Originally Posted by
Dave Therhino
In the Pensacola event I believe it was a fan blade fragment that depressurized the airplane.
I was simply pointing out that, while the fuel load required for an engine failure that depressurizes the airplane is covered by the ETOPS fuel reserve rules, the fuel required if you add drag from a nacelle with a severely damaged or missing inlet is not covered.
Dave's point is important.
The fuel policy of the operator covers various possible failure events, but not all.
Fuel policies do not cover any fundamental change to the drag count of the aircraft, other than a windmilling fan. There is no adjustments for the loss of the cowl, opening of the cowl, deflection of a slat upwards into the flow, major birdstrike causing loss of radome etc. Most of these have occurred, and fortunately, the drag counts have not been enough on the day to cause a deficit on the fuel side, but they all have the potential to impact the flight dynamics and control authority of the aircraft.
We are dismayed routinely by what messes the crews can get up to, as in recent oddities with upsets, low-level scenics in B777s, etc, when the bits come off the plane it is up to a pilot to work out how to make that fly if it is possible. Occasionally it is not, or the crew don't get the time to sort it out. UAL232, UAL 811, QF32, QF72, etc, the crews were able to be effective. Both of the SWA fan failures, the one into Pensacola and the more recent one, as well as the B777 fan separation, are examples of crews dealing with the problem. Sully's swim is also, and he highlights a simple truth; what else do you expect the pilot to do? Pilots are going to be the first on the accident scene... but, the training and experience that underlies their day-to-day driving provides the basis for contingent capabilities. On the other hand, the USBangla Dash 400 at Katmandu kind of sets the other end of the spectrum.
Computerizing aircraft to reduce the human input comes with it's own certainties of failures and ensures that the final recovery opportunities of a device that has the potential to develop creative solutions is available, even with its fallibilities.
Passengers will opt to go fly with one or no pilots if it is going to be a dollar less out of their pocket. If the HAL 9000 goes feral with them on board, they will complain about the injustice all the way to impact, but then, so would the passengers in the A320 into the alps, and the B737 into Guangdong province...
