Piper PA-32R-300, VH-CUU

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 take-off 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 take-off 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 take-off 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 take-off. With this loading the aircraft was outside of the allowable centre of gravity envelope.

The pilot had used the incorrectly calculated lesser take-off weight for his estimation of the take-off 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 take-off from short or soft fields. The first of these is designated the Short Field, Obstacle Clearance take-off 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 liftoff, 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 take-off with the same requirements except that the aircraft is to be accelerated to 92 kts before the flaps are slowly retracted.

Analysis

The accident

The investigation disclosed that although there was a minor anomaly in one magneto, the engine was capable of delivering full power. Accordingly, it is likely that the aircraft was flown off the strip with full power available and applied, although it cannot be discounted that there may have been a minor power reduction at some stage due to the loose blade terminal in one magneto. However, the power loss was almost certainly perceived rather than actual, such perception being created by the aircraft sinking after the flaps were raised at an airspeed lower than specified. The pilot did not confirm a power loss from engine instrument indications.

The pilot's natural tendency would be to maintain the nose up climb attitude or raise the nose to try to maintain a climb. This would have caused the speed to further reduce as was evidenced by the pilot reporting that the airspeed dropped to 60 knots. When this occurred, the pilot lowered the nose to maintain airspeed and controlled the flight path to avoid obstacles. The aircraft continued to descend to a point where he had to reduce power and flare the aircraft for the inevitable forced landing. The aircraft landed heavily, most probably in a stalled condition.

Human factors

This accident therefore had very little to do with the pilot's ability to physically handle the aircraft. It instead involves a corporate culture that allowed poor aircraft and crew selection, inadequate flight preparation, incorrect briefing, and real or perceived peer pressures on the pilot, to combine to place the pilot into a situation from where an accident was essentially inevitable. In other words, a human factors accident.

Human factors is about people in their living and working situations; about their relationships with machines, with procedures, and with the environment about them; and also, about their relationships with other people. (ICAO Circular 216-AN/131).

In applying certain techniques to the investigations of the human factors involved in aircraft accidents, BASI uses the Reason accident causation model, and, in the report into the 1993 Piper Chieftain accident in Young NSW (BASI Investigation Report 9302743), defined the common elements in an organisational accident as:

• latent failures which arise from deficiencies in managerial policies and actions within one or more organisations. Often these organisational factors are not immediately apparent and may lie dormant for a considerable time.
• local factors, being conditions which can affect the active failures. These include such things as task and environmental conditions.
• active failures, being errors or violations which have an immediate adverse effect. These unsafe acts are typically associated with operational personnel.
• inadequate or absent defences which fail to identify and protect against technical and human failings arising from the three previous elements.

Latent failures

Latent failures can be weaknesses or inadequacies within the management of organisations which are not immediately apparent. They can remain dormant for extended periods. These organisational factors can impact upon the workplace to create an environment or a corporate culture which increases the probability of errors or violations and weakens the systems defences which are designed to minimise the consequences of unsafe acts. These latent failures become apparent when they combine with local triggering events and circumstances such as active failures, resulting in a breakdown of the system.

In relation to this accident the organisational failures included:

• inadequate management by the chief flying instructor who:
  • scheduled an operating pilot with low total and no recent experience on the type,
  • did not conduct a comprehensive briefing both prior to the exercise and prior to the take-off on the accident flight.
  • gave a briefing prior to the accident flight that did not reflect the manufacturers requirements.
• On a broader scale:
  • the company did not provide adequate management of its human resources.
  • the selection procedures for determining who should operate which flight were inadequate.

Active failures

Active failures are unsafe acts which most generally involve the actions of operational personnel. Such failures can be divided into two distinct groups; errors and violations. Errors may be of two basic kinds and involve attentional slips or memory lapses, and mistakes. Violations may be deliberate deviations from a regulated practice or prescribed procedure.

The significant unsafe act in this occurrence was that the pilot made a mistake by raising the flaps at too low an airspeed.

Local factors

These include such things as task and environmental conditions. A significant local factors in this accident was that the chief flying instructor was part of the ownership and management of the company. Accordingly, the authority gradient between the chief flying instructor and pilot was very steep and the pilot would be unlikely to doubt the judgement of a respected peer who had been instrumental in his training and employment. Other local factors were:

• the chief flying instructor did not adequately assess the knowledge and skills of the pilot relative to this particular operation
• the pilot was neither experienced nor current on type.
• the pilot did not use the proper procedure to account for the weight of his passengers.
• the pilot did not mentally prepare himself for this flight
• the aircraft used for the operation was inappropriate for the task in that the strip at Taggerty was too short for the combination of aircraft type, its load, and the take-off procedures being employed.

The inadequate or absent defences included:

• the company's requirements for pilot currency on type were inadequate
• the pilot's training did not prepare him for this set of circumstances
• the assessment of the pilot's skills during licence renewals and endorsements were inadequate
• the company did not ensure its pilots were complying with the statutory requirements for weight calculation.

CONCLUSIONS

Findings

1. The aircraft had one minor anomaly in one magneto but was otherwise serviceable for the flight.
2. The company selected an inappropriate aircraft and an inadequately prepared pilot to undertake the task.
3. The pilot was neither experienced nor current on the type.
4. The pilot used an incorrect procedure for calculating the weight and the performance of the aircraft.
5. The briefings given to the pilot by the chief flying instructor were inadequate.
6. Because of the steep authority gradient the pilot was unlikely to doubt the decisions of the company and the chief flying instructor.

Significant Factors

1. The aircraft was significantly heavier than the pilot had calculated.
2. The strip length available was insufficient for the intended operation.
3. The take-off procedure utilised by the pilot was incorrect.
4. The pilot retracted the flaps at too low an airspeed.
5. The aircraft's speed deteriorated to the point where a forced landing was inevitable.
6. The pilot was forced to land on unsuitable terrain.