Port Isabel

Aerial photos were being taken of the mishap aircraft. Mission called for a simulated water landing (actual water landing prohibited) by flying as close as possible to water. Copilot at controls descended aircraft to about 6 feet, then gradually reduced clearance to 6-12 inches above water, airspeed 105 mph. Copilot inadvertently allowed aircraft to touch water. On touchdown, aircraft decelerated violently and broke up, ejecting several of the occupants and coming to rest inverted. Examination of aerial photos shows aircraft hull at touchdown was slightly nose down vice normal landing attitude; water contact made at location of nose landing gear doors. Photos show outward rupturing of forward hull structure, nose gear doors missing. Hull at rear of step showed two parallel, 3-feet long by 2-in wide, fore-to-aft and outboard-to-inboard penetrations. Floor of shallow lagoon known to have scattered debris from petroleum explorations; however, no positive determination of aircraft contact with submerged object could be made. Seven occupants were killed while three others were injured.