Investigation into Secretive Surveillance Aircraft Accident in Malta 24 Oct 2016
The French BEA-D (Le Bureau Enquêtes Accidents Défense – Air UPDATE: renamed the BEA d’État [BEA-É] in 2018 in recognition of its role in all state aircraft) has issued a progress report into the loss of US registered SA227 AT Merlin IVC surveillance aircraft N577MX of Luxembourg based CAE Aviation operating from Malta for the French Government on 24 October 2016.
During the initial climb, 4 seconds after rotation, the aircraft pitched nose up, then rolled right around 150 degrees, reaching just over 260ft above ground level, before descending about 3 seconds later.
The aircraft rolled to the left prior to impact with the ground, 130 meters to the right of the take-off axis and approximately mid-runway.
The flight lasted about 10 seconds. There was a post crash fire. All 5 on board died.
N577MX had been modified from March 2015 to March 2016 and was officially owned by a company registered in Missouri. Different photographs in the BEAD-Report show an aircraft with a FLIR/EO sensor turret (though we believe this to be a US Air National Guard Bureau stock photo of a C-26) and another of N577MX two belly small radomes and a blade antenna. In its modified state the aircraft had a total of 6 seats.
The aircraft was owned and operated by CAE Aviation, a company formed in 1971, who conduct aerial surveillance and airborne geophysics operations as well a providing aircraft for parachute training. It is said to be unrelated to the Canadian company CAE but is an agent for Wescam. CAE Aviation are said to also operate N919CK (registered to a trustee in Delaware) in Malta.
The flight crew were employees of CAE Aviation. The Commander was aged 30 and the Co-Pilot aged 70. Both had FAA licences.
The rear crew consisted of a Tactical Coordinator and two Systems Operators aged between 32 and 52. The organisation that employed them is not revealed but press reports claim they worked for a French intelligence agency and the aircraft was conducting missions off the coast of Libya.
The aircraft was not fitted with a Flight Data Recorder. A acoustic spectral analysis of ground based video recordings shows that during the taxy out the rotational speeds of the two engines are identical. In flight at least one of the two propellers was operating at at rated speed until impact.
The BEA-D eliminated the possibility that one of the flight crew seats may have come unlocked at rotation (and so resulted in an inadvertent nose up pitch input as it slid aft). They do note that once the nose was 11 degrees above the horizon the ground ahead would not be visible.
Turbulence from the preceding 757 or from buildings was rejected as a possible cause due to a 3 minutes separation and the low wind on the day respectively.
No bird debris was found and no evidence of birds was seen in the surveillance videos or report by witnesses.
The Warning and Caution panel had 7 indicators lit (shown in red or green below), 22 off (in black) and 11 that so far have not been determined (in white). The one red light was for the SAS (stall avoidance system). Investigation is ongoing in this area.
Glare from the sun is a possible factor that has yet to be ruled out, but the BEA-D comment that this on its own would not account for the flight.
The BEA-D say ongoing investigations include into the propulsion systems (engines and propellers), flight instruments and the flight controls. Documents onboard the aircraft were restored in Malta and are to be examined. The modifications to the aircraft and its maintenance are being analysed. A flight test campaign in September 2017 on a similar aircraft is also being analysed. Enquiries in areas of organizational and human factors have began.
We will update this article when more findings are released.
So far the only recommendation is to have a contractual clause when chartering aircraft for the French Government that the BEA-D should be the accident investigation body.