Ansett-ANA Flight 149
Encyclopedia
On 22 September 1966 a Vickers Viscount
aircraft departed from Mount Isa, Queensland
, Australia
for a 73 minute flight to Longreach. Forty-four minutes after takeoff a fire started in one of the engines. The crew were unable to extinguish the fire or feather the propeller
so made an emergency descent with the intention of landing at Winton
, a small town along the route. The fire spread to the fuel tank and weakened the wing structure so that a large part of the left wing
broke away and the aircraft
crashed. All twenty-four occupants were killed. The accident remains the fifth-worst in Australia's civil aviation history.
and twenty passengers.
At 12:52 pm the Flight Service Unit at Longreach heard a radio transmission
from the crew of Flight 149 saying they were making an emergency descent. Two minutes later the crew notified Longreach they had a fire warning for number 2 engine
and had been unable to feather the propeller. At 12:59 pm Longreach received a message relayed by the crew of VH-AEQ saying fire in the engine nacelle
was visible to the crew of Flight 149 and they were diverting to land at Winton airport
, 92 nautical miles (171 km) from Longreach.
At 1:03 pm when only 13.5 nautical miles (25 km) from the airport VH-RMI crashed on Nadjayamba Station
and was engulfed in flames.
. It was damaged in the crash but it provided sufficient information to allow reconstruction of the aircraft's flight path until the moment of impact. This was the first accident investigation in Australia to be aided by information from a flight data recorder. At the time of the accident the aircraft was not equipped with a cockpit voice recorder
.
It was determined that a fire started when the oil metering unit broke free from the cabin pressurisation blower driven by number 2 engine. The fire spread to the wheel bay and then to a fuel cell in the left wing where it became so intense it caused softening of aluminium alloy and loss of strength of the upper boom (or upper flange
) in the wing spar. The spar was critically weakened in the region between number 1 and 2 engines. With the aircraft at a height between 3,500 feet (1 067 m) and 4,000 feet (1 220 m) the outer part of the left wing folded upwards. The propeller of number 1 engine cut open the aircraft cabin before the detached part of the left wing separated from the remainder of the aircraft.
The investigation concluded that the probable cause of the accident was:
When an oil metering unit was installed on a cabin blower after maintenance, locking wire was used to ensure the five securing nuts did not rotate and become loose. In the wreckage of number 2 cabin blower accident investigators found none of the nuts and no locking wire. The investigators believed that when the oil metering unit was last overhauled and installed on number 2 cabin blower the locking wire may have been omitted.
of the Commonwealth Industrial Court
. Ansett-ANA was represented by Walter Campbell, British Aircraft Corporation
by Gordon Samuels
, and the Department of Civil Aviation by Edward Williams. The Inquiry first sat on 26 April 1967 and concluded on 31 August 1967.
The aircraft made 12,858 flights and flew for 18,634 hours since new. It flew for 6,586 hours after its last complete overhaul in February and March 1966.
Vickers Viscount
The Vickers Viscount was a British medium-range turboprop airliner first flown in 1948 by Vickers-Armstrongs, making it the first such aircraft to enter service in the world...
aircraft departed from Mount Isa, Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
for a 73 minute flight to Longreach. Forty-four minutes after takeoff a fire started in one of the engines. The crew were unable to extinguish the fire or feather the propeller
Propeller (aircraft)
Aircraft propellers or airscrews convert rotary motion from piston engines or turboprops to provide propulsive force. They may be fixed or variable pitch. Early aircraft propellers were carved by hand from solid or laminated wood with later propellers being constructed from metal...
so made an emergency descent with the intention of landing at Winton
Winton, Queensland
-Qantas:Winton was one of the founding towns of the Australian airline Qantas. The first board meeting was held at the Winton Club on 10 February 1921.-Waltzing Matilda:...
