The pilot reported that on departure from Coconut Island when he retracted the gear he heard an abnormal clunk. The gear unlocked light extinguished, but the pilot noticed that the aircraft was 10 knots slower in cruise indicating that the gear doors were not fully closed. On arrival at Horn Island the gear was selected down and there was no down indication for the left main gear. The pilot recycled the gear twice, changed gear indicator globes, tried sideslipping, and followed all procedures set out in the Emergency Checklist for failure of the main gear. A 500 ft flight over the airport and inspection from the ground confirmed all three wheels were extended but it could not be confirmed if they were locked. The pilot commenced an approach to runway 08 after emergency services were in place. After touchdown the left gear collapsed, and the aircraft came to rest off the left side of the runway but within the flight strip. The left gear retraction rod had failed during gear retraction at Coconut Island.

The flight was being conducted as a command check of the handling pilot, who occupied the left control seat. The pilot in command was the non-handling pilot. During an asymmetric circuit, with the left propeller feathered, the landing gear was lowered on mid-base at a height of about 600-700 ft. Because of the aircraft configuration, primary attention was given to the approach path while awaiting the build-up of the landing gear down-line hydraulic pressure.

At about 400-500 ft, the hydraulic landing gear lever was returned to the neutral position after both pilots confirmed the landing gear down-line pressure was above 500 PSI. The landing gear latch lever was then moved from the spring lock to the positive lock position without having first monitored the green landing gear light. The handling pilot called for the final flap setting (3/4 flap) as the aircraft descended below the 300 ft commit height, below which a go-around would not be attempted. Having made the final flap selection, the non-handling pilot then checked the green light, and the landing gear down-line pressure for 500 PSI minimum.

He noticed that the red unsafe landing gear light was illuminated but had experienced this situation before, with a red light showing and the landing gear warning horn sounding (the warning horn on this occasion was not operating). He assumed that the problem was due to a micro switch and felt that a safe landing could be made if the landing gear pressure was kept above 500 PSI, and the brakes used gently. The decision was made to continue to land after visually checking that the right landing gear was down. A lack of time and the state of the left sliding cockpit window did not allow for a visual check of the left landing gear.

Consideration was given to raising the latch lever and moving the hydraulic lever to "crack" the landing gear, and then selecting down again to re-lock. However, the aircraft was approaching the threshold, and the pressure was above 500 PSI with the landing gear hydraulic lever in neutral. On touchdown, the pilot in command observed the pressure at 500 PSI and immediately pushed the hydraulic lever down to keep the pressure up. This enabled the aircraft to roll the length of the runway, slowing to walking pace. During the final roll out, the flaps were selected up, resulting in the right landing gear very slowly retracting. As this occurred, the handling pilot closed the right mixture control. The propeller was almost stationary as the aircraft settle onto one blade.

A post-flight inspection found that the right landing gear spade lock had been locked out before the landing gear had completed the extension cycle. This action prevented the hook on the extension jack from engaging the spade lock and closing the micro switch. The action of retracting the flaps whilst the landing gear hydraulic selector was down, allowed hydraulic pressure to bleed from the landing gear down line, resulting in inadvertent retraction.

FACTUAL INFORMATION

A Boeing 767 (B767) aircraft departed Perth for Melbourne on climb to the flight planned level of flight level (FL) 370. The aircraft was being controlled by Melbourne Sector 1. This position was a procedural control position which used flight progress strips (FPSs) to manage aircraft separation. A number of FPSs were required for each aircraft under control. The FPSs designated the planned route of an aircraft.

After reporting at RERON, a position southeast of Perth, the crew requested a change of level to FL330. The change of level was approved by the Sector 1 controller. The controller annotated the new level of FL330 on the B767's FPSs.

While the Sector 1 controller was receiving coordination on three other aircraft from Perth Flight Service the crew of the B767 requested a change of level to FL350. The Sector 1 controller approved the change of level and then completed the coordination. The controller did not annotate the B767's RUFLE position FPS, the last FPS for the aircraft, with the amended level. This FPS indicated that the B767 was to operate at FL330.

The Sector 1 controller transferred the B767 to Perth Flight Service (FS) to maintain communications via High Frequency (HF) radio. The FS operator passed the B767's RIDLE position to the Sector 1 controller after the crew reported at that position. The aircraft's level of FL350 was reported to, and correctly read back by the Sector 1 controller.

