Fuel exhaustion

The pilot reported that the aircraft departed with eight imperial gallons (36 litres) of fuel indicated on the fuel gauge for a one hour aerobatic training flight. The aircraft had just been refuelled, with 20 litres being added to a calculated 25 litres remaining. The flight was authorised for one hour on a planned fuel burn of 24 litres/hour and a calculated quantity of 45 litres useable.

The aircraft departed the training area 55 minutes after engine start with the fuel gauge (believed to be inaccurate/completely unreliable below 5 imperial gallons) flickering around the empty position. The pilot rejoined the circuit on the upwind leg for runway 09. During the descent prior to turning crosswind, at about 1,200 ft above the ground, the engine failed. The pilot elected to land straight ahead on the runway remaining. During the descent the engine regained power momentarily, which resulted in a potential overshoot of the runway. The pilot commenced a series of 'S' turns to lose height in an attempt to touch down prior to the upwind threshold.

As he flared, the engine again regained power momentarily. The aircraft finally touched down in the grass overrun area where it ran through a ditch and then into a fence.

At Youanmi, fuel is supplied in 200 L drums. It is the pilot's responsibility to move the drums and pump the fuel into the aircraft. The pilot reported that he did not add the extra fuel as the gauges indicated there was 1,270 lb of fuel remaining and this was more than the minimum requirement. Although there was a discrepancy between the expected fuel burn on the flight up and the apparent actual burn, he indicated he did not consider it was significant. He assumed the difference was the result of a minor gauging problem. The pilot had a 15-minute wait before the passengers arrived, and he was able to depart for Perth.

The return flight was uneventful until top of descent. As the pilot commenced descent the right engine lost all power. During his trouble checks the pilot noted that both fuel gauges read 240 lb. He was unable to restart the right engine and the flight was continued on one engine. The pilot reported the engine shutdown to air traffic services and indicated that he suspected fuel starvation. The aircraft was cleared direct to Perth. Although the pilot believed fuel might be the problem, he decided not to divert into Pearce air force base but instead continued to Perth. He did however, request to track via overhead Pearce. The pilot later observed that had the second engine failed, he could have glided safely to either Pearce or Perth.

Following the aircraft's arrival in Perth, and after the passengers had disembarked, the fuel gauge indications were reported as 40 lb on the left and fluctuating between 100 and 180 lb on the right. The aircraft was defueled and 15 L (26 lb) removed from the left tank and 3 L (5 lb) from the right. When all fuel was drained from the aircraft the left gauge read 0 lb and the right gauge 125 lb.

The pilot's fuel planning figure indicated the aircraft would use 1,574 lb of fuel for the return flight to Youanmi, without including any of the variable and fixed reserves. The fuel drain indicated the aircraft actually used 1,619 lb. The pilot's flight plan indicates that the time intervals for some of the legs flown were longer than planned. In addition, there was the 6% difference in fuel burn between the two flight planning programs considered. It is not possible to determine, without additional research, the accuracy of the program used by the pilot. These differences probably account for the additional fuel used.

An engineering investigation determined that both fuel gauges had been replaced 3 days prior to the occurrence and a fuel calibration completed. This calibration had been completed using a system common to general aviation (the gauges were reset to zero and known amounts of fuel added to check the accuracy of the indications) but not recommended by the manufacturer. The gauging system was reported as serviceable after this calibration. Following the occurrence, the right gauge was reset to zero and another calibration was completed using the general method. A subsequent calibration using the manufacturer approved method (special test equipment) found that the right gauge was under-reading by 25 lb.

The reason for the false reading reported on the right gauge during and following the occurrence was not identified.

One of the purposes of fuel flight planning is to provide pilots with a means of cross checking the accuracy of their fuel gauges. It would be unlikely that any aircraft would burn 43% less fuel than expected on any one flight (379 instead of 679 lb). Consequently, it should have been obvious to the pilot that the gauge readings were unreliable when he checked the quantities at Youanmi, particularly in the light of his general and type experience. Why the pilot did not identify the discrepancy as significant could not be determined from the evidence available.

The aircraft was involved in spraying operations. The pilot reported that at the end of the third load for the day, while pulling out of the final spray run and banking to the right, the engine failed suddenly and completely. The pilot rolled the wings level and flew towards a farm track at an oblique angle. While slewing the aircraft around to the left to align it with the track, the left wing hit a wire fence. This slewed the aircraft further to the left where it ran into another fence and nosed forward hitting the propeller on the ground.

