On June 2, 1999, a Grumman G-164A (registration N73PB) was involved in an aviation accident near Monaville, TX. Investigators recorded the probable cause as: The pilot's failure to ensure the airstrip surface was adequate for the aircraft's weight and landing gear configuration, specifically by not accounting for soft ground on the sides of the runway. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An agricultural airplane nosed over upon landing at a private airstrip when its main gear sank into soft ground along the runway edges, despite the center appearing dry and firm.
What happened
The pilot was conducting a landing operation at a privately owned airstrip for an agricultural aircraft. Upon final approach, the pilot observed that the runway surface appeared to be in good condition and completely dry. However, as the main landing gear of the airplane made contact with the ground, the wheels immediately sank into the soft soil. This sudden loss of support caused the aircraft to pitch forward violently, resulting in a nose-over onto its back.
Post-accident assessment revealed that while the center of the landing area remained dry and firm, the sides were significantly softer than anticipated. The pilot noted this discrepancy between the visual appearance of the runway and the actual ground conditions as the primary factor in the incident.
Probable cause
The pilot's failure to ensure the airstrip surface was adequate for the aircraft's weight and landing gear configuration, specifically by not accounting for soft ground on the sides of the runway.