ANA Skymaster Amana Crash - Inquiry

Inquiry

The Minister for Civil Aviation, Thomas White, appointed Justice William Simpson of the ACT Supreme Court to conduct an Air Court of Inquiry into the crash of the Amana. The Inquiry opened in Perth on 7 February 1951. Justice Simpson was assisted by two assessors – Captain J.W. Bennett, a pilot with British Commonwealth Pacific Airlines; and Mr D.B. Hudson, an aeronautical engineer with Qantas Empire Airways. The Commonwealth Crown Solicitor was represented by L.D. Seaton and B. Simpson. Australian National Airways was represented by George Pape. The Department of Civil Aviation was represented by Henry Winneke. The Air Pilots' Association was represented by Francis Burt. The Inquiry sat in Perth for 12 days; heard evidence from 67 witnesses and concluded on Tuesday 20 February.

Western Australia's Deputy Mineralogist gave evidence that he had identified magnesium hydroxide, a corrosion product, in fuel passages in one of Amana's engines. Counsel for the Department of Civil Aviation explained that evidence gathered during investigation of the crash indicated water in some of the fuel on board Amana was responsible for the corrosion products found in engines numbers 1 and 4; for the rough running of an engine heard by a number of witnesses; and for the intermittent failure of all engines, leading to the aircraft descending to ground level. The Inquiry heard evidence from the Department of Civil Aviation's Acting Chief Inspector of Air Accidents, C.A.J. Lum, a former RAAF Douglas C-47 Dakota pilot, who described his personal experience of a flight in 1946 in which all fuel tanks were checked for the presence of water prior to take-off and the flight proceeded normally for 20 minutes until both engines began running roughly. Lum returned to the aerodrome and checked again for water in the tanks, this time finding a significant amount of water. Counsel for the Vacuum Oil Co. explained that it was almost impossible for water to be introduced to an aircraft during refuelling, and vigorously rejected the theory that water in the fuel contributed to the crash.

Counsel for the Commonwealth Crown Solicitor presented evidence that the Amana was on fire before it first struck trees. Counsel for the widow of one of the victims suggested the crash may have been caused by the elevator trim tab jamming in the diving position.

In April 1951 Justice Simpson advised the Minister for Civil Aviation that new evidence had become available. The Minister gave permission for the Inquiry to be re-opened. The Inquiry re-opened in Melbourne on 4 June 1951. The Department of Civil Aviation had recently completed tests on the DC-4 fuel system. The tests showed that when an engine boost pump was operating, a vortex in the engine fuel tank prevented water from entering the engine. The tests also showed that when the boost pump was turned off, any water would soon find its way into the engine. The Department of Civil Aviation believed this might explain why all engines were operating normally during the takeoff but at least one engine began to run roughly around the time the engine boost pumps would be turned off. However, Justice Simpson stated that the re-opened Inquiry served only to confirm his view that the Amana's loss of power was not due to water in the fuel.

Justice Simpson's report was tabled in the House of Representatives on 28 June 1951 by the new Minister for Civil Aviation, Larry Anthony. The Inquiry found that the Amana suffered total loss of engine power on at least one occasion, followed by rapid loss of its height and it struck the ground. However, the evidence did not allow the court to determine the cause of the total loss of engine power. Consequently the court was unable to determine the cause of the accident. Simpson stated he was satisfied water had not been introduced into the Amana's fuel system in Sydney, Melbourne, Adelaide or Perth.

The Inquiry uncovered two deviations from the Air Navigation Regulations although it did not consider these deviations contributed to the accident:

1. ANA was not in the practice of performing a fuel-drain check immediately after each re-fuelling, as required by Air Navigation Orders.
2. On the fatal flight, 8,545 feet of photographic film were carried as cargo. Air Navigation Orders specified that a maximum of 3,000 feet of photographic film may be carried.

The Inquiry also uncovered three irregularities in the safety regulation of civil aviation in Australia although none of these irregularities contributed to the accident. Justice Simpson's report contained recommendations to deal with the irregularities:

1. fuel companies that supply fuel to aircraft should be required to check every compartment in a tanker wagon for the presence of water each time fuel in the tanker wagon is replenished.
2. when fuel was being drained from an aircraft's tanks to check for the presence of impurities, the sample should be collected in a transparent vessel to allow more reliable identification of any water that might be present.
3. when pilots who regularly fly four-engine aeroplanes perform 6-monthly checks for renewal of their commercial pilot licences, the check should be carried out in a four-engine aeroplane rather than in a two-engine aeroplane as was the common practice.

During the House of Representatives debate on the report, the Minister, Larry Anthony, stated that he had already asked fuel companies to check their tanker wagons for the presence of water after each replenishment, and the relevant Air Navigation Order would be amended to require fuel to be drained into transparent containers. He stated that his Department did not intend to amend the relevant Air Navigation Order to require pilots of four-engine aeroplanes to perform the periodic checks in a four-engine aeroplane because it considered it was more challenging to fly with one engine inoperative in a two-engine aeroplane than in a four-engine aeroplane.