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Old 28th Apr 2004, 09:06
  #42 (permalink)  
TAC On
 
Join Date: Feb 2004
Location: australia
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scud_runner and others. It seems there may be a little lack of understanding of the rules and concept of ETOPS.


The "ETOPS rule" to which you refer is a PLANNING rule. 90/120/180 (and later 207) minutes, is on 1 eng in still air. This is then worked as a distance which is promulgated in the relevant company documentation as a planning distance limit. Once underway, should you draw s hit as trumps, if you are on your ETOPS distance limit, you could well be more than the prescribed time getting to where you now want to go. This is legal.
I don't know of the incident to which you refer, but assuming their PLANNING was done within the applicable distance limit, then no "rule" was broken. Given the charting and documentation that we recieve for an ETOPS operation, it is unlikely that the aircraft was dispatched outside this distance limit.
My company has designated 1200nm for 777 on 180 minutes ETOPS. Given a headwind of (say) 80 knots this would take about 3:45 to get to the ETOPS alternate, in the worst case scenario. Perfectly legal.

As a point of interest, when testing the new 777ER, Boeing test pilots shut down one, somewhere over the Pacific, then ran for 5 hours until arriving at some god forsaken place.

To my colleagues and myself, who are into this stuff on a daily basis, the scarey factor is the cargo fire. Engines and systems on dedicated/purpose built ETOPS aircraft are designed and certified to higher standards of redundancy than those of past aircraft. Also, fortunately fire fighting and suppression have been vastly increased in these design requirements.

WRT to engines, consider this. It is generally accepted that start and takeoff are the two highest stress times for turbine engines. Given that by the very nature of the operation, the ETOPS aircraft will have significantly less cycles than will its short haul sister, should there be any inherent design or maintenance weakness, in a powerplant, it should, logically, show up earlier in the short haul sister.

The bottom line is: If you wish not to embrace the concept and new technology of ETOPS, then don't do it. There are plenty of guys around that have an open enough mind to learn and understand the way things are, and are prepared to ride the train while it passes you by.

TO
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