PPRuNe Forums - View Single Post - B737 Abort decision with engine overheat indication.
Old 14th October 2004 | 08:04
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80/20
 
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Hudson: Engine fire warnings in the simulator are usually preceded by an engine overheat indication.
All the 737 sims I have used, made by CAE and Flight Safety, did not work like this. The malfuction descriptions were:
Engine fire: Engine fire handle/bell and engine overheat light will come on at the same time.
Engine overheat: (simulates a bleed duct leak upstream of the bleed control valve) Engine overheat light will come on, retarding the thrust lever (below 75%) will extinguish the overheat light.
I thought this would be the same for all but obviously not. What sims are you referring to Hudson? (Not doubting your facts just curious.)

The background for Both Boeing and Airbus’ go-minded philosophy came after a RTO study by ATA and AIA in 1989-90. Part of their conclusion was that:
Only slightly more than one-fourth of RTO accidents and incidents actually involved any loss of engine thrust.
They studied 46 RTO overrun accidents for the western transport jets which caused more than 400 fatalities. Additional 28 serious incidents would likely have been accidents if the overrun areas had been less forgiving.
Approximately 80 percent of the overruns were avoidable.
The conclusion was that in most cases the airplane was capable of continuing the takeoff and either land at the departure airport or divert to an alternate. In other words, the decision to reject the takeoffs appears to have been “improper” in many accidents.

Most pilots know how difficult it is to make good decisions during a real life high-speed malfunction. The best go no-go decision are based on good underlying procedures, always ready for the unexpected and common sense. Common sense can not be given as set rules by manufacturers. Boeing gives the following statements in their FCOMs:
This manual is written under the assumption that the user has had previous multi–engine jet aircraft experience and is familiar with basic jet airplane systems and basic pilot techniques common to airplanes of this type. Therefore, the FCOM does not contain basic flight information that is considered prerequisite training. It is not possible to develop checklists for all conceivable situations…. the captain must assess the situation and use sound judgment to determine the safest course of action.

One example of this common sense and judgments is to consider your stopping margin during preflight. Typically we will use a balanced field V1 - that is in theory that engine-out-go distance = engine-out-stop distance

But the actual runway available is usually longer than the minimum balanced field length required. I like to discuss this with myself and my crew. E.g. "today we have more than 1000 mtr stopping margin, which is good"… or .."today we have only 100 mtr stopping margin and must be go-minded"


Given the chance to consider, would I RTO for engine overheat light & master caution at 100 kts?
With 1000 mtr stopping margin – yes
At exactly balanced field with no stopping margin – no.

Last edited by 80/20; 14th October 2004 at 11:55.
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