Circumstances

The pilot was undertaking a private flight with four people on board. The aircraft was en route from Flinders Island to Essendon when the right engine suddenly stopped. The pilot reported that he suspected that the right fuel tank was empty, even though both gauges were indicating full. The engine was restarted after switching to obtain fuel from the left tank. Some ten minutes later both engines stopped. The pilot feathered both propellers and diverted towards the landing strip at Yarrum.

The aircraft was landed just short of the strip breaking off the left landing gear and left engine. The four persons on board evacuated without injury. The aircraft fuel tanks were found to be essentially empty. There was no evidence of external leakage. The pilot regularly flew two return flights (four sectors) from Essendon to Flinders Island on a full tank of fuel and the accident flight was the last leg of such a sequence. It was determined that prior to the sequence of four flights the pilot's wife, also a licensed pilot but not rated on the type, had telephoned the maintenance organisation who prepared their aircraft requesting that the tanks only be filled to three quarters capacity.

This was to provide a lower weight for a possible intermediate landing. The maintenance personnel were not sure that they could accurately determine three quarters capacity and filled the tanks until both gauges read just in excess of three quarters and the fuel level at the tank filler was visually seen to be one inch above the bottom of the tank. The pilot said that prior to the first flight of the sequence he visually assessed the quantity and considered the tanks to be full. Accordingly, his conduct of the sequence of flights was based on this assessment, and on his calculations of fuel usage during the flights.

Due to the dihedral of the wings and the position of the fuel filler at the wing tip it is not possible to make a visual assessment of the fuel quantity once the fuel level has dropped below about three quarters capacity. Consequently, no visual assessments were made prior to the next three take-offs. The pilot did not add fuel prior to those take-offs even though fuel was available. Post accident calibration of the fuel flow system disclosed that the engines were consuming very slightly more fuel than shown by the fuel flow gauges.

A fuel tank quantity indication system calibration carried out in February 1992 showed that the indications were not linear. A calibration chart was provided which showed the correct quantities at each indicator division. There had been no deficiencies recorded on the maintenance release in relation to either the fuel quantity or fuel flow indication systems. After the accident the fuel quantity indication system for the right wing was found serviceable, the left wing system was unserviceable, most probably due to impact damage.

Calculations of fuel used over the four sectors flown until the aircraft ran out of fuel show that the tanks would have had to be approximately 80% full when the aircraft commenced the flight sequence. There was no evidence that fuel was pilfered while the aircraft was left unattended.

Significant Factors

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

1. The aircraft was fuelled to less than full tanks.

2. The pilot incorrectly believed that he had commenced the four sector sequence with full tanks.

3. No visual check of fuel quantity was possible once the quantity was below approximately 75% full.

4. The fuel flow indicating system was inaccurate.

5. The pilot assessed that there was sufficient fuel for the flight on the basis of:

a. a belief that he had commenced the four sector sequence with full tanks,

b. his knowledge of the fuel consumption rates of the engines,

c. the elapsed time of the first three sectors, and

d. fuel quantity gauge indications.

6. The aircraft fuel tanks did not contain sufficient fuel for the flight.

VH-FKI was tracking to Argyle via Fitzroy Crossing at Flight Level (FL) 250 and was approaching its descent point. VH-JJX had departed Kununurra, was on a climb to FL240 and was tracking via route T37. The aircrafts' tracks crossed to the west of Argyle creating the possibility for a traffic conflict. At the time of the potential conflict the duty Air Traffic Controller was working with the aircraft in his own sector (Sector 2) and supervising a trainee controller on another sector (Sector 1).

The rated ATC from Sector 1 was absent on a short-term break. Due to technical restrictions, it was not possible to combine the Sector 1 & 2 consoles during this period (the normal method of covering a short-term break). The controller, realising that the aircraft would probably be in conflict during their respective descent and climb, decided to calculate a minimum lateral separation point between the aircraft and issue VH-FKI with a clearance for its descent which, he believed, would maintain the minimum required separation. To calculate the lateral separation, point the controller had to leave his console and draw a lateral separation diagram on the wall chart display.

During this process he incorrectly used the Curtin to Argyle instead of the Fitzroy Crossing to Argyle track for VH-FKI. Consequently, the minimum lateral separation point calculated by the controller was incorrect and the clearance issued to VH-FKI did not ensure the aircraft would be separated by the required minimum standard (1000 ft vertical separation at least 10 minutes prior to crossing). Fortunately, prior to commencing descent the pilot of VH-FKI checked the position of VH-JJX and delayed his descent until the aircraft had passed.

Safety Action

1. The Civil Aviation Authority (CAA) will publish a lateral separation diagram for the tracks to alleviate the need to draw a diagram on the wall chart.

2. The CAA have taken action which will allow the Sector 1 and Sector 2 consoles to be combined should it be necessary.

While in cruise the pilot heard a bang, the engine started vibrating and suffered an almost total power loss. The pilot was able to carry out a successful forced landing onto a disused agricultural strip. A bulk strip of the engine found that the #1 cylinder connecting rod bolts had failed. The connecting rod cap had also failed. The engine was severely damaged, and further investigation was not possible. It is suspected that incorrect torque of the connecting rod bolts could have been a contributing factor to their failure.

