The helicopter departed Waste Point helipad at about 0925 to resupply huts with rations and fuel, and to undertake feral animal control. Apart from the cargo, a second crewmember and a passenger were carried.

The aircraft approached the first hut (Tin Hut) in clear sky conditions with nil wind. The pilot said he carried out an aerial inspection of the landing area before commencing a landing towards the north. As the aircraft turned onto final approach at an altitude of about 6000 feet, with speed reducing to 20 knots, the engine lost power and the main rotor RPM drooped below the green arc. With about 100 metres left to run to the landing area, and unable to increase engine power, the pilot attempted an autorotation approach. The helicopter landed heavily and bounced before the tail rotor struck the ground. At the time of the accident the aircraft was being flown at about maximum gross weight. Manufacturer information indicated that the aircraft should have been capable of hovering in ground effect with regard to the ambient altitude/temperature conditions.

The engine was subsequently removed from the aircraft and bench tested. No operational problems were revealed. The fuel control unit was then removed from the engine and tested. The test revealed that the fuel control unit had a slower than acceptable acceleration response time. This was due to contamination of the fuel control unit with what appeared to be sand. It is considered likely that in a marginal situation of high gross weight and altitude, any delay in fuel control response for increased engine power may have resulted in a considerable loss of height whilst the fuel control unit was responding to demand.

The reason why the fuel control unit was contaminated could not be positively determined. The fuel control filter was serviceable and should have prevented the passage of grit into the fuel control unit. However, prior to engine start with the aircraft boost pump operating, fuel from the aircraft fuel supply can bypass the fuel pump and filter. Such contamination of the fuel supply need only have happened once, leaving the fuel control unit contaminated in such a way as to only become apparent at some later stage when engine response was critical.

The aircraft was conducting a vertical take-off near a McDonalds Restaurant as part of a fund raising activity. At about 300 feet the right rear cabin door detached from the aircraft whilst being closed by a crew member.

Investigation revealed that the door lower track was cracked and deformed and the upper track had slight deformation sufficient to allow the door to separate from the aircraft. The first section of the crack in the lower track was discoloured indicating it had been present for some time.

Maintenance procedures have been amended to include a detailed inspection of the door and attaching hardware into the five weekly routine servicing schedule.

PK-GIB was tracking from Taroom to Udiko. JA8182 was tracking from Rockhampton to Armidale. Both aircraft were cruising at flight level 370 (F370). The tracks cross at approximately 60 nautical miles (nm) east of Taroom. PK-GIB was instructed to descend to F350 and to be established at that level by 20nm east of Taroom.

Due to language problems between the controller and the Indonesian crew, the controller was later not certain whether the crew had understood the clearance to be level at F350 by 20nm (the lateral separation point) or 30nm east of Taroom. After some further discussion, the controller finally established that the aircraft had not levelled at F350 until 41nm east of Taroom thereby compromising procedural separation standards.

An experienced instructor was conducting a routine flight proficiency check on a pilot from his company. During a practice emergency, where a jammed tail rotor pedal was simulated, the pilot being checked allowed one skid to contact the ground while the aircraft was yawing to the left. Control was regained and a further hour of flying was completed. Post flight inspection revealed that the tail boom had been creased as a result of the ground contact.

The aircraft was returning to land with a glider tow rope attached when it landed heavily causing part of the tail wheel structure to collapse. The aircraft yawed rapidly to the left, but the pilot was able to regain control. Shortly after control was regained the aircraft yawed rapidly to the right. As the aircraft was heading towards a group of people on the ground the pilot deliberately ground looped the aircraft to avoid striking them. The aircraft came to an abrupt stop causing the right wing to strike the ground fracturing the wing spar.

Subsequent inspection revealed the tow rope stretched taut to a strip light at the side of the runway and both tail wheel actuating springs were detached.

 

As the aircraft was climbing through 7,700 feet, 25 miles from Wagga, the pilot gave a Mayday call and reported returning to Wagga due to a fire in the left engine. Emergency services were alerted. Shortly after, the pilot reported the fire was extinguished and the engine had been shut down. The aircraft returned for a safe landing.

