Civil Aviation Authority of New Zealand
21 December 2004
MEDIA RELEASE
For further information contact:
Bill Sommer
Tel: 04-560 9411 or
027-546 8216
The accident report can be viewed on the CAA web site,
www.caa.govt.nz, under "Accidents & incidents", or use this link:
http://www.caa.govt.nz/Accident_Reports/ZK-SPK_Fatal_25Dec2002.pdf
Begins
Stall led to fatal microlight aircraft crash
ZK-SPK, 3.5 km south-west of Thames, 25 December 2002
A Civil Aviation Authority accident report has concluded that a Bantam B22J microlight aircraft stalled and was not recovered in the height available. The pilot and his passenger died when the aircraft crashed into a level farm paddock adjacent to Orongo Road near Thames.
On Wednesday 25 December 2002 at about 1430 hours, the owner-pilot of ZK-SPK and a passenger departed Thames airfield for a local flight. Several people saw the aircraft flying in the Thames area; initially in the hills performing steep turns, then later over the township, timber mill, and the farming district west of Thames. The microlight aircraft was seen to suddenly roll to the left and steeply descend toward the ground. Shortly thereafter, the wreckage of the aircraft was found by a local farmer.
The pilot was qualified for the flight and to carry a passenger on his aircraft. The investigation eliminated the possibility of aircraft structural failure, or an engine or airframe defect. There was no evidence of a bird strike or of pilot incapacitation.
The description of the final manoeuvre up to when a witness lost sight of the aircraft is consistent with a wing drop stall that led to a spin and this was supported by the disposition of the wreckage.
Other witness observations, and photographs retrieved from the passenger's camera, indicate that the pilot performed low-level flying and steep turns prior to the accident. This could suggest that the pilot was keen to show his passenger, who was a student pilot, the characteristics of the Bantam aircraft.
The area where the accident occurred has an abundance of large flat paddocks perfectly suited for forced landing practice, and the pilot may well have decided to demonstrate at least the early stages of a practice forced landing to his passenger.
On this type of aircraft, when the throttle is closed or the engine is completely switched off, the nose must be lowered immediately to maintain flying speed. If this action is not taken promptly, the high drag and low inertia of the aircraft will lead to a very rapid decay in airspeed. If the airspeed is low to begin with, stall onset will be very rapid.
The investigation concluded the aircraft stalled and was not recovered in the height available. The stall possibly resulted from the pilot's shutting off the engine in order to practice or demonstrate a forced landing, and not maintaining sufficient airspeed in the process.