19990520005479A

Pilot reported that the acft engine failed, and the acft crashed approximately 5 miles west of the arpt, the pilot/sole occupant suffered fatal injuries, the acft has substantial damage, other circumstances are unknown. (.19) on may 20, 1999, about 1404 eastern daylight time, a classic aircraft corporation S-51D homebuilt airplane, N25VV, registered to classic aircraft corporation, impacted with the terrain during a forced landing near tamarac, Florida. Visual meteorological conditions prevailed at the time, and no flight plan was filed for the 14 CFR part 91 personal flight. The airplane was destroyed. The airline transport rated pilot was fatally injured. The flight had departed the fort Lauderdale executive airport, fort Lauderdale, Florida, at 1349. The purpose of this flight was to accumulate the 40 hours of flight on the airplane required before certification. After takeoff, the pilot headed west and was about 5 nautical miles west of the airport, when he radioed the control tower that he was having a problem raising the landing gear and he wanted to return to the airport. The airplane was identified on radar as being at an altitude of 1,300 feet, and heading westbound. At 1404:24, he radioed that he had lost the engine. Radar and radio contact was lost shortly thereafter. A witness in the area said he heard the engine loosing power, and sputtering. The witness further said the airplane made a controlled descent to the ground. After impact with the ground the cockpit area was engulfed in flames. (-23)investigated accident involving an experimental aircraft. The aircraft a S-51D lost engine power @ 10 min. After take-off and had to make an emergency landing, missing the sawgrass expressway by 30 yards and landing into trees. The aircraft caught fire after inpact killing the pilot. (.4)on the morning of the accident the airplane had flown for about 1.2 hours, landed, was refueled, and shut down for a an unknown period of time. After start up the pilot taxied to the active runway, and was delayed in taking off by ATC, due to traffic. The time between engine start and takeoff was about 16 minutes. About 11 nautical miles west of the airport, the pilot radioed the control tower that he was having a problem raising the landing gear and he wanted to return to the airport. The pilot then radioed that he had lost the engine. Radar and radio contact was lost shortly thereafter. A witness heard the engine loosing power, and sputtering. The witness also observed the airplane make a controlled descent towards the ground. A test run of the engine was performed and revealed that when the engine was brought to cruise rpms, and running for about 10 minutes, the fuel temperature reached 153 degrees f, which set up a vapor lock condition, the fuel pressure needle fluctuated, went to zero, and the engine completely shut down. The engine was allowed to cool and then started again. On the second run the fuel temperature reached 152 degrees f, the RPM and fuel pressur e fluctuated, and the engine completely stopped, similar to the first run. A test on a similar airplane revealed that while cycling the landing gear, wheels would pass in front of the radiator scoop. With the gear partially up, but not in the wheel well, the gear almost completely blocked the radiator scoop, which would have caused colling air to be blocked or deflected.