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Summary

Summary

A Piper Lance and a Piper Cherokee from the same company departed early in the morning from their base at Albury NSW for Mount Beauty Vic. At Mt Beauty they were to both pick up a full complement of passengers for a flight to Taggerty Vic. and to return later to Mt Beauty. Five of the passengers boarded the Piper Lance at Mt Beauty and their flight to Taggerty was uneventful.

The aircraft were on the ground at Taggerty for approximately six hours. Prior to departure from Taggerty the Piper Lance pilot was briefed by the pilot of the Cherokee, who was the company's chief flying instructor to select 10 degrees of flap (one notch) in order to conduct a short field take off. Five passengers boarded the Piper Lance. The pilot started the engine and taxied after the Cherokee to the southern end of the 790 metre, grass strip. After the Cherokee had departed he lined up on the strip, ran the engine up to full power, checked static RPM and manifold pressure were satisfactory, then released the brakes.

The pilot said that the aircraft accelerated to 70 knots and lifted off normally. He said he established a positive rate of climb at about 80 knots and selected the landing gear and flaps up. As he was raising the flaps the engine appeared to become sluggish, climb rate vanished and airspeed reduced. The pilot had to lower the nose to keep the aircraft flying above the stall speed. The pilot turned to the left to manoeuvre round a large tree as the aircraft continued to lose height. The aircraft impacted into a soggy field some 500 metres from the departure end of the strip. At impact the aircraft was in a nose high attitude, with the left wing down and had a high rate of descent. Both main landing gears were pushed upwards and then dislodged and the nose gear was folded back into the nose wheel well. The aircraft slid to a stop and the passengers were able to evacuate suffering only minor injuries. One passenger went back into the aircraft to assist the pilot to evacuate.

The passengers advised that the aircraft seemed to accelerate slowly and lifted off right at the end of the airstrip. They reported that a warning horn was heard shortly after the aircraft became airborne and stayed on until the aircraft crashed.

The aircraft

The investigation found that the aircraft was properly certificated, had been maintained and serviced correctly, held sufficient fuel for the flight, and had no pre-existing defects recorded on the maintenance release. At impact the landing gears were down and the flaps were up. There were no anomalies found with the airframe and other aircraft systems.

The engine

The engine was examined and, after some minor impact damage had been repaired, was test run and found to be capable of delivering full power. One anomaly was found during the post accident examination and engine run. A blade terminal within the left magneto was a loose fit and showed signs of minor electrical arcing.

The pilot

The 23 year old pilot had been involved with the company since his teenage years. He had completed all of his training with the company and was currently employed by them, mostly flying twin engined aircraft. He did not normally fly the Piper Lance, had only flown a total of 20 hours in the aircraft and, prior to this day,last flew it for half an hour, 14 weeks prior to this accident.

Flight preparation

The Piper Lance was not normally used for this operation; it was replacing a twin engined aircraft which was unserviceable. The pilot was advised late the previous night by the chief flying instructor that he was required for the flight, replacing the normal pilot who had suddenly become unavailable. Due to the late notification and the early start out of Albury the pilot did not get time to study the flight manual, nor did he receive a comprehensive briefing from the chief flying instructor who was flying the Piper Cherokee aircraft. The chief flying instructor was part of the ownership and management of the company.

The pilot estimated the take off weight of the aircraft by using a standard weight of 80 kilograms for each occupant. The statutory requirements pertaining to takeoff weight calculations require that, for aircraft carrying seven passengers or less, the actual weight of each passenger shall be used. The pilot advised that he had been aware of this requirement during his training some years before but had forgotten it, and he did not recall it being mentioned as a part of any licence renewal or aircraft endorsement checks. By using the standard weight computation the pilot calculated the takeoff weight to be 1555 kg which included 100 kg for fuel. After the accident the fuel load was found to be 115 kg. By utilizing the actual fuel and passenger weights, the takeoff weight was calculated to be 1629 kg. This made the aircraft 74 kg heavier than the pilot thought and just 4 kg below its maximum permitted gross weight of 1633 kg for takeoff. With this loading the aircraft was outside of the allowable center of gravity envelope.

The pilot had used the incorrectly calculated lesser takeoff weight for his estimation of the takeoff distance required. On that basis he had calculated that he needed 720 metres and therefore the 790 metre strip was adequate. By utilising the correct weights, and the actual wind and temperature at the time of the accident, the strip length required was calculated to be 920 metres. This strip length is what is required for the aircraft to accelerate, lift off and climb to a height of 50 feet.

The aircraft's Pilots Operating Handbook, which was located in the glove box of the aircraft after the accident, details two procedures that can be used for takeoff from short or soft fields. The first of these is designated the Short Field, Obstacle Clearance takeoff and requires, for a heavy aircraft:

  • the flaps to be set at 25 degrees, the second notch,
  • the aircraft to be rotated at 53 knots
  • after lift off, gear is selected UP at 58 knots, and
  • flaps to be slowly retracted after 87 knots is attained, and
  • accelerate to 92 kts, the best flaps up rate of climb speed.

The second procedure is the Soft Field takeoff with the same requirements except that the aircraft is to be accelerated to 92 kts before the flaps are slowly retracted.

 
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