Executive summary
On the first topdressing flight for the day the take-off run was longer than normal due to a blocked injector in the number 8 cylinder. During the take-off the right wing passed through a six foot tall hedge of dense thistles which bordered the downsloping airstrip for the lowest third of its length. The thistles had not been present when the pilot operated from the airstrip previously. Thistles became entrained between the wingtip and the aerodynamic balance horn, deflecting and jamming the ailerons, causing the aircraft to roll uncontrollably to the right. The aircraft came to rest at the bottom of a steep ravine. The pilot received fatal injuries in the accident.
Related Recommendations
Alert the civil aviation authorities of other countries where these aircraft are operated, to the potential hazards.
Advise all New Zealand operators of FU24 aircraft, of the potential for light growth to jam the ailerons of these aircraft.
Consider the publication of a warning in the Flight Safety Magazine or elsewhere, relating to the vulnerability of such control configurations to such tall vegetation.
That no further permission be granted for operations from the Rotomahana Block Airstrip, until the thistles have been removed.
Consider if a requirement exists for a fence/guard to be developed by the manufacturer, e.g. similar to that used to protect the elevators on the Pilatus Porter.