BOEING AND GENERAL Electric are proposing a revised plan to test the effectiveness of modified acoustic panels on the GE90 engine which suffered ice-impact damage during a crucial natural-icing flight-test on 9 October.

The icing test is the last significant hurdle to be overcome before the GE90-powered 777 is certificated and delivered to British Airways.

GE hopes that the revised plan could lead to certification by 30 October. Sources close to the European Joint Aviation Authorities, which has to certificate the airframe/engine combination before BA can operate it, believe this date is "optimistic", however.

The US Federal Aviation Administration says that continuing function and reliability testing does not need to be started afresh as a result of the problem.

It also says that component tests of the new panels should be made before putting them into the engine and completing a second natural-ice test.

GE plans to send strengthened panels to Boeing so that flight-tests can be re-started around 23 October, but is proposing to the FAA that it waive new natural-icing tests and rely instead on the component test to prove the modification.

GE is studying various solutions, including replacing the panels with a glass-fibre-reinforced plastic fairing and strengthening the present design.

Source: Flight International