Boeing is studying an increase in the weight of the 777X to close to the ultimate design limit as it struggles to find a launch customer and stick to its late 2002 entry into service target.
News of the weight boost option emerged as General Electric reversed policy and revealed surprise plans to restart a study into increasing the thrust of the GE90 to as much as 112,000lb (498kN).
The new growth plan could increase the 777-200X take-off weight by around 6,800kg (15,000lb) to 340,500kg. Potential buyers include American Airlines, Air France, Delta Air Lines, Egyptair, Malaysia Airlines and Thai Airways International.
Thai president Tamanoon Wanglee says the airline could make a decision next year to purchase the -200X.
Despite the success of the competing Airbus A340-500, the US manufacturer remains committed to launching the ultra-long-range 777 derivative. "I believe we can get the aircraft sold in a short period of time," says product marketing director Joe Ozimek. "We've never been deterred in the -200X market and we clearly know where we are going with this aircraft. We are still looking for entry into service by late 2002 or early 2003 so we don't have to start for a year."
News of the weight increase study emerges as Boeing has issued requests for information (RFI) to engine makers for an auxiliary power and thrust unit (APTU). The company is studying the APTU as a means of boosting thrust by around 10,000lb to improve take-off performance at heavy weights. Companies expected to respond to the RFI include Allison, with its AE3007, and General Electric, with its CF34 and a civil, derated, version of the F414.
GE's surprise return to studies of the much larger GE90 was revealed by company president Jim McNerney. "We have been reluctant to do a 98,000-102,000lb thrust engine because there is no market. Now, Boeing is beginning to talk about a bigger aircraft and airlines are discouraging them on things like the thrusting APU. We are ready to do that big engine and our investment on the GE90 will pay off," he predicts. The GE move, if sanctioned by the company, will help counter the growing strength of Rolls-Royce and Pratt & Whitney, both of which are developing growth 777 engines beyond 100,000lb thrust.
Although Ozimek says "-it is good to have options", Boeing sources say that "-the thrusting APU will not fly" and the bigger engine solution is the prefered option. The sudden flurry of 777 engine activity is also being traced to the British Airways requirement which calls for 95,000lb-thrust engines on up to 26 of the 32 higher gross weight 777s on order and option. Boeing confirms that P&W's PW4098 engine, originally developed for the stretched 777-300, "can be offered" on the 777-200ER "without major structural changes".
Source: Flight International
