A young pilot who crashed into a microlight over Masterton's aerodrome was following the local practice, which was however against Civil Aviation Rules.
Joshua Christensen, 20, and Craig McBride, 66, were killed when their planes collided just south of Hood Aerodrome on 16 June 2019.
A report by the Transport Accident Investigation Commission (TAIC) into the crash has found similar dangers at other busy local aerodromes, with many developing their own ad hoc practices.
TAIC chief investigator of accidents Naveen Kozhuppakalam said in this case, the Cessna piloted by Christensen should have given way to the Tecnam microlight piloted by McBride.
"The Cessna's route to join the circuit was non-standard and disregarded civil aviation rules, but the pilot had been trained to do it this way in accordance with this accepted local practice at Hood Aerodrome.
"The Commission's report underscores how vital it is that pilots keep a lookout for other aircraft, listen to radio calls from other planes, obey civil aviation rules, and follow standard operating procedures."
Christensen, who had started work with Skydive Wellington two months previously, had just dropped off four parachutists before radioing his intention to come in to land.
He was joining the circuit via a wide right turn for the left-hand runway, while the Tecnam piloted by McBride was in the circuit approaching the right-hand runway.
McBride, a member of the Wairarapa Aero Club, had right of way and was in front of the Cessna but may have been hidden from the other pilot's view below the Cessna's engine.
The larger, faster plane hit the microlight on the right side.
The two aircraft initially tangled before separating and spiralling to the ground where they burst into flames.
Christensen was following the instruction he had been given, which was to take off from the tarmac runway but come down on the grass landing strip.
This "non standard join" had been introduced at Hood Aerodrome five years previously to ensure the plane would stay clear of any parachutes and to minimise noise impact on nearby Masterton.
"While the procedure was well intended and known about by local pilots, it had created a potential hazard, especially for pilots less familiar with Masterton."
In 2020, the Authority brought three charges of "exposing individuals to risk, harm and illness" against Christiansen's boss, Lloyd and his company Sky Sports Ltd in relation to the crash.
Both pilots made the correct radio calls signalling their intention to land but it was not clear whether either of them were listening to the other.
There was no evidence Christensen reacted to the presence of the little microlight ahead of him.
"While it may have been challenging to visually detect ZK-WAK, the radio calls from ZK-WAJK should have alerted the pilot of ZK-CBY that there was an aircraft ahead that needed to be located and avoided."
This was also identified as a possible factor in two other fatal mid-air collisions at uncontrolled aerodromes - Paraparaumu in February 2008 and Feilding in July 2010.
Following the crash, Masterton District Council, which owns the aerodrome, closed the furthest left of the three runways.
However, the TAIC report noted there was still the risk of another mid-air collision if aircraft crossed flightpaths while coming into land on the remaining two runways.
Wider problem with uncontrolled aerodromes
The report revealed many small aerodromes, of which there are dozens around the country, have developed their own ad hoc rules, which sometimes conflicted with aviation rules.
However, they get little oversight.
The Civil Aviation Authority (CAA) has instead focused on higher "risk consequence" of an accident at large aerodromes, which have to be certified and audited regularly.
In August 2019 - following the Masterton crash - the Authority issued a warning, reminding pilots that failure to keep the rules could be fatal.
In April it signed a memorandum of understanding with WorkSafe to work more closely together, and in May this year it told TAIC it was "considering" whether there were any regulatory or guidance issues with the status quo.
- Unattended aerodromes differ widely in their compliance with Civil Aviation Rules and in reporting near misses and other safety problems
- Gaps in communication between the CAA, WorkSafe and local bodies about who should do what for safe operation of unattended aerodromes
- Aerodrome managers lack adequate training and support
Commission investigators who visited several of aerodromes found most managers did not have an aviation background and none had been given formal training.
"In some cases, they had been given the role based on their experience managing council green spaces.
"As one manager said, they knew how to grow and cut grass and aerodromes typically had a lot of grass."
- Educate pilots about the common factors in mid-air collisions and the skills required to avoid them (such as actively listening to radio calls)
- Encourage reporting of safety-related incidents or concerns at unattended aerodromes
- Ensure managers and users of unattended aerodromes fulfil their safety responsibilities and get training and support
- Work more closely with WorkSafe, Local Government NZ, NZ Airports Association and other decision-makers.
The CAA has accepted all the recommendations but is unable to give a timeline by when they will be achieved.
RNZ
