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Ansett-ANA Flight 325

From Alfawiki
Ansett Australia
IndustryAirline
Founded1935
FateFirst fatal accident in 1961
Headquarters
Sydney
,
Australia


Template:Use Australian English Template:Infobox Aircraft accident

During the evening of 30 November 1961, Ansett-ANA Flight 325, operating a route from Sydney Airport to Canberra Airport in Australia aboard a Vickers Viscount 720, disintegrated mid-flight and crashed shortly after departure due to encountering a severe thunderstorm. All fifteen individuals on board perished.

Approximately nine minutes following takeoff, radio communications ceased; however, authorities initially received no confirmation of a crash. The following day, debris and a fuel slick were discovered floating on the surface of Botany Bay, Sydney. The aircraft had been caught within a thunderstorm and exposed to intense turbulence, leading to structural failure and impact with Botany Bay less than 3 miles (4.8 km) from its departure point.[1] [2] [3]

This tragedy marked the first fatal incident for Ansett Australia since its founding in 1935.[4]

The flight

File:TVC.pdf
Transcript of Sydney Airport control tower communications on the night of the accident.[5]

Ansett-ANA Flight 325, registered as VH-TVC and named "John Oxley", departed Sydney Airport from runway 07 at 7:17 pm local time for its scheduled 128 nmi (237 km) journey to Canberra. The aircraft was leased from Trans Australia Airlines as part of an exchange involving a Douglas DC-6B. Onboard were pilot Stan Lindsay; co-pilot Ben Costello; two flight attendants, Aileen Keldie[6] and Elizabeth Hardy; along with eleven passengers.[1][3][7]

At the time of departure, intense thunderstorms with heavy rainfall were present both north and south of the airport. Over Sydney Airport itself, cloud cover was approximately 800 feet (240 m), but no thunderstorm activity was detected. Flight 325 was observed entering cloud shortly after liftoff.[8] Despite this weather situation, five other aircraft also departed during this period.[1]

Flight instructions directed the crew to climb eastward toward the Tasman Sea until reaching an altitude of 3,000 feet (910 m), then execute a turnaround and proceed westward toward a radio navigation aid located about 6+1⁄2 miles (10.5 km) west of the airport near Padstow, New South Wales. From there, the flight was to turn southwest en route to Canberra. The crew was instructed to maintain an altitude no lower than 5,000 feet (1,520 m) when passing over the airport.[1]

Five minutes post-departure, Flight 325 reported reaching 6,000 feet (1,830 m). Approximately three and a half minutes later, Sydney air traffic control attempted routine radio contact but received no response. No further transmissions were made by Flight 325. When the aircraft failed to arrive at Canberra Airport, authorities concluded an accident had occurred and planned an aerial search at first light.[1][9]

Around nine minutes after takeoff, the outer segment of the right wing—specifically beyond station 323 near the No.4 engine—separated from the aircraft, including the wingtip and aileron.[3] The plane subsequently crashed into Botany Bay.[3] The severe thunderstorm over Botany Bay produced such intense rain, thunder, and lightning that no witnesses observed or heard signs of the crash. Investigator Frank Yeend noted that "the weather was so bad that this aircraft crashed in the middle of a major city without anybody having seen it or heard anything that would give cause to alarm."[1]

All four engines were recovered with the main wreckage in Botany Bay.[10]

Search and recovery

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Upon losing radio contact with Flight 325 and the aircraft disappearing from the radar screen at the control tower, the Alert Phase of search and rescue operations was activated.[Note 1] Authorities including the NSW Police, Royal Australian Air Force, Royal Australian Navy, and Volunteer Coastal Patrol were alerted. A broadcast was made over the radio channel used by coastal shipping vessels. The Department of Civil Aviation’s air-sea rescue launch stationed in Botany Bay conducted patrols along the bay’s shoreline. When Flight 325 failed to reach its destination, search efforts escalated to the Distress Phase. In the hours following loss of contact, no reports of an aviation accident surfaced, leading to concerns that the aircraft might have gone down in the Tasman Sea. At dawn the following day, two Douglas DC-3 planes commenced searching east of Sydney, supported by a helicopter and multiple motor launches scouring Botany Bay.[4]

Shortly after sunrise, a helicopter crew spotted debris floating on Botany Bay.[12] The air-sea rescue launch crew investigated and recovered a damaged piece of upholstery, which airline personnel identified as originating from a Vickers Viscount pilot's seat. On beaches northeast of Botany Bay near Bunnerong Power Station, cabin fragments and human remains were discovered. In the southern area of the bay, the outer portion of the right wing bearing registration VH-TVC was found partially submerged near Kurnell.[Note 2][13]

Later that day, police and navy divers explored a significant fuel slick in central Botany Bay and uncovered scattered wreckage of VH-TVC resting in about 25 feet (7.6 m) of water roughly 1.6 miles (2.6 km) north of the right wing section.[1][4][13][14] The crash site was located approximately 2.8 miles (4.5 km) southeast of Sydney Airport.[Note 3][15]

