Pitts. We have never had a MOD 45 exceedance before the first shaft rupture. That was one ofthe most confusing aspects of the entire issue.
DB yeah I'm sure and you know I'm sure its a very fine piece of kit with clever people involved at every step. Its very clear that there is a motivation to get the 225 flying with the interim solution and good luck to all concerned but this is an interesting situation.
You say no MOD45 exceedance but just look where the limit is now to where it was! Read it for yourself in S7/2012 AAIB and I quote:-
At the time of the first accident in May 2012, the MOD-45 and MOD-70 indicators only included amber thresholds; these were ‘learned’ thresholds each with a maximum value of 0.6
After the accident to G-REDW, Eurocopter published EC225 Service Bulletin No 45-001, in July 2012 that included the introduction of a red threshold and lowered the fleet-wide maximum threshold values for both indicators. For MOD-45 the amber alert was reduced to 0.3 and a red alert of 0.4 was introduced.
After the accident to G-CHCN, Eurocopter published an Emergency Alert Service Bulletin (ASB), on 21 November 2012, which removed the maximum amber alert threshold for MOD 45 and lowered the red alert threshold to 0.2.
I guess you guys know where it is now but crikey that's some difference!
Another interesting aspect of the in-cockpit MOD45 warning is that it is a shift in thinking for EC because after G-REDL they resisted AAIB recommendation for an in cockpit chip warning system I believe, suggesting that existing checks were sufficient.