The pilot reported that after completion of the first heat of a pylon race, flying at 100 feet above the ground, the aircraft was climbed to 350 feet in preparation for landing. The throttle was closed to reduce speed and within about 15 seconds the engine began to run roughly. The pilot opened the throttle but there was no response from the engine. The aircraft was landed in a paddock.

Significant Factors

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

1 Engine power loss, for undetermined reasons.

2 Unsuitable terrain for a forced landing.

The pilot had planned to fly an aircraft equipped with fixed landing gear. However, the keys for this aircraft could not be found so he flew another aircraft of the same type, but which had retractable landing gear. On arrival at the destination aerodrome, the pilot forgot to lower the landing gear and landed with the gear retracted.

The pilot of VH-WZB had completed an IFR training session at Tailem Bend and departed for Adelaide, maintaining 4,000 feet and flying in and out of cloud. He was advised by Adelaide Flight Service of opposite direction IFR traffic, VH-NIQ, enroute from Adelaide to Tailem Bend to conduct IFR training and maintaining 5,000 feet.

A short time later an electronic traffic alerting system installed in VH-WZB alerted the pilot of an aircraft approaching head-on at the same level. The instructor descended the aircraft rapidly to 3,500 feet and the traffic, which was identified as VH-NIQ, passed overhead.

The Flight Service Officer had overlooked amended details concerning VH-NIQ revising its cruising altitude to 4,000 feet.

The pilot noticed an abnormal noise as the landing gear retracted following take-off from Bathurst Island. After selecting the gear down in the circuit area at Snake Bay he noticed that all three gear down lights were illuminated.

A normal circuit and landing was carried out, but during the landing roll as the nosewheel contacted the runway it collapsed rearwards, allowing the underside of the nose and both propellers to contact the runway.

Subsequent investigation revealed that the nose gear retract actuating rod had failed at the drag brace rod-end fitting. Because of the location of this failure the gear down microswitches were still actuated, giving the pilot a false gear down and locked indication.

After landing the helicopter in a confined area the pilot had some reservations about its ability to climb over adjacent trees. He identified an area that appeared suitable for a run-on landing in the event of the need to reject the take-off.

After commencing the take-off, the pilot realised that there was insufficient power available to clear the trees and manoeuvred the helicopter for a run-on landing in the area he had previously identified.

During the ground run, just before the helicopter came to a stop, the ground gave way into an underground cavity. The helicopter pitched forward, and the main rotor struck the ground.

Air traffic control (ATC) cleared the pilot of VH-EWF to descend to 5,000 ft and to divert left of the 144 VOR radial as required to avoid weather. However, the pilot subsequently diverted to the right of the 144 radial. A breakdown in separation standards occurred with VH-XFT, a scheduled passenger flight outbound from Rockhampton, on climb to 7,000 ft and tracking via the 116 VOR radial.

The pilot of VH-EWF had requested clearance to track 5 NM left of the 144 radial. He was advised by ATC that the clearest conditions were to the west of that radial. The pilot later advised that he had diverted 5 NM left (west) of track. However, he had subsequently diverted to the right of the 144 VOR radial, and at 15 NM from the aerodrome, the aircraft was established on the 125 VOR radial.

The aircraft was engaged in parachute-jumping operations which involved free-fall jumps from 10,000 ft. Five parachutists were carried on each flight. The aircraft had operated normally during earlier flights that day and the pre-take-off engine run-up revealed no abnormalities.

The pilot reported that as the aircraft approached 300 ft and he was about to make the first power reduction shortly after take-off, there was a momentary power fluctuation. He decided to turn back towards the runway but during the turn the engine started to miss significantly and lose power to the extent the aircraft could not maintain height. The engine failed to respond to the normal trouble-checks which included switching the electric fuel pump on.

As the aircraft descended through 100 ft it was apparent that the engine was producing no power. The pilot extended full flap when he heard the aural stall warning and subsequently commenced the landing flare too early and had to lower the nose before attempting a second flare for the landing. The aircraft impacted heavily and almost immediately rolled over onto its back.  The five parachutists, who were unrestrained, were injured in the accident and the pilot received minor injuries when his seat detached from the floor rails.

The loss of engine power was the result of an excessively rich fuel/air mixture. Investigation revealed rubber deposits jammed under the variable adjustment needle in the engine-driven fuel pump, blocking the return port. This resulted in an oversupply of fuel to the metering unit and an excessively rich fuel/air mixture. The rubber had originated from the internal lining of the fuel hoses between the pump and the metering unit. The fuel/air mixture was further enriched when the pilot switched on the electric fuel pump, resulting in the complete loss of engine power.