, a small town along the route. The fire spread to the fuel tank and weakened the wing structure so that a large part of the left wing
Wing
A wing is an appendage with a surface that produces lift for flight or propulsion through the atmosphere, or through another gaseous or liquid fluid...
broke away and the aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...
crashed. All twenty-four occupants were killed. The accident remains the fifth-worst in Australia's civil aviation history.
The flight
Ansett-ANA Flight 149, a Vickers Viscount registered VH-RMI, took off from Mount Isa at 12:08 pm Eastern Standard Time and climbed to an altitude of 17,500 feet (5 334 m) for the flight of 316 nautical miles (585 km) to Longreach. On board were two pilots, two air hostessesFlight attendant
Flight attendants or cabin crew are members of an aircrew employed by airlines primarily to ensure the safety and comfort of passengers aboard commercial flights, on select business jet aircraft, and on some military aircraft.-History:The role of a flight attendant derives from that of similar...
and twenty passengers.
At 12:52 pm the Flight Service Unit at Longreach heard a radio transmission
Transmission (telecommunications)
Transmission, in telecommunications, is the process of sending, propagating and receiving an analogue or digital information signal over a physical point-to-point or point-to-multipoint transmission medium, either wired, optical fiber or wireless...
from the crew of Flight 149 saying they were making an emergency descent. Two minutes later the crew notified Longreach they had a fire warning for number 2 engine
Aircraft engine position number
Aircraft engine position number is a method to identify the location of engines on multi-engined aircraft. Aircraft engines are numbered from left to right from the view of the pilot looking forward.-Twin-engined aircraft:* #1 - port - on the left...
and had been unable to feather the propeller. At 12:59 pm Longreach received a message relayed by the crew of VH-AEQ saying fire in the engine nacelle
Nacelle
The nacelle is a cover housing that holds engines, fuel, or equipment on an aircraft. In some cases—for instance in the typical "Farman" type "pusher" aircraft, or the World War II-era P-38 Lightning—an aircraft's cockpit may also be housed in a nacelle, which essentially fills the...
was visible to the crew of Flight 149 and they were diverting to land at Winton airport
Winton Airport
Winton Airport is an airport serving Winton, Queensland, Australia. It is located northeast of Winton and operated by the Winton Shire Council.-Facilities:...
, 92 nautical miles (171 km) from Longreach.
At 1:03 pm when only 13.5 nautical miles (25 km) from the airport VH-RMI crashed on Nadjayamba Station
Station (Australian agriculture)
Station is the term for a large Australian landholding used for livestock production. It corresponds to the North American term ranch or South American estancia...
and was engulfed in flames.
Investigation
Investigation of the accident was difficult because most of the aircraft was destroyed in the impact and subsequent fire. The aircraft was equipped with an early flight data recorderFlight data recorder
A flight data recorder is an electronic device employed to record any instructions sent to any electronic systems on an aircraft. It is a device used to record specific aircraft performance parameters...
. It was damaged in the crash but it provided sufficient information to allow reconstruction of the aircraft's flight path until the moment of impact. This was the first accident investigation in Australia to be aided by information from a flight data recorder. At the time of the accident the aircraft was not equipped with a cockpit voice recorder
Cockpit voice recorder
A cockpit voice recorder , often referred to as a "black box", is a flight recorder used to record the audio environment in the flight deck of an aircraft for the purpose of investigation of accidents and incidents...
.
It was determined that a fire started when the oil metering unit broke free from the cabin pressurisation blower driven by number 2 engine. The fire spread to the wheel bay and then to a fuel cell in the left wing where it became so intense it caused softening of aluminium alloy and loss of strength of the upper boom (or upper flange
I-beam
-beams, also known as H-beams, W-beams , rolled steel joist , or double-T are beams with an - or H-shaped cross-section. The horizontal elements of the "" are flanges, while the vertical element is the web...
) in the wing spar. The spar was critically weakened in the region between number 1 and 2 engines. With the aircraft at a height between 3,500 feet (1 067 m) and 4,000 feet (1 220 m) the outer part of the left wing folded upwards. The propeller of number 1 engine cut open the aircraft cabin before the detached part of the left wing separated from the remainder of the aircraft.
