ASER
With respect to the Torque Limiter:-
I owe you and the rest of the PpruNe fraternity an apology insofar as the TL DOES appear in the RFM Pre Take Off, After Take Off and Pre Landing checklist with the qualification 'AS REQUIRED' - the same as your own checklist.
Clearly somebody has considered the possible need for the TL when the book was written although we seem to have standardised on a scenario here at the school where the TL is not used for normal ops. That's why it doesn't appear on our 'training' checklist.
The ambiguity leaves us no further forward but as Jim says, sacrificing the MGB/Engine to save the airframe is probably better than sacrificing the airframe to save the MGB/Engine.
As for flying around with the TL on all the time - probably not a good idea. As for using it for normal ops - in the absence of any history of MGB overtorques I can't see it as justified. Given the acceptance of the TL by the RFM 'Normal Procedures' I can no longer claim it to be unacceptable to use it and will need to eat my share of humble pie over that. However, the analysis, I believe, is in favour of using it only when you have a clear possibility of an overtorque. Even then there may be some circumstances (I can think of one example when you are landing in the mountains with lots of down-drafting) where it may be better to have it OFF rather ON.
With respect to the MGB:-
3.2 If, with all engines operative, the TQ is 121 thru 125% for 10 s maximum no inspections are necessary.
3.3 If, with all engines operative, the TQ is 121 thru 125% for more than 10 s or it is more than 125%, send the data to the Manufacturer. Then do the recommended inspections.
3.4 If, with one engine inoperative, the TQ is more than 176%, send the data to the Manufacturer. Then do the recommended inspections.
These are the official procedures the customer MUST carry out.
That's the best I can do at the moment. No clear indication of the asymmetric scenario as mentioned previously but the MM would seem to reinforce the 'normal' situation where both engines are producing equal torque. The consensus here is that the designers forgot to to consider this scenario when they designed the software along with the scenario where 'ITT Matching' is selected as this will also generate a torque differential.
G
Edit - Typo plus note about ITT Matching
Last edited by Geoffersincornwall; 15th Jun 2009 at 13:18.