Loss of control

The pilot intended to carry out a touch and go landing at the strip, from which he had operated on numerous occasions. He reported that the aircraft floated for some distance before touchdown, whereupon he immediately selected flaps up and applied full power. The aircraft started to swing towards the left, and suspecting an engine failure, the pilot shut down both engines and applied maximum braking. He slewed the aircraft to the right to avoid a dam at the end of the strip. The aircraft was arrested by a wire fence beyond the end of the strip, with the left maingear leg torn off. It was found that the left flap had not retracted, although the right flap had retracted normally and the cockpit indication was that the flaps were up. The strip was narrower than required for an ALA, and was bordered on each side by a one metre high oat crop. As the aircraft swung to the left, it is likely that retardation of the crop on the left wing added to the drag on that side. The aircraft had landed with a tailwind component. During the investigation, it was reported by several persons that asymmetric flap retraction was a known problem on this aircraft type, and was caused by dirt or other contamination of the flap tracks. The symptoms of the malfunction are similar to those associated with a loss of engine power on the particular side. The pilot had not been aware of the problem.

The pilot made a normal approach to land on Runway 13 with two stages of flap but at a higher than normal airspeed of about 75 knots. He recalled that the flare for landing was good but the aircraft "didn't want to sit down" even with the power off. He reported that as soon as the aircraft touched down it veered to the right and he was unable to control it with the use of rudder but he did not use the brakes. The pilot had assessed the wind for landing as being a slight crosswind from the left. As the aircraft left the runway, the pilot re-applied the power and the aircraft apparently did not climb away as expected but drifted to the right. The pilot then closed the throttle and was aware of the aircraft going up on one wheel but he was not aware of the aircraft hitting both wingtips on the ground as it slewed around and sheared off the gear. Two Civil Aviation Authority Examiners of Airmen who witnessed the accident reported that the wind at the time of the accident was 110 degrees 10-15 knots gusting 20-25 knots. Consideration of the circumstances points to the pilot having induced a wheelbarrow effect in an attempt to pin the aircraft on the runway for landing followed by the effect of a strong crosswind as the pilot attempted to go around from a loss of control situation. This accident was not the subject of a formal on scene investigation.

Circumstances:

The pilot of the Cessna was operating in conjunction with an agricultural aircraft. As the latter aircraft was making an approach to land, the Cessna pilot indicated that he would make an inspection of a nearby strip. The agricultural pilot observed the Cessna making a low pass over the second strip, with the wing flaps selected up. He lost sight of the Cessna as he concentrated on his own landing. The Cessna was subsequently found to have collided with the ground in a left hand turn with 45 degrees of bank, with almost no forward speed and a higher-than-normal rate of descent. The flaps were retracted, and the engine was rotating at high rpm at the time of impact. The wreckage was located 50 metres to the left of the centreline and in line with the DEPARTURE end of the strip that the pilot was inspecting. The investigation did not disclose any defects with the aircraft that may have contributed to the accident. The investigation found that the aircraft was in a fully stalled condition at the time of collision with the ground. It appeared that the pilot made a low flapless inspection pass along the wet flight stip. At the end of the pass with full power he pulled up and entered a left hand turn. During the entry to the turn the aircraft stalled and there was insufficient height to complete a recovery. The factors which caused the pilot to lose control of the aircraft could not be positively determined. However, investigations of accidents that have occurred under similar circumstances, indicate that overconcentration on some aspect of the flight, e.g. the flight strip inspection or distraction by something outside the aircraft can result in a pilot paying insufficient attention to the operation of the aircraft. This in turn can lead to a loss of control at low level, often with insufficient time and height available for the pilot to recover before the aircraft collides with the ground.

Significant Factors:

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

1. The pilot probably allowed his attention to be diverted from the operation of his aircraft.

2. The pilot did not maintain sufficient airspeed for safe flight.

3. There was insufficient height available to complete a recovery from a stalled condition.

Circumstances:

The pilot was preparing to depart with a crosswind of about 15 knots from the right. At the time, the aircraft left wing fuel tank was about two thirds full, while the right tank was empty. The pilot performed a flapless take-off, rotating the aircraft at 50 knots, then climbed using a higher-than-normal nose attitude. Shortly afterwards the aircraft commenced to roll to the left, probably because of the low airspeed, and the lateral weight imbalance. The pilot attempted to raise the left wing by use of the aileron, but the aircraft stalled and struck the ground in a left wing low, 20 degree nose down attitude. The aircraft was still undergoing flight testing for type certification and its Certificate of Airworthiness. Data obtained from the test flight schedule indicated that the normal lift-off speed for this aircraft is 63 - 65 knots, with a 48-knot stalling speed in the zero-flap configuration. The pilot indicated that he had lifted the aircraft into the air at 50 knots on previous occasions, but this would have been done under more ideal conditions. The reason he attempted to take off below the recommended airspeed was on this occasion not determined. This accident was not the subject of an on-site investigation.

