Flight

Findings as to causes and contributing factors:
1. For unknown reasons, the aircraft descended in the direction of flight at high speed until it exceeded its structural limits, leading to an in-flight breakup.
2. Based on the captain’s blood alcohol content, alcohol intoxication almost certainly played a role in the events leading up to the accident.

Findings as to risk:
1. If cockpit or data recordings are not available to an investigation, the identification and communication of safety deficiencies to advance transportation safety may be precluded.
2. If Canadian Aviation Regulations Subpart 703 operators are not required to have a Transport Canada–approved safety management system, which is assessed on a regular basis, there is a risk that those companies will not have the necessary processes in place to manage safety effectively.
3. If safety issues, such as concerns related to drug or alcohol abuse, are not reported formally through a company’s safety reporting system, there is a risk that hazards will not be managed effectively.
4. Transport Canada’s Handbook for Civil Aviation Medical Examiners(TP 13312) does not address the complete range of conditions that may be affected by drug or alcohol dependence. As a result, there is an increased risk that undisclosed cases of drug or alcohol dependence in commercial aviation will go undetected, placing the travelling public at risk.
5. If there is no regulated drug- and alcohol-testing requirement in place to reduce the risk of impairment of persons while engaged in safety-sensitive functions, employees may undertake these duties while impaired, posing a risk to public safety.

The fuel pump gear manufacturer’s allowance of set-up gears made from a nonconforming material to be put in the production inventory system, the installation of a nonconforming gear in the accident airplane’s production fuel pump, and the gear’s failure, which resulted in a loss of fuel flow to the engine and the subsequent loss of engine power.

The collision with the ground was due to the deliberate and planned action of the copilot who decided to commit suicide while alone in the cockpit. The process for medical certification of pilots, in particular self-reporting in case of decrease in medical fitness between two periodic medical evaluations, did not succeed in preventing the copilot, who was experiencing mental disorder with psychotic symptoms, from exercising the privilege of his licence. The following factors may have contributed to the failure of this principle:
-The copilot’s probable fear of losing his ability to fly as a professional pilot if he had reported his decrease in medical fitness to an AME,
-The potential financial consequences generated by the lack of specific insurance covering the risks of loss of income in case of unfitness to fly,
- The lack of clear guidelines in German regulations on when a threat to public safety outweighs the requirements of medical confidentiality.
Security requirements led to cockpit doors designed to resist forcible intrusion by unauthorized persons. This made it impossible to enter the flight compartment before the aircraft impacted the terrain in the French Alps.

Shot down by the pilot of a Venezuelan Air Force fighter.

The following findings were identified:
- The first compressor turbine blade failed after a fatigue crack, which had begun at the trailing edge, propagated towards the leading edge. The blade finally fractured in tensile overload. The separated blade fragment caused other blades to fracture and the engine to stop.
- The fatigue crack in the trailing edge of the blade was likely initiated by the trailing edge radius having been below the specification for a new blade.
- The P&WC Repair Requirement Document 725009-SRR-001, at the time the blades were overhauled, had generic requirements for trailing edge thickness inspections but did not specify a minimum measurement for the trailing edge radius.
- The higher engine power settings used by the operator since August 2014 were within the flight manual limits. Therefore it was unlikely that the operator’s engine handling policy contributed to the engine failure.
- The operator had maintained the engine in accordance with an approved, alternative maintenance programme, but the registration of the engine into that programme had not been completed. The administrative oversight did not affect the reliability of the engine or contribute to the blade failure.
- It was likely that the maintenance provider had not followed fully the engine manufacturer’s recommended procedure for inspecting the compressor turbine blades. It could not be determined whether the crack might have been present, and potentially detectable, at the most recent borescope inspection.
- The operator had not equipped its pilots with flotation devices to cover the possibility of a ditching or an emergency bale-out over or near water.
- The pilot had demonstrated that he was competent and he had the required ratings. However, it was likely that the operator’s training of the pilot in emergency procedures was inadequate. This contributed to the pilot making a hasty exit from the aeroplane that jeopardized others.

Due to lack of evidences, the cause of the accident could not be determined.

The cracking of a solder joint of both channel A and B resulted in loss of electrical continuity and led to RTLU (rudder travel limiter unit) failure.
The existing maintenance data analysis led to unresolved repetitive faults occurring with shorter intervals. The same fault occurred 4 times during the flight.
The flight crew action to the first 3 faults in accordance with the ECAM messages. Following the fourth fault, the FDR recorded different signatures that were similar to the FAC CB‟s being reset resulting in electrical interruption to the FAC‟s.
The electrical interruption to the FAC caused the autopilot to disengage and the flight control logic to change from Normal Law to Alternate Law, the rudder deflecting 2° to the left resulting the aircraft rolling up to 54° angle of bank.
Subsequent flight crew action leading to inability to control the aircraft in the Alternate Law resulted in the aircraft departing from the normal flight envelope and entering prolonged stall condition that was beyond the capability of the flight crew to recover.