A combination of human error and mechanical failure may have caused the air crash that killed 154 people at Madrid airport on August 20, the Spanish daily El Pais reported, quoting sources of the investigation as saying.

The Spanair MD-82 did not have its wing flaps and slats deployed, according to a preliminary report issued earlier by an investigating commission. The flaps and slats help to lift aircraft on take-off.

A recording contained in the plane’s black box indicated that the pilots requested permission for take-off from the control tower before going through the entire after-start checklist, omitting to check the position of the flaps and slats, according to the sources quoted by El Pais. The plane had been delayed by more than an hour by the discovery of a faulty temperature gauge, which mechanics disconnected.

The pilots may also have wanted to make use of the availability at that moment of the control tower, which was busy during the high tourist season, the sources were quoted as saying. A cockpit warning mechanism should have sounded to alert the pilots that the flaps and slats were not in order, but it failed to function. The plane, which was en route to the Canary Islands, crashed after rising 12 metres above the ground. Almost identical circumstances caused the crash of another MD-82 in 1987 in Detroit, where 154 people were also killed, El Pais said.