[gorm]

It was changed in 737-400. Before it only took air from the right engine, but 737-400 took from both. In the Kegworth air disaster, which was caused by a failed blade and the system causing a fire trying to compensate by injection of more fuel, the pilot assumed the fire was in right engine and turned it off as crew never notified them which engine was burning. When they discovered the error the speed was too low to kickstart the engine.

https://en.wikipedia.org/wiki/Kegworth_air_disaster

[yetihehe]

You would think that such a complicated machine would have some better method to notify pilot which engine failed, instead of "does it smell like right or left engine".

[0_____0]

There are a series of gauges associated with each engine, but in a high workload situation it might take some effort to make sense of them.

[_cenw]

I assumed it was the 300 because that was the big overhaul with a new marketing name, and the 400 is often only described as a stretched 300.

I can't actually find a single source on which one it was.