777 GE90 rpoblems...how come?
Thread Starter
Joined: Mar 2006
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From: USA
777 GE90 rpoblems...how come?
Hi all,
With respect to this thread, does anyone have any idea how such an event could happen? I thought that THRUST HOLD mode was designed to prevent exactly such an occurence. I'd imagine that this problem would occur on an Airbus, not a Boeing.
With respect to this thread, does anyone have any idea how such an event could happen? I thought that THRUST HOLD mode was designed to prevent exactly such an occurence. I'd imagine that this problem would occur on an Airbus, not a Boeing.
Joined: Jun 2001
Aviation Qualifications: ATPL
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From: 3rd Rock, #29B
how does it do that in hold?
Hi.
When I went from the B767 LHS back to the B747 LHS, the first rotate we did resulted in all 4 throttles retarding at liftoff with "hold" annunciated. Problem was the TAT signal was erroneous to the TAT/EPRL and gave a reduced limit EPR... the limit protection remains active. The GE90-110/115B issue may act through similar mechanisms where the EEC/FADEC is anomalous in it's software...(or not)
rgds.
When I went from the B767 LHS back to the B747 LHS, the first rotate we did resulted in all 4 throttles retarding at liftoff with "hold" annunciated. Problem was the TAT signal was erroneous to the TAT/EPRL and gave a reduced limit EPR... the limit protection remains active. The GE90-110/115B issue may act through similar mechanisms where the EEC/FADEC is anomalous in it's software...(or not)
rgds.
Joined: Aug 1999
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Not fully familiar with the issue but who said the throttles retarded ? AD says its EEC s/w not TMF/Autothrottle so the engine rollback probably occurs without the throttles moving. probably looks just like an engine failure ...
Joined: Nov 1999
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From: Tir Na Nog
777-300ER = GE 90 115k
Etihad is also doing rated thrust T/O till further notice, actually using the TO bump when able.
A couple of High Vib incidents on the EY Engines has required 2 engine changes of late and Etihad has suspended all ETOPs operations/routings on the 777 fleet.
I am told that some internal damage was found and all a/c are to be BSI before resuming ETOPS...
Etihad is also doing rated thrust T/O till further notice, actually using the TO bump when able.
A couple of High Vib incidents on the EY Engines has required 2 engine changes of late and Etihad has suspended all ETOPs operations/routings on the 777 fleet.
I am told that some internal damage was found and all a/c are to be BSI before resuming ETOPS...
Joined: Apr 2003
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From: Australia
Thread Starter
Joined: Mar 2006
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From: USA
btw, the FAA doesn't have any say in the ops of Emirates does it? I thought only Boeing could issue an AD stating that max thrust be used. Can someone enlighten my darkness please?
Joined: Mar 2002
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From: Florida
Boeing can only issue recommendations, albeit quickly,(to all its operators worldwide). the FAA issues mandates and transmits them to all regulatory agencies worldwide, which in effect raise the Boeing recommendations already on file to mandated actions.
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From: wales
FAA mandates requirements for Boeing aircraft as certification authority for type. Airbus is french DGCAC , now EASA . On the basis of these certifications as far as i am aware most aviation authorities would then mandate these instructions , i.e 'AD'S ' automatically. Certainly is the case in the middle east with the 'ER' operators.
