Jump to content

1946 Australian National Airways DC-3 crash

Add links
From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Grandiose (talk | contribs) at 22:21, 18 December 2011 (Partial self-revert per GAN.). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Seven-Mile Beach crash
An aircraft in flight with city buildings in background
Douglas DC-3 similar to VH-AET
Accident
Date10 March 1946
SummaryCrash into sea
SiteSouth of Cambridge Aerodrome, Hobart, Australia
42°52′S 147°31′E / 42.86°S 147.52°E / -42.86; 147.52
Aircraft
Aircraft typeDouglas DC-3
RegistrationVH-AET
Flight originHobart, Tasmania
DestinationMelbourne, Victoria
Passengers21
Crew4
FatalitiesAll (25)
Survivors0

On 10 March 1946 a Douglas DC-3 aircraft departed from Hobart, Australia for a flight to Melbourne. The aircraft crashed into the sea with both engines operating less than 2 minutes after takeoff. All twenty-five people on board the aircraft died. It was Australia's worst civil aviation accident.[Note 1][2]

An investigation panel was promptly established to investigate the accident. The panel was unable to conclusively establish the cause but it decided the most likely cause was that the automatic pilot was inadvertently engaged shortly after takeoff while the gyroscope was caged. The Department of Civil Aviation took action to ensure that operation of the automatic pilot on-off control on Douglas DC-3 aircraft was made distinctive from operation of any other control in the cockpit, and that instructions were issued impressing on pilots that gyroscopes should be un-caged prior to takeoff.

An inquiry chaired by a Supreme Court judge closely examined three different theories but found there was insufficient evidence to determine any one of them as the cause. This inquiry discovered that the Captain of the aircraft was diabetic and had kept it secret from both his employer and the Department of Civil Aviation. The judge considered the Captain's diabetes and self-administration of insulin probably contributed significantly to the accident but he stopped short of making this his official conclusion.

The inquiry also uncovered four irregularities in the regulation of civil aviation in Australia. In his report, the judge recommended modification of the lever actuating the automatic pilot. He also made four other recommendations to deal with the irregularities.

The flight

The Australian National Airways aircraft registered VH-AET arrived at Cambridge aerodrome at 8:15 pm local time, about four hours late. The return flight to Essendon Airport was scheduled to depart at 4:50 pm, but did not occur until 8:50 pm.[3]

On board were 21 passengers, 3 pilots and an air hostess.[3] Douglas DC-3 (and C-47) aircraft were normally crewed by two pilots but on 10 March the third seat in the cockpit of VH-AET was occupied by a supernumerary pilot who was making his first flight with the airline.[4] The weight of the aircraft was about 900 pounds (408 kg) below the maximum authorised weight.[Note 2][5]

The takeoff was into a light southerly wind towards Frederick Henry Bay and the sea. Observers at the aerodrome reported that the takeoff was normal, and both engines were operating perfectly.[3]

Witnesses in the vicinity of Seven-Mile Beach[Note 3] estimated that the aircraft reached a height of about 400 ft (122 m)[Note 4] before turning slightly and descending. The aircraft cleared the land and crashed into Frederick Henry Bay about 300 yards (275 m)[Note 5] beyond the water's edge and a mile (1.6 km) from the western end of Seven-Mile Beach.[3][9] After takeoff it flew for less than 2 minutes[9][10] and covered a distance of only 2.9 nautical miles (5.4 km).[Note 6]

Recovery

Wreckage

Rear fuselage inverted on Seven-Mile Beach. The tailwheel is visible. The vertical stabiliser has been torn off.
External image
image icon Newspaper photograph of rear fuselage after it had been dragged ashore using a rope attached to the tailwheel

On learning of the crash at nearby Seven-Mile Beach employees of Australian National Airways raced from Cambridge aerodrome to lend assistance. About 45 minutes after the crash the rear fuselage came to the surface a short distance off-shore. Donald Butler,[Note 7] one of the employees, feared the air hostess might still be trapped in her seat in the rear of the fuselage. He took a length of rope, swam out to the floating piece of structure, attached the rope to the tailwheel and then swam back to the beach. The rear fuselage was dragged ashore but there was no-one inside.[12][13]

