Las Palmas/Madrid  - Around 1,000 people Wednesday attended a funeral mass for the 154 victims of last month's Madrid air crash in Las Palmas, capital of the Canary Islands that were home to 72 of the dead.

Guests included Spain's Crown Prince Felipe, his wife Letizia, Prime Minister Jose Luis Rodriguez Zapatero and opposition leader Mariano Rajoy.

"All of the Canaries have been covered by a blanket of grief," Archbishop Francisco Cases said at the funeral, which followed a bigger one in Madrid last week.

A Spanair MD-82 jet en route to Las Palmas crashed off the runway after take-off on August 20. Eighteen on board survived.

Also on Wednesday, Spanair said that after the crash, it instructed pilots to increase checks on takeoff warning systems of McDonnel-Douglas planes/

A commission investigating the accident has found that the wing flaps of the MD-82 which crashed were not correctly deployed, according to a preliminary draft report leaked to the media. Spanair confirmed that it had received a copy of the report.

The flaps are moveable panels on the rear edge of a plane's wings that help lift it on take-off.

The take-off warning system that should have alerted the pilots about the problem did not sound off, the report was quoted as saying.

The same problem occurred on an MD-82 that crashed in Detroit in 1987, also killing 154 people.

The plane maker McDonnell Douglas subsequently advised pilots to check the take-off warning mechanism before every flight, but Spanair instructions only included checks before the first flight of the day and when the crew changed.

Spanair did not exist when McDonnell Douglas issued the recommendation, which it had not been informed of, operational director Javier Muela was quoted as saying.

The plane that crashed began its journey in Barcelona. Muela said it was not known whether the pilots checked the warning system during the stopover in Madrid.

He denied that a failure to do so could have caused the accident.

Spanair has, however, revised its handbooks to include checks of the warning mechanism before every flight, Muela said.

Several pilots, meanwhile, stepped down from the investigating commission in protest at the leaking of the draft of the preliminary report to the press, according to the daily El Pais. (dpa)