Hydrogen Alpha
9th Sep 2011, 11:31
Hi,
I'd really appreciate some help here - I'm struggling badly.
I am trying to get a good figure for the typical MEW for a B777-200 & B777-200ER (say Pratt power as a datum, accepting that Rolls are lighter and GE heavier), but the data sources I have - and definitions of MEW - just don't reconcile.
To be as brief as I can;
- Both Airbus' & Boeing's MEW definitions appear to be identical - "structure, powerplant, systems, furnishings and other items that are an integral part of the aircraft configuration, including fuilds contained in closed systems" - and Operator Items are excluded.
- Despite the reference to "furnishings", Airbus confirm to me that they regard seats as Operator Items, and not part of the MEW (which must be logical).
- However, the Boeing position on seats (from published and proprietary data) appears to be ambiguous. Not clear at all whether they are "in" or "out" of the MEW.
- In terms of actual weights, Boeing's now ancient B777 ACAP from 1998 shows an "illustrative" OEW for the 777-200ER of 304,500 lbs, while a United Airlines W&B shows the MEW for the same aircraft type as 281,575 lbs - apparently BEFORE the weight of seats are deducted, implying a net MEW, without seats, of about 260,000 lbs.
- So where's the problem? The problem is that airframe-specific W&B Booklets I have for two airline's B777-200ER fleets show
average fleet OEWs of 328,591 lbs and 322,292 lbs respectively, way above the ACAP fugure, which point to "Basic Empty Weights", without seats, of around 285,000 lbs - 25,000 lbs above the figure implied from the UA W&B. (I also have a reference showing GECAS' B777-200ER fleet having an OEW of 319,700 lbs).
Any feedback will be very much appreciated. I really struggle to believe that the MEW of the B777-200ER without seats could be as low as 260,000 lbs, but I hope my doubts are misplaced.
Thanks in anticipation,
HA
I'd really appreciate some help here - I'm struggling badly.
I am trying to get a good figure for the typical MEW for a B777-200 & B777-200ER (say Pratt power as a datum, accepting that Rolls are lighter and GE heavier), but the data sources I have - and definitions of MEW - just don't reconcile.
To be as brief as I can;
- Both Airbus' & Boeing's MEW definitions appear to be identical - "structure, powerplant, systems, furnishings and other items that are an integral part of the aircraft configuration, including fuilds contained in closed systems" - and Operator Items are excluded.
- Despite the reference to "furnishings", Airbus confirm to me that they regard seats as Operator Items, and not part of the MEW (which must be logical).
- However, the Boeing position on seats (from published and proprietary data) appears to be ambiguous. Not clear at all whether they are "in" or "out" of the MEW.
- In terms of actual weights, Boeing's now ancient B777 ACAP from 1998 shows an "illustrative" OEW for the 777-200ER of 304,500 lbs, while a United Airlines W&B shows the MEW for the same aircraft type as 281,575 lbs - apparently BEFORE the weight of seats are deducted, implying a net MEW, without seats, of about 260,000 lbs.
- So where's the problem? The problem is that airframe-specific W&B Booklets I have for two airline's B777-200ER fleets show
average fleet OEWs of 328,591 lbs and 322,292 lbs respectively, way above the ACAP fugure, which point to "Basic Empty Weights", without seats, of around 285,000 lbs - 25,000 lbs above the figure implied from the UA W&B. (I also have a reference showing GECAS' B777-200ER fleet having an OEW of 319,700 lbs).
Any feedback will be very much appreciated. I really struggle to believe that the MEW of the B777-200ER without seats could be as low as 260,000 lbs, but I hope my doubts are misplaced.
Thanks in anticipation,
HA