By Andrea Shalal

RAF FAIRFORD, England (Reuters) - European authorities have certified an interim fix for a power gearbox issue with engines on Airbus Group SE's <AIR.PA> A400M transport aircraft, paving the way for countries to resume normal operations of the planes, company officials said on Saturday.

"It's good news. It means that we're going to be alleviating the pain of the nations sooner," Fernando Alonso, president of Airbus Military Aircraft, told Reuters. "It means they will essentially be able to use the aircraft normally again."

Alonso said the European Aviation Safety Agency would now require initial inspections of the planes after 650 flight hours, up from 100 hours, with follow-up inspections to be required every 150 hours, up from the 20-hour cycle imposed after the gearbox issue first emerged in late December.

The EASA certification clears the way for Italy’s Avio, a unit of General Electric Co <GE.N>, to begin retrofitting engines on existing planes with a modified part to replace the one with cracking. It can also begin producing new power gearbox kits with the part integrated.

Airbus said the certification of the interim fix came a month or more sooner than planned. The company is continuing to work with GE and Avio on a long-term solution for the gearbox.

Alonso said Airbus was also focused on adding tactical capabilities to the big transport plane, and has delivered the first aircraft capable of tactical tasks to France.

The new plane offers armoring protection, refueling, the ability to airdrop loads, landings on some non-prepared runways and equipment to detect and counter enemy radars and missiles.

Airbus has delivered 27 A400M aircraft to date, including a fourth plane delivered to Germany on Friday, the company said.

Nearly all the aircraft have been affected by the engine issue, although only it affects only the two clockwise turning engines on each of the four-engine aircraft.

It was not immediately clear how quickly Avio could build and deliver the retrofit kits for planes already delivered. Work on the kits, and production of power gearboxes with the modified part would start immediately, Airbus officials said.

Airbus officials also disputed an article in Germany's Spiegel magazine, which cited a link between cold temperatures in the back of the aircraft and irregular air flows that could affect paratrooper operations.

"There is no link," said an Airbus spokeswoman.

Airbus said it was working on both issues, and would install a more efficient thermal curtain near the back of the plane by the end of the year to keep the back of the cabin warmer. The company is also examining a possible readjustment to the air flow system that would send more warm air to the back of the plane. No timing was given on that issue.

It cited progress on qualifying and certifying the aircraft for paratrooping operations with one side door only, or using the ramp.

"Safety is paramount in this development program and we would note that the current regulations are very much stricter than those applied to legacy aircraft," the company said.

(Reporting by Andrea Shalal; additional reporting by Madeline Chambers in Berlin, editing by Louise Heavens)