A question I have asked before but still no answer on here, I would suspect that the MEL item in question has been used before and again would of expected TOWS to be found INOP before MEL item was fixed, and so would of expected some form of feedback that may have changed the conditions for this item inside the MEL ?
It would seem the use of the MEL/CB had
nothing to do with the non-functioning of the TOWS. If the theories quoted here are correct, then pulling the RAT Heater CB leaves the TOWS functioning. The question is whether the RAT Heater "on" at an inappropriate time should have led to futher trouble shooting, and not quick use of the MEL, as per:
The MEL stated the RAT heater,IF INOPERATIVE, may be isolated and deferred. The RAT heater WAS NOT inoperative , and, as an engineer that would have had me asking questions !
Now bonatti says he would have been asking further questions. Good on him, and his company, if that is encouraged / permitted etc.
Regrettably, I would say most companies in practice would have done what was done in the Spanair accident. Can we make the MEL fit? If so, then do it... It does not matter if the "component" is stuck On, Off, Intermittant etc. Often (would not be appropriate here) no CB is pulled - you are just left with an intermittant system and repeated failure messages. On other occasions the CB is pulled - and whether or not the system was strictly "inoperative" before, it is now, and so the MEL can be used.
I'm not saying I like it - just that is in practice what happens
NoD