Boeing and Rolls-Royce are confident that certification of the Trent 890-powered 777-200 Increased Gross Weight (IGW) version of the Boeing twinjet is "on target" to be completed by the end of March, despite a rescheduling of testing because of some late changes in engine configuration.

The release of modified engine hardware, meanwhile, will enable operators of Trent-powered 777s to initiate 180min extended-range twin operations (ETOPS) flights.

R-R is now installing the modified engine parts, which centre around a revised radial drive shroud tube, on the Emirates-liveried test aircraft. This will enable Boeing to start the rescheduled function-and-reliability testing which is required for the supplementary ETOPS certification.

This will include cycling at temperatures between -30íC and 30íC, but is not the 1,000-cycle test required for initial ETOPS certification, says Boeing.

A second Emirates aircraft could be made available to the test effort to help catch up with the schedule, the company adds.

According to Phil Hopton, R-R's project director for RB.211 and Trent engines, the manufacturer wished to carry out the function-and-reliability test-flights using the latest production configuration, which resulted in a rescheduling of the programme.

Hopton adds that US Federal Aviation Administration type-certification flight-testing has been completed and approval of the Trent-powered 777 IGW, along with 180min ETOPS certification, is expected by the end of March, as originally scheduled.

The revised shroud tube hardware is now being despatched to operators to enable their in-service 777-200As to be modified, and this will enable them to initiate 180min ETOPS flights. "We had a mutual agreement with the operators that they would delay the start of 180min ETOPS flights until the revised hardware has been installed," says Hopton.

British Airways, meanwhile, became the first customer to take delivery of a 777-200IGW, on 7 February, following receipt of US and European type approval for the General Electric GE90-powered version of the aircraft. ETOPS certification had been granted to the airframe/engine combination two days earlier.

Function-and-reliability tests of the Pratt & Whitney PW4090-powered 777-200IGW have also been completed. Certification is expected by the end of February. The first aircraft will be delivered to United Airlines in early March, one of 14 for the airline this year.

Source: Flight International