The Royal Australian Navy deployed clearance divers along with HMAS Kimbla, a boom defence vessel, to Botany Bay to raise the principal wreckage of VH-TVC.[18] After one week, Kimbla was succeeded by HMAS Walrus, a smaller workboat from which navy divers continued operations over several weeks, recovering numerous smaller fragments.[1][14][19]

The right tailplane was absent from the main debris field. Eventually, navy divers located missing sections of this tailplane near where the outer right wing segment had been found, suggesting it detached prior to water impact.[14][16]

Many small components, including several from the number 4 engine nacelle, were discovered on Kurnell peninsula, positioned southward of the detached right wing portion. The distribution of wreckage extended roughly along a north-south axis with heavier debris concentrated in Botany Bay to the north and lighter fragments scattered toward Kurnell peninsula in the south.[16]

Since the aircraft lacked both a flight data recorder and cockpit voice recorder, it was critical to recover as much wreckage as possible for examination.[Note 4][1][21] Recovery operations persisted for three months.[22]

The upper portion of the rudder was not recovered during initial salvage efforts. Twelve years later, this missing rudder section was discovered submerged in shallow waters near Kurnell Beach within Botany Bay.[Note 5][23]

Investigation

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As fragments of VH-TVC were gradually retrieved from Botany Bay, they were arranged in a Sydney airport hangar to facilitate the investigation into the accident's cause. The right tailplane and the outer portion of the right wing showed minimal damage upon water impact, whereas the primary wreckage in Botany Bay exhibited severe fragmentation, indicating a very high-impact velocity.[Note 6][17] No indications of pre-existing mechanical defects or failures were discovered.[1][10]

It became evident that the spar within the right wing had fractured, causing the outer wing section to be ripped away by aerodynamic forces. The lower flange of the wing spar failed due to upward bending at station 323, attributed to extreme stress.[Note 7] The wing was subjected to loads exceeding its design limits while flying at speeds likely surpassing the maximum safe speed of 260 knots (480 km/h) indicated airspeed.[1][3] Due to violent movements during the right wing failure, the right tailplane also experienced excessive stress and detached from the fuselage.[25]

Engineers involved in the inquiry estimated that for the spar failure observed in VH-TVC, the aircraft must have been exceeding its maximum speed of 260 knots (480 km/h), and while undergoing a strenuous recovery manoeuvre by the pilots, encountered a powerful gust possibly reaching 100 feet per second (30 m/s). At that time, research aircraft had recorded gusts up to 72 ft/s (22 m/s) inside thunderstorms.[1] Investigators referenced the crash of Capital Airlines Flight 75, a Vickers Viscount that crashed in Maryland, USA in May 1959 after encountering severe thunderstorm turbulence.[26]

The debris was distributed along a north-south alignment. By estimating terminal velocities for key wreckage components, investigators approximated the aircraft’s position, altitude, and speed during structural breakup. They concluded that the outer section of the right wing detached when the plane was south of its planned route, flying northward at an altitude between 3,500 and 5,500 feet (1,070 and 1,680 m).[10][27] This occurred when it was expected to be near 9,000 feet (2,740 m), heading west over a radio navigation beacon located nine miles away. The investigation required a plausible explanation for this significant deviation from its intended course.[1]

The inquiry team examined a US scientific publication titled The Thunderstorm from 1949, which suggested that when two thunderstorms are separated by less than 6 miles (9.7 km), severe turbulence is likely in the clear air between them. Investigators proposed that Flight 325, flying westward between two mature storms, encountered such turbulence causing loss of control and rapid descent into a thunderstorm south of the airport. While attempting to escape northwards, possibly to avoid further storm effects, ongoing strong turbulence led to another loss of control. The aircraft accelerated to or beyond its maximum safe speed, and amid efforts by the crew to regain command, it encountered sudden extreme turbulence resulting in failure of both the right wing and tailplane.[1]

Board of Accident Inquiry

In 1962, a Board of Accident Inquiry was established to thoroughly examine all factors related to the Flight 325 accident. The panel was led by Justice Spicer of the Commonwealth Industrial Court, part of the Australian Industrial Relations Commission. The Board commenced its sessions on 12 June 1962, convened over 24 days, and concluded its work on 27 July 1962.

The investigation determined the following:

The accident resulted from an in-flight failure of the starboard outer wing caused by tensile overload on the lower spar boom at station 323 during upward bending. This likely occurred due to a combination of maneuvering and gust forces when the aircraft exceeded speeds of 260 knots. Evidence strongly suggests that prior to the structural failure, there was a loss of control which caused the speed to increase beyond 260 knots. The most plausible reason for this loss of control is that the aircraft encountered unexpectedly severe turbulence that prevented the pilots from regaining full command.Cite error: Closing </ref> missing for <ref> tag[3][28]

The Inquiry strongly advocated for enhanced collaboration between meteorological services and air traffic control. It also recommended equipping Australian airline aircraft with weather radar systems to enable pilots to detect and avoid dangerous weather conditions. Consequently, by 1 June 1963, all Australian airliners were mandated to carry weather radar equipment.

