GUY NORRIS / LOS ANGELES

Boeing has issued its fourth, and probably final, set of technical requirements for engines for the 7E7 family, and could make its supplier selection by mid-April.

The "Phase 4" requirements document calls for proposals for two distinct engines covering the 55,000-60,000lb (245-267kN)-thrust range for the base/short-range 7E7 and 70,000lb-thrust plus for the stretch. However, the manufacturer says "this does not signal that any sort of decision has been made in terms of both the family members we have outlined. We still don't know if it is going to be one or two engine types, or one or two engine manufacturers." Phase 3 proposals were submitted in November.

The "big three" engine makers are expected to supply "final" engine configurations by the end of February, though "business conversations" will continue up to Boeing's final decision sometime after 31 March. Boeing says that "we've said this [decision] will be around mid-year, but it may happen earlier".

Boeing originally planned to decide on the engine choices for the 7E7 around the end of 2003, but slipped the selection into "mid-2004" when thrust requirements diverged with the evolution of the short-range, base and stretch variants in the third quarter (Flight International, 11-17 November 2003).

General Electric is thought to be offering a GE90-based GEN-X family with different fan sizes, while Pratt & Whitney has similarly defined two offerings based around a core derived from its F119 military powerplant. Rolls-Royce is believed to be taking a different approach and is studying scaling the core rather than the fan for its two proposals.

Source: Flight International