Originally Posted by
Jetstream67
Like so many safety issues we will only really know the statistical answer looking back.
The move to twin engines was paralleled by increased reliability of engines and redundancy of systems and more obsessive maintenance processes and the flight crews desire to arrive safely too on failure of engine #1. The sum of those factors is still being calculated
The Customer is a realist: They like cheap flights and if the chances of making it to a safe landing are increasing vs last time they don't care much about the reliability of the most reliable parts . . most are more scared of a nut-case fellow passenger
Folks,
One thing I can say without doubt, because I was in the middle of it --- when EROPS (ETOPS/EDTO) was first established in Australia and NZ (and bear in mind no European nation allowed it for years after --- long range twins were "not safe") perhaps the statistics were not as sophisticated as now (after all, there was no huge body of statistics for big twins) but one thing is for certain!!
No supporters of the changes proposed, and those involved in the regulatory approvals (FAA, whatever CASA was then -CAA?, Boeing, P&W and GE, AIPA, QF etc.) considered big twins "safer" or "as safe" as a B747, but the risk of a multiple engine failure was ALARP- As Low As Reasonably Practicable, and that assessed residual risk was seen as acceptable.
Don't forget --- quite properly, in my opinion, many engine failures were excluded from the calculations --- fundamentally any engine failure not in the EROPS phase of the flight. Failures on takeoff, bird-strikes etc did not count.
Increased concern about hold fires and Class D compartments falling out of favour was years down the track, as were lithium batteries, and, if I recall correctly, the very first edition of AS/NZ 4360, Risk Management
Other system redundancies were carefully considered (the B767 has better electrical redundancy than the B747) --- but the "biggie" was engine failure) and aircraft modified compared to a non-ER B767, and it was all about the B757/767, because Airbus didn't want to know, because JAA/UK CAA etc., and all the European pilot unions said NO!!. ITS NOT SAFE!! I don't remember the exact timescale, but the A310, the first Airbus so certified was quite a few years after Boeing.
So Dick's basic proposition is correct, in the genesis of EROPS/ETOPS/EDTO, all accepted (whether it was right or wrong) that long range twins were not "as safe" as a three or four engine aircraft, but they were "safe enough" (my words)
--- and "absolute safety", "safety is our first priority" and the present CASA selectively preferred interpretation of S.9A of the Act did not get a look-in.
And Dick's proposition that the Act should be amended, as agreed by Barnaby and Albo, as Minister and Shadow Minister, remains a necessary change, has been a necessary change since 1998, 20 years --- without which we will not see proper application of risk management principles across the board in aviation in Australia --- it will be confined to those with the commercial power.
Tootle pip!!