Forced/precautionary landing

While in cruise the pilot heard a bang, the engine started vibrating and suffered an almost total power loss. The pilot was able to carry out a successful forced landing onto a disused agricultural strip. A bulk strip of the engine found that the #1 cylinder connecting rod bolts had failed. The connecting rod cap had also failed. The engine was severely damaged, and further investigation was not possible. It is suspected that incorrect torque of the connecting rod bolts could have been a contributing factor to their failure.

Significant Factors

1. Engine power was lost when the #1 connecting rod detached.

The pilot reported that the initial launch was slow, and that he held the nose down until the speed increased to about 50 knots, at which time he began a normal climb. At about 100 feet the speed decreased, the pilot lowered the nose, and the launch cable parachute deployed over the canopy. The parachute and wire wrapped around the right wing and pulled the glider towards a line of trees. The pilot banked left to avoid the trees and was able to level the wings before ground impact. The aircraft struck the ground whilst still sideslipping left, tearing off the landing skid and fracturing the left wing.

Relevant Factors

1. The pilot failed to avoid the tow cable after its release.

2. Control was lost due to the cable being wrapped around the right wing.

During a crop spraying operation, the pilot noticed oil on the windscreen. Because the amount of oil was increasing, he decided to proceed to a private airstrip to make a precautionary landing. As the aircraft climbed away from the cotton field, smoke was observed issuing from the engine cowl. The pilot advised his markers he would attempt an emergency landing at Cudgewa airstrip. Shortly after there was a loud noise as the propeller separated from the engine.

The aircraft was landed in a wheat field but overturned during the landing roll due to the soft surface. The hopper contained 150 litres of chemical at the time of the accident, some of which splashed over the pilot. The propeller was found to have separated from the engine drive shaft after the retaining nut which secured the propeller to the shaft had come off. The bolt designed to secure the retaining nut on the propeller shaft was missing for reasons which were not determined.

The pilot had calculated he would arrive at his destination five minutes before last light. Ten minutes before last light he realised the light was fading, so decided to land at a property airstrip he could see below. During the landing roll the left wing of the aircraft struck the star pickets of a barbed wire fence. The aircraft yawed to the left and the right main gear collapsed. The pilot had not seen the fence until it was struck by the left wing.

The aircraft had been operating normally except for a report that the airspeed indicator was under-reading in cruise and the engine had been difficult to start for a number of days. On the morning of the accident the aircraft was flown from Karratha to Nanutarra in support of another aircraft. The pilot had been told that the Nanutarra strip was in good condition. However, this proved not to be the case as the surface was covered with brush up to one metre in height and the landing area was only ten metres wide.

The landing was uneventful, but the pilot had to remove some brush from the landing gear after landing. Prior to departure on the accident flight the pilot discussed the condition of the strip with the pilot of the other aircraft. This second pilot, who owned VH-WMV, paced out 500 metres of reasonable strip and indicated the pilot should use this for take-off. The pilot, still concerned, paced out a further 150 metres giving 650 metres in all. Although neither pilot referred to it, the take-off distance chart in the Pilots Operating Handbook (POH) indicated that 426 metres of ground roll was required in the prevailing conditions.

The pilot was also concerned about a shed at the end of the strip and decided that, in the event of an emergency during the take-off, he would steer the aircraft to the left of the shed. The aircraft was again difficult to start, and the owner's assistance was needed. During the taxy for take-off, the pilot had to use the auxiliary fuel pump, on several occasions, to keep the engine running. Although he completed the pre-take-off checks the pilot did not complete a magneto function check as he believed the strip surface was inadequate and he wanted to keep the use of high-power settings to a minimum.

The pilot did run the engine up to full power, against the brakes, before commencing the take-off roll. At that point all engine indications appeared normal. During the take-off roll the pilot concentrated his attention on keeping the aircraft in the centre of the very narrow section of reasonable strip. At the end of the 650 metres, he selected the normal climb attitude and lifted off at, what he believed was, about 75 knots. Immediately after liftoff the stall warning sounded and the pilot lowered the nose slightly, at the same time turning left to avoid the shed.

The aircraft continued to descend until it collided with trees. The aircraft came to a stop 150 metres to the left of the strip centreline and 1400 metres from the start of the take-off roll. The pilot reported that after liftoff he felt that the aircraft was not performing to expectations and that the engine had lost power. A post-accident inspection of the engine disclosed that the compression on two cylinders was probably below serviceable limits at the time of the take-off.

