On July 9, 1995, a North American T-28B (registration N28TP) was involved in an aviation accident near Ramah, CO. Investigators recorded the probable cause as: Gross positive (upward) overloads on both the wings and the horizontal stabilizers, with failure of the stabilizers occurring primarily due to positive upward leading edge torsion. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During maneuvering in visual meteorological conditions, a T-28 experienced in-flight structural failure resulting in separation of both wings and the horizontal tail assembly. Investigation attributed the failure to gross positive upward overloads on wings and stabilizers, with stabilizer failure due to leading edge torsion. The pilot-owner held a current authorization; the second pilot's authorization had expired.
Incident Summary
While maneuvering in visual meteorological conditions, the airplane sustained an in-flight structural failure. This failure resulted in the separation of the left and right wings and the horizontal tail assemblies.
Investigation Findings
Investigation revealed that the principal failure modes were gross positive (upward) overloads on both the wings and the horizontal stabilizers. Failure of the stabilizers occurred primarily due to positive upward leading edge torsion.
Pilot Information
The pilot-owner possessed a current letter of authorization to serve as pilot-in-command of the T-28. The second pilot's letter of authorization had expired.
Probable cause
Gross positive (upward) overloads on both the wings and the horizontal stabilizers, with failure of the stabilizers occurring primarily due to positive upward leading edge torsion.