Qantas744ER From San Marino, joined Jun 2005, 1079 posts, RR: 4 Posted (1 year 7 months 2 weeks 6 days 8 hours ago) and read 760 times:
Hi,
A question has been in my mind for a while:
Atlas Air and Polar air both belong to the Atlas Air World Wide holdings, but Atlas Air 744's have GE CF6-80C2B5F with 60,800Lbs and Polar Air's 744's have GE CF6-80C2B1F 58,000 Lbs. Both airlines have the max MTOW of 875,000Lbs for their 744's but why the different engine ratings? they do not really operate from all to different airports.
My main questions is if Atlas air needs and engine replacement on one of their 744's they cant use the B1F because it has 2,800 Lbs less of thrust and i think there are changes to be done to the B1F to change it to a B5F right?
Such as EEC changes etc. and using 3 B5F's and 1 B1F doesnt work so the plane has to wait for a B5F to get shipped?
I know there are not any big differences between the two but how long does a thrust upgrade take?
Ad can somebody tell me for sure that Atlas uses the higher thrust B5F?
Leo
Helicopters can't fly; they're just so ugly the earth repels them.
Jetlagged From United Kingdom, joined Jan 2005, 1886 posts, RR: 7 Reply 1, posted (1 year 7 months 2 weeks 6 days 7 hours ago) and read 740 times:
Atlas certainly do use the -B5F engine. I didn't know Polar used the -B1F. Polar's aircraft were ordered before Atlas bought Polar. They have a different Boeing customer ID:
Atlas aircraft are 747-47UF
Polar/GECAS aircraft are 747-46NF
Atlas and Polar aircraft seem to be operationally interchangeable. The World Air Routes Polar Air Cargo DVD includes one flight with an Atlas registered 744 (MC suffix).
The two engines are identical, the changes would be in the FADEC system (not EEC). I don't know how long it takes to convert one to the other, but I would imagine that if a B1F was needed to be converted to B5F this could be done in less time than the engine change itself would take.
If four B1Fs were installed on an Atlas 744, the FMC would also have to change to reflect that. The -B1F performance data may be part of the Atlas FMC software load, and so controlled by pin programming. If not Polar's FMC operating program would have to be loaded, but that process only takes a few minutes.
The glass isn't half empty, or half full, it's twice as big as it needs to be.
Qantas744ER From San Marino, joined Jun 2005, 1079 posts, RR: 4 Reply 2, posted (1 year 7 months 2 weeks 6 days 7 hours ago) and read 738 times:
Quoting Jetlagged (Reply 1): Atlas certainly do use the -B5F engine. I didn't know Polar used the -B1F. Polar's aircraft were ordered before Atlas bought Polar. They have a different Boeing customer ID:
Atlas aircraft are 747-47UF
Polar/GECAS aircraft are 747-46NF
Atlas and Polar aircraft seem to be operationally interchangeable. The World Air Routes Polar Air Cargo DVD includes one flight with an Atlas registered 744 (MC suffix).
The two engines are identical, the changes would be in the FADEC system (not EEC). I don't know how long it takes to convert one to the other, but I would imagine that if a B1F was needed to be converted to B5F this could be done in less time than the engine change itself would take.
If four B1Fs were installed on an Atlas 744, the FMC would also have to change to reflect that. The -B1F performance data may be part of the Atlas FMC software load, and so controlled by pin programming. If not Polar's FMC operating program would have to be loaded, but that process only takes a few minutes.
Great Answer thanks!
Can you also confirm B5F is 60,800Lbs and B1F is 58,000Lbs?
leo
Helicopters can't fly; they're just so ugly the earth repels them.
Now lets take the B1F and B5F for B5F is states 60,030 Lbs of maximum thrust. But that is not the full maximum thrust like it is stated under PW TCDS's and RR TCDS's. The Maximum ideal thrust is 60,800Lbs, but because of certain notes in the CF6 TCDS this thrust is not stated under maximum continuous thrust but under Ideal which in the other TCDS's is included in maximum continuous thrust. SOo for some strange reason with this specific engine you have to scroll down to the notes to see what the actual continuous maximum thrust is.
So to clear up B1F 58,000Lbs
B5F 60,800Lbs
Helicopters can't fly; they're just so ugly the earth repels them.
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