OldAeroGuy
Thats one of the eye opening stats along with if you spread these faiuures out over a 126 ship fleet nearly 2/3rds of them (63%) could have suffered an IFSD without losing ETOPS certification and that with 80,000 hours per month we should expect up to 1.6 shutdowns per month. Which means that the 3 GE90 IFSD over the last 6-8 weeks are nothing to be concerned about!(?) At least according to the rules.
In fact, although .02 per 1000 engine hrs. are the standard for 180 min. ETOPS, actual fleet performance for ETOPS twins is about .005 per 1000, or about four times better than necessary.
I will direct you to
Federal Register / Vol. 68, No. 114 / Friday, June 13, 2003 ... which, states FAA computed shutdown rates for 1997/98 for all three certified powerplants implies that the GE at least was mighty close to breaching even that 0.02 /1000 rate. It is a facinating document for many reasons I recomend it. FAA quoted in context..
The Boeing Model 777–200 series airplane powered by Pratt & Whitney PW4077 engines was approved for ETOPS on May 30, 1995 and entered service in June 1995. By all accounts, it was a very successful new model introduction. This was followed by ETOPS approval of the 777–200 powered by General Electric GE90–77B and Rolls-Royce RB211–Trent 877–17 engines in October 1996. The inflight shutdown (IFSD) rate for all three engine types was zero for at least the first year in service. The Pratt & Whitney PW4000 reached a peak 12-month rolling average engine IFSD rate of .018/1000 hours in October 1996. The General Electric GE90 reached a peak of .021 for one month in July 1998 and the Rolls-Royce Trent reached a peak of .016 in December 1997. Although the inflight shutdown rates stayed within the allowable .02/1000 hour standard for 180-minute ETOPS, significant design problems were discovered on each engine type after ETOPS approval. During the first two years after ETOPS approval of each engine type on the Model 777 series airplanes, the FAA was concerned that the design problems being discovered may have indicated a failure of the early ETOPS process to identify those failure modes before they occurred in service. Some failure modes had the potential to result in inflight shutdowns had they occurred under different circumstances or had they not been detected during maintainence for unassociated reasons..
Thanks to all who are taking the time to contribute to this thread, 3 pages and no flames, remarkable!