Serious Injury During Aircraft Maintenance
A contractor technician was lockwiring the drainplug of the left no. 4 flap screwjack gearbox while another technician, who was concurrently working on the right main landing gear brake system, applied hydraulic power to the aircraft.
When the hydraulic system was activated, the left no. 6 wing spoiler closed onto the lockwiring technician, seriously injuring him.
The preliminary investigation revealed deficiencies in aircraft maintenance safety procedures and equipment.
These concerns were immediately brought to the attention of both the RCAF technical authority and the contracted air maintenance organization, which undertook numerous rectifying and prevent actions to ensure this accident would not reoccur.
The investigation then focussed on supervision and organizational factors that preceded the accident.
The investigators identified “numerous organizational safety stressors” including:
- contract, facilities, organization and personnel disruptions;
- training and supervision of apprentices with too few supervisors; and
- a mismatch between contractor resources and operational demands which cumulatively increased the safety risk being incurred to meet these demands.
Additionally, the investigation determined that the contracting and accreditation mechanisms were insufficient to detect this situation and reliance on the contractor to self-identify the risk could create a potential conflict of interest within an incentivized performance contract.
This highlights a safety assurance gap for contracted maintenance that should be addressed by the RCAF.
Exposure to energized airplane systems can result in serious injury to maintenance technicians if proper controls are not followed. Hazardous energy controls are required when technicians could be exposed to unexpected energization, startup, or release of hazardous energy during service or maintenance activities. Boeing has made internal process improvements to control airplane hazardous energy within Boeing factories and on Boeing flight lines and is making these improvements available to the aviation industry through updates to the aircraft maintenance manual (AMM).
Boeing primarily discuss the concept of lockout, tagout, and tryout (LOTO).
Other Aerossurance articles that have discussed injuries during maintenance include:
- Dangers of Aircraft Tyre Inflation: we look at a number off accidents while inflating aircraft tyres
- UPDATE 3 August 2019: Hurried Door Inspection Results in Fall From Aircraft
- UPDATE 8 September 2019: B747-400F Tyre Explosion During Inflation
UPDATE 15 March 2017: Inflite Engineering Services were fined £160,000 in court after an incident at Stansted Airport on 10 June 2015. Two workers were injured when the mobile elevated work platforms they were using were knocked over when another employee closed the wrong circuit breaker, inadvertently operating the air brake.
Aircraft maintenance companies are reminded that not all risks are covered by the Aircraft Maintenance Manual and additional measures need to be introduced.
The HSE investigation found: “no suitable risk assessment was in place and there was a lack of effective monitoring.”
UPDATE 6 July 2017: We discuss one possible solution to occurrences such as this in Deliberate Action: A Mindful Method from the Nuclear Navy
Aerossurance is pleased to be supporting the annual Chartered Institute of Ergonomics & Human Factors’ (CIEHF) Human Factors in Aviation Safety Conference for the third year running. This year the conference takes place 13 to 14 November 2017 at the Hilton London Gatwick Airport, UK with the theme: How do we improve human performance in today’s aviation business?