When the aircraft was inspected after the accident, there was only half a litre of fuel drained from the entire fuel system. The flight time since the last refuel was consistent with fuel exhaustion. After the accident, the engine was started and ran normally.

The pilot reported he took a number of tourism industry passengers on a familiarisation flight over a proposed tourist route between Jandakot and Cervantes. He was on the return flight to Jandakot, with his second group of passengers on board, when he was forced to land the aircraft in a paddock due to fuel exhaustion.

The pilot had accumulated a lot of flying hours, predominately in helicopters, but had limited twin-engine, fixed-wing aircraft experience. He had recently completed an endorsement onto the aircraft type and had flown a total of 7 hours in the aircraft at the time of the forced landing. This included the 5 hours flown during the familiarisation flights.

On the evening prior to the occurrence, the pilot had filled the fuel tanks in preparation for the familiarisation flights. Before departing Jandakot on the first leg, he had drained 40 L out of the fuel tanks due to weight restrictions. He was not able to visually check the contents once he had drained the fuel and did not note the level before he started the drain. He paid little attention to the fuel gauges enroute as he normally monitored fuel contents by using fuel flow and elapsed time.

During the return flight, the pilot elected to land at Cunderdin to correct a fuel imbalance which had appeared after he added 200 litres of fuel at Cervantes. He used a bucket and hose to transfer fuel between tanks. He reported that he was not aware of how fuel could be cross fed between tanks whilst airborne.

The pilot became concerned about the state of the fuel contents enroute to Jandakot. He was convinced there was sufficient to continue to his destination, which was, by then, the closest airfield. The aircraft was less than 3 km south of Jandakot when the engines stopped.

Calculations indicate that a total of 620 L had been added to the aircraft before and during the flights. At the reported fuel flow of 94 L/hour a total flight time of 6 hours 35 minutes should have been available. The engines stopped after 5 hours, leaving 150 L unaccounted for. The pilot reported there had been recent instances of fuel theft from the Jandakot apron. As he had refuelled the aircraft the evening before the flights, he suspected the missing fuel had been stolen during the night.

The pilot had just bought the aircraft and was delivering it to his home. The previous owner had not flown the aircraft extensively and was unable to assist with performance and fuel information. As a result, the owner used the cruise performance information available in the pilot's handbook. This information showed an endurance of 7.9 hours and a range of 845 miles.

After refuelling to full tanks at Hughenden the pilot intended flying to Barcaldine and refuelling there. The turbulence enroute was considerable so the pilot elected to depart early the next morning to avoid the turbulence. He dipped the tanks and found that they were over half full. Since he considered that this would give him four hours of endurance he departed for Roma without refuelling. The ground speed obtained during the flight would have required a flight time of 223 minutes to Roma. While enroute, the engine failed due to fuel exhaustion. He conducted a forced landing on a road and obtained fuel to complete the flight.

The pilot later learned that the endurance figures quoted in the handbook were optimistic. He also found that the actual fuel used during flights was much higher than he had expected. By completing full flight plans he has been able to establish accurate fuel consumption figures for his aircraft.

After the landing the pilot attempted to activate the ELT using the remote control on the aircraft instrument panel. The unit did not operate because of a flat Lithium battery in the remote-control unit. After the battery was replaced, the unit was able to function correctly.

The pilot had flown the aircraft from Porepunkah to Wangaratta where he added fuel. He then continued the flight as planned to Hoxton Park. On the evening before the return flight to Porepunkah the pilot travelled to Hoxton Park to check the aircraft. He used a dipstick to calculate the fuel remaining and estimated there was a total of 200 L, 90 L in the right fuel tank and 110 L in the left. He considered this was sufficient for the flight and declined the opportunity to add more fuel at that time.

The next morning the pilot completed a pre-flight inspection of the aircraft, including another check of the fuel quantity. He again estimated the fuel remaining to total 200 L. Approximately 90 minutes after departure, whilst the aircraft was cruising at 6,500 ft, the engine started to misfire, then experienced a complete loss of power. A forced landing was carried out following the pilot's unsuccessful attempt to restore power. The aircraft landed heavily and skidded along the ground for about 90 m, during which time the nose landing gear separated from the fuselage. The pilot and three passengers escaped without injury.