Diver Glen Thorne[Note 8] found pieces of wreckage scattered over a wide area of the sea bed. The aircraft had disintegrated and there were few recognisable pieces of structure.[7] Key parts of the wreckage were eventually recovered from the seabed by Thorne working from Royal Australian Navy ship HMAS Huon.[15] The wreckage was in about 18 ft (5.5 m) of water.[Note 9][16]

Bodies

About 4 hours after the crash the mutilated body of a woman was washed onto Seven-Mile Beach. Fifteen minutes later the body of a man was washed ashore. It was later identified as the body of the chief pilot. At intervals until 6:30 am another 5 bodies were washed ashore.[13] The next day, another 3 bodies were washed ashore.[16] The bodies were badly mutilated and either naked or clad only in vestiges of underclothing, indicating the severity of the impact with the water.[4][12] One body was missing a leg.[12] A head, severed from its body, was recovered in the vicinity.[17]

The bodies of 21 of the 25 people on board were eventually recovered from the beaches around Frederick Henry Bay. The remaining 4 bodies were never found.[Note 10][11][20] One body was found on the beach at Sandford, about 5 miles from the point of impact.[21] The body of the supernumerary pilot[Note 11] was not identified until 19 days after the accident.[22]

Two years after the accident, a human thigh-bone was found on Seven-Mile Beach. Police believed the bone came from one of the bodies never recovered.[23][24]

Investigation

The Director-General of Civil Aviation[Note 12] promptly established a panel to investigate the accident. The panel was chaired by John Watkins.[Note 13] The panel identified 25[Note 14] possible causes of the accident.[30] In its interim report to the Director-General on 20 March 1946[27] the panel reduced these possible causes to 3:[14]

  • Inadvertent engagement of the automatic pilot - The autopilot's gyroscope[Note 15] was recovered from the wreckage and found to be caged so it was suggested that the automatic pilot might have been engaged inadvertently at a height of about 400 ft (120 m) causing the aircraft to descend into the sea. Engagement could have occurred when the co-pilot intended to select fuel cross-feed off after takeoff.[27][31][32] The investigation panel considered inadvertent engagement of the automatic pilot to be the most likely explanation of the accident.[30]
  • Bird strike - A fortnight after the accident the mutilated body of a large bird was found on Seven-Mile Beach. It was considered the bird, which had a wingspan of about 6 ft (1.8 m), may have struck the aircraft cockpit, distracting or incapacitating the pilots.[33][34] Alternatively, the bird could have struck the aircraft's pitot tube, damaging it and causing inaccuracy in the pilots' airspeed indicator.[35]
  • Pilot illness - The panel considered the pilot may have collapsed suddenly.[14][29]

Inquiry

On 24 April 1946 the Minister for Civil Aviation, Arthur Drakeford, appointed Mr Justice Simpson of the Supreme Court of the Australian Capital Territory to conduct an inquiry into the accident.[36] Counsel assisting the inquiry was to be Henry Winneke.[Note 16][30]

Justice Simpson examined the evidence in detail, including the evidence put forward in support of the 3 most likely causes identified by the investigation panel. He eventually found there was insufficient evidence to consider any of the theories proved.[37][38] Justice Simpson's report of the findings of his inquiry was made public by the Minister on 11 June 1946.[39] Simpson said he was satisfied the accident was not caused by failure of any part of the aircraft's structure, its engines or its controls; or failure to remove any of the flight-control clamps prior to takeoff.[Note 17][40][41]

Automatic pilot

John Watkins, Chairman of the investigation panel, told the Inquiry the only evidence supporting the theory that inadvertent engagement of the autopilot caused the accident was that the gyroscope was recovered from the wreckage and it was still caged. If the autopilot had been engaged at a height of about 400 feet it could explain the swift descent into the sea.[27]

The Flight Superintendent of Australian National Airways, Captain P.T.L. Taylor, told the Inquiry he did not believe the accident could have been caused by inadvertent engagement of the autopilot. He said if that happened, the pilot could dis-engage the autopilot before losing 50 ft (15 m) in altitude.[35]

