The pilot was taxiing along the river at a speed of about 35 knots. At the end of the taxi run he initiated a turn to line up for take-off by applying full power and left rudder while holding the control column back. As the aircraft began to turn, the pilot sensed that the aircraft felt unusual. He closed the throttle, and noticed that the left pontoon float had separated from the wing and was being dragged by the fuel line. The water rudder was lowered and the pilot steered the aircraft towards the bank of the river. However, while concentrating on the left wing, the pilot did not notice that the right wing had insufficient clearance from trees on the river bank, and a collision ensued.

The pilot was mustering over sandstone which was laced with shallow gorges and gullies. After sensing a shudder and engine miss, the pilot elected to carry out an immediate precautionary landing and landed on an outcrop of rock. While still at high RPM, the pilot moved the pedals and cyclic control to ensure that the skids were on a firm footing and tightened the collective friction. However, shortly after he exited the aircraft to inspect the idling engine, the helicopter pitched rearwards and slid off the rock into the gorge.

After arrival in the Maroochydore circuit area the pilot was unable to extend the landing gear by normal or emergency methods. A visual check from the control tower confirmed that the wheels were only partially extended. The pilot was advised by the tower controller to divert to Archerfield for a landing. The aircraft was subsequently landed at Archerfield on the grass alongside Runway 10 left. Investigation revealed that the aircraft hydraulic system had been fitted with low pressure hose instead of high pressure hose. The supply hose to the "up" side of the nosewheel actuator had burst under system pressure allowing the hydraulic fluid to escape.

The aircraft was being used for mustering when the engine began to run roughly and lose power. The pilot turned towards the nearest cleared area but he was unable to maintain rotor rpm with the power that was available. The pilot initiated an autorotative descent, from approximately 40 feet above ground level, and the aircraft touched down in the cleared area on the heels of its skids. The aircraft bounced forward, onto the toes of the skids, and rolled to the left. The pilot lifted the aircraft clear of the ground, in an attempt to regain control, however it turned through 360 degrees several times before touching down again and coming to a stop. The tail boom and tail rotor were damaged during the landing. The precise cause of the loss of power could not be determined however the movement of the exhaust valve in No. 3 cylinder was found to be restricted by a build up of gum on the valve stem and one spark plug was found to be inoperative. Most mustering operations take place at low level and at a slow speed, as was the case in this accident, and this lack of performance potential makes a successful, damage free, autorotational landing unlikely.

During the landing roll at approximately 65 knots, the aircraft began to veer to the left. The undercarriage position indicator still showed the gear down and locked, but the left wing then began to drop. By the time the left wingtip touched the ground, the left maingear green light had gone out and the landing gear warning horn activated. The aircraft skidded for about 200 metres with the left wingtip on the grass, and came to rest some 50 metres from the runway centreline. An inspection of the aircraft by the pilot after the accident revealed that the left main leg had detached completely from its mounting and the main pivot pin was missing.

Circumstances:

The pilot reported that, very shortly after liftoff from Runway 15, he heard a loud bang. He was advised by one of the passengers that the baggage door, situated on the upper right side of the fuselage above the wing trailing edge, had opened. Apart from a high noise level, aircraft behaviour seemed unchanged. The pilot said that he recalled a section in the Pilot's Operating Handbook which stated that the flight characteristics of the aircraft would not be affected by an unlatched door in flight. He reassured the passengers to this effect. As the aircraft climbed through about 150 feet, with landing gear still extended and flap still at 15 degrees, the pilot reduced engine power to what he thought was about 1800 RPM and turned left to land on the eastern section of Runway 06. He had assessed there was insufficient length of Runway 15 remaining to land straight ahead. As the aircraft turned with 15-20 degrees angle of bank, it was seen to adopt a nose-low/left-wing-low attitude and impact the runway. The pilot reported that the aircraft was in a nose low attitude and close to the ground when it rolled left. He applied right aileron and full power but was unable to prevent the left wing striking the runway surface. The initial impact was 83 metres left of the Runway 15 centreline on a heading of approximately 090 degrees magnetic. The left wing tip contacted the ground first followed by the nose. The aircraft skidded 51 metres before coming to rest. The landing gear collapsed during the impact sequence. Neither the pilot nor any of the passengers reported hearing the stall warning operate prior to impact. The surface wind at the time of the accident was estimated to have been from the south-east at 10 15 knots. There was no significant turbulence. On inspecting the aircraft, the baggage door was still attached to the airframe via its two hinges. The hold-open stay was broken. No fault was found with the door locking mechanism, either through the external locking handle, or the internal lever. The royalite plastic lining, including the protective cover for the internal lever, and insulation material had been torn from the inner face of the door and were found adjacent to the runway. The internal locking knob was securely stowed in the locked position. The pilot reported that it was his habit to check the door as he stepped on to the wing to enter the cockpit. As far as he could recall, the door was locked prior to the flight. Photographs taken of the aircraft shortly after the accident appear to show the external locking handle in the stowed position. However, it is possible for the handle to be stowed and the locking pins to be located outside the fuselage skin, thus leaving the door unlocked. Because of accident damage, the operation of the stall warning system could not be tested. The pilot could not recall the speed of the aircraft during the turn. It seems probable, in view of the aircraft configuration and the engine power setting, that the airspeed was closer to, rather than substantially higher than, the basic stalling speed of the aircraft. The luggage door is positioned on the upper right side of the fuselage above the wing trailing edge. It is hinged on the top of the fuselage with the hinge line parallel to the aircraft centreline. With the door open, the airflow pattern over the rudder/tailplane could be altered. There is no reference in the Aircraft Flight Manual or the Pilot's Operating Handbook to operations with the baggage door open. However, there is reference in the Operating Handbook to the actions to be taken in the event of the cabin door becoming unlatched in flight (flight characteristics unaffected). It was this that the pilot recalled at the time of the occurrence and which led him to reassure his passengers that there was no cause for concern. This knowledge could also have influenced his decision to turn left and land on the remaining section of the other runway.

