Trouble brews for Airbus Group as the company struggling to meet the deadlines for the delivery of A400M military transport planes as it faces renewed pressure from France and other European buyers to meet performance and delivery pledges.

Primarily due to issues at an Italian subcontractor that have sparked potential compensation claims, the A400M has been plunged into uncertainty again, after partly successful efforts to overcome delays on Europe’s largest defense project.

Airbus is yet to provide any assurance to inquiries by France, which has written letters to the company, about whether problems with Italian-built gearboxes and other threats to the A400M’s military effectiveness will be resolved this year, severl people who had knowledge about the issue.

Gearbox flaws that require the planes to be checked every 20 flight hours, incomplete defensive systems and limits on certain types of parachute operation are the three major problems that have caused concerned for France that have been claimed to hamper the troop and heavy equipment carrier even as there is urgent needs in sub-Saharan Africa and Iraq.

“No, not right now, and especially not in the required timetable, which is by the end of this year”, said one person familiar with the matter when asked if Airbus had been able to give clarity on resolving them.

There have been no comments from the French government. Airbus said it did not comment on discussions with buyers.

In order to give Europe an independent airlift capability, Belgium, Britain, France, Germany, Luxembourg, Spain and Turkey – the seven members of the North Atlantic Treaty Organization have ordered the A400M.

The country may have to buy other transport planes as well and would exercise its right to compensation for delays in deliveries of the A400M, said German Defence Minister Ursula von der Leyen last week.

Problems continue to beset the project launched in 2003 and Airbus is expected to add to the more than 5 billion euros it has already written off despite the A400M receiving a 3.5 billion euro bailout in 2010 and Airbus later overhauled its management.

A vulnerability in cockpit alarm systems was exposed last year after a fatal crash that is still being investigated.

Then early this year tough new inspections were started after a crack was found inside a power gearbox (PGB) made by General Electric’s Italian unit Avio Aero.

“It is currently the main problem and it generates uncertainty about the number of aircraft that can be delivered this year, because it is still unknown how many PGBs Avio can provide,” a person close to the project said.

The person said that things had improved since GE bought it in 2013 and added that Avio’s Turin factory “must be modernized”.

“We are committed to improving our production”, an Avio spokesman said but declined comment on the A400M.

Industry sources said that Airbus hopes to have a certified long-term solution in place for the gearboxes in September and believes it is making progress.

“We know it is very frustrating for our customers and are working extremely hard with our engine suppliers and specifically Avio to work out a solution and implement it as quickly as we can,” an Airbus spokeswoman said.

(Adapted from CNBC)