The Sector 1 controller was then relieved at the position by another controller. The two controllers conducted a handover/takeover of the position. The relieved controller could not remember conducting a final check of the FPSs, as was his normal practice, before leaving the position.

The crew of the B767 reported to the new Sector 1 controller that the aircraft was now back on Very High Frequency (VHF) radio and was at position ROMPA at FL350 at 54 (time 1754 UTC). The Sector 1 controller coordinated the position report to Adelaide Sector 4 but read the level of FL330 from the RUFLE FPS. The Adelaide Sector 4 controller read back and annotated the B767 FPS with FL330. During this coordination sequence the Sector 1 controller was interrupted by a transmission from another aircraft.

The crew of the B767 subsequently transferred to Adelaide Sector 4 and reported at RUFLE at FL350. There was no breakdown of separation.

Sector 1 was combined with Sector 5. Traffic was light and less than normally experienced at the position for the time of day. The first controller had worked until 1300 ESuT that morning and then returned for the evening "Doggo" shift at 2300. He had two hours sleep in the afternoon and felt rested. He operated the position from approximately 0300 to 0445.

ANALYSIS

There were two opportunities to correct the error after the relieving controller assumed responsibility for the position. The first being when that controller started operating at the position and the second when the crew of the B767 reported at ROMPA at FL350. However, the incorrect annotation on the RUFLE FPS was not detected.

The reason for these errors not being detected or why the first controller did not annotate the RUFLE FPS could not be ascertained. It was probable that the physiological effects due to the early time of day and the low level of activity combined to reduce the controllers' vigilance and/or use of standard practices.

SIGNIFICANT FACTORS

1. The Sector 1 controller did not annotate all the B767 FPSs with the approved level of FL350.

2. The relieving controller did not detect the error in the RUFLE FPS during or after the handover/takeover.

At about 200 ft after takeoff the engine began to run roughly. The pilot elected to abandon the takeoff so that the aircraft could be landed on the remaining length of runway. After a high flare for landing the aircraft touched down heavily. The left landing gear leg was broken off and the aircraft came to rest off the left side of the runway.

The relative humidity was assessed as being around 80% and there had been recent light rain at the aerodrome. The pilot reported that the aircraft manufacturer considered carburettor icing as the cause of the rough running.

FACTUAL INFORMATION

An instrument flight rules (IFR) Cessna 310 (C310) departed South Grafton for Kempsey on climb to 7,000 ft. The pilot in command (PIC) had originally planned to operate from South Grafton to Coffs Harbour and then to Kempsey. He had advised flight service (FS) of the amended plan prior to departure. FS had passed the amended flight plan details to Coffs Harbour tower. The operator at the FS position responsible for the area had recently conducted a handover/takeover. Two FS areas were combined on the console. This was normal practice when traffic numbers reduced to a level that could be managed by a single operator. Traffic was light to moderate across the combined areas. The PIC of the C310 reported a departure time of 20 (0820 UTC) and on climb to 7,000 ft to the FS operator. The departure report transmission was the first to be received by the FS operator on this shift and he was unable to clearly hear the departure report. He increased the air-ground volume and requested the PIC of the C310 to confirm the aircraft's planned level. The FS operator did not request the PIC to repeat the departure report. The FS operator believed the departure time was 12 after he checked the console clock to confirm the time. He then annotated the flight progress strip (FPS) departure box for the flight of the C310 with 12. (The console clock was adjusted and operating correctly and these transmissions were made at a time when the clock would have displayed 0821.)

The FS operator co-ordinated the departure time and level for the C310 with the aerodrome controller (ADC) at Coffs Harbour tower. Based on the departure time of 0812 and the time interval for the flight of the C310, the FS operator calculated that the aircraft's estimate for Kempsey was 0838. The ADC had the same estimate, based on the departure report from the FS operator. The aircraft's actual estimate, based on the correct departure time of 0820, was 0846. The ADC was responsible for providing separation between IFR aircraft in controlled airspace (CTA) from ground level to 10,000 ft. Coffs Harbour tower controllers used visual and procedural methods to separate aircraft in CTA. There was radar coverage down to approximately 6,000 ft in the vicinity of Coffs Harbour, but there was no radar display installed in the tower. Radar was used by controllers located in Brisbane for separation in the CTA above 10,000 ft in the Coffs Harbour area. The track of the C310 crossed the CTA steps to the south-west of Coffs Harbour and the PIC required a clearance from the ADC. While co-ordinating the departure from South Grafton, the FS operator asked the ADC if he required the PIC to transfer to the Coffs Harbour frequency immediately.