Significant Factors:

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

1. The pilot probably did not adequately check the security of the baggage door before flight.

2. The baggage door opened as the aircraft took off.

3. In the subsequent landing, for reason(s) which could not be established positively, the pilot was unable to prevent the left wing from contacting the ground.

Recommendations:

There have been a number of accidents to M-20 aircraft involving in-flight opening of the baggage door. In at least two cases overseas, the accidents were fatal and involved loss of control at low speed. In a non-fatal accident overseas, airspeed and vertical speed indications became erratic after the baggage door came open and contributed to the pilot stalling the aircraft. In Queensland in 1984, in circumstances strikingly similar to the accident under discussion here, the pilot of an M-20 aircraft was attempting a landing after the baggage door opened shortly on take-off. He reported that the aircraft "fell away" as it crossed the end of the runway. The aircraft struck the runway surface right wing first, sustaining substantial damage. The pilot did not hear the stall warning sound. These examples indicate that the influence of an open baggage door on the flight characteristics of the Mooney 20 could be significant. Following the first fatal accident, a Service Bulletin dated 28 September 1988 was issued by Mooney Aircraft Corporation (SBM20-239) applying to various serial numbers of M20J Models to prevent in-flight opening of the baggage door. The Bulletin contained instructions to modify the inside latch on the baggage door and was incorporated in Australian Civil Aviation Authority Airworthiness Directive AD/M20/44 dated 23 February 1989. The baggage door inside latch was not a factor in this accident. However, that such modification action to the latch was considered necessary to prevent in-flight opening of the door raises a number of other aspects. These include:

1. Whether any warning device (such as a warning light in the cockpit) is necessary to alert the pilot that the door is not locked.

2. Whether any special technique is required during approach and landing to ensure safe control of the aircraft with the baggage door open.

3. Whether any warning should be included in the Aircraft Flight Manual about possible control problems in the event of the baggage door opening during flight.

4. Whether any flight test program is necessary to determine the handling characteristics of the aircraft with the baggage door open. It is recommended that the Civil Aviation Authority examine the above aspects with a view to ensuring the maximum safety level for Mooney 20 operations consistent with practicable economic considerations.

Prior to commencing operations in the area the pilot carried out an aerial reconnaissance to check the location of powerlines. He stated that he had almost completed the second load when he had the feeling that he was running out of chemical. He believes that he momentarily looked at his instruments to check for pressure and load remaining and temporily forgot about the presence of the powerlines. He subsequently saw the powerlines as the aircraft was approaching the end of the run, just before they were struck by the canopy of the helicopter. Control was maintained with difficulty, and when the pilot noticed that the aircraft was trailing wires he decided to land. The landing in a cleared paddock was heavy, causing the skids to collapse, and the main rotor to flex downwards, striking the tailboom and severing the tail rotor. The pilot stated that the powerlines were difficult to see because of wire sag and the backdrop of trees and buildings. This accident was not the subject of an on-site investigation.

Because of deteriorating lift conditions, the pilot elected to make an outlanding. The paddock selected had been recently ploughed and the surface was soft. Almost immediately after touchdown the glider yawed, then groundlooped through 90 degrees, resulting in a compression fracture of the fuselage. It was likely that the glider had been affected by a sudden wind gust shortly after touchdown, and the pilot had been unable to maintain directional control.

The pilot was making a landing approach in moderate crosswind conditions. Touch-down was made in a three-point attitude at an airspeed of about 40 knots. Immediately afterwards, the pilot experienced difficulty in preventing the into-wind wing from rising. He elected to go around and applied full throttle, but was unable to maintain directional control. The propeller struck the ground and the aircraft cartwheeled before coming to rest. Recorded aerodrome information received by the pilot indicated that the surface wind was gusting above the aircraft maximum demonstrated crosswind component. On final approach, the pilot became aware that a significant crosswind existed, but he continued the approach, using a short field landing technique. When directional control was lost after touchdown and a go around was attempted, the combination of an uncontrolled turn downwind, the low airspeed and a gusty wind caused the aircraft to stall.

The pilot reported that a power loss occurred as the aircraft climbed through an altitude of about 35 feet. The subsequent forced landing was made onto newly cultivated ground, the skids dug in, and all four skid legs were bent. On exiting the aircraft, the pilot noted a strong smell of what he considered to be burnt clutch linings. An inspection of the aircraft revealed a worn clutch. Although the clutch was still within serviceability limits, it is considered possible that some slippage occurred which resulted in the loss of power to the rotor system. This accident was not the subject of an on-site investigation.