Madrid - The airline Spanair did not heed the safety recommendations of McDonnell Douglas, the maker of the MD-82 jet that crashed at Madrid airport on August 20, killing 154 people, press reports said Tuesday.

Quoting a preliminary draft report by an investigating commission, the reports said the plane's wing flaps, which provide extra lift, were not extended properly for a reason that remains unclear.

The pilots ignored the problem, because the security mechanism that should have alerted them of it was not in order.

A similar problem occurred before a MD-82 crashed in Detroit in 1987, also killing 154 people.

McDonnell Douglas then recommended that pilots check the security mechanism before every flight, but Spanair regulations only include checks before the first flight of the day and before changes of both pilots, the commission said.

McDonnell Douglas merged with Boeing in 1997.

The causes of the Madrid accident remain unclear. Eighteen of the 172 people on board survived the crash. (dpa)