The Chief Technical Adviser of Australian National Airways, Thomas Lawrence,[Note 18] told the Inquiry he did not think there was any evidence to indicate the aircraft's autopilot was engaged at the time of the accident. He thought the crash was the result of a combination of factors.[42][44][45]

John Watkins said that in his report to the Director-General he had made recommendations and they were already being actioned. His recommendations included:

  1. operation of the automatic pilot on-off control on DC-3 aircraft should be made distinctive from operation of any other control in the cockpit.
  2. instructions should be issued impressing on pilots that gyroscopes should be un-caged prior to takeoff.
  3. the practice of using passenger-carrying flights to give experience to pilots under instruction should be reviewed urgently.[28]

Bird-strike

Michael Sharland,[Note 19] honorary ornithologist to the Tasmanian Museum, told the Inquiry he had been shown the mutilated remains of a dead bird and had identified it as a gannet, a fishing bird known to dive on its prey from heights from 50 ft to 500 ft. He was unable to say how the bird had died but said its injuries suggested it had been in a collision with a heavy, fast-moving body.[6][34] Captain P.T.L. Taylor said he thought a bird-strike on the aircraft's pitot tubes could have caused the crash.[35]

Justice Simpson rejected the bird-strike theory, saying the descent of the aircraft was caused by forward-movement of the control column in the cockpit. He was unable to state what caused this movement of the control column.[37][38][40]

Medical

The inquiry discovered that the chief-pilot of the aircraft, Captain Thomas Spence,[Note 20] was diabetic and had been discharged from the RAAF in September 1941 as medically unfit. In early 1942 he applied for a commercial pilot licence but did not declare his diabetes.[47][48] In a medical examination for the purpose of obtaining the licence, and at all subsequent examinations, Spence had shown no sign of diabetes. A specialist in diabetes[Note 21] told the Inquiry it was almost impossible to detect diabetes in a person who wished to withhold it.[47]

The inquiry also received evidence that a friend[Note 22] had asked Spence about his diabetes in relation to his employment as a pilot. Spence had asked his friend to keep it quiet so his employment would not be jeopardised.[30][49][50]

The senior route captain for Australian National Airways, Captain Douglas Way,[Note 23] told the inquiry he was unaware Spence was treating himself with insulin. Captain Way said he knew Spence had been discharged from the RAAF as medically unfit but Spence had told him it was a minor complaint discovered when he was in Canada and when he returned to Australia he found himself cured.[42][44][45]

At a medical examination in October 1943 for renewal of his commercial pilot licence Spence told the examiner he had been in hospital with influenza and a carbuncle. The examiner did not inquire further on the matter. Investigations with Brisbane Hospital for the purpose of informing Justice Simpson revealed that Spence's hospitalisation was for diabetic pre-coma.[48] Justice Simpson agreed that Spence had misled many people.[51]

Spence was scheduled to have a medical examination on 11 March and it was considered plausible that he may have taken extra insulin in order to prepare himself for the examination.[51] An overdose of insulin, or irregular doses, can distort the senses and cause the muscles to be unco-ordinated.[47][52]

Counsel assisting the Inquiry, Henry Winneke, advocated that the cause of the accident was Spence's diabetes.[51][53] Justice Simpson was critical of the Director-General's investigation panel for considering 25[Note 24] possible causes of the accident but failing to consider that the Department's negligence in licensing a diabetic pilot might have been the root cause of the accident.[30] After the inquiry had received all available information related to Spence's diabetes, Justice Simpson said the insulin reaction of the pilot might have had a considerable bearing on the accident.[49]

In Justice Simpson's report to the Governor-General he wrote that he could see much to support the theory that the most likely cause was Spence's actions in the cockpit while he was adversely affected by insulin. However, in his report he didn't determine that the accident had been caused by Spence's medical condition because there was insufficient evidence to completely prove the theory.[37][38][40]

Irregularities

During the court of inquiry Justice Simpson became aware of four irregularities and listed them in his report.

