Doves wrote:
Doves wrote:
First of all I’m not exactly a spotter (try to figure out!)
Second: Perhaps I am saying, among the others, the same thing like sombody else:
ETOPS are to be revised some way.
From the BIBLE:
In modern turbofan engines, compressor surge is a rare event. If a compressor surge (sometimes called a compressor stall) occurs during high power at take off, the crew will hear a very loud bang, which will be accompanied by yaw and vibration. The bang will likely be far beyond any engine noise, or other sound, the crew may have previously experienced in service.
Compressor surge has been often mistaken for blown tires, or a bomb in the airplane.
The flight crew, may be quite startled by the bang, and in many cases, this has led to a rejected take off above V1, which have sometimes resulted in injuries, loss of the airplane, and even passenger fatalities.
Compressor stall may be caused by engine deterioration, or may be the result of ingestion of birds, ice, or foreign objects. Its effects may be the final sound from a “severe engine damage”.
In a turbine engine compression is accomplished as the air passes through the stages of the compressor. The air flowing over the blades can stall just like the air over the wing. When this occurs, the passage of air through the compressor becomes unstable and the compressor can no longer perform its duty. This means that there is no more the correct relation between the fuel and the air in the the engine.
Engine surge can be accompanied by visible flames forward out the inlet and rearward out the tailpipe. Instruments may show high EGT, EPR or rotor speed changes.
Depending on the reason for the compressor stall, there many types of surges:
- A single self-recovering surge (the only one I have ever experienced a few times in 40 years, during landing on an MD-80 and the reverse was still deployed by 60 kts)
- Multiple surge prior to self-recovery
- Multiple surges requiring pilot action in order to recover
- A non-recoverable surge
When a compressor surge is not recoverable, the engine will decelarate to zero power as if the fuel had been chopped. This type of surge can accompany a severe engine damage.
Now I am asking:
Who told the crew of BA268, that:
1) There has not been an ingestion of bird/s, pieces of tyre or any other foreign object by the engine number 2?
2) The engine had not been severely damaged?
3) The flames (many feet long) and the sparks (incandescent pieces of metal) did not invest some vital part of the aicraft?
4) One or more of the tyres did not blow out?
5) The cause of the explosions had not been an explosive device?
Good research you have found the words that
I wrote several years ago.
However in regard to the bolded questions above, the engine
experts also considered the symptomatic response, to the crew, of combinations of those events that you question. These symptoms taken together with the likelihood of a serious degradation of the aircraft's airworthiness were embodied in the recommended actions to the flight crews regarding continued operation of the aircraft.
I am not saying that we recommended the operation of the aircraft to its original destination, but only that the aircraft is likely safe to fly for an extended period of time with proper consideration of all the symptoms or event conditions to the crew.
Again and again in this thread I am not making a judgement about the crew's actions (I leave that to the CAA) but only am pointing out that the decision making process can be soundly performed with the data and ground advice available to the crew.