Would ETOPS Have Made A Difference?
avgenie
I am not sure. If the 900's were on a two engine aircraft, they probably would not have ETOPS approval beyond the lowest level at this point in time. But, they would still be flying.
ETOPS certification involves assessment of aircraft and engine reliability and enhanced training requirements of the aircraft operator's flight crews, mantenence personnel for both aircraft and engines and even the personnel that do the route planning.
The current approval standard for 180-minute ETOPS is 0.02 shutdowns per 1,000 hours of engine operation. That’s amounts to an in-flight shutdown rate of one every 50,000 hours. Many of the world’s 92 ETOPS operators are achieving 0.01 shutdowns per 1,000 hours or, for twinjets on eight-hour ETOPS flights (accumulating 16 hours of total engine time per flight), an average IFSD of one every 6,200 flights. This level of demonstrated safety has prompted many operators and authorites to opt for longer planned diversion times, from 240 minutes to virtually "unrestricted" ETOPS. Statistically, twin engine planes have a lower likelyhood of a diversion compared to 3 or four engine planes.
ETOPS REGULATORY REQUIREMENTS
a. All two-engine airplanes and three- and four-engine passenger-carrying airplanes operated under part 121 are required to comply with 14 CFR 121.161. This regulation imposes special requirements for ETOPS for these airplanes. These operations are defined as:
(1) Two-Engine Airplanes. These are flights whose planned routing contains a point farther than 60 minutes flying time from an adequate airport at an approved one-engine inoperative cruise speed under standard conditions in still air.
(2) Passenger-Carrying Airplanes with More Than Two Engines. These are flights whose planned routing contains a point farther than 180 minutes flying time from an adequate airport at an approved one-engine inoperative cruise speed under standard conditions in still air.
If you would like detailed information to the requirements and how they must be satisfied, copy and paste the address into your browser for the the FAA site below:
http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/2e0f31985abd83ef8625746b0057fd06/$FILE/AC%20120-42B.pdf