What happened
On 3 June 2010, a DC-9-82 with registration SE-DFY, operated by SAS, was performing a positioning flight from Tarbes Pyrénées Airport in France to Oslo, Norway. The aircraft had been undergoing long-term storage at a maintenance facility operated by TARMAC.
Shortly after departing on runway 02, Air Traffic Control (ATC) notified the flight crew that a large object had been discovered on the runway near the takeoff path. While the crew did not notice any immediate irregularities during the takeoff roll, the presence of debris on the runway prompted the crew to reduce airspeed and abandon planned technical system checks. To ensure the aircraft's integrity, the crew requested a visual inspection by a French Air Force Mirage fighter jet. Although the fighter pilot reported no visible missing panels, the crew elected to divert to Stockholm/Arlanda for a more thorough inspection.
The investigation
An investigation by the Swedish Accident Investigation Authority (SHK) focused on the condition of the aircraft's stabilizer area. Upon arrival at Arlanda, a subsequent hangar inspection confirmed that the right upper stabilizer panel had indeed separated from the aircraft.
Investigators examined the fastening hardware and found that the detached panel was only secured by four screws out of the required sixteen. Furthermore, the left upper fairing assembly was found to be improperly secured, with several missing or loosely fitted fasteners. The investigation also reviewed the maintenance records and work practices at the TARMAC facility, specifically looking at tasks such as the lubrication of the horizontal stabilizer and jackscrew, which might have necessitated the removal of these panels.