Investigation Summary
The aircraft, N577MX, was a highly modified surveillance platform built in 1983. In 1985, it underwent significant flight control re-routing and Stall Avoidance System (SAS) modifications to accommodate specialized equipment. These modifications were protected under ITAR (International Traffic in Arms Regulations), and the French maintenance facility responsible for the aircraft in 2016 did not possess the specific documentation for these changes. On the morning of the accident, the aircraft performed a normal takeoff roll, but immediately upon rotation, it began an uncommanded pitch-up. Analysis of security camera audio and GPS data showed the aircraft reached a 34-degree pitch and a 152-degree bank angle within 10 seconds. The investigation found that the SAS FAULT light had illuminated prior to impact. Because the aircraft lacked a Flight Data Recorder (FDR) and Cockpit Voice Recorder (CVR), investigators could not definitively prove which specific failure occurred, but they narrowed the cause to a mechanical failure in the elevator control line that prevented the pilot from pushing the nose down.
Final Conclusions
The investigation, led by the BEA-E (Bureau d'Enquêtes et d'Analyses pour la sécurité de l'Aviation civile : État), concluded in report I-2016-15-A that the accident resulted from a technical malfunction. This malfunction likely originated in the specific, non-standard modifications of the aircraft's flight controls and the application of maintenance that did not account for these modifications. The most plausible scenario was a failure or jamming of the elevator control line, though inadvertent SAS activation or a snapped HF antenna cable jamming the elevator remained secondary possibilities.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
Employed by CAE Aviation.
Monitoring Pilot
Not certified to fly the SA227, but not required to be for his role.
Systems & Failure Modes
Stall Avoidance System (SAS)
A stick-pusher system designed to prevent stalls by automatically pushing the control column forward. In this aircraft, the SAS had been modified and relocated near a water drain, potentially increasing the risk of inadvertent activation or failure.
Elevator Control Line
The mechanical cables connecting the cockpit control column to the elevator surfaces. Investigators believe a rupture or jam in the nose-down cable prevented the pilot from counteracting the steep pitch-up.
HF Antenna
A non-standard cable extending from the forward fuselage to the vertical stabilizer. One theory suggested this cable snapped and wrapped around the elevator, though no debris was found on the runway to support this.
Interesting Facts
- 01The aircraft was not equipped with a CVR or FDR as it was not legally required for its surveillance category.
- 02All five occupants were French nationals; three were employees of the Directorate-General for External Security (DGSE).
- 03The aircraft had been modified in 1985 for a shell company allegedly used by the CIA.
- 04Post-crash analysis of cockpit annunciator filaments showed the SAS FAULT light was active before impact.
- 05The aircraft reached a maximum altitude of only 260 feet before the fatal descent.
Safety Actions & Advisories
Maintenance Documentation Review
The investigation highlighted the danger of performing maintenance on modified aircraft without access to the specific technical documentation for those modifications, particularly when restricted by ITAR.
Known Controversies & Unanswered Questions
Mission Purpose Discrepancy
Reference ↗The Maltese government initially claimed the flight was a French customs operation against trafficking, but French customs denied involvement. The French Ministry of Defence later confirmed the passengers were intelligence officials.