The ADC suggested that the PIC remain on the FS frequency. The Aeronautical Information Publication (AIP) states that "Except in special circumstances, pilots of aircraft are required to comply with the radio communication requirements appropriate for the "Classes of Airspace-Services and Requirements" table. The table indicates that the pilot of an IFR aircraft operating outside controlled airspace (OCTA) must report to air traffic control, prior to entering CTA, and request a clearance. The PIC had conducted similar flights and had transferred to the ADC's frequency to obtain a clearance through controlled airspace. Therefore, he was expecting to transfer to the ADC frequency when the aircraft was west of Coffs Harbour. There was no equipment limitation or other reason for the PIC of the C310 not communicating directly with the ADC. The ADC issued a clearance for the aircraft to track from Grafton to Kempsey at 7,000 ft and requested the FS operator to advise him when the PIC required descent. The FS operator issued the clearance to the PIC. The PIC readback the assigned level and queried the FS operator regarding when to transfer to the Coffs Harbour frequency.

The FS operator advised that there was no requirement to transfer frequency at this stage and requested the PIC to advise the aircraft's descent point. A short time later a new operator assumed responsibility for the FS position. The PIC of the C310 requested a change of level to 6,000 ft and the FS operator co-ordinated the change in level with the ADC. The ADC recleared the C310 at 6,000 ft and this clearance was issued by the FS operator. The PIC reported that the aircraft's descent point was 26 NM by distance measuring equipment (DME). The FS operator advised the ADC of the aircraft's descent point. The ADC was expecting a BAe146, operating a regular public transport flight, to taxi at Coffs Harbour for departure and assessed that the flight may conflict with the C310. The ADC asked the FS operator "Where is he now please" (meaning the C310). The FS operator, in turn, requested the PIC of the C310 to report his DME distance. The PIC advised that the aircraft was at 19 DME. This distance was consistent with the expected position of the C310 based on the incorrect departure time and estimate for Kempsey.

The ADC believed that the aircraft was to the south-west of Coffs Harbour. The ADC issued a clearance for the C310 to leave the CTA on descent, which was relayed by the FS operator to the PIC. The aircraft's actual position was to the north-west of the aerodrome, outside controlled airspace and approaching the CTA steps. The BAe146 had planned to Sydney and the intended track crossed the track of the C310 approximately 17 NM south-west of Coffs Harbour. The ADC co-ordinated a departure clearance for the BAe146 with Brisbane Sector 15 (SEC15) and advised the controller that the aircraft would depart at 36. The SEC15 controller issued departure instructions to the ADC and the crew of the BAe146 was subsequently issued a clearance to depart Coffs Harbour on climb to an amended level of FL160. Using procedural control, the ADC was required to issue instructions to the crews of aircraft to establish and maintain either a lateral, vertical or longitudinal separation standard. There were a number of procedures which could have been used by the controller to separate the C310 and the BAe146. The BAe146 departed and the crew reported their departure to the ADC. The SEC15 controller contacted the ADC and advised him that there was an aircraft on radar to the southwest of Coffs Harbour at 16 NM, that had just entered the CTA step. The radar display had displayed a secondary surveillance radar (SSR) code 2000 squawk indicating that the unknown aircraft was at 6,000 ft. The SEC15 controller asked the ADC whether he was aware of any other aircraft.

