This February 2007 accident report is provided by the National Transportation Safety Board.
Aircraft: Cessna 414.
Location: Dickinson, N.D.
Aircraft damage: Substantial.
What reportedly happened: The pilot reported that when he attempted to lower the landing gear during approach, both main landing gear indicators failed to show a down and locked condition.
After several attempts at recycling the landing gear, he tried to use the emergency gear extension method, but still did not get the down and locked indication. The pilot radioed his predicament to someone on the ground at the airport, then made a low pass so that the position of the landing gear could be verified. The person on the ground said the landing gear appeared to be down. The pilot attempted to land. During touchdown the right main gear retracted.
Post-accident examination of the landing gear system revealed no anomalies.
Probable cause: The undetermined failure of the emergency landing gear system and the retraction of the right main landing gear during landing.
For more information: ntsb.gov/ntsb/brief.asp?ev_id=20070208X00157&key=1