Air disaster in Queensland, Australia
On 10 March 1949 a Lockheed Lodestar aircraft became airborne at Coolangatta, Queensland, Australia for a flight to Brisbane. Before reaching a height of it suddenly pitched nose-up, stalled and crashed onto its belly beyond the end of the airstrip.
Fuel from the aircraft's tanks caught fire and the aircraft burned fiercely. All 21 people on board died, either of injuries during the crash or in the ensuing conflagration. It was the worst civil aviation accident in Queensland at the time, and the second-worst accident in Australia. It occurred exactly three years after the worst, the ANA DC-3 crash near Hobart on 10 March 1946.
Investigation of the crash uncovered some errors in the information used to determine the position of the aircraft's centre of gravity. It became clear that the aircraft had taken off with its centre of gravity slightly outside the approved limits. Investigators also found evidence that the takeoff may have been performed with the elevator trim tab still set for landing. If the elevator trim tab had not been set for takeoff this would have been exacerbated by the incorrect position of the centre of gravity and the aircraft would have been uncontrollable.
The flight.
"Queensland Airlines" used Lockheed Lodestar VH-BAG to conduct a regular passenger service between Brisbane, Casino, Coffs Harbour, Coolangatta and Brisbane. VH-BAG arrived at Bilinga airstrip, on the outskirts of Coolangatta, from Coffs Harbour with 11 of its 16 passenger seats occupied. Some passengers left the aircraft at Bilinga and others boarded for the flight of to Archerfield Airport in Brisbane.
The aircraft was parked at the "Queensland Airlines" terminal for about a quarter of an hour before departing at 11:15 am local time. On board were 16 adult passengers and 2 infants, 2 pilots and an air hostess. All passenger seats were occupied. Observers saw the aircraft taxi to the end of the strip, turn around and promptly commence its take-off run.
The crash.
The take-off appeared to be normal until the undercarriage was retracted. The aircraft quickly pitched nose-up into an almost vertical attitude. First the aircraft rolled to the right until the wing was almost vertical, then it rolled to the left. The aircraft reached a height estimated to be between and then began descending and curving to the left. It continued to descend until it crashed onto its belly, tree stumps tearing open the underside of the left wing and the fuselage beneath the cabin door. The aircraft slid for only about before stopping about beyond the end of the strip. It came to rest in the shallow waters of a swamp at the edge of the airstrip. Within seconds of the crash, flame and black smoke erupted from the wreckage.
Only a small number of people were at the airstrip and saw the crash. The airport groundsman and an airline staff member grabbed portable fire extinguishers, jumped into a car and raced across the airstrip. Others at the airstrip and nearby beaches ran towards the burning aircraft. The aircraft's cabin door had been torn away by a tree stump and lay about behind the aircraft but despite the open doorway no-one inside the passenger cabin attempted to escape. Fuel floating on the surface of the water was burning fiercely, making it dangerous to approach the wreckage. One of the first witnesses to reach the scene believed he saw two people at the front of the passenger cabin who were alive but before he could get close enough to investigate he was driven back by flames.
A fire engine from Coolangatta arrived within minutes of the crash. The boggy swamp made it difficult to manoeuvre the vehicle close to the wreckage. Firemen initially attacked the fire with portable fire extinguishers and then used the fire engine to pump water from the swamp onto the blazing wreckage. Two firemen found a way around the burning fuel on the surface of the water and climbed onto the wing with their hose. The fire burned fiercely for 30 minutes but was not completely extinguished for another hour. Apart from the outer wings and the tail section, little of the aircraft was recognisable. Both halves of the tailplane were visibly bent downwards. The wreckage of the wings and engine mounts also showed they had suffered severe downward bending indicating the severity of the impact. The charred body of one of the pilots was half-way out a cockpit window, suggesting he survived the crash and attempted to escape from the wreckage.
At 3:15 pm police, ambulance and volunteers began to remove the bodies of victims from the wreckage. By 4:30 pm 20 bodies had been recovered. All were burned beyond recognition. Searching for the body of the final victim, a rope was attached to the row of burned seats and a truck was used to move the seat row. Underneath the seats was the body of a man, almost submerged under the water, his face protected by the swamp water and still recognisable.
Investigation.
The Director-General of Civil Aviation immediately appointed an investigation panel comprising specialists from the Department of Civil Aviation. Evidence from eyewitnesses led the panel to conclude that the aircraft climbed to a height of less than and then stalled. An initial investigation of the aircraft showed no evidence of any failure in the control system. The throttles were fully open, the magneto switches on, and the propellers in fine pitch. The undercarriage was retracted, but the flaps were extended 15°. The disposition of the cables on the trim tab mechanism showed a setting typical of a landing.
In its report the panel stated the accident was caused by the aircraft being loaded so its centre of gravity was behind the rear limit. The report also stated that incorrect setting of the elevator trim tab may have been a contributory cause.
