The engine lost power soon after take off due to the failure of the welds securing the airflow straightener vane located in the hot air box. The liberated vane was sucked into and blocked the airflow through the carburettor throat. The CAA airworthiness branch is investigating the need for these vanes as they are not fitted to all Pawnee aircraft and their failure can have catastrophic results.

The initial clearance passed to the crew of VH-TJB was for cruise at FL 350. Sector 3E contacted Launceston Tower with an amendment for the aircraft to cruise at FL 330. After departure the crew reported on climb to FL 350.

The error happened because the Launceston Aerodrome Controller became pre-occupied with another task and omitted to pass the amended level details onto the crew. The situation was recognised and resolved before the aircraft reached FL 330.

Prior to departure the pilot had calculated that there was sufficient fuel onboard for the flight. About 11km from Alice Springs aerodrome, with the left tank selected, the engine failed. The pilot selected the right tank, the engine restarted, and the flight continued towards the field.

Shortly after the aircraft entered downwind for runway 06 at 3200 feet, about 4km from the aerodrome, the engine failed again. The pilot advised the tower controller that the aircraft "was out of fuel" and was cleared to land as required.

After the aircraft landed safely on runway 24, the pilot visually checked the tanks. The right tank appeared empty but there was 30-40 mm depth of fuel in the left tank. The left tank was selected and the engine started normally, the aircraft was then taxied to the parking area.

When the aircraft was refuelled 156 litres of fuel was added to the right tank and 122 litres to the left tank. Each tank holds 150 litres of useable fuel. All the fuel drains were checked by an engineer and were contaminated by dirt and water.

The pilot of VH-MGW requested taxi clearance for take-off and reported in receipt of automatic terminal information service (ATIS) "Echo". The runway nominated by the ATIS was runway 35. The aircraft was cleared to taxi, but shortly after, the pilot requested runway 30 for departure. The Surface Movement Controller (SMC) then issued the following instruction: - "Mike Golf Whisky taxi for change of runway 30, hold short of runway 35." A Boeing 737 VH-CZD had been cleared to land on runway 35 and was beginning to flare for landing. VH-MGW was then observed to cross the holding point for runway 35. After repeated calls from the SMC the pilot of VH-MGW finally stopped his aircraft close to the edge of the flight strip. The Boeing was not instructed to go-around as it was at the point of touchdown and considered by ATC to be committed to landing.

The pilot of VH-MGW stated he did not see the holding point markings until he had been instructed to stop by the SMC. He said the holding point markings had been changed and was planning to stop at the "old" holding point position. He also stated that he was aware of the landing Boeing 737.

The aircraft departed Sydney at 0752 hours EST on a scheduled commercial air transport flight, landing at Cowra and Young before terminating at Forbes at 0940 hours. The aircraft subsequently departed Forbes at 1545 hours for the return flight to Sydney via West Wyalong, Forbes, Young, and Cowra, departing Cowra at 1815 hours with six passengers on board.

During the flight the pilot was monitoring the fuel state, and became concerned that there may not be sufficient fuel on board to reach Sydney. When the aircraft was overhead Camden, the pilot saw the right hand fuel contents gauge indicating near empty and immediately decided to divert to Bankstown. Sydney Approach advised the pilot that the aircraft was closer to Hoxton Park. As a result, the pilot elected to divert to Hoxton Park, landing at 1856 hours at an estimated weight of 2765 kg. The aircraft was refuelled, departed Hoxton Park and landed safely at Sydney. Hoxton Park has a pavement restriction which restricts normal aircraft operations to aircraft up to a maximum take-off weight of 1350 kg.

Prior to departing Forbes, the pilot had calculated the aircraft fuel requirements, and was satisfied that adequate fuel remained to complete the flight without refuelling. However, he had made an error in his calculations, and had omitted to take into account fuel consumed during take-off and climb as required by the company fuel policy.

SIGNIFICANT FACTORS

The following factors were considered relevant to the development of the incident.

