BOEING747400
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B744 And B744ER Questions

Sun Oct 20, 2002 3:07 am

Why does the new Qantas B744ER (VH-OEE) have the GE CF6-80C2B1F engines which are normally for the non-ERs only? And why do both Saudi Arabian and Virgin Atlantic B744 have the GE CF6-80C2B5F engines which are normally for the ERs only? I don't understand this but assume that the ER designation is not entirely based on the power of the engines but on other factors such as MTOW? I think that the same concept applies for the B777 but I'm not exactly sure. Can anyone please explain this phenomenon to help me understand it better? Thanks.
 
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RE: B744 And B744ER Questions

Sun Oct 20, 2002 4:48 am

All airplanes have optional engines with different power, and optional weights, for sure it continues in the 747-400 series, as it was on the Classic...
xxx
On the Classic - they had some 20 to 25 DIFFERENT max gross weights, and about nearly as many engine options... The second day the 400ER got on the market for sale, I bet Boeing started their second and third options for weights. And in the next few months, more options will be offered...
xxx
FAQ "What is the weight of a 747...?" - it varies... which one, which model, which series, which airline, combi, cargo or passenger...???
xxx
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AFa340-300E
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RE: B744 And B744ER Questions

Sun Oct 20, 2002 11:00 pm

Hello BOEING747400,


Basically: yes, the ER designation is based on MTOW for both the 747 and 777 derivatives.


The 747-400 is available at weights up to 396,900kg (875,000lb). The -400ER starts at 412,775kg (910,000lb). This MTOW difference is due to the heavier structure, undercarriage and wings of the -400ER -- which retains some components designed for the -400F. Other, less significant, upgrades are also featured on the -400ER (front wingroot fairing, cockpit upgrades, etc.).


As far as the 777-200 is concerned:
o The "A-market" derivatives (-200) are airplanes at weights between 229,520kg (506,000lb) and 247,210kg (545,000lb).
o The "B-market derivatives (-200ER, formerly -200IGW) are airplanes at weights between 263,080kg (580,000lb) and 297,560kg (656,000lb).

Hope that helps. If you are interested in more details on the 747-400 vs. -400ER differences: Boeing 747-400X, ER & QLR.


Best regards,
Alain Mengus
Air Transport Business
 
BOEING747400
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RE: B744 And B744ER Questions

Mon Oct 21, 2002 1:12 am

Hello AFa340-300E:

It makes no sense for the Qantas 747-438ER to have 4 GE B1F engines since they are not powerful enough to handle the increased MTOW of 910,000 lbs.? Generally speaking, you definitely need more powerful engines for higher MTOW requirements and that'll be true for both B744ER and B777ER/LR.

If the Saudi Arabian and Virgin Atlantic B744s have GE B5F engines, then they should be called the ER versions because those powerplants are too powerful to have the MTOW of 875,000 lbs.?

Thanks,

BOEING747400
 
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RE: B744 And B744ER Questions

Mon Oct 21, 2002 1:40 am

Hello BOEING747400,

The thrust requirement is mostly driven by weight but also field performance and maintenance.

As you point out, the heavier an airplane is, the more thrust it needs. Uprated engines, however, improve the airplane's field performance -- at hot'n'high airfields in particular. This may explain why Saudia has picked the B5F (60,800lb).

I'm a bit surprised to see that Qantas would have selected the B1F (58,000lb) for their -400ERs since the airline will likely operate the airplanes at nearly MTOW on both sectors of the LAX-SYD and LAX-MEL routes. Has this anything to do with reducing the amount of thrust to length the on-wing lifetime by pushing the EGT margin limitation further down the road... I don't know.


But once again, 'ER' designates a nominal MTOW increase and a few other features that go alongside. Engine selection does not change anything here.
Saudia's and Virgin's are -400s.
Qantas' are -400ERs (well, the new ones).

There's an official Boeing document on Page 5 of my article that summarizes the changes of the -400ER vs. the -400.


Best regards,
Alain Mengus
Air Transport Business
 
LAXintl
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RE: B744 And B744ER Questions

Mon Oct 21, 2002 3:40 am

One reason Qantas might not have selected the B5F version is that the engine is really not required.
The potential initial airports that the aircraft might serve like LAX, LHR, SYD and MEL are at or near sea level with nice long runways.
Comparing the runway performance charts for the B1F versus B5F version, the aircraft can operate up to 910000lbs with the B1F at all the airports up to quite high temparatures.
LAX - Runway 25R - 31c degrees
MEL- Runway 16 - 32c
SYD - Runway 34L - 39c
LHR - Runway 27R - 37c

From the desert to the sea, to all of Southern California
 
BOEING747400
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RE: B744 And B744ER Questions

Tue Oct 22, 2002 3:33 am

Hello AFa340-300E:

Let me correct you that the B5F is rated at 62,100 lbs. (not 60,800 lbs.).

I'd like to know what type of B744 would be able to fly non-stop between BKK and LAX. Thai Airways uses the B744 with only one stop-over between BKK and LAX. Also, I'd like to know what type of B744 would be able to fly non-stop between BKK and JFK (through Europe as this route is probably shorter than the other way around the globe). I would imagine the B744ER can do BKK-LAX non-stop and the B744QXLR would be able to do BKK-JFK non-stop but I'm not quite sure about that. If that would be the case, then I guess Thai Airways could be one of the biggest customers of the B744ER and B744QXLR.

Thanks,

BOEING747400
 
AFa340-300E
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RE: B744 And B744ER Questions

Tue Oct 22, 2002 5:06 am

Hello BOEING747400,

Sorry for the stupid mistake on thrust rating!

I have no data to provide you for the -400ER or -400XQLR for BKK-LAX or BKK-SIN, but the A340-500 is slated to operate the latter route. The 747s would have fairly sizeable payload restrictions and probably a capacity in excess with what Thai Airways is looking for. That said, an order for either of the Jumbos should not be ruled out.


Best regards,
Alain Mengus
Air Transport Business
 
rendezvous
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RE: B744 And B744ER Questions

Wed Oct 23, 2002 11:48 am

Yes, the Qantas planes will be operation at or nearly at MTOW. I've seen a couple of times the LAX flight from SYD having to sit on the taxiway before takeoff to burn off fuel because it was over the MTOW.
 
Mr.BA
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RE: B744 And B744ER Questions

Wed Oct 23, 2002 7:03 pm

MTOW is usually very close to the Maximum Taxi Weight. Surely they didn't load the plane up to its very maximum? That would be cool to see!  Smile
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