The Civil Aviation Authority (CAA) has released the final report of its safety investigation into the cause of a fatal accident near Pukaki Aerodrome, on 25 July 2020.
The aircraft, ZK-DKQ, was a Taylor Monoplane which is a single-seat, amateur-built wooden aircraft powered by a Volkswagen 1600cc engine driving a Rishton two-bladed wooden propeller.
The pilot was well regarded and received an excellent rating on his most recent microlight instructor renewal in late 2019.
CAA’s Safety Investigation Report found no evidence of any mechanical or flight control system failure that may have contributed to the accident. The absence of recorded data or witnesses limited the ability of the investigation to determine how the aircraft departed controlled flight. Two scenarios that could not be excluded were aircraft factors, a pilot handling error, or a combination of both.
The report also notes the pilot was faced with a challenging situation given his lack of currency in wing- drop stalling and spinning, and likely a significant level of disorientation.
CAA Deputy Chief Executive Aviation Safety, David Harrison says this unfortunate accident serves as a reminder to all pilots to obtain dual instruction if they are not current in specific exercises or on a new aircraft type. A lack of pilot currency is a well-known contributing factor to many accidents. This accident also highlights the risks of operating aircraft for which the spin characteristics are unknown.
Taylor Monoplane Class 1 Microlight, ZK-DKQ, was operated on a private flight in the vicinity of Pukaki aerodrome on 25 July 2020.
The pilot was in the process of self-rating(1) on the single-seat aircraft and departed Pukaki aerodrome around 1355 to practise stalling(2).
The investigation determined the aircraft entered an unrecovered flat spin(3) most likely subsequent to a wing drop stall. It was not possible to determine whether correct recovery inputs were made during the spin without recovery, or whether aircraft factors prevented recovery.
Once the aircraft entered the fully developed flat spin, recovery may not have been possible, regardless of pilot control inputs.
Following the accident, a Part 149 Authorised Recreation Organisation (ARO), the Recreational Aircraft Association of New Zealand (RAANZ) made changes to the pilot currency and renewal requirements in their exposition. Due to this action, no safety recommendations were issued to the ARO.
This accident serves to remind all pilots that a lack of pilot currency is a well-known contributing factor to many accidents. The CAA recommends pilots to obtain dual instruction if they are not current in specific exercises or an aircraft type.
Following its investigation, the CAA has made the following safety actions recommendations:
A CAA safety investigation seeks to provide the Director of Civil Aviation with the information required to assess which, if any, risk-based intervention tools may be required to attain CAA safety objectives.
The purpose of a CAA safety investigation is to determine the circumstances and identify contributory factors of an accident or incident with the purpose of minimising or reducing the risk to an acceptable level of a similar occurrence arising in the future.
The safety investigation does not seek to ascribe responsibility to any person but to establish the contributory factors of the accident or incident based on the balance of probability.
(1) Teaching himself versus undergoing instruction to gain proficiency on the aircraft type.
(2) Aerodynamic stall is a condition where the wing’s angle of attack increases beyond a certain point such that lift begins to decrease. The angle at which this occurs is called the critical angle of attack.
(3) A spin is a sustained spiral descent of a fixed-wing aircraft, with the wing’s angle of attack beyond the stall angle.