Originally Posted by
Chu Chu
I wonder if anyone has realistic figures for this, but if the chance of an engine failure on a given flight is one in 100,000, and the chance of a single fault failing both engines is one in a billion, this would mean that one of every 10,000 engine failures is a dual failure. In that scenario, when the left engine failed, the odds of the right engine failing would immediately jump by a factor of 10 (from one in 100,000 to one in 10,000).
I'm not rightly sure I follow your math(s). Aren't you mixing independent and dependent probabilities in your analysis?
And speaking of landing up North, FAA regs require a passenger recovery plan in the ops manual for polar ops:
Passenger recovery plan. Revised regulation 14 CFR 121.135 requires that for all ETOPS flying beyond 180 minutes (excluding 207-minute ETOPS, as explained above), and for all polar operations, the air carrier must develop a plan to ensure the well-being of passengers and crew members at each approved en route alternate airport listed in this carrier's operations specifications. Because challenging alternate airports tend to be found in the most remote parts of the world, passenger recovery plans are no longer required for ETOPS below 180 minutes.
This passenger recovery plan must address the safety and comfort, in terms of facilities and accommodations, of stranded passengers at the diversion airport. As its name suggests, it must also address their prompt retrieval from the airport.
Polar operations also require passenger recovery plans, as codified in this rulemaking's polar policy. Initially implemented as an FAA policy letter in 2001, this polar policy also requires diversion airport planning, another key ETOPS concept. Despite these similarities, however, polar operations are distinct from ETOPS because North and South Polar operations entail unique requirements, such as special onboard equipment and a fuel freeze strategy.
AERO - The New FAA Etops Rule
Again, I presume there is something similar in the European regs.