The investigation concluded that the probable cause of the accident was:
The means of securing the oil metering unit to the no. 2 cabin blower became ineffective and this led to the initiation of a fire within the blower, which propagated to the wing fuel tank and substantially reduced the strength of the main spar upper boom. It is probable that the separation of the oil metering unit arose from an out-of-balance condition induced by rotor break-up but the source of the rotor break-up could not be determined.
When an oil metering unit was installed on a cabin blower after maintenance, locking wire was used to ensure the five securing nuts did not rotate and become loose. In the wreckage of number 2 cabin blower accident investigators found none of the nuts and no locking wire. The investigators believed that when the oil metering unit was last overhauled and installed on number 2 cabin blower the locking wire may have been omitted.
Inquiry
A Board of Accident Inquiry was appointed to investigate all aspects of the accident. The Board was Chaired by Sir John SpicerJohn Spicer (Australian politician)
Sir John Armstrong Spicer was an Australian lawyer, politician, cabinet minister and judge.Spicer was born in the Melbourne suburb of Prahran, but was taken to England by his family in 1905 and educated at Chelston School, Torquay. His family returned to Australia in 1911 and he attended Hawksburn...
of the Commonwealth Industrial Court
Australian Industrial Relations Commission
The Australian Industrial Relations Commission, or AIRC , was a tribunal with powers under the Workplace Relations Act 1996. It was the central institution of Australian labour law...
. Ansett-ANA was represented by Walter Campbell, British Aircraft Corporation
British Aircraft Corporation
The British Aircraft Corporation was a British aircraft manufacturer formed from the government-pressured merger of English Electric Aviation Ltd., Vickers-Armstrongs , the Bristol Aeroplane Company and Hunting Aircraft in 1960. Bristol, English Electric and Vickers became "parents" of BAC with...
by Gordon Samuels
Gordon Samuels
Gordon Jacob Samuels AC, CVO, QC , was a British-Australian lawyer, Judge and Governor of New South Wales from 1996 to 2001. Born in London in 1923, Samuels was educated at University College School and Balliol College, Oxford. After serving in the Second World War, he was called to the bar and...
, and the Department of Civil Aviation by Edward Williams. The Inquiry first sat on 26 April 1967 and concluded on 31 August 1967.
Aircraft
The aircraft was a Vickers Viscount 832. It was ordered by Ansett-ANA in 1958, was assigned serial number 416 and made its first flight in April 1959. It was registered in Australia as VH-RMI and entered airline service in May 1959. At the time of the accident its cabin was configured for 63 passengers.The aircraft made 12,858 flights and flew for 18,634 hours since new. It flew for 6,586 hours after its last complete overhaul in February and March 1966.
Memorials
A year after the accident a memorial was unveiled at the accident site on Nadjayamba Station, 12 statute miles (19 km) west of Winton. On the fortieth anniversary of the accident a second memorial was unveiled on the main street of Winton.See also
- Ansett-ANA Flight 325Ansett-ANA Flight 325On 30 November 1961 a Vickers Viscount aircraft departed from Sydney, Australia late in the afternoon for a flight of 128 nautical miles to Canberra. There were thunderstorms to the north and south of the airport. From about 9 minutes after takeoff the crew of Ansett-ANA Flight 325 did not...
- Vickers Viscount VH-TVC - MacRobertson Miller Airlines Flight 1750MacRobertson Miller Airlines Flight 1750On 31 December 1968 a Vickers Viscount aircraft departed from Perth, Western Australia for a flight of 724 nautical miles to Port Hedland. The aircraft crashed 28 nautical miles short of its destination with the loss of all twenty-six people on board...
- Vickers Viscount VH-RMQ - List of disasters in Australia by death toll
- List of accidents and incidents involving commercial aircraft
- List of accidents and incidents involving airliners by location