Investigation Summary
The flight was a multi-leg journey originating in Tunis with a scheduled stop in Nice before continuing to Paris. Shortly after lifting off from Nice-le Var Airport, the aircraft exhibited an uncommanded left bank. The crew was unable to counteract the roll, and the aircraft inverted before crashing approximately one kilometer north of the airfield. The investigation focused on the dual control column assembly, discovering that a control chain had slipped off its sprocket in the co-pilot's station. This mechanical displacement physically jammed the entire aileron circuit, leaving the pilots with no lateral control. The design of the Languedoc's control columns made these chains difficult to inspect and properly tension, which investigators identified as a critical design flaw that facilitated the failure.
Final Conclusions
The accident was caused by a total loss of lateral control resulting from a jammed aileron circuit. The jam occurred when a control chain slipped off its sprocket within the co-pilot's control column. This failure was attributed to a design fault that made the chains difficult to set, maintain, and inspect, leading to an undetected unsafe condition prior to take-off.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Systems & Failure Modes
Aileron Control Circuit
The mechanical linkage responsible for lateral (roll) control, which became physically jammed.
Control Column Chain and Sprocket
A specific mechanical assembly within the dual control columns where a chain slipped, causing the jam.
Interesting Facts
- 01The accident is the deadliest involving the SNCASE Languedoc aircraft type.
- 02The crash killed several notable figures, including French actresses Lise Topart and Michèle Verly, American actress and ballet dancer Harriet Toby, and British shipowner John Emlyn-Jones.
- 03Thirteen of the 38 victims were British nationals.
- 04The aircraft was powered by four Pratt & Whitney R-1830 SIC-3-G engines.
- 05Investigators found the control chain mechanism was nearly impossible to inspect thoroughly during routine maintenance due to its placement.
- 06The crew consisted of four members, all of whom perished in the accident.
Safety Actions & Advisories
Control Column Inspection Review
The investigation highlighted the difficulty of inspecting the control chains, leading to recommendations for improved access and maintenance procedures for the SE.161 Languedoc's flight controls.