Investigation Summary
The accident highlighted a series of technical and administrative failures regarding aircraft weight and balance. The official load chart, prepared by the Department of Civil Aviation based on RAAF data, contained several critical errors. It did not account for the fact that the Lockheed Lodestar's main undercarriage retracted rearwards, shifting the center of gravity (CofG) further aft during flight. Additionally, the passenger seats were installed 1 inch (25 mm) further apart than specified on the chart, and approximately 18 kg of catering supplies stored at the rear of the cabin were omitted from calculations. While the load sheet for the flight indicated a CofG of 39.2% Mean Aerodynamic Chord (MAC), just over the 39% limit, post-crash analysis determined the actual CofG was approximately 43.4% MAC once the gear was retracted. This extreme rearward balance made the aircraft tail-heavy and unstable. Investigators also found the elevator trim tab mechanism set in a position typical for landing, suggesting the crew failed to reset the trim for takeoff, possibly due to distractions during a boarding dispute involving the airline's Chief Pilot and Traffic Manager.
Final Conclusions
The investigation concluded the primary cause was the aircraft being loaded such that its center of gravity was significantly behind the rear limit, rendering it longitudinally unstable. A contributory factor was the incorrect setting of the elevator trim tab for takeoff. The instability was triggered or worsened when the undercarriage was retracted, causing a further rearward shift in the center of gravity that exceeded the pilot's ability to maintain control.
Video Analysis
No video analysis linked for this case file yet.
Systems & Failure Modes
Elevator Trim Tab
A small surface on the elevator used to neutralize control column pressure; an incorrect setting for landing instead of takeoff contributed to the uncontrollable nose-up pitch.
Retractable Undercarriage
The Lodestar's main gear retracted toward the rear, which shifted the aircraft's center of gravity aft, a factor not included in the official loading charts.
Interesting Facts
- 01The aircraft was a Lockheed 18-56 Lodestar manufactured in 1942.
- 02The rear center of gravity limit for the aircraft was 39% of Mean Aerodynamic Chord (MAC).
- 03Post-crash calculations estimated the actual center of gravity reached 43.4% MAC after gear retraction.
- 04The official load chart failed to account for the rearward movement of the center of gravity during undercarriage retraction.
- 05The elevator trim tab was found in a position typical for landing rather than takeoff.
- 06The flaps were found extended to 15 degrees, which was the standard takeoff setting.
- 07The crash resulted in the longest-running coronial inquest in Queensland's history at the time, lasting 16 days.
Safety Actions & Advisories
Loading Regulation Reform
Following the crash, the Minister for Civil Aviation hinted at stricter regulations regarding the loading of aircraft and the accuracy of load charts provided to operators.
Known Controversies & Unanswered Questions
Secrecy of the Investigation Report
Reference ↗The Minister for Civil Aviation refused to make the official investigation panel's report public, leading to significant criticism from legal counsel and the press during the coronial inquest.