Weather conditions at 6,500 ft at the time of the accident were fine, with a temperature of 1 degree Celsius, and a dew point of minus 10 degrees Celsius.

An on-site examination of the aircraft indicated no evidence of an engine defect which may have contributed to the accident. No fuel was found in either fuel tank, and only a small quantity could be collected from the remaining fuel system. There was no evidence of fuel having vented or leaked from the fuel cells or the engine area, nor were there indications of excessive fuel consumption.

The recent flight history of the aircraft and relevant fuel purchases were examined. It was determined that there would most likely have been a total of about 100 lts remaining in the fuel cells when the pilot added a further 122 lts at Wangaratta. Using average fuel consumption figures for the aircraft type, and flight times obtained from the pilot, it was estimated that there had been insufficient fuel on board to complete the flight to Porepunkah.

When the pilot had refuelled at Wangaratta, he observed fuel bubbling up from each fuel inlet and assumed the fuel cells were full. He did not use a dipstick to confirm the quantity, nor did he look into the fuel inlets to observe the fuel levels after he removed the fuel nozzle from each inlet. There would have been about 222 L on board the aircraft when the pilot departed Wangaratta and not 303 L, as should have been the case if the fuel tanks had been filled to capacity. Subsequent observations of fuel quantity indications on the dipstick may have been influenced by this false assumption.

The helicopter was in level flight at 500 ft above ground level and nearing its destination when, without warning the engine stopped. The pilot conducted a forced landing into a clearing, damaging the right skid. Post flight inspection revealed only a small quantity of fuel in both tanks.

The pilot later confirmed that the helicopter had run out of fuel. He said he had been "pushing" a headwind and had flown a higher indicated airspeed to maintain a reasonable ground speed. He was surprised that the actual fuel consumption was 38 Litres/hr instead of the 32 he planned on. He also said that the Fuel Low warning light was unserviceable and that the fuel gauges were inaccurate.

During a cattle mustering operation, the helicopter suffered a total power loss at about 80 ft AGL. The resultant heavy landing spread the skids, and the main rotor severed the tail boom. Both occupants were able to exit the aircraft safely.

Post flight examination found there was no fuel in the helicopter's tanks. The tanks were intact.

The pilot has not responded to a request for information.

On final approach to land the helicopter in a clearing to refuel, the engine misfired and stopped. During the subsequent autorotation, the pilot managed to restart the engine. The engine faltered again on late final approach. The pilot attempted to stretch the glide to the clearing and managed to land the helicopter clear of the trees. The run-on landing was heavy. The pilot who was the only occupant, was able to exit the helicopter safely.

The skid gear and lower fuselage of the helicopter were damaged. The tail rotor drive was struck by the main rotor during the run-on landing.

The pilot confirmed that the helicopter had run out of fuel.

Approaching home base, towards the end of a charter flight, the pilot became concerned about a low fuel quantity indication on the fuel gauge, so he advised his company by radio that he was landing in a paddock about 7 nm south-south-east of Moorabbin. He also requested that fuel be brought to him.

After landing and shutting down the engine, the pilot realised that the nearest access to the aircraft by road was blocked by a canal and a fence. He therefore decided to reposition the aircraft to facilitate refuelling. After starting the engine and having hover-taxied a short distance with an estimated 20 kt tailwind and at about 10 ft above the ground, the helicopter's engine flamed out due to fuel exhaustion. The aircraft touched down, heels of the landing skids first, on uneven terrain. The main rotor severed the tail boom, and the helicopter rolled over.

According to the pilot, the fuel gauge registered 45 US gallons when he commenced the charter. He believed this was sufficient fuel to complete the flight using a fuel burn off rate of 25 US gallons per hour. However, since leaving base, the engine had operated for an estimated one hour and 50 minutes, including the time spent at ground idle. Unusable fuel is 10 pounds (1.7 US gallons). Only a very small amount of fuel was found in the tank after the accident.

No fault with the engine or the airframe has been reported to have contributed to the accident. Both of the electric fuel boost pumps were serviceable and operating at the time. The aircraft was not equipped with the optional, low fuel warning light system.

Significant Factors

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

1. The pilot did not exercise sound fuel management procedures.