No fatalities

Boeing B-29 Superfortress crash in Lake Mead during research flight (45-21847)

Lake Mead, United States of AmericaFlight

On July 21, 1948, a Boeing B-29 Superfortress (registration 45-21847) operated by United States Air Force - USAF (since 1947) was involved in an aviation accident near Lake Mead, United States of America in flight. No fatalities were reported. Investigators recorded the probable cause as: Pilot error resulting in a loss of depth perception during a low-altitude pass over water caused the aircraft to strike the surface at high speed. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 8 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 2026-08-05Data APIEditorial standards

A modified Boeing B-29 Superfortress crashed into Lake Mead during a low-altitude research mission. All five crew members escaped safely before the aircraft sank, and the wreck was later recovered largely intact.

What happened

The incident involved an electronic reconnaissance variant of the Boeing B-29 Superfortress, specifically adapted for operations in Arctic environments. The aircraft was conducting a research flight focused on testing a secret missile guidance system that utilized solar tracking for navigation.

During the mission, the pilot executed a low pass over calm water at high speed. As the plane descended from high altitude to skim the surface, the pilot lost depth perception. This error caused the large aircraft to strike the water at approximately 230 mph. The impact was severe enough to shear off three of the four engines, leaving only one attached. The fuselage skipped along the lake surface before coming to a stop.

Once stationary, the aircraft began taking on water and started to sink. The crew of five successfully evacuated into life rafts and waited for rescue. All personnel survived the incident without reported fatalities.

Findings

The wreckage was later located by sonar at a depth of 170 feet. The airframe remained largely intact, with the primary damage being the loss of engines number two, three, and four due to the initial impact with the water surface.

Probable cause

Pilot error resulting in a loss of depth perception during a low-altitude pass over water caused the aircraft to strike the surface at high speed.