Significant Factors

1. Engine power was lost when the #1 connecting rod detached.

The pilot reported that the glider collided with power lines during an outlanding, cartwheeled and landed inverted. The pilot was trapped for thirty minutes before being able to free himself. The accident occurred at the end of a 500km distance badge attempt. The pilot, who was visiting from England, had assessed his position over the Warby Hills as being satisfactory for a final glide into Benalla.

After leaving Warby Hills he encountered sink and diverted to land on a known emergency landing strip on the north shore of Lake Mokoan. The sink was heavier and more persistent than expected and the pilot had to manoeuvre to land in a field short of the emergency strip. The pilot noted power lines on the approach, however the sink was such that he was unable to avoid colliding with them.

Significant Factors

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

1. The pilot was forced to carry out an outlanding.

2. The pilot misjudged the approach.

3. The pilot was unable to avoid power lines on the approach.

Co-ordination was received by Darwin Control from Unjung Pandang for VR-HOZ tracking via air route A461, advising its estimated time at BUTPA and that it was maintaining FL330. The level was read back by the Darwin controller, who then co-ordinated this information to Perth International Flight Service Unit without advising the flight level as this was not required by standard procedures.

The Darwin controller then requested information from Unjung Pandang on V8-RBC, inbound to Darwin on air route B583, which is a converging route with A461. V8-RBC had an estimated time of arrival at the ELBIS position within 10 minutes of the estimated time of arrival for VR-HOZ at the BUTPA position. This required that both aircraft be vertically separated by 2,000 feet when they arrived at these reporting positions. In sequence V8-RBC and VR-HOZ positions for ELBIS and BUTPA were co-ordinated by Perth International Flight Service Unit to Darwin Control, advising that both aircraft were maintaining FL370.

Darwin Control queried the level of VR-HOZ and asked that confirmation be obtained from the aircraft. As a precaution V8-RBC was instructed to descend to FL350. Darwin Control contacted Ujung Pandang who confirmed that VR-HOZ was maintaining FL330, but when contact was made with the aircraft the pilot advised that they had been cleared to FL370 by Manila while in Philippine airspace.

Although the incorrect co-ordination received by Darwin Control resulted in the required vertical separation not being maintained, the aircraft had not come into close proximity of each other when vertical separation was re-established.

Safety Action

The Civil Aviation Authority have issued a local operating instruction at Darwin which requires flight levels to be included in co-ordination between Darwin Control and Perth International Flight Service Unit.

The aircraft was landed with the landing gear retracted. The pilot advised that he may have been distracted during the approach by his aerial inspection of the strip.

The pilot reported that the initial launch was slow, and that he held the nose down until the speed increased to about 50 knots, at which time he began a normal climb. At about 100 feet the speed decreased, the pilot lowered the nose, and the launch cable parachute deployed over the canopy. The parachute and wire wrapped around the right wing and pulled the glider towards a line of trees. The pilot banked left to avoid the trees and was able to level the wings before ground impact. The aircraft struck the ground whilst still sideslipping left, tearing off the landing skid and fracturing the left wing.

Relevant Factors

1. The pilot failed to avoid the tow cable after its release.

2. Control was lost due to the cable being wrapped around the right wing.

The flight was scheduled as a dual instrument training flight. As the student brought the aircraft to a stop prior to the engine run-up the gear-up warning horn momentarily sounded, and the gear-up warning light flashed once or twice. The instructor took control and checked the landing gear warning systems.

As he could find nothing wrong and he could not reproduce the momentary warning signals he deduced that it was safe to proceed with the flight. He did decide to test the integrity of the gear warning system before returning to the Jandakot circuit area. The flight proceeded normally with all landing gear indications and warnings operating correctly during the departure, an instrument approach and overshoot and a practice engine failure. During a second approach the landing gear did not extend when selected down.

Following a period of trouble shooting the landing gear was extended using the manual extension system. Three green lights were obtained, and the aircraft was landed at Jandakot. As the aircraft cleared the runway, the gear unsafe horn started to sound and the gear-up light started to flash. The pilot stopped the aircraft, confirmed that the three green position lights were indicating down and locked, the landing gear lever was in the down position, the gear motor circuit breaker was out and that the gear relay circuit breaker was in.

Whilst he was visually checking the circuit breakers, the gear motor momentarily made a sound. The pilot considered shutting down the aircraft but before he could take any action the aircraft gently rocked, and the right main landing gear collapsed. The three green gear down and locked lights were still illuminated. Subsequent investigation disclosed that the landing gear motor relay contacts were fused together creating a permanent landing gear up circuit.

The two aircraft were vectored by Perth Approach and given appropriate clearances to facilitate their relative arrivals at Jandakot from Perth. VH-AUC climbed to a higher altitude than cleared and caused a separation breakdown. The pilot in command of this aircraft was an instructor and had the other aircraft sighted but allowed her concentration to lapse and did not detect that her student had climbed in contravention of their airways clearance.

Shortly after the aircraft took off, the left engine lost power and the pilot shut it down. A successful single engine landing was conducted at the departure airfield. It was discovered after landing that the left hand engine torque indicator circuit breaker had popped. The company engineers could not reproduce the fault. The fault has not reappeared.