Documentation of evidence and calculation of acceleration in aircraft accident reconstruction

Abstract

This paper presents results from the reconstruction of the crash of a twin-engine, low-wing airplane on final approach. These results are used to demonstrate the reverse projection method for documenting physical evidence and the kinematic method for calculating aircraft acceleration. The documentation of evidence and the calculation of acceleration, previously shown using airplane test data, are now shown using airplane accident data. The use of reverse projection to complete the documentation of physical evidence that was not preserved is discussed.

Keywords:

• small airplane
• airplane crash
• accident reconstruction
• accident severity
• camera reverse projection
• computer reverse projection

Acknowledgement

The authors thank counsel for the airplane manufacturer – Robert C. Gebhardt of Wilson Elser Moskowitz Edelman and Dicker LLP and J.T. Wells Blaxter of Blaxter Law – for permission to present the results of the present study including permission to use the photographs of Figures 2, 3 and 8–10. The authors also thank counsel for the airplane passenger and counsel's investigator for permission to use the photographs of Figures 4– 6 (which were also used in Figures 12, 13 and 15–18); the authors acknowledge that counsel's permission to use these photographs in the present study does not imply counsel's agreement with the results of the present study.

Notes

1. The lateral components of acceleration with respect to the terrain and with respect to the earth a_L are generally undefined (generally equal to zero).

2. Rounding of converted values was done in accordance with the American Society of Mechanical Engineering rules [1].

3. The photographs of Figures 2 and 3 were taken during the third inspection. Identifying markings on the sides of the cabin section in Figures 2 and 3 have been greyed out.

4. The photographs taken 2 weeks after the accident were more useful in the present study because the views of the drainage ditch were not obstructed by the airplane.

5. The date stamp on the photographs has been greyed out.

6. Distinctive features on background structures in Figure 9 have been greyed out.

7. The translation of the centre of gravity of the airplane from the end of the principal impact to the final rest was 4.36 m.

8. With the exception of forward pressure bulkhead damage, neither structural deformation nor component separation during the principal impact is shown.