The pilot was familiarising himself with the Sidelinger replica Hurricane before continuing with a flight test program that had already been partly completed by another pilot. He conducted one circuit and landing with the landing gear down. After a short break he took off again and departed the airfield for aerial work. After take-off he retracted the landing gear and noted a normal gear-up cockpit indication.

On return to the airfield, the pilot selected the landing gear down but received an unsafe gear cockpit indication. He checked the landing gear circuit breaker was in and then cycled the selector lever twice more but without success. He then attempted to lower the landing gear using the emergency lowering method. He reported, however, that the emergency lowering system would not operate.

Committed to a gear up landing, the pilot elected to land on the 270 degree grass strip. The pilot said that he approached at minimum speed and touched down tail wheel first with throttle closed and the fuel and electrical systems secured. The aircraft then skimmed along on the underside air scoop before eventually nosing forward and damaging the propeller and air intake. The owner subsequently reported the cause of the landing gear failing to lower via the normal system was a faulty selector switch. The reason why the emergency lowering system would not operate was not determined.

The pilot was assisting in flood rescue operations and was directed to a homestead where several people had climbed onto its roof to escape from the fast-flowing flood waters, which had risen to the height of the roof line.

He approached the homestead at a height of about 2m above the water level, then hovered the helicopter alongside the roof to allow an elderly person to board. This person had had a safety rope attached to him to prevent him from slipping off the steeply pitched roof. As he climbed onto the skids his weight moved the helicopter slightly sideways, and the rope snagged on the roof causing the helicopter to descend. The pilot was unable to arrest the downward movement in the height available before the helicopter struck the water and sank.

All occupants escaped, the pilot recovered the ELT and activated it.

FACTUAL INFORMATION

A Boeing 747 (B747) aircraft departed from runway 16 at Melbourne for Bangkok on climb to 3,000 ft. Runway 27 was the nominated departure runway but the aircraft required a departure from runway 16 for operational reasons. Additionally, the crew advised that they could not comply with the requirement to not exceed 250 kts below 10,000 ft. The crew of the B747 tracked the aircraft via a standard instrument departure (SID) that required them to turn right and intercept the outbound track, to the northwest of the aerodrome.

Shortly after the B747 became airborne the aerodrome controller (ADC) requested departure instructions, from the DEP N controller, for a pending Boeing 727 (B727) aircraft departure to Adelaide from runway 27. The B747 was climbing slowly and would cross the intended track of the B727. The ADC suggested to the DEP N controller that the B727 be maintained at 3,000 ft, on departure, after the crew of the B747 had been approved to, and had climbed that aircraft above 4,000 ft. However, the DEP N controller believed that the B727 would climb faster than the B747 and he intended to radar vector that aircraft behind the B727. The DEP N controller approved the departure of the B727 on the planned track. He then approved the crew of the B747 to climb to FL200 and cancelled the speed restriction. He also instructed the crew to cancel the SID and to turn left onto a heading of 270 degrees.

The DEP N controller had been operating at the console for approximately three hours. A busy traffic period had just finished, and traffic numbers were reducing. Traffic levels were moderate when the B727 departed.

After the B727 departed the DEP N controller cancelled the speed restriction below 10,000 ft and approved the crew to track direct to Bordertown on climb to FL200. These measures were meant to assist in increasing the horizontal distance between the two aircraft which were on near parallel westerly tracks with the B747 to the south of the B727.

When both aircraft were approximately 20 NM to the west of Melbourne and at similar levels, the DEP N controller assessed that he could radar vector the B747 behind the B727. He instructed the crew of the B747 to turn right onto a heading of 340 degrees. As the crew was turning the aircraft, the DEP N controller observed that the separation standard of 3 NM was going to be infringed. He instructed the crew of the B747 to turn left onto a heading of 240 degrees. Both crews reported sighting the other aircraft. Separation reduced to 1.5 NM horizontally and 700 ft vertically before radar separation was re-established. There was a breakdown of separation.

ANALYSIS

The DEP N controller did not establish vertical separation between the two aircraft before attempting to radar vector the B747 behind the B727. An instruction to the crew of the B747 to maintain a level 1,000 ft below the level of the B727 would have caused a minor delay to the climb of the B747 but would have ensured that separation was maintained.

SIGNIFICANT FACTORS

1. The DEP N controller did not use appropriate separation assurance techniques.

Sequence of Events

Following an extended period of hovering practice and a circuit, the student remarked that the lateral trim was heavy. The instructor flew another circuit. He noticed that increasing left cyclic control pressure was required to prevent the helicopter from rolling right. At about 150 ft AGL a loud metallic "springing" noise was heard and a reaction felt through the controls and airframe. The cyclic pressures returned to normal. The helicopter was landed safely and closed down.

An after-flight inspection found that the lateral trim springs had parted, and right cyclic control was restricted to about 50% of the normal control authority.

Safety Action

Following this incident, the Civil Aviation Safety Authority was notified and made two submissions for the manufacturer to take urgent action. The manufacturer had been aware of a potential problem involving undue wear on a shaft in the trim assembly which could cause binding. A service letter, SL-13, which called for an inspection at each 100-hour inspection and annually was issued prior to this incident. Service Bulletin, SB-19, which called for a mandatory inspection of the trim shaft to determine the minimum diameter of the shaft was issued on 16 April 1997. Time of compliance was within the next 50 flight hours or by 31 May 1997, whichever came first.

