Fellow pilots, pardon me if my question sounds stupid. I am new and really confused about the A320 bleed system. Suppose we have a single engine failure at low level, during ECAM actions, my company recommendation is to turn on the APU for additional electrical support, however, it is not common practice for us to use the APU for bleed support for the packs.
Correct me if i am wrong but according to the best of my knowledge, wouldn't using APU bleed as additional support will give your engines a slight boost in performance because packs rob bleed air and slightly decreases your engine performance, isn't it? if this is true, then why not use APU bleed incase of one engine out?.
Ive asked many senior ranking officers and captains around me but most of them do not give me a straight answer and keep beating around the bush. However, one senior officer did told me that, we can use it, depending on which engine has failed, and wether it is damaged or not, because if we turn on cross bleed, the damaged engine might cause foreign objects to enter the bleed system. Is this true? But if the engine is already damaged, wouldn't we have pushed the engine fire pushbutton and shut off the corresponding engine bleed valve? how is it possible then to get contamination? where can i find more info about this issue? because ive seen searching through the FCOMS and CBT but cant seem to find the answer to this
. Your comments and answers are aprreciated, thank you all in advance.