Engine Alliance is claiming better-than-predicted fuel burn in service for its GP7200 engine on the Airbus A380, and hopes Airbus will officially recognise this by revising the aircraft's performance manual next year.
"The average range of delivered GP7200-powered A380s is 0.7% ahead of the datum in Airbus's A380 'Orange Book' performance handbook," said the then Engine Alliance president Jim Moravecek at last month's Dubai air show. Moravecek has since returned to Engine Alliance partner Pratt & Whitney and been replaced by Mary Ellen Jones.
The A380's performance relative to guarantees was highlighted by Emirates Airline president Tim Clark when Flight International compiled its in-service report on the super-jumbo recently. "Meeting the performance guarantees doesn't come into it - she's ahead of her nominals," he said.
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The General Electric/P&W joint venture says the current A380/GP7200 Orange Book is based on both the GP7200 flight-test airframe (MSN009) and the first production aircraft (MSN011). It says the average performance demonstrated by the GP7200-powered aircraft delivered so far (including MSN011) is showing a 0.7% margin relative to the Orange Book.
"Based on that consistent performance and by assessing additional engines to be delivered in the coming months, we anticipate the opportunity for further revisions to the Orange Book," says Engine Alliance. But it concedes that "any adjustment is an Airbus decision".
Airbus says the production GP7200s fitted to delivered A380s have "an improved specific fuel consumption level over the initial GP7200 engines on the development aircraft" and this is already reflected in the Orange Book.
"Indications are that there is a +0.7% performance margin of the GP7200-powered A380 relative to the model reference," says Airbus. "We will reassess this margin next year, as per normal Airbus practice, which may lead to a modification of the model reference."
According to Engine Alliance, the GP7200 beat Airbus's original A380 performance target by 0.9%, which it claims puts it 1% ahead of the current Rolls-Royce Trent 900 that is in service with Singapore Airlines and Qantas.
Moravecek says the only way R-R can counter the GP7200's claimed 1% advantage is "by offering money". R-R is developing a Trent 900EP package incorporating Trent 1000 technology, which it expects to deliver a 1% gain in fuel burn from 2012. But Moravecek dismisses this threat, saying that the GP7200 "is as good as the Trent 1000 from a technical standpoint".
Source: Flight International