned that winds would be necessarily light to get Cat2/3 conditions and I agree with one exception. We go to St. John's, Newfoundland on a regular basis and it is not at all unusual to get Cat2 conditions with winds at 90 degrees and greater than 10knots. My previous aircraft was a B737-200 and limits were 15kts. I can remember at least one occasion when we did a sucessful approach with the max. allowable. I'd hate to have to divert without even trying for what seems to be an unreasonably conservative limit. But there you go I guess...

in the company that I turn up for now and then the cross wind limit on the boeing 400/500 for Cat 3 is 10kts. To be honest, any more and she makes a dogs dinner of the whole thing in auto land mode. On the A330 its a non event, like wise on a S/E Approach....yawn.

Transport Canada uses Working Note 4 as the basis for certifying CAT II Autopilots. That requires a minimum demonstrated capability of 15 kt Head/15 Kt Cross/10kt Tail. In reality these are the minimums & most manufacturers will try to get the highest wind conditions they can - bearing in mind that one failure (Excess Dev) & you're back to the drawing board as you have to demonstrate a 95% success rate.

If memory serves for CAT III, you get 50% of whatever max winds you demonstrate a successful (read no Approach Warnings) landing in. By coincidence we did the final CL65 HGS testing at St. John's and I remember winds well above 20 kt in less than CAT III conditions (and waiting while a scheduled service came in - "No RVR available").

Lockheed L1011 (longbody aircraft):

Crosswind limit 35knots.
Approach/land (autoland) at this wind works just fine.
Keep in mind...dry runway required for the above.

The Trident folks got it right...!

Ah, Lockheed...!