Airbus remains concerned about the progress of development of the A400M transport's TP400 turboprop engine and warns that several critical elements must be completed in the coming months if the tentative late-July target for the much-delayed first flight is to be achieved.

"The engine is the critical path - it's my number one concern," says Airbus executive vice-president programmes Tom Williams. The TP400 should have had accrued 1,500h of ground testing by beginning of last year, says Williams, but to date has completed just 600h.

The engine slip was cited by EADS as a key reason behind the one-year delay in the start of A400M deliveries to launch customer the French air force announced last October.


"We originally wanted a certificated engine for flight-testing," says Williams. But with that proposition ruled out, he says Europrop International must complete 1,400h of ground testing and 50h on the [Lockheed Martin] C-130K flying test bed (FTB) to clear the TP400 to power the A400M on its first flight.

Flight-testing of the TP400 by the UK's Marshall Aerospace, which should have begun last year, has been delayed as the installation of the engine on the C-130K had to be halted in December to replace the torque transducer, says Williams, who hopes the FTB will be airborne by March or April.

Williams says that if a testing rate of around 100h a month can be sustained through to the second quarter, he is optimistic that the required flight and ground test hours will be accrued by mid-year.

"That would mean we could fly in June," he says, but another critical pacing factor - the revised FADEC engine control software - will not be available until the following month. "That means that the earliest we can fly the first aircraft is the end of July," he says.

According to an EADS source, the first shipset of TP400s to power the first flight-test A400M is due to be delivered to the assembly line for installation in February.

Williams concedes that the manufacturer has its own "internal issues" on the A400 programme management: "The A400M was developed under the old GIE [consortium] model with national-based development teams," he says. "Now I'm pretty comfortable that enough actions are in place to have the aircraft ready in time."

Pictures of the first A400M ...