Media versions of Boeing 777 performance
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Media versions of Boeing 777 performance
Trying to make sense of press and TV comments on the RR Boeing 777 performance in relation to the missing aircraft out of KUL. Maybe a real 777 dispatcher/pilot/engineer or similar can answer what would be a reasonable fuel load and take of weight/mass and total range for the trip, assuming normal operation and reserves. Still air and ISA normal would do.
Can a 777 really climb to 45000ft and have 1.2 or 1.3 protection? What might be the realistic ceiling with that departure fuel, weight, assuming ISA + a bit?
Assuming fairly warm air at 5000ft, what kind of cruise speed and fuel flow, and therefor range could it achieve? One 'broadsheet' claiming eight hours....maybe not....Clearly many people assume that the whole planet is covered by radar, and the same report mentioned also assures us that 5000' is 'under radar'.
Talk of two transponders. Assume this is correct.....either #1, or #2....not two different types as has been mentioned. ( aware of engine parameters on ACARS statement. There was mention of 'engine transponders' as if they would show up on secondary radar )
Twice or more I've heard about the fire axe being carried in the passenger cabin. Have to assume nobody does that.
It's understandable that the news hounds and TV anchors are under pressure to keep stoking up the drama when the only hard news remains as 'Plane with a lot of people on board missing', but some of the information claimed to be from experts seems either wrongly interpreted, or from the wrong type of experts, such as travel trade people and politicians.
Wondering what Boeing 777 PPRuNers make of the technical statements being made. Some of the coverage can't be improving matters for those closely involved.
Can a 777 really climb to 45000ft and have 1.2 or 1.3 protection? What might be the realistic ceiling with that departure fuel, weight, assuming ISA + a bit?
Assuming fairly warm air at 5000ft, what kind of cruise speed and fuel flow, and therefor range could it achieve? One 'broadsheet' claiming eight hours....maybe not....Clearly many people assume that the whole planet is covered by radar, and the same report mentioned also assures us that 5000' is 'under radar'.
Talk of two transponders. Assume this is correct.....either #1, or #2....not two different types as has been mentioned. ( aware of engine parameters on ACARS statement. There was mention of 'engine transponders' as if they would show up on secondary radar )
Twice or more I've heard about the fire axe being carried in the passenger cabin. Have to assume nobody does that.
It's understandable that the news hounds and TV anchors are under pressure to keep stoking up the drama when the only hard news remains as 'Plane with a lot of people on board missing', but some of the information claimed to be from experts seems either wrongly interpreted, or from the wrong type of experts, such as travel trade people and politicians.
Wondering what Boeing 777 PPRuNers make of the technical statements being made. Some of the coverage can't be improving matters for those closely involved.
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Media versions of Boeing 777 performance
I refrained from posting on the main thread because it is too crowded there.
There are two simple reasons to this and both have already been mentioned in the main thread:
1, ZBAA is very busy and extra holding fuel does not harm. One of the most useless things in aviation is the fuel you did not uplift (the others being the runway behind you and the altitude above you).
2. Fuel at ZBAA is generally cheaper than Malaysia so why not tanker to save a few bob for the company.
My 2 cents.
There are two simple reasons to this and both have already been mentioned in the main thread:
1, ZBAA is very busy and extra holding fuel does not harm. One of the most useless things in aviation is the fuel you did not uplift (the others being the runway behind you and the altitude above you).
2. Fuel at ZBAA is generally cheaper than Malaysia so why not tanker to save a few bob for the company.
My 2 cents.
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Just wondering, that's all........
Increased fuel uplift would seem to make it even less likely that a 777 would file for an initial cruise FL of 450. Someone on another forum suggested a weight permitted final level of 410 at the tail end of a long flight depending on temps. I simply wouldn't know. Anyway I've just checked the biography of two of the journalists filing these sort of statements, and I suspect they were spicing up the numbers for effect or merely guessing, knowing their sub editors were not likely to spot 'oblate spheroids' or poor quality fiction. Last time I was much over 40000ft in a big aeroplane, it was very light and ceiling limited due to cabin altitude and something like electronic stuff altitude guarantee guidelines. There was a theoretical 1.2g protection in smooth air, and not too much gap between high and low speed buffet........not one of your new wide-bodies with super-critical wing and 777 level of technology though. I did one jump seat ride in a 777, but apart from the fact that it was over water and had only two engines didn't take much notice.
Funny how quoted experts so often aren't as expert as the bloke in the pub......
Increased fuel uplift would seem to make it even less likely that a 777 would file for an initial cruise FL of 450. Someone on another forum suggested a weight permitted final level of 410 at the tail end of a long flight depending on temps. I simply wouldn't know. Anyway I've just checked the biography of two of the journalists filing these sort of statements, and I suspect they were spicing up the numbers for effect or merely guessing, knowing their sub editors were not likely to spot 'oblate spheroids' or poor quality fiction. Last time I was much over 40000ft in a big aeroplane, it was very light and ceiling limited due to cabin altitude and something like electronic stuff altitude guarantee guidelines. There was a theoretical 1.2g protection in smooth air, and not too much gap between high and low speed buffet........not one of your new wide-bodies with super-critical wing and 777 level of technology though. I did one jump seat ride in a 777, but apart from the fact that it was over water and had only two engines didn't take much notice.
Funny how quoted experts so often aren't as expert as the bloke in the pub......
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OGAH, I agree with your observations about the bloke in the pub.
So far it's all smoke and mirrors without proven facts, except she's definitely missing.
At those dizzy heights, even in the cruise, you may start feeling the buffets coming on, but not being able to tell whether they are hi- or lo-speed buffet. Never mind increased loading with zoom climbs or steep turns. Scary.
I have thought about what if I were paxing in the same situation. What can I do, even with all my aviation skills and knowledge ? Sitting ducks. Even more scary.
So far it's all smoke and mirrors without proven facts, except she's definitely missing.
At those dizzy heights, even in the cruise, you may start feeling the buffets coming on, but not being able to tell whether they are hi- or lo-speed buffet. Never mind increased loading with zoom climbs or steep turns. Scary.
I have thought about what if I were paxing in the same situation. What can I do, even with all my aviation skills and knowledge ? Sitting ducks. Even more scary.