  1. When Thomas Spence had applied for a commercial pilot licence the RAAF Director-General of Medical Services had been acting as assessor for the Department of Civil Aviation. The Director-General had neglected to check Spence's RAAF medical history.
  2. A medical examiner had failed to check Spence's statement that his recent hospitalisation was due to influenza. The truth was that Spence had been suffering a serious diabetic condition.
  3. VH-AET was approved to carry 24 persons. On 10 March 1946 the aircraft took off with 25 persons on board - a full complement of 21 passengers, an air hostess and 3 pilots instead of the usual 2.[Note 25]
  4. No flare path had been lit to illuminate the runway for takeoff and any unexpected return to the aerodrome for landing.[54]

Recommendations

Justice Simpson made five recommendations:

  1. The practice of allowing pilots under instruction to gain experience in the cockpit of aircraft carrying passengers should be reviewed.
  2. The levers that actuate the automatic pilot and the fuel cross-feed should be modified so they have a different appearance.
  3. A regulation should be made to prohibit taking off at night without a flare path or other runway lighting system; and it should be compulsory for the flare path to remain lit until there is no longer a possibility the aircraft might return to the airport to land.
  4. Ground engineers completing daily inspections should keep copies of their inspection records.
  5. Medical examinations for issue or renewal of pilot licences should be made by doctors chosen, and paid for, by the Department of Civil Aviation.[40][55]

Coronial inquest

The Tasmania Coroner, Mr Sorell, investigated the deaths of the 21 people whose bodies had been recovered.[11][20] He determined that the causes of their deaths were multiple fractures and injuries but he was unable to say how or in what manner they met their deaths.[9]

The aircraft

The aircraft was constructed in 1942 as a Douglas C-47-DL transport aircraft with a Douglas serial number 6013. It was assigned the US military serial number 41-18652 and in 1943 was delivered to the US Army Air Force in Brisbane. In November 1944, it was sold to the Commonwealth of Australia.[31] Twelve C-47s were purchased by the Commonwealth of Australia and hired out under charter to aviation companies, six to Australian National Airways.[56][57]

The aircraft was registered VH-AET by the Commonwealth and hired out to Australian National Airways on 20 December 1944.[31][56] Australian National Airways converted it to the civil aircraft configuration about a year before the crash.[58][59] VH-AET flew for 7,477 hours.[31]

