Swearingen Expediter ulykke i 2016 - En vemmelig sak - ASN

Status:	Final
Date:	Monday 24 October 2016
Time:	07:20
Type:	Swearingen SA227-AT Expediter
Operator:	CAE Aviation
Registration:	N577MX
C/n / msn:	AT-577
First flight:	1983
Total airframe hrs:	9261
Cycles:	3503
Engines:	2 Garrett TPE331-11U-611G
Crew:	Fatalities: 5 / Occupants: 5
Passengers:	Fatalities: 0 / Occupants: 0
Total:	Fatalities: 5 / Occupants: 5
Aircraft damage:	Destroyed
Aircraft fate:	Written off (damaged beyond repair)
Location:	Malta-Luqa Airport (MLA) (   Malta)
Phase:	Takeoff (TOF)
Nature:	Official state flight
Departure airport:	Malta-Luqa Airport (MLA/LMML), Malta
Destination airport:	Malta-Luqa Airport (MLA/LMML), Malta
Flightnumber:	LXC77

Narrative:


A Swearingen SA227-AT Expediter, registered N577MX, was destroyed after impacting terrain during takeoff from Malta-Luqa Airport. All five crew members sustained fatal injuries. The Expediter operated on a surveillance mission for the French Ministry of Defence. 
The aircraft left its parking stand at 07:15 and was cleared to line up and then take off at 07:18 for a standard instrument departure termed SUDIK 2B. The engines were throttled to full power and the brakes released at 07:19.
On lift-off, the retraction of the landing gear was initiated, and the aircraft continued to increase its pitch attitude. When the pitch angle reached 34°, the aircraft entered a power-on stall and banked suddenly to the right until it was three-quarters inverted. The bank angle was reduced at the apogee of the flight path, and then the aircraft continued its flight nose down.
The aircraft hit the ground with a 38° nose-down attitude, a bank angle of approximately 70° to the right and a symmetrical installed power on the two engines. A total of approximately ten seconds elapsed between lift-off and impact.

The Expediter operated on a surveillance mission for the French Ministry of Defence. The aircraft had been modified several times. Flight control modifications were carried out in 1985 prior to delivery to a shell company that was known to be used by the CIA. 
After being acquired by CAE Aviation, new sensors were installed in 2011 along with TCAS, TAWS, extra fuel tanks and HF/UHF antennas. In 2016 old sensors were removed and new sensors and antennas were installed.
The aircraft maintenance was performed in conformity with the maintenance programme by a French company in accordance with an FAA Repair Station approval. The maintenance company did not have the specific documentation for the flight controls modification carried out in 1985, which was protected under ITAR (International Traffic in Arms Regulations).

Probable Cause:

Causes of the accident:
Investigations show that a technical malfunction was the cause of the accident. This malfunction probably originated in the specific modifications of the aircraft and in the application of an inappropriate maintenance to these modifications.
Three scenarios can be envisaged:
- rupture of the HF antenna, which then wrapped around the elevator control surface;
- inadvertent activation of the SAS, countered by the pilot;
- jamming of the elevator due to a technical failure in the flight control line.
Given the condition of the wreckage and the absence of witness reports from the crew, only a flight data recorder could have enabled the BEA-É to confirm one of these hypotheses.
However, in consideration of the factors detailed in the analysis, the hypothesis of damage to a component of the elevator control line remains the most plausible explanation.