Aircraft

Template:External media The aircraft involved was a Vickers Viscount 720 model with serial number 46, registered as VH-TVC. Its maiden flight took place on 17 November 1954. Delivered to Trans Australia Airlines on 8 December 1954, it bore the name John Oxley in tribute to an early Australian explorer and surveyor.

On 7 March 1960, VH-TVC was leased to Ansett-ANA and configured to carry 48 passengers.Cite error: Closing </ref> missing for <ref> tag

Throughout its service life, VH-TVC completed 12,010 flights accumulating a total of 16,946 flight hours.

See also

Notes

  1. ↑ In 1961, Sydney Airport's control tower utilized an early civil radar system, where the operator monitored a dimly lit enclosure focusing on a small screen to detect radar echoes from aircraft.[11]
  2. ↑ The right wing’s outer segment was located approximately 1,500 feet (460 m) from shore near Bonna Point, north of Balboa Street.
  3. ↑ The main wreckage lay on a magnetic bearing of 140° from Sydney airport,[15] situated 8,350 feet (2,550 m) north and 100 feet (30 m) east of the detached right wing segment.[16][17]
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  4. ↑ Following Mr Justice Spicer’s inquiry into the fatal crash of Fokker Friendship Trans Australia Airlines Flight 538 in November 1960, it was recommended that flight data recorders be installed on all turbine-powered Australian airline aircraft. This recommendation had been implemented; however, Viscount aircraft had not yet been equipped with such devices at the time Flight 325 was lost.[20]
  5. ↑ A local resident at Kurnell found this rudder fragment on 2 March 1974.[23]
  6. ↑ All four engines were confirmed to be operational at impact. The propeller blade angles allowed investigators to estimate that the aircraft struck the water at speeds between 300 and 400 knots (560 and 740 km/h).[8][10] Autopsies revealed that all occupants perished instantly due to the force of impact.[24]
  7. ↑ Station 323 is located just beyond engine number 4 on the right wing.[3] All four engines were recovered with the main wreckage in Botany Bay.[10] Small components from engine number 4’s nacelle detached simultaneously with the outer right wing section and were found on Kurnell peninsula.[16]

References

  1. ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 Cite error: Invalid <ref> tag; no text was provided for refs named Yeend
  2. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named VVN
  3. ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 Cite error: Invalid <ref> tag; no text was provided for refs named ASN
  4. ↑ 4.0 4.1 4.2 Cite error: Invalid <ref> tag; no text was provided for refs named MJ179
  5. ↑ Spicer 1962, pp. 4–6, 26, 35–38
  6. ↑ Robinson, Margaret (1996). Keldie, Aileen Margaret (1936–1961) Australian Dictionary of Biography. Retrieved 5 December 2012
  7. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named AA
  8. ↑ 8.0 8.1 Cite error: Invalid <ref> tag; no text was provided for refs named S22
  9. ↑ Canberra Times, "Airliner Believed Down In Sea," 1 December 1961, p.1
  10. ↑ 10.0 10.1 10.2 10.3 10.4 Cite error: Invalid <ref> tag; no text was provided for refs named MJ183
  11. ↑ Job 1992, p. 178
  12. ↑ Airliner Split Open In Crash Canberra Times 2 December 1961 page 1
  13. ↑ 13.0 13.1 Spicer 1962, p. 6
  14. ↑ 14.0 14.1 14.2 Job 1992, p. 180
  15. ↑ 15.0 15.1 Spicer 1962, p. 48
  16. ↑ 16.0 16.1 16.2 16.3 Spicer 1962, p. 15
  17. ↑ 17.0 17.1 Spicer 1962, p. 7
  18. ↑ HMAS Kimbla Royal Australian Navy
  19. ↑ Vital Plane Parts Found Canberra Times 18 January 1962 page 3
  20. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named MJ187
  21. ↑ Developments in Flight Recorder Equipment and Analysis – p.2 Archived 31 March 2012 at the Wayback Machine Retrieved 9 September 2011
  22. ↑ La Perouse – Blast From The Past. Retrieved 9 September 2011
  23. ↑ 23.0 23.1 Job 1992, p. 186
  24. ↑ Spicer 1962, p. 8
  25. ↑ Job 1992, p. 182
  26. ↑ Job 1992, p. 185
  27. ↑ Spicer 1962, p. 16
  28. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named CT1591

Bibliography

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  • Lua error in Module:Citation/CS1/Configuration at line 2123: attempt to index field '?' (a nil value). Fyshwick, Australia. pp. 200. ISBN 1-875671-01-3
  • Lua error in Module:Citation/CS1/Configuration at line 2123: attempt to index field '?' (a nil value).

Template:Aviation accidents and incidents in Australia Template:Aviation accidents and incidents in 1961

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