When a dual engine flame-out is encountered, and the engines themselves are not damaged such as in the case of Air Transat Flight 236, why is the RAT deployed for emergency power instead of using the engine generators?
I imagine that the engines themselves will still be spinning sufficiently quickly in the wind to generate enough electrical power. Of course, I'm not saying that a RAT should be removed, because in a different scenario, both engines could simply explode and their generators would be useless. But I'm wondering why, in the case of fuel exhaustion, the engine generators are not used at all, and we rely only on the RAT / batteries. Is it because connecting a generator to windmilling engines would slow them down too much and causes unnecessary drag during the glide? Or is it because the engine generators are optimized for much higher rotational speeds?