On May 17, 1987, a Lake LA-4 (registration N527B) operated by Shelton, John W. Jr. was involved in an aviation accident near Stafford, VA. Investigators recorded the probable cause as: The pilot's failure to maintain clearance from a submerged object during takeoff, which resulted in hull penetration and detachment of the right pontoon. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A seaplane collided with a submerged object during takeoff, causing the right pontoon to detach and the aircraft to sink in shallow water. No injuries were reported among the pilot or passengers.
What happened
The incident occurred during the initial phase of flight as the aircraft was attempting to depart from a body of water. As the seaplane accelerated along the surface, it struck an object that was submerged beneath the waterline. The impact was significant enough to penetrate the hull structure of the aircraft.
Following the collision, the structural integrity of the right pontoon was compromised. The force of the impact dislodged the right pontoon from the main fuselage. Without the support of both pontoons, the aircraft lost buoyancy and stability. It sank rapidly into the water, which was approximately four feet deep at the location of the accident. Despite the substantial damage to the airframe, the vessel did not capsize immediately.
Shortly after the aircraft settled on the bottom, a nearby boat responded to the situation. The crew of the assisting vessel approached the submerged seaplane and initiated recovery operations. They successfully towed the damaged aircraft from the water to the shore. All individuals aboard were extracted safely without medical attention required.
Probable cause
The pilot's failure to maintain clearance from a submerged object during takeoff, which resulted in hull penetration and detachment of the right pontoon.