A mechanic who repaired a technical problem on a Spanair jet that crashed in Madrid in August, killing 154 people, did not follow the instructions of plane maker Boeing.
The technician had carried out a last-minute fix to the plane after the MD-82 plane bound for Spain's Canary Islands had to abort its first take-off, the daily newspaper El Mundo says.
The plane, suffering a problem with a temperature gauge just before the accident on 20 August, had been forced to return to the boarding gate area so it could be fixed.
The temperature gauge, which is linked to 25 other mechanisms including the sound alarm, failed to warn the pilots there was a problem with the wing flaps, the paper said.
Both El Pais and El Mundo last month leaked extracts of the preliminary report into the crash that said the wing flaps, which help lift planes on take-off, had not properly extended when it attempted to take off.
The pilots were not aware of the problem until it was too late because a warning alarm failed to work, said the reports.
The plane managed to climb 12 metres into the air before it tilted slightly to the left and then hard to the right before crashing.
Only 18 people survived the crash, making it Spain's deadliest air accident in 25 years.
The plane was made by McDonnell Douglas, which merged with Boeing in 1997.
Spanair has said it is company policy to check the flaps three times before every flight.