The AAIB has simply launched the under report right into a 2018 Helicopter Incident at Aberdeen airport. 2 crew and 16 passengers have been onboard the plane.
The helicopter was returning to Aberdeen after a routine passenger flight. During a traditional strategy to land the touchdown gear appeared to deploy usually however at landing the nostril touchdown gear collapsed as a result of failure of the A-frame pintle pin. Owing to a low gas state the passengers have been disembarked while the helicopter was in a low hover. The plane was then landed safely, utilizing sandbags to help the fuselage.
During the next investigation, the operator recognized bush, which ought to have supported the pintle pin, had not been fitted into the A-frame when it was put in 50 flying hours earlier than the incident flight (Figure 1). The investigation recognized a number of human components points which contributed to the accident, together with shift staffing ranges, lack of expertise and fatigue. The helicopter producer subsequently revealed Service Information Notice 3259-S-32 notifying operators of this failure mode and an Alert Service Bulletin (ASB) 32A003, requiring an inspection to make sure the right set up of the pintle pin bushing. The ASB was subsequently mandated by EASA Airworthiness Directive 2018-0190.
History of the flight
The helicopter had returned to Aberdeen and accomplished a traditional strategy to land. When the touchdown gear was chosen down, all of the indications have been regular however through the touchdown the flight crew heard a “crunching noise” and the helicopter appeared to settle in a extra nose-down angle than regular. The flight crew introduced the plane again into the hover and requested help from their engineering organisation.
An inspection, carried out whereas the helicopter was hovering, confirmed that the nostril touchdown gear actuator had separated from the A-frame and each have been hanging from the touchdown gear bay. Due to a low gas state, passengers have been disembarked with the helicopter in a low hover. It was then hover taxied to a different stand the place it landed on sandbags, positioned by floor engineers, to help the ahead fuselage.
A subsequent examination, carried out by the operators engineering organisation, recognized that the separation of the A-frame from the actuator had been attributable to failure of the pintle pin which secured the A-frame to the touchdown gear actuator (Figure 1). The head of the failed A-frame decrease pintle pin was recognized throughout an inspection of the touchdown website. The pintle pin bushing was discovered to be lacking from the set up.
Approximately 50 hours previous to the incident flight, on 7 June 2018, the A-frame (Figure 1) had been changed throughout a routine upkeep enter following experiences of “notchy” steering. of the pintle pin.
Figure 1 – EC175 Nose touchdown gear actuator and A-frame
The operator’s investigation recognized that the Aircraft Maintenance Manual (AMM) process, detailed on a variety of work playing cards, for the substitute of the A-frame had not been accomplished appropriately. This particulars that on elimination the pintle pin bushing must be faraway from the A-frame being changed and put in within the substitute A-frame.
This switch had not been carried out, so the A-frame fitted to G-EMEA didn’t have a pintle pin bushing fitted. The design of the nostril touchdown gear is such that, when the nostril touchdown gear actuator is connected to the A-frame affirmation of the presence of the pintle pin bushing is problematic. An unbiased inspection, carried out on completion of the duty, didn’t determine that the bushing had not been put in. The lack of bushing induced put on and eventual failure of the pintle pin.
Information, obtained by the operator after this occasion, confirmed that, previous to this incident no less than two different operators had skilled related occasions. Following these occasions, the helicopter producer issued an replace to the AMM work playing cards regarding the A-frame substitute on…