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N380UA
23rd Apr 2002, 07:54
Hi all
I’ve been told that the Airbus autopilot will disengage on auto land when the angel is greater than 3.15°, so how do you fly a CAT I approach in auto land config.? Is there any merit to it and if so, why this limitation?
Cheers

52049er
23rd Apr 2002, 08:52
Cant see that written anywhere in the tech manuals. Where did you hear that?

N380UA
23rd Apr 2002, 09:08
Heard that from some 320 drivers on the continent. I tried to find something to that regard in the books but with no avail. I only have Boeing experience hence my Q..

RadarContact
23rd Apr 2002, 15:15
What angle are you referring to here?

3.15° sounds like Glide Path...but that has nothing to do with CAT I capability, so I'm a little confused about the question...

N380UA
23rd Apr 2002, 15:36
RadarContact

The problem was a CAT I approach with a 3.5° GP angel. Now some 320 drivers said that it would not be possible under auto land as the max angel which the ship can handle is 3.15°, which struck me somewhat awkward. Apparently the MD11 shows similar restrictions.

320DRIVER
23rd Apr 2002, 16:04
I don't think the autopilot would disengage per se but it is a limitation in the FCOM not to use GP with an angle of more than 3.15 deg. Possibly has to do with the flare mode algorithm and I am sure it is common to many other aircraft.

sandhu
23rd Apr 2002, 16:27
3.15 is glideslope limation as per FCOM for autoland but i have done autoland at much higher angles though in cat 1 met conditions without any disconection of autopilot, but the flare is pretty prounced.
sandhu

N380UA
24th Apr 2002, 06:27
A great many thanks to all. Your info helped me out a lot.
cheers

HOMER SIMPSONS LOVECHILD
27th Apr 2002, 12:39
Sandhu,is it a limitation for autoland operation or for LVP operation? If it is the former(as per Boeing)then you should not be conducting an autoland, regardless of the met conditions!

sandhu
27th Apr 2002, 17:19
Hye HOMER
You are right but this a new limitation introduced about a year back and autolands mentioned were carried out on earlier dates but the crux of the matter is that NO THE AUTOPILOT DOES NOT DISENGAGE.
regards
sandhu