1. The pilot failed to accurately determine the total fuel required for the flight from Forbes to Sydney.

2. During the sector from Cowra to Sydney, the pilot realised there was insufficient fuel in the aircraft to safely complete the flight.

3. As a result of the late appreciation of the aircraft's critically low fuel state, the pilot was forced to divert to an aerodrome suitable for Piper PA 31 operations only in emergency situations.

The pilot reported that the helicopter's engine lost power during normal cruise flight. A forced landing was conducted into small trees resulting in the helicopter catching fire and being destroyed. Later inspection of the wreckage by an aircraft engineer revealed a hole in the crankcase caused by a connecting rod which had separated from the crankshaft.

The pilot reported that the left engine RPM had been wandering slightly during the cruise. She joined the circuit at Grafton for runway 18 and when on base, selected flap to 5 degrees and switched the landing lights on. Just prior to the turn onto final approach, at about 400 feet above ground level and just prior to selecting the landing gear down, the aircraft suddenly yawed and rolled to the left. This was accompanied by a 60 percent decrease in left engine torque indication. The pilot said that, by the time she stabilised the aircraft, it was on short final. Flaps were then selected to 20 degrees and the landing gear selected down as per the pre-landing checklist, but it was obvious that the landing gear would not be fully extended before touchdown. The pilot considered overshooting the approach but decided she was committed to land. The aircraft touched down with the landing gear partially extended.

Attempts were made to obtain from the pilot further information regarding the approach flown and when various checks were done as well as the reported torque loss. However, these attempts were unsuccessful.

The left engine was removed from the aircraft and subject to a strip examination. No reason for the torque loss could be identified.

There was a busy traffic sequence into Sydney with aircraft being required to hold at Bindook. At 0745 hours the crew of VH-RMD, which was cruising at Flight Level (FL) 390, were told by Sector 7 air traffic control to descend to FL 290 by Bindook. Due to the heavy traffic Arrivals control advised Sector 7 at 0746 hours that Bindook was full and that all arriving aircraft were to be held outside Sydney arrivals control airspace.

At 0747 hours the Sector 7 controller told the crew of VH-RMD to descend to FL 350 by 100 miles Sydney, for holding at 100 miles Sydney in a left hand two minute pattern. The aircraft had about 10 miles to run to the 100 mile point and the aircraft systems required re-programming to meet the new clearance limit.

There was not enough time allowed by the air traffic control instruction for the crew to be able to meet the requirement. Just one and a half minutes after being advised of the new clearance limit the crew advised air traffic control that they were at 100 miles Sydney and were still at FL 390. The pilot was instructed to turn left onto a heading of 300 degrees and the aircraft was monitored as it descended. No loss of separation occurred.

VH-SAI departed Sydney Airport for aerial work east of the coast in the Victor 1 transit lane. The helicopter was later observed following the coastline contours, within the Sydney Control Zone. The pilot subsequently reported that the flight path of the helicopter had been affected by the southeasterly wind, resulting in the aircraft inadvertently straying into controlled airspace.

The flight was planned from Launceston to Hobart via Clark. This requires that the aircraft track via the 149 degree radial from Launceston to Clark. From Clark, the inbound track to Hobart is 122 degrees. When the pilot requested a taxi clearance at Launceston, the air traffic controller responded with a taxi clearance and an airways clearance in the same transmission. The airways clearance was 'Hobart One 7000'. This is a standard instrument departure (SID) which involves tracking direct from Launceston to Hobart, not via Clark as planned. The clearance was not prefixed with the word 'amended' as it should have been, to reflect that the aircraft was being cleared on a route different than the one planned by the pilot.

The pilot read the clearance back and a short time later departed. After departure, the pilot made the required departure report including advice that he was tracking via 'Hobart One'. Later, when the pilot called Hobart Control Tower, it was found that he had tracked via his planned route and not via the route cleared by air traffic control.