Significant Factors:

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

1. The pilot rotated the aircraft at a speed below the optimum take-off speed.

2. The pilot failed to maintain flying speed.

3. Loss of control with insufficient height available to effect a recovery.

The pilot had only just taken delivery of the helicopter. After attending a party he invited an acquaintance to inspect the aircraft and listen to a compact disc player which was installed. The pilot stated that the helicopter battery did not seem to have much charge and since he knew the aircraft was to be used in the morning, he decided to start the engine. He believed that there was a note in the Flight Manual stating not to leave the engine running too long without engaging the main rotors. He therefore engaged the rotor and the next thing he could recall was that the helicopter was on its right side. The pilot, although the owner of the helicopter, was not qualified or authorised for night flying. He had consumed some alcohol at the party, and there is some doubt as to whether a takeoff had been intended. Nevertheless, by starting the engine and engaging the main rotor, the pilot should have been aware that an inadvertent takeoff was possible.

Circumstances:

A night take-off was initiated from runway 21. The runway was wet, with patches of standing water on the surface. Light rain was falling, with a south-easterly surface wind of 10 to 15 knots. The crosswind component was close to the maximum specified for this type of aircraft. Just prior to reaching rotation airspeed the left mainwheel apparently entered a pool of standing water, and the pilot reported that at the same time the aircraft was subjected to a strong wind gust. The aircraft swung to the left and the pilot was unable to maintain directional control. The pilot thought that the aircraft may have commenced to aquaplane, and he closed the throttle immediately. There was no attempt made to apply brakes. The aircraft departed the runway to the left, crossed the grass flight strip, and continued for approximately 85 metres, before colliding with a levee bank and coming to rest in a drainage ditch. No evidence of aquaplaning was subsequently found. This accident was not the subject of an on-scene investigation.

Significant Factors:

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

1. Patches of standing water on the runway which were not visible to the pilot.
2. Loss of directional control following penetration of standing water and/or sudden wind gust.
3. The pilot did not apply braking in an attempt to slow the aircraft prior to the collision with a ditch.

The helicopter was lifting an industrial straddle platform from the top of a large, 300 foot high, cooling tower at an electric power station. As the helicopter took up the load, the sling-rope snagged on a small lug on the right landing gear skid. The 420 kilogram load, hanging from the right skid, caused the helicopter to bank rapidly to the right. During this rapid bank, one end of a 2 metre long plastic pipe, held by the crewman at the right rear doorway, contacted 3 of the main rotor blades. Within less than 5 seconds the rope unsnagged from the skid with a sudden jolt as the load positioned itself at the full extension of the rope beneath the cargo hook. Simultaneously the pilot regained a level attitude but found that the helicopter was already descending slowly, under control, within the approximately 30 metre wide opening of the top of the cooling tower. Because the pilot feared that the "jolt" had been possible damage sustained by the helicopter, he continued the descent gently towards the inside base of the cooling tower. A few metres above the base, the pilot jettisoned the load which subsequently damaged the inside of the tower. After jettisoning the load, the pilot landed the helicopter lightly on its skids inside the tower. The crewman got out and inspected the helicopter as best he could as the pilot kept the engine running. As no damage was seen the pilot carefully flew the helicopter out of the tower and landed nearby as the crewman proceeded out on foot. There was nowhere inside the tower for the helicopter to safely shut down. The sling rope had been lightly attached to the skid before the flight by availing of a loop in the rope and one wrap of adhesive tape. The intention of lightly attaching the rope to the skid was to avoid the possibility of the rope being accidently caught on the rear protrusion of the skid during the lift. During the hook-up of the load, the helicopter encountered some turbulence which caused the helicopter to move forward of the desired hover position. During this forward movement, the thick rope slid aft along the right skid and a core strand of the rope snagged on a small lug which meant that the pilot could not jettison the load. At the time, the crewman was restrained at the right rear doorway. His task was to give manoeuvring directions to the pilot and to attach a hook on the far end of the sling rope to the load with a length of plastic pipe. The 420 kilogram load hanging from the right skid placed the helicopter outside the lateral centre of gravity limits for pilot control. Just as the helicopter banked rapidly right, the straddle platform lifted clear of the tower long enough for the helicopter, with the load still dangling from the right skid, to move into the stack opening where a slow descent commenced in a slight downdraft. During the preflight planning, the pilot and the crewman did not consider it possible for the thick rope to snag on either of the 2 small lugs which are designed for the attachment of ground handling wheels. The use of the adhesive tape held the rope close enough to the top surface of the skid for the rope to come into close proximity with the lugs.

