MIA93FA198

A preflight weather briefing was not obtained before departure. Thunderstorms with heavy rain showers were forecast. During the flight an individual in the airplane requested weather advisories from the UNICOM operator who advised the crew of a thunderstorm near the airport. The flight proceeded toward the thunderstorm according to witnesses but there were no witnesses to the accident. The airplane minus the right wing was recovered. Examination of the airplane revealed that the left wing separated near the wing root and about 20 inches outboard of the outboard fuel sensor due to overload. The right wing failed near the wing root due to overload. Examination of the flight controls revealed no evidence of pre-impact failure or malfunction. Examination of the engine assembly minus the magnetos, and fuel pump housing revealed no evidence of pre-impact failure or malfunction. No occupant had an instrument rating. No determination could be made as to who was flying the airplane.

History of flight

On September 19, 1993, about 1615 Atlantic standard time, a Socata TB 10, N104F, registered to Efrain Lopez, crashed in the North Atlantic Ocean near the Rafael Hernandez Airport, Aguadilla, Puerto Rico, while on a 14 CFR Part 91 personal flight. Visual meteorological conditions existed at the Rafael Hernandez Airport at the time of the accident and no flight plan was filed. The airplane was destroyed, and the owner, who was a student pilot and one passenger were fatally injured. The private-rated pilot has not been recovered and is presumed to be fatally injured. The flight originated from the Eugenio Maria De Hostos Airport, Mayaguez, Puerto Rico, about 1530.

Reportedly, the flight departed Mayaguez en route to Aguadilla, Puerto Rico, and between 1550 and 1600, an individual in an airplane broadcast on the UNICOM frequency at Aguadilla requesting weather advisories. The individual monitoring the UNICOM radio who is a certified weather observer advised the individual in the airplane that the weather was "turning bad." He also advised the individual that there was a thunderstorm located southeast of the airport moving northwesterly. The individual in the airplane then advised the UNICOM operator that the flight would proceed to the Isla Grande Airport. There was no further radio communication with the airplane and the radio communication was not recorded.

According to a witness who lives about 4 miles south of the Rafael Hernandez Airport and was outside between 1615 and 1645, he stated that there was rain, thunder, and lightning which was associated with a storm that was located near the airport. He then observed a small airplane with colors that matched the accident airplane flying northeasterly about 2,000 feet toward the storm. He then lost sight of the airplane and did not see the airplane crash. According to another witness who was outside between 1630 and 1645, he stated that there was a thunderstorm approaching from the east moving westerly. He observed an airplane with colors that matched the accident airplane flying north-northeast bound about 300 feet above ground level toward the storm. The airplane was last seen flying eastbound along the coast toward the storm. He did not witness the airplane crash.

Personnel information

Information pertaining to the first pilot is contained in NTSB Form 6120.4. Information pertaining to the second pilot is contained in NTSB Form 6120.4 Supplement E. No determination could be made as to who was flying the airplane at the time of the accident. Seating positions were not determined.

Aircraft information

Information pertaining to the airplane is contained in NTSB Form 6120.4 and 6120.4, Supplements A and B.

Meteorological information

Information pertaining to weather is contained in NTSB Form 6120.4 and 6120.4, Supplement R. Radar photographs were taken at 1544, 1559, and 1615 local time centered on the San Juan, Puerto Rico, repeater scope. The 1544 photograph reveals an area of level two with pinpoint level three radar returns east of Mayaguez extending north to just east of Aguadilla, Puerto Rico. The 1559 photograph reveals that the level two returns had expanded northwestward and the level three returns increased in size. The 1615 photograph reveals a level three cell near Aguadilla, Puerto Rico. Visual satellite images were prepared at 1531 and 1601 local time. The 1531 image indicates an area of convective weather located east of a line from Mayaguez to Aguadilla, Puerto Rico. The 1601 image indicates that the convective weather was moving northward. There were no pilot reports available in the National Weather Service archives for the period from 1300 to 1700. According to the terminal area forecast prepared for Aguadilla on September 19, 1993, issued at 1235 local time in part states, visibility of 3 statute miles, thunderstorms with heavy rain showers.

Communications

According to the San Juan International Flight Service Station personnel, there was no record of any services provided to the call sign N104F on the day of the accident.

Wreckage and impact

The wreckage which was located about 18 degrees 29 minutes 36 seconds North Latitude, 067 degrees 09 minutes 30 seconds West Longitude, was recovered, and examined on November 4, 1993. The wreckage consisted of the airframe which was impact damaged, the horizontal stabilator and vertical stabilizer with flight control surfaces attached, the engine and propeller assembly, and a section of the left wing. Examination of the airframe revealed that the left wing separated about 30 inches outboard from the attach point. The top spar cap was fractured from the web and displaced up. Examination of the fracture surface revealed signatures consistent with overload failure. The main spar of the recovered portion of the left wing was measured to be about 7 feet 6 inches and was bent rearward. Examination of the fracture surfaces of the outer section of the left wing revealed signatures consistent with overload failure. The outboard fracture surface of the left wing was located about 20 inches outboard of the outboard fuel sensor. The separated section of the left wing was not recovered. The right wing which was not recovered separated near the wing root. Examination of the fracture surface reveal signatures consistent with overload failure. The top spar cap of the right wing spar was displaced up.

Examination of the cockpit flight controls revealed that the horizontal interconnect between the pilot's and copilot's control columns which connects to the vertical control column was separated from the vertical control column. Examination of the fracture surfaces revealed signatures consistent with overload failure. The aileron and elevator control surfaces push-pull rods were broken at the bellcrank in the cockpit area. Examination of the fracture surfaces revealed signatures consistent with overload failure. The elevator and rudder control surfaces push-pull rods were broken at the mid range bellcrank but connected to the forward bellcrank. Examination of the fracture surfaces of the midrange bellcrank revealed signatures consistent with overload failure. The interconnect between the pilot's and copilot's rudder pedals was broken. Examination of the fracture surfaces revealed signatures consistent with overload failure. The elevator and rudder control surfaces push-pull rods were attached at each rear bellcrank. The stabilator actuating rod was connected to the control surface but the tube was separated from the forward forked end which was connected to the bellcrank. The four rivets which connect the tube to the forward forked end of the tube were not located. The stabilator actuating rod was removed from the airplane for metallurgical examination which revealed that there was some deformation of the rivet holes in both separated sections. The throttle quadrant controls were damaged.

Examination of the engine revealed that the carburetor and attached air box assembly was separated but the throttle, mixture, and carburetor heat control cables were attached to their respective controls. Examination of the fracture surface of the carburetor revealed signatures consistent with overload failure. The propeller governor was also separated but the control cable was still attached. Examination of the fracture surfaces revealed signatures consistent with overload failure. The magneto housing was damaged due to submersion and the mount bolts were installed in the accessory case. Additionally, the ignition leads were only attached at the spark plugs. The propeller which was attached to the crankshaft propeller mounting flange could not be turned by hand. Both propeller blades could be rotated in the propeller hub and examination of one of the blades revealed a slight "S" bend. The cylinders and pistons