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A Sampling from the Archives:
David Haddon Holladay Papers

Accident Investigation

David Holladay was an aviation safety consultant and accident investigator. After retiring from the Air Force, he became head of the aerospace safety curriculum at the University of Southern California. The Holladay papers contain accident investigation case files; reference and research files; and manuals and other published material. The selected items on display come from one of the accident investigation case files.

The Accident :

On 24 November 1973, a Mooney M-20 crashed following an in-flight separation of the left wing. During his investigation, Holladay conducted a careful examination of the wreckage.

notes on aircraft reconstruction and examination
views of the Mark 20 airplane

Holladay created display boards for use when testifying about accident investigations. The illustrations shown here were just two of the display boards created for this accident case.

Holladay identified the contributory causes of the in-flight failure as: "the design of the wing, the selection of materials, the fabrication of those materials in respect to assembly, quality control during assembly and production, and the provision of information by the manufacturer, and the manufacturer's responsibility for surveillance of his product."

The NTSB investigation found improperly bonded glue joints and deteriorated ribs and auxiliary wing spars. The probable cause was improper maintenance, inadequate inspection by maintenance personnel, and material failure of the wing structure.

Mooney wing illustration

 

Additional information on this, and other accident case files, is available in the archives.