An investigation revealed indications of heavy detonation in No 1 cylinder. The side of the piston was burnt, which had allowed the sump to pressurise and dislodge the dipstick. Engine oil was then pumped out of the open dipstick hole and streamed back to the turbocharger, generating a large volume of smoke. There was no evidence of fire damage.

It was reported that the engine had suffered from an episode of rough running some 15 engine hours earlier. Rubber deposits had been found partially blocking the fuel injectors, but the source was not determined. The injectors were cleaned and the aircraft returned to service. It is likely that the partially blocked injectors resulted in a lean fuel mixture being supplied to the No 1 cylinder, resulting in detonation. The detonation created localised hot spots, causing pre-ignition and the burning of the piston.

While operating in a high out of ground effect hover, the pilot heard a change in the engine noise. He noted that the engine torque needles had split by about 60% with the number two engine torque needle reading high. He also noted that the main rotor revolutions per minute (RPM) had increased to maximum (redline). He assessed the problem as a power turbine governor high-side failure and controlled engine parameters by retarding the power lever for number two engine before performing a gentle run on landing in a nearby paddock.

The air pressure line (Pr line) between the power turbine governor and the fuel control unit was found to have broken in the sleeve near the pipe flare where it was attached to the power turbine governor. The broken pipe allowed pressurised air to escape, thereby causing a governor high side failure.

The company chief engineer determined that the stainless-steel pipe broke because it was misaligned at the fitting to the fuel control unit. This placed the pipe under stress which eventually caused it to break near the other end fitted to the power turbine governor.

On descent into Devonport regular public transport aircraft, VH-WZI, made radio calls on the Flight Service (FS) frequency and on Devonport Mandatory Traffic Advisory Frequency (MTAF) prior to leaving controlled airspace at 10000 ft. There was no response from any other aircraft. When VH-WZI was approximately 18 NM north of Devonport, FS asked Air Traffic Control (ATC)for the position of VH-WZI. A short time later FS advised VH-WZI that ATC had VH-IJM on frequency 17 NM north of Devonport tracking for Hobart at 7500 ft. At this, VH-WZI terminated the descent and initiated a climb to 8000 ft in visual meteorological conditions. VH-IJM was transferred to the FS frequency and separation was effected. The crew of VH-WZI sighted VH-IJM half a mile to the right and below but it was extremely difficult to see VH-IJM due to underlying cloud cover.

The pilot of VH-IJM was flying to visual flight rules. VH-IJM had transferred to the ATC frequency at least 20 NM north of Devonport in order to obtain a clearance into controlled airspace which starts north of Devonport. The pilot was monitoring one radio frequency at a time. He was unaware of VH-WZI until he saw it.

The captain of VH-WZI believes that on routes where there is traffic climbing or descending to locations under controlled airspace, then the design of the airspace should be such that frequency separation is not encouraged; otherwise, procedures should be established to cater for such occurrences.

The manager of FS advised that where an aircraft is single very high frequency (VHF) radio equipped (or a pilot is monitoring only one frequency), with similar circumstances a similar incident could reoccur.

The current procedures for pilots and air traffic personnel, combined with the existing airspace configuration, do not prevent this type of incident from occurring.

Significant Factors

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

1. The pilots of both aircraft complied with existing rules and regulations.

2. Air Traffic Services provided more than the required service.

3. The combination of existing rules, procedures and airspace does not prevent this type of occurrence.

The student pilot was on his first solo flight. During the final approach the instructor observed the aircraft pitch nose up and then down sharply as the student over-rotated and then pushed the control column forward. The aircraft touched down heavily on the nosewheel. Post flight inspection revealed nosewheel and engine mount damage.

The pilot's circuit entry procedure resulted in the aircraft joining the circuit too late and too low. The turn onto final was low and the pilot elected to land on the grass verge on the south side of the runway. The aircraft landed heavily, and the landing gear collapsed.