Distracted with troubleshooting the engine problem, the pilot allowed the airspeed to decay to the point where the stall warning activated. The airspeed decreased further during the initial flare and a high sink rate developed which the pilot was unable to correct, resulting in the heavy touchdown. The nose gear leg failed in overload and the aircraft nosed over onto its back.

Investigation of the pilot's seat revealed it had been repaired some time prior to the accident. The repair differed from the original design and compromised the lock function. During the accident sequence, the lock withdrew and the two unrestrained parachutists who were located behind the seat moved forward and pushed the seat out of the tracks. Single-point restraint lines were fitted for use by the parachutists, but they had not been used.

Significant factors

The following factors were determined to have contributed to the accident.

1. Rubber debris had detached from the internal lining of engine fuel hoses, contaminating the engine-driven fuel pump and resulting in an excessive fuel supply to the engine with subsequent loss of power.
2. Activation of the electric pump in accordance with the flight manual procedure resulted in an oversupply of fuel to the engine with a complete loss of power.
3. The airspeed decayed sufficiently to preclude a safe forced landing.

SAFETY ACTION

As a result of the investigation, interim recommendation IR950014 was issued to the Civil Aviation Authority on 16 February 1995.  It stated:

The Bureau of Air Safety Investigation recommends that the Civil Aviation Authority and the Australian Parachute Federation evaluate the adequacy of current legislation with regard to restraints for parachutists in aircraft.

The Civil Aviation Authority response to this recommendation dated 27 April 1995 stated:

I refer to BASI Interim Recommendation IR950014 regarding an accident involving parachute operations at Nowra.

The report notes that no restraints were being worn by the occupants of the aircraft and opines that their injuries would have been more severe had the single-point restraints (which were fitted to the aircraft) been used.

In 1991 the Authority conducted a study in response to a request from the Australian Parachute Federation (APF) to delete the requirement to wear any restraint on take-off, landing and below 1000 ft. CAO 20.16.3 permits the use of approved single-point restraints for parachutists in lieu of the normal seat belts or safety harness. The APF expressed some concerns about the possibility of a restraint snagging a parachute and causing premature opening. The Federation was also of the view that the use of single-point restraints could cause more injuries than not using them.

The Authority concluded that the advantages and disadvantages of single-point restraints were fairly evenly balanced.  However, at about this time a fatal crash occurred to an Army Pilatus Porter aircraft, where the main cause of injuries and deaths was unrestrained bodies flailing around the cabin.  Also, several accidents occurred in the USA to larger aircraft in parachuting operations, which were attributed to loss of control following movement of the centre of gravity.  As a result of these accidents, it was decided to confirm the requirement for some form of restraint. The APF at the time indicated that they preferred the single-point restraint option over a full seatbelt or safety harness.

Notwithstanding, our earlier study of this requirement, it is agreed that this issue needs further examination. A review will be carried out in conjunction with the APF.

Response status: Closed-accepted

The Bureau of Air Safety Investigation intends producing an article for inclusion in a future edition of the Asia-Pacific Air Safety magazine concerning the problems associated with non-standard aircraft repairs.

As the pilot taxied his aircraft towards his normal parking place on the G.A. apron he was aware of an aircraft to his right parked next to the refuelling installation, and a refuelling tanker parked on the apron to his left.

It is common to have tankers on the apron, although this tanker was parked further away than normal from the aircraft it was servicing. The pilot was concentrating on ensuring clearance from the parked aircraft to his right, and experienced sun glare when looking towards the tanker.

Although the aircraft was taxiing on the centreline of the taxiway, the pilot realised too late that the left wingtip would not clear the tanker and was unable to prevent a collision which damaged the wingtip and aileron.

Factual Information

Sequence of Events

The crew of VH-SSV planned for a flight from Bankstown to Coffs Harbour as VH-SSW. The plan nominated flight within controlled airspace (CTA). A change of aircraft occurred and, after taxiing to the holding point, it was established that air traffic control (ATC) would require a delay before issuing a departure clearance into CTA. The crew therefore decided to proceed outside controlled airspace (OCTA) and departed at 0642 ESuT, climbing below the CTA steps.

At 0646 the aircraft passed the Hawkesbury Bridge, and the crew transferred to the flight service (FS) area frequency of 125.7 MHz. They requested that the flight service officer (FSO) inquire of Sydney Sector 1 (Sec 1) if an airways clearance was available as they had planned about 70 minutes earlier. This request was not relayed to Sec 1 until 0654 due to the workload on FS 4. At the time of the co-ordination, the sector controller had not received the flight plan details at the console.

Also at this time, the FSO passed traffic information on two IFR aircraft which were in the area and in possible conflict. Consequently, the crew of one of these aircraft (VH-KZQ) and the crew of VH-SSV arranged mutual vertical separation. During this time, the crew of VH-SSV reported maintaining 6,000 ft to FS.