The ADC advised that he was aware of a C310 estimating Kempsey at 38, and as the time was then 38, the C310 should be OCTA. The ADC then requested the crew of the BAe146 to report their level. The crew reported that the aircraft had left 7,000 ft. There had been no instructions by the ADC to establish a lateral or time standard to separate the aircraft. The BAe146 had passed through the level of C310 while both aircraft were in the area of conflict. There had been a breakdown of separation. ANALYSIS It was probable that the FS operator did not hear the departure time and estimated the time incorrectly after checking the console clock. The operator's misreading of the clock may have been due to the similarity of the last two digits and the transposition of the "2" and "1". He only requested the PIC to repeat the aircraft's intended level and consequently missed an opportunity to confirm the departure report. Had the FS operator requested the PIC to repeat the entire departure report it was likely that the error would have been detected. The ADC sought to establish the position of the C310 through the FS operator. However, the ADC did not explicitly request "the pilot to report position". The ADC used imprecise and non-standard phraseology to the FS operator. Had the ADC used standard phraseology it was likely that the FS operator would have requested and obtained a position report from the pilot consisting of a distance and direction from Coffs Harbour. This information would have clarified the position of the C310 for the ADC. Consequently, he would have issued instructions to maintain separation. However, the report of "19 DME" from FS confirmed the ADC's expectation that the C310 was to the south-west of Coffs Harbour, approaching the descent point and would be shortly leaving CTA. The FS operator requested a DME distance from the PIC when the ADC asked where the aircraft was. By inference, the request was for a position report; yet the FS operator reduced the request to one element of a position report.

Consequently, another opportunity was lost to compare the actual and expected positions of the aircraft. The PIC was prepared for and expected to change frequency from FS to Coffs Harbour Tower frequency to obtain a clearance. Had the FS operator and the ADC operated in accordance with standard procedures; the PIC would have transferred to the tower and communicated directly with the ADC. This would have reduced the possibility of the misunderstanding of the position information requested by the ADC from the pilot. If the PIC had transferred to the tower frequency it is likely that the ADC would have requested the PIC to either report leaving CTA, or a level or a DME distance that would have established the aircraft OCTA, before clearing the crew of the BAe146 to depart. Alternatively, the ADC would have assumed that they were both in CTA and would have issued appropriate instructions to separate the aircraft. Either of these measures would have ensured the two aircraft remained separated. The operation of the SSR transponder in the C310, and the consequent display and the recognition of the symbol on the Brisbane sector radar display, by the controller, provided an increased level of safety for the air traffic system.

SIGNIFICANT FACTORS

1. The FS operator misheard the departure report and did not request the PIC of the C310 to repeat the report.

2. The FS operator misread the console clock.

3. The ADC did not use correct phraseology when requesting the position of the C310 from the FS operator.

4. The FS operator did not request the PIC to "Report position".

5. The FS operator and the ADC did not follow standard operating procedure when they agreed to leave the PIC of the C310 on the area frequency.

The Cessna 210 was engaged in flying tourists between Broome and Cape Leveque. The pilot had been with the company for one and half months and had flown eight hours in the Cessna 210. A substantial portion of his previous flying experience was in Cessna 172 and 182 aircraft. The pilot flew the aircraft to the Cape Leveque landing area at approximately 0930 WST. At around 1100, he loaded the aircraft and embarked his passengers; four adults and a five month old baby being held by his mother. The weather was fine with a light south easterly breeze. The pilot then attempted to start the engine but the starter would not energise. After consulting with the company's chief pilot, the pilot successfully started the engine.

The pilot completed his pre-take-off checks and began the take-off run. After approximately 200 metres, the pilot's side window opened. The pilot stated that the sudden noise surprised him and that he was concerned about dust entering the cabin and upsetting the passengers. He attempted to close the window whilst continuing the take-off run. The pilot stated that he managed to close the window but it immediately opened again. He recalled noticing in his peripheral vision that the aircraft was veering left. Evidence indicated that the aircraft veered approximately ten degrees left and continued in a straight path diverging from the runway centre.

The pilot returned his attention back to the take-off and believing the aircraft had sufficient airspeed, attempted to continue the take-off. He stated that just as he was pulling back on the control column to take off, the aircraft seemed to decelerate. Evidence indicated that the aircraft wheels struck freshly graded sand on the edge of the flight strip. Witness evidence and the wheel tracks in the sand indicated that the aircraft had pitched nose up and banked right with the right landing gear remaining in contact with the ground. With the throttle open, the aircraft continued for approximately 72 metres towards scrub adjacent to the runway.