The rear limit for the centre of gravity was 39% of Mean Aerodynamic Chord. The load sheet prepared for the fatal flight indicated the centre of gravity of VH-BAG was at 39.2% of Mean Aerodynamic Chord. The load sheet was based on a load chart prepared by the Department of Civil Aviation and based on information supplied by the RAAF. During the investigation, inquiries were made with the US Civil Aeronautics Administration and this revealed an error in the load chart. The main undercarriage of the Lockheed Lodestar retracted to the rear so that retraction caused the centre of gravity to move rearwards but this was not taken into account in the design of the load chart. Other errors also came to light. The passenger seats were further apart than shown on the load chart, causing the centre of gravity to be further to the rear than calculated, especially when the aircraft was fully loaded. Up to of food and beverages for the passengers were stored at the rear of the passenger cabin but were not taken into account on the load chart. Investigation of the accident concluded that after the aircraft's undercarriage retracted, the centre of gravity would have been at about 43.4% of Mean Aerodynamic Chord. With the centre of gravity 4% of MAC behind the rear limit the aircraft would have been tail-heavy and longitudinally unstable.
The aircraft had been in daily civil operations in Australia since November 1946 so the investigators assumed there must have been numerous flights with the centre of gravity significantly more than 39% of Mean Aerodynamic Chord. It was necessary for the investigators to find something unique about the fatal flight of VH-BAG that would explain its sudden climb immediately after take-off and the pilot's inability to regain control and prevent the aircraft crashing. The aircraft's tailplane was one of the few parts of the aircraft not destroyed by fire. The position of the elevator trim tab spool appeared to be in the normal position for landing rather than a typical position for take-off. The investigators concluded that on the final takeoff it was likely that the elevator trim tab was still set for landing. This, coupled with the aircraft being tail-heavy and longitudinally unstable after undercarriage retraction, caused the aircraft to pitch nose-up so strongly that the pilot was unable to retain control or prevent the aircraft stalling.
Minister for Civil Aviation Arthur Drakeford made a public announcement that the accident had occurred because the aircraft was tail-heavy and unstable as the result of incorrect loading. The Minister said the operator had not taken adequate steps to ensure safe loading of its aircraft and he hinted that stricter regulation of the loading of aircraft was being considered.
The Minister announced that a public inquiry into the accident was unnecessary because the exact cause had been determined by his Department's investigation. He also refused to make public the investigation panel's report. This secrecy attracted criticism.
Inquest.
Post-mortem examinations were performed on the bodies. In addition to varying degrees of incineration, fractures of the skull, legs, arms and wrists were found. Even if the aircraft had not caught fire, a number of the occupants would have died from injuries they received in the crash.
An inquest into the deaths of the 21 occupants was conducted by the Southport District Coroner Mr P.W. Shepherd. The inquest was conducted over a period of 16 days, making it Queensland's longest-running coronial inquest. The inquest heard from 22 witnesses.
Counsel representing the aircraft operator, "Queensland Airlines", asked that the report of the investigation panel be made available to him. He complained that the report was critical of "Queensland Airlines" and yet he did not have the opportunity to read it, test its validity or cross-examine members of the investigation panel. He also complained about the implication that "Queensland Airlines" was guilty of causing the crash and said legal counsel for some of the parties were using the Coroner's inquest to prepare for legal action against "Queensland Airlines". He interrupted evidence being presented by a member of the Department's investigation panel to ask that the panel's report be made available. Counsel representing the Department of Civil Aviation passed this request to the Director-General of Civil Aviation but the Director-General's response was that the report was not to be made available to legal representatives or the public.
The Queensland Attorney-General, Mr Devries, announced that Coroners' reports were confidential and for the benefit of the Attorney-General. He said the report by Mr Shepherd into the deaths of 21 people at Bilinga airstrip on 10 March would not be made public. This decision attracted criticism.
Aircraft loading.
"Queensland Airlines" and its agents did not have weighing scales for use with passengers and luggage. The Traffic Manager for "Queensland Airlines" advised that sets of weighing scales had been purchased but were not in use because they had not been approved by the Department of Weights and Measures. He said that at every port other than Bilinga passengers could use some other company's weighing scales, and passengers intending to board at Bilinga could use the weighing scales at the nearby railway station. Staff of "Queensland Airlines" at Bilinga asked passengers to estimate their weight. The company allotted particular seats to its passengers but passengers did not always occupy the seats allotted to them.
The weight of the aircraft at the time of take-off was within the maximum limit specified in its certificate of airworthiness. After the undercarriage retracted, the aircraft's centre of gravity was behind the rear limit by between 4.3% and 4.9% of Mean Aerodynamic Chord.
The Chief Pilot of "Queensland Airlines" told the inquest he did not believe the accident was caused by incorrect loading of the aircraft. He said the load sheet showed the aircraft's centre of gravity was at 39.2% of Mean Aerodynamic Chord and therefore only slightly outside the approved limit. He said if the aircraft's centre of gravity was significantly behind its rear limit the pilot would become aware of it before the aircraft left the ground. It was his opinion that some other mechanical problem must have occurred to cause the accident.
Air hostess.
The body of the air hostess was found in the cockpit rather than near the hostess's seat at the rear of the passenger cabin. The Chief Pilot of "Queensland Airlines" suggested the pilot would have examined the waybill and would have been aware the aircraft was tail-heavy. It was likely he asked the air hostess to sit in the cockpit during the take-off to eliminate the tail-heaviness. The Chief Pilot told the inquest the loading chart