VH-TQL had planned a flight from Williamtown to Sydney at FL120 and at 0647 the crew reported taxiing at Williamtown on area frequency as Williamtown ATC had not yet commenced duty. RAAF ATC were due to commence services at 0700. This taxi call is required to be co-ordinated with Sec 1, and this was completed at 0651, delayed due to workload on FS 4.

At 0653 the crew of VH-TQL reported to FS its departure of 0652 and, as the airspace was uncontrolled, they were required to remain OCTA until Sec 1 could issue an airways clearance. As a result, VH-TQL was levelled at 8,000 ft to remain OCTA while awaiting airways clearance.

The FSO providing the FS 4 service had received from Sec 1 an expectancy  that VH-TQL would be given an airways clearance with little or no delay and therefore instructed the crew to contact control on 123.4 MHz on reaching 8,000 ft for a clearance and asked the crew to report approaching 8,000 ft before leaving his frequency. 123.4 MHz is Sydney Arrivals Control and the responsibility for informing that controller lies with Sec 1.

At 0654 FS 4 co-ordinated with Sec 1 regarding the request from VH-SSV for an airways clearance. This was the first time that Sec 1 had been passed information on this aircraft but agreed to take the aircraft on frequency for processing. FS 4 instructed the crew of VH-SSV to contact control on 126.9 MHz (Sec 1) for a clearance. It is the responsibility of Sydney Departures Procedural control to inform Sec 1 when an aircraft that has planned in CTA from Bankstown departs OCTA and requires a clearance en-route. This co-ordination was not carried out.

As the crew of VH-SSV were transferring frequencies, they observed that they had passed the next control area step and elected to climb to 8,000 ft OCTA while awaiting their airways clearance from Sec 1. Due to a delay in the issuing of the clearance, the aircraft was levelled at 8,000 ft in order to remain OCTA. As their track was 002 degrees, both 8,000 ft and their previous cruising level of 6,000 ft were contrary to the table of hemispherical cruising levels.

At 0655 FS 4 co-ordinated the departure time of VH-TQL with Sec 1. The Sec 1 controller found that he had four aircraft OCTA all wanting airways clearances. He decided to instruct all four to remain OCTA until he had identified them on radar so that he could guarantee adequate separation within CTA. This resulted in a short delay for both VH-TQL and VH-SSV while on separate control frequencies and both maintaining 8,000 ft on conflicting tracks.

While Sec 1 was co-ordinating the clearances for the two aircraft with arrivals control, the initial radar returns indicated that the aircraft were in close proximity and on converging headings. The sector controller issued VH-SSV with a radar vector OCTA for collision avoidance. Traffic information was passed to both crews, and a mutual sighting was achieved during the turn manoeuvre.

The aircraft passed approximately 600 m apart at the same altitude.

Flight Planning

It is common practice for pilots to plan IFR in CTA ex Bankstown and then elect to proceed OCTA when ATC issue a delay for an airways clearance. It is also common practice for crews to hold a second, OCTA, plan in the cockpit for such eventualities. However, they do not submit this OCTA plan as the pilots prefer to operate IFR in CTA and they believe that ATC will always send them OCTA if such a choice exists on the flight plan. This causes problems in the distribution of flight details to FS.

Co-ordination

When an aircraft departs OCTA from Bankstown having planned in CTA, Bankstown ATC are required to pass the details to Sydney FS and Departures Procedural. Departures Procedural then passes this information on to Sec 1 for processing.

Hemispherical Levels

IFR aircraft are required to be flown in accordance with the table of hemispherical cruising levels. On this occasion the crew of VH-SSV chose to fly at a non-hemispherical level. The correct altitudes for their track would have been 5,000 ft and 7,000 ft in lieu of 6,000 ft and 8,000 ft.

Change of Level OCTA

The crew of VH-SSV were maintaining 6,000 ft when transferred by FS to control frequency. Shortly after, they initiated climb to 8,000 ft to remain OCTA in the belief that a clearance would be given by the time they reached that level, however the delay in obtaining the clearance resulted in the aircraft maintaining 8,000 ft. Neither the crew nor ATC informed FS of this change in altitude, which is contrary to requirements.

The FSO did not pass traffic to either aircraft in the belief that they were separated by IFR cruising levels, but he was aware of the requirement for VH-SSV to pass through the level of VH-TQL once ATC issued approval for climb into CTA. He considered that ATC would separate the aircraft on climb as both were on control frequencies with an expectancy of an airways clearance almost immediately (as this was normal practice).

Control Frequencies/Airspace Configuration

The two aircraft were transferred to separate ATC frequencies by the FSO. This was common practice but was not in accordance with Local Instructions. It resulted in neither crew being able to hear transmissions involving the other at a time when they were on conflicting tracks. The correct procedure would be for both aircraft to contact Sec 1 whose airspace they were about to enter.