The left wing struck a tree, slewing the aircraft left. The aircraft then continued sliding right before travelling forward into the scrub, impacting trees and stopping. The pilot and passengers evacuated through the right door. The aircraft's ELT operated correctly. It is probable that the pilot was distracted from controlling the take-off by the sudden and unexpected noise created by his window opening. There was sufficient available runway length for the pilot to discontinue the take-off and secure the window once stopped. The pilot could have also continued the take-off and attended to the window once safely airborne. He decided, however, to close the window while continuing the take-off. With his attention diverted in attempts to latch the window, he did not keep the aircraft tracking along centre of the runway. After the pilot realised that the aircraft had diverged left, he decided to continue the take-off without regaining the runway direction. The aircraft failed to become airborne, possibly slowed by the sand along the runway perimeter.

The pilot reported that after a normal approach in light wind to runway 14 at Coolangatta, followed by what appeared to be a normal touchdown, the nose gear collapsed. The aircraft came to rest nose down, supported by the propeller, 320 m from the runway threshold. The aircraft was undergoing first of type testing in accordance with CASA Flight Test Format for CAO 101.28 category aeroplanes. On the day of the accident the pilot had been conducting climb and stall tests at close to the maximum take-off weight (MTOW) at near the most forward centre of gravity. The maximum landing weight (MLW) is 1315 kg and the centre of gravity (CG) limits are between 1930 mm (forward) and 2132mm (aft) from the datum. At the time of landing, the approximate weight and balance was 1240 kg and 1948 mm. Examination of the runway revealed that the nosewheel had scored the surface for about 0.6 m at a point 87 m from the runway threshold (187 m from the runway end).

No further marks occurred until propeller strikes appear 133 m from the runway threshold, 187 m before the aircraft came to rest. Examination of the damaged nosewheel strut, which is a hollow metal tube, indicated that the fracture occurred at a point on the tube which may indicate defective welding or corrosion. Furthermore, where the strut was attached to the fuselage there was minimal movement or flexibility in the attachment to absorb shock or pressure. During static weight and balance measurements, the static weight on the nosewheel was 182 kg. Consequently, when the aircraft was landed at a heavy weight with a forward CG, excessive force may have been exerted on the nose gear the landing, causing it to fail.

The pilot has recommended that the structural integrity of the nosewheel strut be further investigated, redesign of the strut attachment, and a check of the elevator control system. He further recommended that the forward CG limit be reduced, and calibration of the airspeed indicator be carried out.

FACTUAL INFORMATION

The AS350 helicopter was engaged in a controlled burn of a logging coupe. A drip torch was slung underneath the helicopter. It dripped ignited napalm gel on command to initiate burning on the ground. The drip torch weighed 250 kg when fully loaded with napalm.

The pilot advised that while at 50 kts and 200 ft over cleared ground, the helicopter suffered a hydraulic failure. It banked violently to the right and the hydraulic warning light began to flash but the loud warning horn never activated. He turned the hydraulics off using the switch on the collective lever and regained level flight. The helicopter then banked to the right but not as severely. He tried to electrically release the drip torch from the cargo hook but it failed to detach. He then tried the mechanical release but the load still failed to detach. At the request of the pilot, the crewman on board also tried to mechanically release the drip-torch, but still the load would not release. For four minutes, the pilot flew the helicopter back to the airstrip under control, hydraulics off, with the hope of releasing the sling load and performing a run-on landing. He flew one circuit without being able to release the sling load. Then at about 40 kts and 200 ft AGL, the helicopter banked sharply left, pitched nose down, yawed left and entered a left spiral from which the pilot could not recover before ground contact. A crewman watching from the ground said that the helicopter banked smartly to the left and nosed down almost vertical to the ground with the drip torch swinging wildly underneath. Finally the helicopter landed on top of the drip torch. The main rotor and the tail rotor blades impacted the ground but the helicopter did not roll over.

After the accident it was discovered that the main rotors had struck the tail boom and the tail rotor drive shaft was severed. It has not been determined whether the drive shaft was severed in flight during an unusual manoeuvre or when the helicopter landed on top of the drip torch.

The load-ring attaching the drip torch cable to the cargo hook was oval in shape. The client provided the load-ring as part of the drip torch equipment. The ring had been manufactured to suit a slightly different type of cargo hook which may also be fitted to an AS350. Prior to being used operationally, inflight trials had been conducted with the load-ring to ensure it was not prone to dynamic roll out from the hook. The ring was in good condition and had been in service successfully for a considerable time. After the accident it was discovered that it was possible for the load ring to lodge itself partially around the cargo hook housing under negative "G" conditions. Once lodged around the housing, the rim of the only weld on the ring could snag on the housing. In this condition, neither the electrical nor the mechanical release system could detach the snagged load-ring.

