Chinook WT II
|Accident Investigation Report|
1.1 History of FlightThe flight took place on the morning of 31 May 2003, from a private strip on the family property of the deceased. There were no other family members at home at the time and no witnesses. The exact time of the flight and subsequent crash is not known.
1.2 InjuriesThere was only the pilot on board the aircraft, he was killed by the impact.
1.3 Damage to AircraftThe leafy end of a branch protruded from the nose of the aircraft with the butt end of the branch back toward the tail of the aircraft. The disposition of the branch shows that the aircraft was travelling backward when it hit the tree.
The elevator horn was also bent in such a way as to indicate that the aircraft was travelling backwards when it impacted the branch.
The aircraft had significant frontal and left wing damage consistent with ground impact. The frontal area of the cockpit had collapsed rearward to the pilot's seating position. The left wing drag cable was broken consistent with forward impact.
The right trailing wing edge had damage consistent with a light impact with tree foliage consistent with the aircraft travelling backwards.
1.4 Pilot In CommandThe pilot in command was a 47 year old male. He held a student pilot certificate issued 27 June 2002. His log book records that he had accumulated 30.3 hours of flying which was all dual training. It also shows an entry on Feb 28, 2003 stating first solo, however there is no CFI/instructor validation against this entry. His instructor has advised the AUF that the student was definitely not at solo level and required further training before he would be safe for solo flight. This is supported by the student training records.
The pilot's training had all been conducted from a substantial training aerodrome with properly formed and marked runways both in excess of 800 metres in length.
1.5 Aircraft InformationThe aircraft was a Canadian manufactured Chinook WT II. It was one of the early generation of ultralights being a high wing monoplane of light alloy tube construction, covered with Dacron. It had a conventional (taildragger) undercarriage. It was powered by a Rotax 447 (40 hp.). The registration lapsed on 24 April 2003.
The owner had purchased the aircraft some weeks earlier and trailered it back to his home.
1.6 ServiceabilityThe Ultralight Aircraft Condition Report (UACR) which was prepared at the time of the aircraft purchase indicates that at the time of transfer (25/4/03) had no outstanding airworthiness deficiencies. The aircraft log books were all in order. A log book entry dated 29 May 2003 states "plane reassembled and taken for high speed taxi runs".
1.7 ELBNot carried.
1.8 WeatherNil significant weather. Fine and sunny, wind light and variable.
1.10 LocationThe private strip was oriented North-South. It was 250 metres long with only about 120 metres of good usable surface. It had a heavily wooded hill with tall trees on the northern end and a creek, trees and cattle yards at the other end. It was assessed by the AUF investigator as unsuitable for ultralight operations. The crash site was approximately 45 degrees to the northwest and 100 metres from the end of the strip 36.
2. WRECKAGE & IMPACT INFORMATION
2.1 Final Flight Path and Impact Point(s)The aircraft impacted a tall tree at a point approximately 20 metres above the ground. Propeller chop marks and broken foliage indicate that the aircraft had been travelling backward at the time of impact with the tree, (tree branch secured to side of aircraft by damaged propeller). After the initial impact the aircraft fell heavily to the ground creating the secondary impact marks to the front of the aircraft.
2.2 ControlsAll control systems were examined and determined to have been connected, operational and working in their correct sense prior to impact. Only impact damage could be found.
2.3 StructureThe aircraft had significant frontal and left wing damage consistent with it falling from the tree and hitting the ground nose first, left wing forward. The ground impact depressions matched the frontal damage on the aircraft.
The frontal area of the cockpit had collapsed backward toward the pilot .
The right wing trailing edge had damage consistent with light impact with tree foliage travelling backwards.
2.4 Engine & PropellerThe Rotax 447 was dismantled and found to meet all the manufacturer's specifications, except for the crankshaft being twisted out of alignment. The displacement of the crankshaft was consistent with rapid engine deceleration which occurred as a result of the propeller strike on the tree branch at high RPM.
All three propeller blades had similar extensive damage which indicated the engine was developing considerable power at the time of impact. The series of chop marks in the branch terminate with one blade wrapped around the branch and locking the branch to the side of the aircraft.
2.5 Fuel SystemThe right fuel tank contained about 75% fuel, and the Right fuel cock was selected ON.
The left fuel tank was empty, but was found to be ruptured. Its fuel cock was OFF.
The carburettor had been dislodged by the impact but was found to contain a full fuel float bowl.
2.6 Cockpit InstrumentsNot applicable.
2.7 DesignThe aircraft had been accepted by the Authority as a factory built aircraft certified in accordance with Civil Aviation Order 95.25.
Facts There were no indications of any aircraft malfunction prior to the crash.
The pilot was a student who had been assessed by an experienced instructor as not being ready for solo flight.
The student's prior training had been conducted from a properly formed and marked aerodrome consisting of either a 800m bitumen runway or a 1000m gravel strip. The accident occurred on a 250 metre substandard strip which had a hill with tall eucalypts at the northern end.
The accident occurred at the northern end.
The pilot was at home alone on the day of the accident
4. SCENARIOThe pilot having somehow become airborne was confronted with either trying to out climb the trees on take-off or attempting a "go-around" after an abortive approach. In his attempts to climb over the trees he has pulled the aircraft into a near vertical attitude* from which it has stalled and performed a tail slide backwards into the trees impacting the branch which became attached to the aircraft, the machine then fell to the ground nose first.
*NOTE. The near vertical attitude needed to perform the tail slide suggests that the aircraft was indeed making a missed approach rather than the initial climb scenario. A Chinook undertaking an initial climbout would not have had the speed/power necessary to attain the extreme nose high attitude needed to get into the tail slide ( it would have stalled and nosed over).
4. ACTION FOR AUFOnce again warn students of the dangers of not undertaking correct supervised instruction.
" The AUF investigates accidents and incidents with the SOLE intention of preventing the same accident happening again."
9 October 2003