737 arming A/T while stationary at aerobridge.
Thread Starter
Joined: Apr 2005
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From: Australia
737 arming A/T while stationary at aerobridge.
Until Boeing changed it's policy, the arming of the autothrottle was left until approaching the take off point. Presumably this was a safety feature in case of an inadvertant touching of the TOGA button (s) on the throttles while taxiing.
That being so, one wonders the rationale behind Boeing's amended requirement to switch on (arm) the autothrottle during before start checks. Surely it would be safer to err on the side of caution and not arm the autothrottle until it is safe to do so as per previous Boeing recommendation - particularly as an inadvertant pressing of either TOGA button after engine start could have disastrous consequences. I understand some Boeing models have a safety device that inhibits the autothrottles from operating unless certain parameters are met but certainly in the case of the 737 Classics there is no such technical protection.
That being so, one wonders the rationale behind Boeing's amended requirement to switch on (arm) the autothrottle during before start checks. Surely it would be safer to err on the side of caution and not arm the autothrottle until it is safe to do so as per previous Boeing recommendation - particularly as an inadvertant pressing of either TOGA button after engine start could have disastrous consequences. I understand some Boeing models have a safety device that inhibits the autothrottles from operating unless certain parameters are met but certainly in the case of the 737 Classics there is no such technical protection.
Joined: Oct 2002
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From: Northport, NW England
Just a guess but I pressume the A/T arm in the preflight is to bring the procedures in line with other types in the boeing family.
My company has just adopted Boeing SOP and it seems to be the case that every fleet will have as close to as identical procedures as possible - whether it suits the fleet or not.
The Aim is for Mixed Fleet Flying between 737/757/747/777... Boeings "Holy Grail".... or Mecca...delete as appropriate.
My company has just adopted Boeing SOP and it seems to be the case that every fleet will have as close to as identical procedures as possible - whether it suits the fleet or not.
The Aim is for Mixed Fleet Flying between 737/757/747/777... Boeings "Holy Grail".... or Mecca...delete as appropriate.
Joined: Feb 2004
Posts: 398
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From: Omicron Persei 8
Would love to see a full blown debate on the "new" B737 procedures!
From my brief dalliance with them they looked like a complete dog's breakfast!
From my brief dalliance with them they looked like a complete dog's breakfast!
Last edited by Capt Chambo; 24th May 2007 at 05:46.
Joined: Jun 2001
Posts: 3,991
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From: UK
Just a guess but I pressume the A/T arm in the preflight is to bring the procedures in line with other types in the boeing family.
Joined: Nov 2006
Posts: 39
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From: UK
They tell us flying is safe these days, pilots don't need systems knowledge and to trust the automatics.
It's all about money, more specifically Boeing's attempt not to be disadvantaged when competing for orders with Airbus and their A320-380 family.
It's all about money, more specifically Boeing's attempt not to be disadvantaged when competing for orders with Airbus and their A320-380 family.
Joined: Jan 2005
Posts: 303
Likes: 56
From: Europe
We used to have a quick and effective evacuation drill, which had to be done by heart. Nowadays, we have a dumbed down Boeing checklist, which takes twice as long to complete, as it is based on a much less logical sequence of actions. I think if it ever comes to that, I'd rather do the old drill first and read that "checklist for dummies" later.
Joined: Sep 2005
Posts: 279
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From: ???
arming A/T before taxi is, 1 to bring it inline with the rest of the boeing family however the most important thing is to reduce the amount of workload on the pilot at the most critical moments eg taxi. to prevent runway incursions.
with the old procedure we had a taxi checklist. which was something like:
select the flaps, check recall, check flight controls, shutdown apu, check trim, check cockpit door is locked. and this was all done while taxiing.
with the new procedures both pilots can direct more of their attention to taxiing.
xetroV: the QRH says that you as captain can perform items by recall that are not recall. however it will be your responsibility if you mess up.
and example of this is a scenario I recently had on the sim.
we were cleared to maintain 4000ft, and maintaining 250kts. the No 2 engine on leveling off wouldn't respond to throttle movements.. ie it was stuck in full T/O thrust. we immediately reduced thrust on No 1 engine but the speed of the aircraft was rapidly rising. we had to according to the checklist take out the QRH find the Engine failure/shutdown NNC and read and do. by that time we would have an overspeed. so instead by recall we just shutdown the engine and then went to the QRH.
with the old procedure we had a taxi checklist. which was something like:
select the flaps, check recall, check flight controls, shutdown apu, check trim, check cockpit door is locked. and this was all done while taxiing.
with the new procedures both pilots can direct more of their attention to taxiing.
xetroV: the QRH says that you as captain can perform items by recall that are not recall. however it will be your responsibility if you mess up.
and example of this is a scenario I recently had on the sim.
we were cleared to maintain 4000ft, and maintaining 250kts. the No 2 engine on leveling off wouldn't respond to throttle movements.. ie it was stuck in full T/O thrust. we immediately reduced thrust on No 1 engine but the speed of the aircraft was rapidly rising. we had to according to the checklist take out the QRH find the Engine failure/shutdown NNC and read and do. by that time we would have an overspeed. so instead by recall we just shutdown the engine and then went to the QRH.
Joined: Apr 1999
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From: UK
I assume this change of Boeing policy reflects tommyfly's changes to SOPs? Or should that be the other way round.. Either way it certainly hasn't reached us yet, our company policy (733) is still to arm the A/T when cleared for line-up.
