A skydiving plane that crash-landed in the Adelaide city park lands last October had run out of fuel, the Australian Transport Safety Bureau (ATSB) has found.
The ATSB investigated the crash at Victoria Park, which seriously injured two skydivers during their Masters Games preparations.
The Cessna 182 had four passengers and the pilot on board when engine problems were noticed over Adelaide's eastern suburbs.
The pilot intended flying back to Parafield Airport in the northern suburbs but the engine cut out, forcing the crash-landing.
A mayday call was sent as the Cessna was steered toward pit straight of the Victoria Park race course.
The aircraft swerved to avoid a car and landed heavily on grass, with two of the passengers being thrown from the Cessna.
Cessna's fuel level might have been misread
The ATSB said the pilot believed there was 110 litres of fuel in the tank, more than enough for the intended brief flight.
The Australian Parachute Federation suggested some fuel might have been lost during manoeuvres.
The Civil Aviation Safety Authority's preliminary investigation suggested two different fuel dipsticks were used, one showing fuel in 10-litre increments and the other showing 20-litre increments.
It said the pilot might mistakenly have believed the plane had 110 litres on board when it only had half of that volume of fuel.
CASA said that would correlate with the flight time until the engine cut out.
"Pilots are reminded of the importance of careful attention to aircraft fuel state," the ATSB official report said.
On 2 October 2015, the pilot of a Cessna 182 aircraft, registered VH-DNZ (DNZ), was tasked to conduct parachute operations. The pilot planned to depart from Parafield Airport, and drop parachutists to land at Victoria Park, Adelaide, before returning to land at Parafield, South Australia.
The target landing zone for the parachutists was Victoria Park, which would require the pilots to obtain a clearance from Adelaide air traffic control (ATC) to enter Adelaide control zone.
At about 1331, DNZ departed from Parafield with the pilot, four parachutists, and 110 L of fuel on board. The aircraft tracked outside controlled airspace, and at about 1340, ATC cleared the pilot of DNZ to track to overhead Mt Lofty at 3,500 ft, where the pilot then conducted orbits. At about 1406, after completing seven orbits, ATC advised the pilot to expect a 30-minute delay.
At about 1420, the engine ran roughly. The pilot abandoned the parachute drop and requested a clearance to track directly to Parafield, due to fuel. The rough running then got worse, so the pilot requested a landing at Adelaide Airport.
At about 1425, the approach controller cleared the pilot of DNZ to descend to 2,000 ft and then for a visual approach to left base for runway 23. Just then, the engine stopped. The pilot made a MAYDAY call, and conducted a forced landing at Victoria Park. The aircraft landed very heavily and two of the parachutists were ejected from the aircraft during the impact. Two parachutists sustained serious injuries, and two were uninjured. The pilot sustained minor injuries and the aircraft was substantially damaged.
Pilots are reminded of the importance of careful attention to aircraft fuel state. ATSB Research report Avoidable accidents No. 5 Starved and exhausted: Fuel management aviation accidents, discusses issues surrounding fuel management and provides some insight into fuel related aviation accidents.
Aviation safety investigation & report: https://www.atsb.gov.au