See also

Notes

  1. ^ It remained the worst until the crash of the Douglas DC-4 Amana in 1950.[1] Prior to 10 March 1946 Australia's worst civil aviation accident was the Douglas DC-2 Kyeema which crashed near Melbourne on 25 October 1938 killing all 18 people on board.[2]
  2. ^ The Certificate of Airworthiness for VH-AET authorised a maximum weight of 25,900 lb (11 748 kg).[5]
  3. ^ Seven-Mile Beach is the northern boundary of Frederick Henry Bay.
  4. ^ The investigation panel carried out some tests in collaboration with the witnesses and determined that VH-AET reached a maximum height of about 400 feet (122 m) before descending into the sea.[6]
  5. ^ Estimates of the distance from the shore to the wreckage vary between 200 yards (183 m)[7] and 400 yards (366 m).[8]
  6. ^ The position of the wreckage of VH-AET was approximately:
    42°52′S 147°31′E / 42.86°S 147.52°E / -42.86; 147.52
  7. ^ Donald James Butler was a maintenance engineer employed at Cambridge aerodrome by Australian National Airways.[11] Butler was able to confirm that Spence did not require any maintenance carried out on the aircraft. Prior to takeoff Butler observed Spence occupying the Captain's seat in the cockpit.[10]
  8. ^ Glen Armstrong Thorne was a diver employed by the Hobart Bridge Company.[14][15]
  9. ^ Newspaper reports of the water depth vary between 15 ft[7] and 18 ft.[8]
  10. ^ The four bodies never found were those of the co-pilot (David John Collum), two male passengers and a female passenger.[11] Some newspaper reports spelled the co-pilot's surname as Colburn.[18][19]
  11. ^ Flt.Lt. Austin Clement Gibson of Glenelg, South Australia had been discharged from the RAAF a week before the accident. He had served as a flying instructor for 5 years.[4][22]
  12. ^ The Director-General of Civil Aviation was Daniel McVey.[15][25] In May 1946 McVey resigned as Director-General and Captain Edgar Charles Johnston[26] began acting as Director-General.[27]
  13. ^ At the time of the Inquiry, John Leslie Watkins was acting Superintendent of Airworthiness and Aeronautical Engineering in the Department of Civil Aviation.[28]
  14. ^ The number of possible causes was also given as 22[14] or 23.[29]
  15. ^ A gyroscope is the core of an aircraft's attitude indicator, a cockpit instrument used during flight at night and in cloud to indicate the aircraft's orientation relative to the horizon. While the gyroscope is accelerating to operational speed the attitude indicator is usually caged (locked) to prevent damage. It should be un-caged prior to takeoff.
  16. ^ Sir Henry Arthur Winneke was knighted in 1957 and later became Chief Justice of the Supreme Court of Victoria (1964) and Governor of Victoria (1974.)
  17. ^ Allen Lauder Hume (engineer-in-charge) and Donald James Butler (maintenance engineer), both employed at Cambridge aerodrome by Australian National Airways, advised the inquiry that all clamps had been removed from the aircraft's control surfaces before takeoff, undercarriage pins had been removed, and the engines were operating normally.[11]
  18. ^ Thomas Fulton Coleman Lawrence (1915 - 2003), aeronautical engineer. In 1965, Lawrence became Chief Superintendent of the Aeronautical Research Laboratories.[42][43]
  19. ^ Michael Stanley Sharland was the author of Tasmanian Birds.[34]
  20. ^ Thomas William Spence was born in 1916. In February 1940 he passed a medical examination admitting him to flying training in the RAAF. He completed his flying course in Canada but was then found to be diabetic and unfit for flying. He was repatriated to Australia in April 1941 and discharged from the RAAF in September 1941. In March 1942 he passed a medical examination for initial issue of a commercial pilot licence.[46][47]
  21. ^ Dr E. Downie of Collins St, Melbourne.[47]
  22. ^ The friend was identified as Mr Whitty. The day after the accident Whitty informed an officer in the Department of Civil Aviation, of Spence's diabetes. The officer sent a memorandum conveying Whitty's information but, apart from calling for Spence's RAAF history file, the investigation panel took no further action. John Watkins said the investigation panel took no further action because it believed Spence's diabetes had no bearing on the accident.[49]
  23. ^ Captain Douglas Rowntree Way.[42]
  24. ^ The number of possible causes was also given as 22[14] or 23.[29]
  25. ^ Evidence was given that when a temporary seat was installed in the cockpit for a supernumerary pilot, a document could be issued to authorise an extra person being carried.[54]

