FARNBOROUGH England (Reuters) - Planemaker Airbus (>> AIRBUS GROUP) on Wednesday sought to allay any concerns over the impact of door problems on its A380 superjumbo after a German broadcaster reported its breakeven target could be delayed by several years.

Airbus said it was testing improvements to the doors after a recent plane diversion and several incidents involving noise onboard and said the programme was still on track to reach breakeven in 2015.

"It's a comfort issue, not a safety issue," a spokesman said at the Farnborough Airshow where Airbus has been displaying a test aircraft with blue stripes above some of its doors, marking the place where new coverplates are undergoing trials.

The door glitches will not affect the group's plans to deliver 30 of the aircraft each year, he added.

On Jan. 4, a Singapore Airlines (>> Singapore Airlines Ltd.) A380 carrying 494 people made an emergency landing in Baku, Azerbaijan, after problems with the door seal led to oxygen masks being deployed.

German broadcaster NDR reported that checking and modifying all the doors to resolve the problem would mean the A380 programme reaching break-even several years later than expected.

The report piled further attention on the superjumbo at the Farnborough Airshow where Airbus has already been under mounting pressure from Qatar Airways over problems in finishing the cabin interior.

The problems that have delayed delivery of Qatar's first three A380s are not officially connected to the door issue, but may not ease efforts to speed up delivery after the head of the airline repeated he was committed to “demanding” standards.

On Tuesday, Chief Executive Akbar Al Baker also called for compensation over the delay and said that besides the cabin problems, the delay was linked to a further issue that he declined to identify. The airline declined further comment.

An Airbus spokesman said it expected a fix for the doors would be approved in the autumn by European safety authorities and it would then be fitted to planes rolling off the production line from 2015, with successive upgrades for planes already in service.

The current plan is to do this during regular maintenance, thus meaning the planes would not be on the ground any longer than usual, he said.

The planemaker has booked orders for 324 of the planes, which each have 16 doors, from 20 customers. So far, 135 have been delivered to 11 customers.

Airbus said fatigue had been found on fewer than 10 percent of the more than 400 doors inspected on the A380.

A380 customer Lufthansa (>> Deutsche Lufthansa AG) said it was aware of the issues but hadn't experienced any problems. A spokesman said if necessary Lufthansa could keep using some old 747s to maintain service but it was not yet clear what the impact would be.

(Reporting by Victoria Bryan and Tim Hepher; Additional reporting by Maria Sheahan in Frankfurt; Editing by Mark Potter and James Dalgleish)

Stocks treated in this article : AIRBUS GROUP, Deutsche Lufthansa AG, Singapore Airlines Ltd.