The cable between the load-ring and the drip torch was not long enough to enable the pilot to land beside the drip torch with its cable still attached to the cargo hook. The existing cable length had proven to be successful during normal operations; its length minimised the potential pendulum effect of the load. If the helicopter pilot had been able to hover safely, hydraulics on, and rest the load on the ground, a crewman could have stood under the helicopter, de-snagged the load ring from the housing, and manually released the load.

With various combinations of helicopter cargo hooks and sling gear equipment, problems in not being able to release a slung load, or inadvertent load release, have been rare. Dimensions for the primary attachment ring to the cargo hook are contained in the AS350 flight manual supplement for the cargo hook. The load ring in use in this accident was larger than the dimensions described in the supplement.

Subsequent inspection of the hydraulic pump, its drive belt, the hydraulic servos, accumulators, and flight controls, found no significant fault with the mechanical aspects of the hydraulic system. No hydraulic fluid leaks were found. No fault was found with the hydraulic solenoid and switches. However several wires were found to be broken, mostly as a result of the damage sustained during the landing. The wire which controlled the hydraulic warning horn was found to be corroded and broken; this broken wire de-activated the warning horn. A wire to the hydraulic on/off solenoid was found to be broken but it could not be determined whether or not this wire was broken before the accident.

The company chief pilot had previously checked out the pilot and found him to be competent coping with hydraulic emergencies; this included successful hovering of the AS350 with hydraulics off. Weather was not a contributing factor in the accident. The helicopter was within its centre of gravity and weight limits.

ANALYSIS

The load ring was larger than allowed by the flight manual supplement. The way that the load-ring caught on the cargo hook housing was most unusual. Momentary negative "G" must have occurred in flight to have lifted the load ring high enough to snag.

Despite a thorough examination of relevant components no definite cause of the hydraulic failure has been ascertained. The problems encountered in flight by the pilot might have resulted from a wiring problem causing an uncommanded intermittent on/off situation with the hydraulics. The pilot may have experienced heavy, non servo assisted controls suddenly followed by servo assisted light control forces. This could partially account for the unusual inflight attitudes experienced by the pilot. The drip torch swinging wildly underneath the helicopter probably exacerbated the pilot's ability to control the helicopter.

SAFETY ACTION

The operator advised that load rings have since been replaced to prevent snagging. The operator has adopted a system of colour-coding load rings and cargo hooks to ensure that wrong size rings are not used on the variety of cargo hooks fitted to different helicopters owned by the company.

The provider of the drip torch has removed the oval load-rings from service and is working closely with the helicopter operator to ensure that sling equipment is compatible with the cargo hook fitted to helicopters used in controlled burning.

The student was approaching first solo standard, having completed some four hours of incident free circuits prior to a dual session of take-offs and landings. During the first take-off from runway 11C, just prior to rotation speed, the student applied full back stick and 'froze' on the controls. The instructor was unable to regain control before the Tomahawk lifted off and stalled at a height of about 30 ft. The aircraft struck the runway under full power, incurring substantial damage. Both the student and instructor were uninjured

After arrival in the circuit, when the landing gear was selected down, the pilot reported there was an unusual noise followed by a pronounced 'clunk', and the extension cycle stopped. The red gear unsafe light was illuminated and the gear motor circuit breaker had tripped. The checklist was reviewed and the pilot attempted to extend the gear using the emergency system. The emergency extension handle unlatched normally however, the handle was very difficult to move and jammed after about 30 degrees of its travel. The pilot eventually landed the aircraft on runway 29C with the landing gear partially extended.

A subsequent investigation revealed that the interconnect shaft between the forward main gear door motor and the rear main gear door lock mechanism had disconnected. This prevented the rear door locks from unlocking. The gear extension electric motor attempted to drive the gear down with the doors still locked closed, the motor stalled and the circuit breaker tripped. The heavy load on the rear doors prevented the pilot from releasing the door latches by the emergency extension system.

The interconnect shaft is normally retained by a bolt and split-pinned nut. These items were missing and were not recovered after the accident. The aircraft had undergone maintenance, which included an inspection of the landing gear, some 16 hours prior to the accident.