Also, the bottom plugs in two other cylinders may have been contaminated and not been working efficiently. The engine had been serviceable during the periodic inspection completed 87 hours prior to the accident. The reports that the airspeed indicator under-read in cruise, the engine was difficult to start, and the difficulty encountered by the pilot in keeping the engine running during taxy may also have been indications of poor engine performance.

The lack of normal acceleration, during the take-off roll, was probably the result of the less than optimum performance from the engine. The drag caused by the brush on the runway may have also been a factor. The pilot was forced to liftoff at the 650-metre mark as the condition of strip, after that point, was poor. Although the pilot reported that liftoff speed was 75 knots, the onset of a stall immediately after liftoff indicates that the speed was below this figure. The POH gives a power-off stall speed of 62 knots.

The power-on stall speed would have been something less than this. Once the aircraft had encountered the onset of the stall condition the pilot was left with no alternative other than to lower the nose and accept a forced landing. Although the pilot had a valid reason for not completing a magneto function check prior to take-off, the contamination of the spark plugs would have shown up during this check had one been carried out.

The helicopter was engaged on local joy flights, each flight being of about 7 minutes duration. After completing several flights, the pilot said he dipped the fuel tanks and determined the remaining fuel quantity to be 70 litres. At the completion of two more flights, the pilot decided to proceed to Albion Park aerodrome to refuel. As the helicopter passed through an altitude of 700 feet on descent to Albion Park the engine stopped. The pilot gave a Mayday call and carried out a trouble check but was unable to identify the reason for the engine failure.

An autorotative landing was subsequently conducted onto swampy grasslands near the northern shore of Lake Illawarra. It was reported that the helicopter touched down on the heels of its skids and pitched forward, decelerating rapidly due to long grass and soft surface conditions. As the helicopter pitched forward the main rotor blades severed the tail boom. A subsequent inspection of the engine failed to reveal the reason for the engine failure.

About 200 feet above the ground on initial climb after take-off, the engine began to run roughly and within seconds it stopped. The pilot attempted a forced landing into the paddock off the end of the airstrip. During the forced landing the aircraft clipped a farm fence and landed heavily. Subsequently, a Civil Aviation Authority Airworthiness Surveyor examined the wrecked aircraft and conducted a successful engine ground run with its ROTAX 532 engine. No defects were found with the aircraft. The nature of the engine failure was consistent with carburettor icing.

Conditions at the time were conducive to carburettor icing; the temperature was 7 degrees Celsius and the dewpoint 5 degrees. A Cessna 152 suffered an engine failure due to carburettor icing while taxiing at the same airport minutes after the accident. This Kitfox was not equipped with carburettor heat. The Civil Aviation Authority is assessing the need for the mandatory installation of a suitable carburettor heat device to the Kitfox.

Significant Factors

The following factors were considered relevant to the development of the accident:

1. The aircraft was not equipped with carburettor heat.

2. The aircraft encountered conditions conducive to carburettor icing.

The pilot decided to divert to Mudgee when deteriorating weather conditions were encountered near Narrabri. Upon arrival in the Mudgee circuit, he positioned the aircraft for a landing on runway 04. On the downwind leg, the before landing checks were completed by reference to a checklist. The aircraft was established on the final approach with all prelanding checks completed. At a height of about 200 feet, both engines lost power simultaneously. The aircraft touched down heavily in a field about 100 metres short of the threshold to runway 04 and was substantially damaged as a result of ground impact forces. The reason for the simultaneous double engine failure was not positively established. However, it is possible that when the pilot carried out the before landing checks, both auxiliary electric fuel pumps were inadvertently selected to the high setting rather than low. Consequently, when the throttles were moved towards the idle position on the final approach, both engines lost power due to an over rich mixture.

The aircraft was engaged in mustering operations and was returning to refuel before continuing the task. At about 30 feet, with about 10 knots forward speed, the engine hesitated once and then stopped. The pilot had insufficient time to enter autorotation or significantly cushion the descent before the aircraft landed heavily.

The pilot reported that during cruise he experienced a loss of engine power associated with rough engine operation. He carried out a precautionary search and landed in a paddock. After landing, the engine was test run and could not be faulted. The pilot, having assessed that the available take-off length and surface conditions were adequate, elected to fly the aircraft from the paddock. The aircraft became airborne later than expected and struck a fence. A landing was made in the paddock immediately past the fence.