After conducting 15 joy flights from the Geelong helipad from about 1145, the pilot flew two passengers on an advertising project. One of the passengers, a local radio announcer, was tasked to perform a live radio cross from the helicopter.

On the commencement of the last approach to land to the south-east, the pilot estimated the wind to be 15 kts from the north-west. He advised that when on short final, 200 metres from the helipad, he noticed a sudden wind shift and the helicopter experienced loss of lift. He increased throttle and collective in an attempt to maintain height and reach the helipad. However, rotor RPM decayed and the helicopter settled into the sea 60 metres short of the helipad.

Subsequent viewing of amateur video footage showed the latter part of the landing approach to be very shallow, followed by a classic example of overpitching with the main rotor disc coning and the RPM audio decreasing as the helicopter descended into the sea.

No fault was reported with the airframe or engine which may have contributed to the accident.

FACTUAL INFORMATION

A Cessna 550 aircraft had departed Wagga on a training flight to Canberra and was maintaining flight level (FL) 170.

A Saab SF340B aircraft had departed Sydney on a regular public transport flight to Albury and was maintaining FL 120 on the route section between Canberra and Albury. Both aircraft were under radar control.

At 1218 ESuT, the crew of the C550 requested descent and were cleared to FL 130 by air traffic control. The pilot read back FL 120 but this incorrect level was not detected by the controller. One minute later the controller informed the crew of the C550 that there would be a delay for further descent due to crossing traffic (the SF340B) on the Canberra to Albury track.

At 1222, the controller noticed that the radar return for the C550 was indicating FL 120 and was 3 NM from the SF340B on crossing tracks. There was a breakdown of separation.

Radar analysis indicated that at the time vertical separation broke down, the C550 had passed through the intended track of the SF340B by approximately 1 NM and that the closest point between the aircraft was 3 NM. The required separation standard was 5 NM horizontally or 1,000 ft vertically.

ANALYSIS

Air traffic control

Because the controller believed he had heard the crew of the C550 read back FL 130 he annotated this on the flight progress strip. This meant that, in his mind, he had provided separation for the conflict he was expecting to occur. He then monitored the aircraft as they passed in the belief that vertical separation would be maintained until he could re-establish radar separation. It was only when he observed on radar that the C550 was maintaining FL 120 that he realised that a breakdown in separation had occurred. At that time, the aircraft had already passed each other, and separation was increasing.

Flight crew of the C550

The crew thought they heard FL 120 given as the descent instruction and when this read back was not questioned, they continued a normal descent to FL 120, believing it to be the assigned level. They did not see the other aircraft and considered that, as air traffic control were providing separation, any instructions to the other aircraft would not have been queried, even if they indicated a climb through the level of the C550.

SIGNIFICANT FACTORS

1. The crew of the C550 read back an incorrect assigned flight level.

2. The air traffic controller did not detect the incorrect read back.

A Cessna Conquest aircraft (VH-YFD) was enroute Perth to Meekatharra via the Mount Magnet VOR at FL250. Another Conquest (VH-FMQ) was flying in the opposite direction, Meekatharra to Perth via the Mount Magnet VOR at FL240. Both aircraft had filed IFR flight plans, were inside Perth controlled airspace and their Mount Magnet position estimates were within 2 minutes of each other. YFD had advised a DME position for descent to Meekatharra and the Perth Centre controller subsequently calculated that the traffic would be passing and may require separation.

When YFD reached Mount Magnet, the pilot transmitted the position to Perth FIS and reported that he was planning to commence descent 2 minutes later. Perth FIS acknowledged the transmission and passed known traffic. Soon after, Perth Centre, unaware that YFD had changed to FIS frequency, unsuccessfully attempted to establish radio contact with YFD to arrange separation with FMQ. YFD had descended through FMQ's level by the time YFD had returned to the correct frequency.

The Perth Centre controller reviewed the aircraft positions and assessed that a breakdown of separation had probably occurred. Day VMC existed at the time of the incident.

The pilot of YFD reported that whilst he was within regulated duty hours, the day's flying program had changed a number of times with diversions and periods of waiting at various airfields in the heat of the day. He also reported that air traffic and company frequencies were very busy at the time of his transit to Mount Magnet.

FIS staff reported that Perth Centre regularly instructed aircraft to call FIS on descent to Meekatharra for traffic. It was also common for aircraft to call on the FIS frequency without prior notice from Perth Centre due to time constraints and workload.

The planning and attention required to cope with flight diversions and associated effects of waiting in the heat, probably fatigued the pilot and reduced his level of attention. His attention may have also been diverted by the radio traffic during the transit to Mount Magnet. A combination of fatigue, distraction and the regular practice of contacting FIS for descent may have influenced the pilot to contact FIS without direction from Perth Centre.

Due to the regular occurrence of aircraft appearing on frequency without prior notification, the FIS operator did not realise that the aircraft was descending without a clearance.

Perth FIS have reported that they and ATC are reviewing coordination procedures.

The pilot stated that he had experienced a landing gear retraction problem the previous week, which was checked by a LAME, but no faults found. On the day of the occurrence, he decided to fly a circuit to verify the landing gear operation.

After take-off the landing gear retracted normally. The pilot continued with the circuit, maintaining separation with an ultralight aircraft also operating in the circuit area.

On the downwind leg the pilot reported the aircraft suffered a radio problem which he attempted to rectify while still maintaining a lookout for the ultralight aircraft. This allowed his attention to be diverted from operating the aircraft and failure to carry out the pre-landing checks, including landing gear extension, resulting in a wheels up landing.