On October 22, 1992, a Cessna 177B (registration N13710) operated by Neill, Dixie Lee was involved in an aviation accident near Las Cruces, NM. Investigators recorded the probable cause as: the pilot's failure to maintain proper airspeed and descent rate during the final phase of landing, resulting in a hard landing and subsequent loss of directional control due to porpoising. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During a night training flight for three landings, the pilot executed a normal approach with VASI guidance but landed hard, causing the aircraft to bounce and porpoise before stopping at the runway edge.
What happened
The pilot was conducting a night training session at an airport, intending to complete three full-stop landings before departing on a night cross-country flight with a passenger. The operation took place under night visual meteorological conditions.
During the final approach for one of these practice landings, the pilot utilized the Visual Approach Slope Indicator (VASI) to maintain proper glidepath alignment. Despite the use of this guidance system, the aircraft touched down on the runway with excessive force. Upon impact, the airplane bounced multiple times and began to porpoise longitudinally along the runway surface.
The bouncing and porpoising motion continued for three or four cycles before the aircraft finally came to a complete stop at the very edge of the runway pavement.
Probable cause
the pilot's failure to maintain proper airspeed and descent rate during the final phase of landing, resulting in a hard landing and subsequent loss of directional control due to porpoising.