F R 3 - 9 7

Home | Update | Latest Issue | Gallery | FR Profile | Datafiles | FR 3/97 BOEING STRETCHES 757 AT LAST by Norbert Burgner To carry more passengers over the same range at lower operating costs, these are the design characteristics of the new Boeing 757-300. With the new version, Boeing wants to offer the airlines a custom-fit solution as an alternative to the Airbus models A321 and A310, as well as, to the McDonnell Douglas DC-10 and Lockheed L1011 TriStars which are due for replacement. By continuing the development of an existing model, Boeing is further pursuing its "derivative philosophy". The new 757 variant is scheduled for its first flight in July of next year, and, beginning in January 1999, it is to enter service for the German holiday carrier Condor (12 orders and 12 options, total volume $875 million). The 757-300 will seat 225 to 289 passengers, giving the airliner a 20 percent higher capacity than the current -200 model. According to Boeing, the -300 has a 48 percent higher freight capacity than its sister model. This is made possible by stretching the fuselage by 7,1 meters. Program manager Bruce Nicoletti points out that this wasn't accomplished by adding additional plugs but, by extending sections 43 and 46. Lengthwise, the stretching brings the 757 in the region of the 767-300. Still, its capacity is below the larger Boeing twin because of the 767's wider body. The 757 body stretch also results in a significantly higher maximum take-off weight (122,6 tons) which is a good seven tons higher than the -200's MTOW. The higher weight also causes the fuel consumption to increase, also. Project chief engineer, Daniel Mooney, admits that in relation to the tripcosts (in $ per Nautical Mile)an increase of 8,5 percent has to be expected. However, he also says that the mentioned higher passenger and freight capacity is reversing this disadvantage, stating that, in the end, the -300 can be operated approximately ten percent cheaper than the -200 (measured in costs per offered seat mile). According to Mooney, there is only little difference in the performance of the two 757 variants. However, in this calculation Boeing is assuming relatively light take-off weights (88 tons for the -200 and 99,7 tons for the -300). Fully seated and fueled (43432 liters), giving the -300 a weight of 122,5 tons, there will probably be another result under the bottom line. To suit the new 757 with competitive performance data is the task for the engines. Both available propulsion options were increased in thrust, as compared to the engines used on the -200 (by 7,5 percent for the Rolls-Royce RB211-535E4B and by up to 15 percent for the Pratt & Whitney PW2043 engines). Such fitted, the -300 is supposed to fly up to 3500 NM, allowing direct flights from New York to destinations such as London or Paris. Supposedly, the Pratt & Whitney turbofans, in spite of their higher thrust, are offering better fuel data than the Rolls-Royce option because they weigh less. Still, it looks like launch customer Condor didn't follow this argumentation and voted in favor of the Rolls-Royce engines, although the rest of Condor's 757 fleet is powered by P&W engines. According to Condor speaker, Herbert Euler, the airline has evaluated all facts and has made the decision for the RR propulsion out of economical reasons. Euler wouldn't go into further details. Bruce Nicoletti is convinced that the 757-300 is the most economical product in the class of 250-seat airliners. As compared to the Airbus models A321 and A310, the new -300 supposedly has lower operating costs of 13 respectively up to 20 percent. However, the 321 has only 185 seats which is 100 less than the new 757. Since the seat mile costs are a function of the seating capacity also, it is easy to construct an advantage for the larger aircraft. The only credit for the A310 is that it is already a 15 year old aircraft. Nicoletti does not like to look at the new 757 as being a new development: "There is not much new about the new 757. We intentionally pursued a philosophy of minimum changes to ensure the commonality with the current 757 fleet." He continues, saying that there have been only minor modifications - mainly structural enforcements and a slight correction of the flap-30 position to lower the nose during approach, such minimizing the risk for tail strikes which are known to be problematic with the 757 design. All together the new 757 is still the old one, says Nicoletti, except for the small but fine difference for the airlines that "... the 757 can now carry more passengers for the same ticket price." From page 28 of FLUG REVUE 3/97 Home | Update | Latest Issue | Gallery | FR Profile | Datafiles | FR 3/97 Copyright 1997 by Motor-Presse Stuttgart. All rights reserved. Last updated February 13, 1997