Circumstances:

On the flight to Bathurst Harbour immediately prior to the accident the pilot-in-command occupied the left pilot seat, and the co-pilot occupied the right pilot seat. Shortly after take-off on that flight the pilot-in-command handed over control of the aircraft to the co-pilot who was very experienced on tailwheel aircraft. The co-pilot landed the aircraft at Bathurst Harbour without any problem. After a short time sightseeing the party boarded the aircraft for DEPARTURE. The copilot was again handling the controls. Taxiing and the initial take-off run appeared normal but when the tail was raised the aircraft swung to the left. The take-off was discontinued but directional control was not regained. The aircraft left the strip and came to rest in a peat bog a short distance further on. After the accident, the co-pilot's rudder pedals were found to be in the stowed position which disconnects them from the rudder control system. It was not determined when the pedals were put in the stowed position, but it was determined that the co-pilot had not been briefed on the rudder pedal stow system.

Significant Factors:

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

1 Inadequate preflight inspection carried out.

2 The co-pilot was not briefed on the rudder pedal stow system.

3 Take-off was attempted with the rudder pedals stowed. 4 Loss of directional control on take-off.

Circumstances:

The pilot was commencing a practice flight in preparation for a 600-kilometre soaring competition task. The weather was fine with a north-easterly wind of 15-20 knots and a temperature of approximately 40 degrees Celsius. Following line-up, the pilot was delayed for approximately fifteen minutes before his aero-tow became available. He then advised the tug pilot that a climb speed of 65 knots was acceptable. The subsequent tow initially appeared normal although observers at the airfield noticed some apparent roll instability. At approximately 1000 feet above ground level (agl) the tug pilot detected thermal activity and began a left orbit to regain the area of lift. With the turn almost completed the right wing was violently "kicked-up" as the aircraft re-entered the area of lift. The tug pilot corrected the upset checked that the glider was not affected and continued the left turn. Approximately five seconds after the upset at about 1300-1500 feet agl the glider released. Observers reported that the glider had banked steeply to the right while apparently still under tow. Following the tow release the angle of bank increased past the vertical the nose dropped steeply, and the glider entered a spiral dive from which it did not recover. It struck the ground in an almost vertical nose-down attitude. The investigation was unable to find evidence of any pre-existing structural or system defect. Pilot medical evidence is inconclusive. The reason the aircraft entered an abnormal flight manoeuvre at an altitude from which recovery should have been possible could not be determined.

Significant Factors:

The following factor was considered relevant to the development of the accident:

1. Control of the aircraft was lost following tow release. The cause of the loss of control was not able to be determined.

Circumstances:

The pilot was conducting mustering operations at low level at the time of the accident. Shortly after the aircraft made a low pass to indicate the position of some animals, it was observed descending at a steep angle. The aircraft commenced rolling to the right just prior to ground impact and was destroyed by a post-impact fire. All essential aircraft systems appeared capable of normal operation prior to the accident. There was no evidence that the pilot had suffered any pre-impact illness or sudden incapacitation. Although all of the precise factors leading to this accident could not be determined, the sequence of events is similar to many other accidents investigated by the Bureau, where the loss of control at low level following a low pass has been due to inattention to aircraft operations by the pilot. It was disclosed during the investigation that although the pilot had a valid mustering endorsement, he had not received any training in recovery from stall/spin conditions, typical of a loss of control in a Cessna 150, at low level.

Significant Factors:

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

1. It is probable that the pilot did not pay sufficient attention to the operation of the aircraft during low-level mustering operations.

2. The aircraft probably stalled and entered an incipient spin.

3. The loss of control occurred at too low an altitude for any recovery attempt to be successful.

Recommendations:

This type of loss of control is a factor in many of the low-level accidents investigated by the Bureau. Training and exposure in incipient loss of control situations, particularly in Cessna 150 type aircraft, is not included in all mustering and associated low flying endorsement programs. The Civil Aviation Authority in Western Australia advised all local pilots of the desirability of obtaining this type of training. It is recommended that the Civil Aviation Authority extend this advice to all pilots in Australia who have approval to conduct fixed wing operations at low level.