Originally Posted by
krismiler
r A300-600 .
The first ETOPS regulations exempted aircraft with 4 engines or 3 turbine engines and date back to the Constellation and Douglas DC4/6 era. The Tristar and DC10 were able to comply, long range twins were a few years away. The early 1980s saw the B767/757 with transatlantic capability and the previous decades old regulations were bought into the modern age to cover this class of aircraft.
Krismiller,
With respect, I think you are getting a few concepts confused.
DC-3/C-47 flew in many parts of the world for years after WWII, without the "benefit" of the 60m rules, otherwise many airline services would have been impossible.
I would suggest that the 60 minute rule, aimed, allegedly and originally at piston engine reliability, should never have applied to turbo-jet aircraft. Such is the unintended consequence of a rule written for one purpose becoming "conventional wisdom".
3/4 engine aircraft cannot, surely, be both "exempt" and "comply" from/with "regulations " that, at the time, only applied to twin engine aircraft.
It has only been years later that certain ETOPS/EROPS/EDTO requirements were applied to ALL HCPT aircraft, mostly but not only to do with hold fire suppression.
Indeed, it was fire suppression limitations (not engine related) that limited the diversion time of a number of EDTO certified aircraft. Despite the statistics, "engine failure" for too long occupied centre stage, when other threats to the aircraft, regardless of the number of engines, that were statistically serious issues.
"Back in the day" 90 minute certification was straightforward, 120 minutes took too long, and some of the steps and stages since have been protracted, but at least, in the last few years, an aircraft can have EDTO certification from Day One.
Tootle pip!!
PS: When on B767, we used to enjoy pointing out to our Jumbo mates that we had better electrical and hydraulic redundancy that a B747 Classic, and fire suppression that they didn't have, at all.