737 autoland nose up
Join Date: Aug 1999
Location: England
Posts: 1,033
I wouldn’t know, but on the 737 the FMC isn’t anywhere near as fundamental as more modern types so my gut instinct is that it wouldn’t be involved in pitch trim. But I don’t have al the manuals and haven't flown one for 15 years so I could well be talking bollocks (why change the habit of a lifetime!).
Join Date: Apr 2010
Location: IRS NAV ONLY
Posts: 1,028
Anyone know for how many units is aircraft aiming when trimming at 400' during autoland?
depending on the FMC current MAC
Join Date: Jan 2018
Location: Amantido
Posts: 605
Originally Posted by Dzosefs
Anyone know for how many units is aircraft aiming when trimming at 400' during autoland? I couldn't find this information in the fcom. Only states it nose up trim.
Regards
Regards
I am going by memory. I don't claim this to be exact information and I don't know how relevant this would be.
Join Date: Jun 2001
Location: 3rd Rock, #29B
Posts: 899
Interesting question, it does but the amount I cannot recall. The B747 classic in. dual-channel used to add 2 units ANU, and that predated the 737 ALAND capability, would think it would be close to that, which is around the incessant whirring that Banana Joe indicates.
Join Date: Nov 2019
Location: USVI
Posts: 142
The Autopilot is flying the aircraft. The FMC provides mach trim and speed trim, hence the comment about performing CAT III autoland W/O FMC is valid. (as long as the AP is fully functional)
The pilot will have to manually trim the ac if the FMC's are inop. and can still perform a CAT III autoland procedure.
Is the question how to manually trim the ac below 400' on final???
The pilot will have to manually trim the ac if the FMC's are inop. and can still perform a CAT III autoland procedure.
Is the question how to manually trim the ac below 400' on final???
Join Date: Feb 2008
Location: earth
Posts: 61
Originally Posted by turbidus
The Autopilot is flying the aircraft. The FMC provides mach trim and speed trim, hence the comment about performing CAT III autoland W/O FMC is valid. (as long as the AP is fully functional)
The pilot will have to manually trim the ac if the FMC's are inop. and can still perform a CAT III autoland procedure.
Is the question how to manually trim the ac below 400' on final???
The pilot will have to manually trim the ac if the FMC's are inop. and can still perform a CAT III autoland procedure.
Is the question how to manually trim the ac below 400' on final???
Ah you got some bogus info in there. Yes, you can do an auto land with no FMCs. That part is correct. However, the FMC has nothing to do with trimming for an auto land, so the trim will work just fine without the FMCs. Not sure where you are getting this info. The proof of the pudding is in the “auto land limitation summary” in the QRH. It lists all the equipment requirements, nowhere does it mention an FMC.
Join Date: Oct 2006
Location: Ankh Morpork, DW
Posts: 611
Originally Posted by turbidus
The Autopilot is flying the aircraft. The FMC provides mach trim and speed trim, hence the comment about performing CAT III autoland W/O FMC is valid. (as long as the AP is fully functional)
The pilot will have to manually trim the ac if the FMC's are inop. and can still perform a CAT III autoland procedure.
Is the question how to manually trim the ac below 400' on final???
The pilot will have to manually trim the ac if the FMC's are inop. and can still perform a CAT III autoland procedure.
Is the question how to manually trim the ac below 400' on final???
Join Date: Feb 2003
Location: Blue sky
Posts: 95
Originally Posted by turbidus
The Autopilot is flying the aircraft. The FMC provides mach trim and speed trim, hence the comment about performing CAT III autoland W/O FMC is valid. (as long as the AP is fully functional)
The pilot will have to manually trim the ac if the FMC's are inop. and can still perform a CAT III autoland procedure.
Is the question how to manually trim the ac below 400' on final???
The pilot will have to manually trim the ac if the FMC's are inop. and can still perform a CAT III autoland procedure.
Is the question how to manually trim the ac below 400' on final???
Last edited by BraceBrace; 9th Feb 2021 at 13:25.
