fire-walling" CFM 56 thrust levers in emergency go-around.

[Tee Emm]

The Boeing 737 Classic QRH advises to aggressively apply maximum thrust following a GPWS pull-up warning. It amplifies max thrust by saying it can be obtained by advancing the thrust levers to the take-off or go-around limit. If terrain contact is imminent, advance thrust levers full forward.

In the simulator "firewalling" the thrust levers does not result in an over-temperature indication. It is known that instances have occurred when inadvertant firewalling of CFM 56 engines has resulted in an over-temp condition. Beyond a certain EGT limit, the engines may have to be inspected for damage.

The question arises thus: If the thrust levers are advanced to the stop during an emergency, is there a safety feature incorporated in the engine design to prevent over-temping beyond the normal EGT limit for take off or go-around thrust. If an engine does overtemp during a max thrust go-around, does this mean the safety feature has failed in its task to prevent a damaging over-heat temp? I seem to recall the RR Spey engine on the F28 had a top-temperature limiting device where fuel flow was automatically reduced if EGT limits were approaching exceedance.

Last year a go-around at max fire-wall thrust resulted in an over-temp which was recorded via the FDR. The pilot was sacked. The circumstances are unclear but would it be correct to say that the over-temp safety feature (if fitted on a CFM 56) should have theoretically cut in to prevent an overtemp sufficiently serious enough to require engine change?

There is no mention in Boeing publications warning of this overtemp danger if the thrust levers are firewalled in an emergency. If in fact overtemping is likely to occur during a go-around, one would think this should be incorporated in simulator design? As it is now, firewalling the thrust levers if ground contact is imminent is a recommended Boeing procedure and thus practiced in the simulator with no apparent adverse indications.