FS Workload

The FSO was rostered to perform the FS 4 duties on his own until 0800 when a relief officer commences duty. The workload builds up after 0630 each morning and becomes very busy from approximately 0645. It has become common practice for the FS 4 operator to request the assistance of the Team Leader to act as co-ordinator during this period.

One reason for this rise in workload is that Williamtown ATC commence duty at 0700 each weekday and this results in an added workload for the FS 4 operator in that an update of all traffic in the Williamtown area is required to be passed to ATC. The process for passing this information is very formal and convoluted.

Findings

1. No flight plan for VH-SSV to depart Bankstown OCTA was submitted.
2. Sydney Departures Procedural did not co-ordinate the departure of VH-SSV as required by Sydney District Local Operating Instructions.
3. The FSO was experiencing a period of heavy workload.
4. The two aircraft were transferred to different control frequencies.

Significant Factors

1. The crew of VH-SSV elected to fly at a non-hemispherical altitude.
2. Neither the crew of VH-SSV nor ATC informed FS4 that the aircraft had changed level while remaining OCTA.
3. The FSO did not pass traffic information on either aircraft to the crew of the other.

Safety Action

As a result of the investigation the following Safety Advisory Notices were issued:

SAN 940093: The Bureau of Air Safety Investigation suggest that the Civil Aviation Authority and the RAAF conduct a joint review of their procedures with respect to:

1. the coordination of traffic information concerning aircraft departing WLM CTR for possible climb or cruise OCTA;
2. notification of the opening of military airspace, with particular reference to RAAF/FIS coordination.

SAN940079: The Bureau of Air Safety Investigation suggests that the Civil Aviation Authority conducts a consultative meeting with local industry to discuss the practices and procedures used for IFR operations in Sydney airspace. This meeting should particularly address those operations departing Bankstown OCTA.

The Bureau issues the following, additional, Safety Advisory Notice:

SAN940095: The Bureau of Air Safety Investigation suggests that the Civil Aviation Authority review the staffing procedures at Flight Service Units to ensure that they are adequately manned during known periods of high workload.

The pilot was conducting a charter flight involving four legs. He was familiar with the routes being flown and carried fuel sufficient to complete all legs without refuelling.

It was the pilot's normal fuel management practice to fly the first leg on the left tank and change to the right tank prior to landing. He would then fly the next leg on the right tank and change to the left tank for landing. This procedure was normally used for each of the remaining legs.

During the second leg the pilot forgot to change to the left tank for landing. He did not recognise his error until taxiing for departure for the final leg to Kununurra. At that point the pilot was uncertain as to the exact contents of each tank although it was evident that the left tank contained significantly more fuel than the right. He decided to fly the final leg using the contents of the right tank with the intention of changing to the left tank for the landing. The pilot was not in the practice of changing fuel tanks during transit due to the inhospitable terrain in the Kimberley region.

The engine stopped, due to fuel starvation, as the aircraft entered the circuit for a low-level approach. The pilot selected the left hand tank, which contained almost two hours of fuel, but the engine did not restart before the pilot was forced to manoeuvre for an abnormal approach and landing. The aircraft was landed across the runway, and the impact was sufficiently hard to cause the mainwheel legs to splay, the nosewheel leg to collapse and the bottom of the fuselage and the propeller to contact the ground. The aircraft stopped within the runway flight strip and the occupants evacuated uninjured.

The aircraft fuel gauges were serviceable, and the aircraft was fitted with a fuel calibration card.

The investigation determined that the pilot did not use a fuel logging system other than a very general mental tally of fuel used. The sequence of events indicates that the pilot failed to complete his pre-landing checks on at least two occasions as he did not change the fuel selector to the fullest tank for landing as was his normal practice. Other evidence indicated that although the fuel gauges were serviceable the pilot ignored their indications because he considered them unreliable. The company provided a fuel dip stick which the pilot did not use even when he became unsure of the actual fuel contents because he thought he had sufficient knowledge of the fuel state. Finally, the pilot was not concerned that the engine might stop as a result of fuel starvation because his experience led him to believe that it would restart quickly once a tank, with fuel in it, was selected.

The pilot was very familiar with the route flown and it is probable that he had become complacent about fuel management.

The pilot had developed a habit of completing a low-level circuit as he believed it assisted his control of aircraft speed. It is possible that the pilot's decision to conduct a low-level circuit contributed to the accident. Had the aircraft been at normal circuit height there may have been sufficient time for the engine to respond to the alternate fuel tank selection.

The operator's check and training system did not disclose the pilot's apparent complacency or unusual circuit procedures as he had performed more than adequately on check rides.