References

  1. ^ The Mercury - 28 June 1950 Retrieved 2011-09-22
  2. ^ a b The Canberra Times - 12 March 1946, p.2 Retrieved 2011-09-15
  3. ^ a b c d The Mercury - 11 March 1946 Retrieved 2011-09-14
  4. ^ a b c Sydney Morning Herald - 12 March 1946 Retrieved 2011-09-21
  5. ^ a b The West Australian - 3 May 1946, p.10 Retrieved 2011-09-27
  6. ^ a b The Advocate - 2 May 1946, p.5 Retrieved 2011-09-25
  7. ^ a b c The Mercury - 14 March 1946, p.13 Retrieved 2011-09-22
  8. ^ a b The Canberra Times - 14 March 1946, p.5 Retrieved 2011-09-24
  9. ^ a b c The Mercury - 26 July 1946, p.9 Retrieved 2011-09-15
  10. ^ a b The Advocate - 1 May 1946, p.5 Retrieved 2011-09-25
  11. ^ a b c d e The Mercury - 23 July 1946, p.11 Retrieved 2011-09-20
  12. ^ a b c The Mercury - 12 March 1946 Retrieved 2011-09-24
  13. ^ a b The Argus - 12 March 1946, p.1 Retrieved 2011-09-14
  14. ^ a b c d e The Mercury - 25 July 1946, p.8 Retrieved 2011-09-22 Cite error: The named reference "M2578" was defined multiple times with different content (see the help page).
  15. ^ a b c The Mercury - 15 March 1946, p.4 Retrieved 2011-09-19
  16. ^ a b The Canberra Times - 13 March 1946 Retrieved 2011-09-19
  17. ^ The Argus - 13 March 1946, p.3 Retrieved 2011-09-22
  18. ^ The Mercury - 21 March 1946, p.5 Retrieved 2011-10-01
  19. ^ Courier-Mail - 13 March 1946, p.3 Retrieved 2011-10-01
  20. ^ a b The Mercury - 29 June 1946, p.4 Retrieved 2011-09-19
  21. ^ The Mercury - 25 March 1946, p.7 Retrieved 2011-09-21
  22. ^ a b Adelaide Advertiser - 30 March 1946, p.11 Retrieved 2011-09-22
  23. ^ The Mercury - 19 March 1948, p.4 Retrieved 2011-09-26
  24. ^ Sydney Morning Herald - 19 March 1948, p.4 Retrieved 2011-09-19
  25. ^ Drinkwater, Derek, Sir Daniel McVey, Australian Dictionary of Biography. Retrieved 2011-12-17
  26. ^ Walker, J.D., Edgar Charles Johnston, Australian Dictionary of Biography. Retrieved 2011-12-17
  27. ^ a b c d The Mercury - 15 May 1946, p.12 Retrieved 2011-09-24
  28. ^ a b The Argus - 4 May 1946, p.3 Retrieved 2011-09-21
  29. ^ a b c The Advocate - 25 July 1946, p.2 Retrieved 2011-09-22
  30. ^ a b c d e The Advocate - 16 May 1946, p.5 Retrieved 2011-09-24
  31. ^ a b c d Aussieairliners Retrieved 2011-09-14
  32. ^ Aviation Safety Network Retrieved 2011-09-14
  33. ^ The Mercury - 1 May 1946 Retrieved 2011-09-16
  34. ^ a b c The Mercury - 2 May 1946, p.10 Retrieved 2011-09-16
  35. ^ a b c The Mercury - 3 May 1946, p.9 Retrieved 2011-10-01
  36. ^ The Argus - 25 April 1946 Retrieved 2011-09-23
  37. ^ a b c The Mercury - 12 June 1946, p.1 Retrieved 2011-09-15
  38. ^ a b c The Advocate - 12 June 1946, p.5 Retrieved 2011-09-26
  39. ^ Sydney Morning Herald - 12 June 1946, p.3 Retrieved 2011-09-24
  40. ^ a b c d The Argus - 12 June 1946, p.3 Retrieved 2011-09-16
  41. ^ The Canberra Times - 12 June 1946, p.4 Retrieved 2011-09-15
  42. ^ a b c d The Advocate - 17 May, p.5 Retrieved 2011-09-27
  43. ^ Vale Thomas Fulton Coleman Lawrence - p.4 or page 6 of 27. Retrieved 2011-09-29
  44. ^ a b The Mercury - 17 May 1946, p.4 Retrieved 2011-09-19
  45. ^ a b Sydney Morning Herald - 17 May 1946, p.5 Retrieved 2011-09-20
  46. ^ The Morning Bulletin - 12 March 1946, p.4 Retrieved 2011-09-20
  47. ^ a b c d e The Advocate - 4 May 1946, p.5 Retrieved 2011-09-26
  48. ^ a b The Mercury - 4 May 1946 Retrieved 2011-09-24
  49. ^ a b c The Argus - 16 May 1946, p.6 Retrieved 2011-09-24
  50. ^ The Canberra Times - 16 May 1946, p.3 Retrieved 2011-09-24
  51. ^ a b c The Mercury - 18 May 1946, p.2 Retrieved 2011-09-24
  52. ^ The Canberra Times - 4 May 1946 Retrieved 2011-09-16
  53. ^ The Argus - 18 May 1946, p.8 Retrieved 2011-10-02
  54. ^ a b The Mercury - 12 June 1946 Retrieved 2011-09-20
  55. ^ The Mercury - 12 June 1946, p.2 Retrieved 2011-09-19
  56. ^ a b The Argus - 13 March 1946, p.3 Retrieved 2011-09-22
  57. ^ The Mercury - 13 March 1946 Retrieved 2011-09-21
  58. ^ The Argus - 12 March 1946, p.3 Retrieved 2011-09-18
  59. ^ The Mercury - 1 May 1946, p.10 Retrieved 2011-09-19
Retrieved from "https://en.wikipedia.org/w/index.php?title=1946_Australian_National_Airways_DC-3_crash&oldid=466592663"