The Australian Transport Security Bureau (ATSB) is reminding helicopter operators concerning the significance of contemplating ability consolidation processes when transitioning pilots to a brand new and technically completely different helicopter sort, and to construct security margins into their operations to offer pilots the perfect alternative to succeed.
The reminders come following the ATSB’s completion of a systemic investigation into an accident involving a Eurocopter (Airbus Helicopters) EC120B helicopter which collided with the water after the pilot skilled a major lack of directional (yaw) management throughout a go-around. The EC120B, registered VH-WII and operated by Whitsunday Air Companies, had departed Hamilton Island Airport, Queensland on 21 March 2018 on a constitution flight to a pontoon at Hardy Reef, on the Nice Barrier Reef, with a pilot and 4 passengers onboard.
Whereas on a gradual approach-to enable a number of birds to disperse-the pilot yawed the helicopter to the left with the intent to land on one among two positions on the pontoon. This subjected the helicopter to a few 20-knot crosswind from the suitable. When roughly 7 ft above the pontoon, the pilot seen a message illuminate on the helicopter’s car engine multifunction show (VEMD) and elected to conduct a go-around.
Throughout the go-around and when about 30-40 ft above the water, the helicopter all of the sudden and quickly yawed to the left. After unsuccessful management inputs to get well from the speedy left yaw, and with restricted time, the pilot was unable to conduct a managed ditching and the helicopter collided with water. The helicopter’s emergency pop-out floats weren’t deployed and the helicopter nearly instantly rolled inverted and quickly full of water.
The pilot and two of the three rear-seat passengers evacuated from the helicopter with minor accidents. Though the affect forces have been survivable, the opposite two passengers (seated within the entrance left and center rear seats) have been unconscious following the affect and didn’t survive the accident. The helicopter later sank and was unable to be recovered.
“The ATSB’s investigation decided it was possible the pilot skilled a excessive workload through the closing strategy to the pontoon and a really excessive workload through the subsequent go-around,” stated ATSB Director Transport Security Dr Mike Walker.
The investigation discovered that though not one of the potential VEMD messages required speedy motion, the pilot thought of a go-around to be the most suitable choice given the circumstances on the time. Throughout the go-around, after the helicopter began quickly yawing to the left, it is vitally possible the pilot didn’t instantly apply full and sustained proper pedal enter to counter the speedy left yaw.
Within the two weeks previous to the accident, the pilot (with a complete of about 1,300 flying hours) had obtained a brand new sort score to fly the EC120B. Whereas accumulating 11 hours expertise in command on the EC120B, the pilot had additionally flown about 16 hours in one other and technically completely different helicopter sort (a Bell 206L3).
“The operator had complied with the regulatory necessities for coaching and expertise for pilots on new helicopter sorts, however had restricted processes in place to make sure pilots with minimal time and expertise on a brand new and technically completely different helicopter sort had the chance to successfully consolidate their expertise required for conducting operations to pontoons,” Dr Walker stated
The EC120B has a clockwise-rotating primary rotor and a ‘Fenestron’ shrouded tail rotor system. In 2005, the helicopter’s producer launched a service letter to remind pilots that Fenestron tail rotors require considerably extra pedal journey than standard tail rotors when transitioning from ahead flight to a hover. A piece of that letter acknowledged that pilots wanted to be ready for a major ahead motion of the suitable foot and that inadequate utility of [right] pedal would end in a leftward rotation of the helicopter through the transition to hover.
The ATSB discovered that the protection margin related to touchdown on the pontoon at Hardy Reef was decreased resulting from a mix of things, every of which individually was inside related necessities or limits. These components included the helicopter being near the utmost all-up weight; the helicopter’s engine energy output being near the bottom allowable restrict; the necessity to use excessive energy to make a gradual strategy with a view to disperse birds from the pontoon; and the routine strategy and touchdown place on the pontoon requiring the pilot to yaw left right into a proper crosswind (in a helicopter with a clockwise-rotating primary rotor system).
As well as, the investigation additionally recognized security components related to the operator’s use of passenger-volunteered weights for weight and steadiness calculations, the operator’s system for figuring out and briefing passengers with decreased mobility, fowl hazard administration on the pontoons, and passenger management at pontoons.
“Since this accident, the operator has carried out a number of extra processes for pilots transferring to new helicopter sorts and for operations at pontoons,” Dr Walker stated.
“This contains pilots conducting solely into-wind operations at pontoons till they’ve obtained 20 hours on sort. The operator has additionally launched a security administration system, and revised processes for acquiring correct passenger weights, along with a number of different proactive security enhancements to its operations.”
Within the 12 months following the accident, the helicopter producer launched a security data discover about unanticipated left yaw in helicopters with a clockwise-rotating primary rotor system. The discover supplied detailed recommendation relating to the circumstances the place unanticipated yaw can happen and the significance of making use of full reverse proper pedal if it happens.
The discover additionally acknowledged that for helicopters with a clockwise-rotating primary rotor system, that pilots choose (as a lot as potential) yaw manoeuvres to the suitable, particularly in performance-limited circumstances.
Dr Walker stated this accident, together with many different earlier accidents, demonstrates the significance of pilots having helicopter sort expertise when confronted with unfamiliar conditions in performance-limited circumstances, and to observe the speedy actions specified by the helicopter producer, which generally contains instantly making use of full reverse pedal enter within the occasion of a lack of yaw management at low peak and airspeed.
“Operators, as a part of their security administration processes, ought to contemplate ability consolidation throughout and following the in command beneath supervision section and supply as a lot consolidation as potential to scale back the chance of transitioning to a brand new plane sort,” he stated.
“That is significantly related for sorts with important variations to these a pilot has beforehand flown and for operations with decreased security margins. Pilots and operators ought to establish and keep away from conditions that current potential for lack of yaw management of their helicopter sort.
“This might embrace planning approaches that may be rejected by turning with the torque of the helicopter. For instance, if crosswind turns are required when touchdown, conduct turns to the suitable in a helicopter with a clockwise-rotating primary rotor system.”
The investigation additionally recognized that the passengers weren’t supplied with adequate directions on function the emergency exits. The passenger seated subsequent to the rear left sliding door was unable to find the exit working deal with through the emergency, and because of this the evacuation of passengers was delayed till one other passenger was in a position to open the exit. The character of the door deal with’s design was such that its goal was not readily obvious, and the placard offering directions for opening the sliding door didn’t specify all of the actions required to efficiently open the door.
“Our investigation emphasises that for helicopter flights over water, given the chance of inversion, capsize and disorientation following a ditching, it’s crucial that passenger security briefings embrace function the passenger’s seatbelt and the placement and operation of the emergency exits,” Dr Walker stated.
“Operators and pilots of EC120Bs ought to make sure that passengers within the rear of the helicopter are particularly briefed concerning the location of the working deal with and the three actions required to open the rear left sliding exit – which is to tug the deal with up, push the door out, and slide the door again.”
You will discover right here the ultimate report: Collision with water involving Eurocopter EC120B, VH-WII, Hardy Reef, Whitsundays, Queensland, on 21 March 2018 (AO-2018-026).
Final replace 16 June 2021