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MasterBates
23rd Jan 2003, 16:26
Hi there.
Iīm just wandering about when modern jets are parked in tailwind (talking 40kts+) with hyd pressure off, what about the flight controls. It surely canīt be healthy all the jerking and slamming (of the controls). In the old days we did have gustlocks, but now they seem obsolete.
Do any companies leave hydraulic pressure on at the gate when parked in strong tailwind?

Best rgds,

M Bates

Notso Fantastic
23rd Jan 2003, 17:26
The control surface power control units are designed to be hydraulically locked when unpowered, so you won't see them swinging about. Non hydraulic controls will always have gust locks fitted, either internal ones in the cable system, or external ones with large bright colours on them.

MasterBates
23rd Jan 2003, 19:06
Well, on the 737 (I used to fly them), where there are both hydraulics as well as cables, the steering column is well known to kick one in the balls again and again in tailwind with hyd pressure off. To counteract the stab trim is often placed full forward, but the 737 surely has no locks. They may be present on some aircraft but not on them all.
:)

Black_Dawn
24th Jan 2003, 07:41
Same for MD80's: no locks either.

BD

QAVION
24th Jan 2003, 08:09
The hydraulic power units on aircraft like 747's are designed to dampen movement (to a degree), but they will still move to their limits/stops. I see this all the time on the 747 and similar aircraft (today, in fact... and it wasn't all that windy). On the larger Boeings however, there is no mechanical feedback to the stick (no danger to the pilots). On windy days, you are more at risk from motion sickness :D

I recall reading somewhere (perhaps the Boeing Maintenance Manual) that hydraulics are to be applied if hurricane force winds are expected (where the aircraft cannot be flown to safety).

Regards.
Q.