HISTORY OF FLIGHT On Saturday, February 19, 1994, at 0950 eastern standard time, a Beech C35, N5962C, collided with trees during a power-off forced landing at Rockville, Maryland. The certificated flight instructor received minor injuries while the student and the only passenger were seriously injured. The airplane was destroyed. Visual meteorological conditions prevailed and a flight plan was not filed. The instructional flight was conducted under 14 CFR 91. The flight originated in Lancaster, Pennsylvania, and the intended destination was Manassas, Virginia. According to the instructor who was in the right seat, the student was receiving instrument training towards attaining his instrument rating. He stated that the flight had departed Manassas, Virginia, earlier that morning to drop off the passenger who was picking up his airplane in Pennsylvania. However, the airplane was not ready so they departed Lancaster en route to Virginia. The instructor stated that en route to their destination at 2000 feet MSL, the engine lost power. He stated that, "...it was a sudden loss of power as if someone had turned the magnetos off." He stated that he took over the controls and he told his student to switch the fuel selector from the right tip tank to the left main tank. He stated that he tried to restart the engine using the emergency procedures and switching fuel tanks, but all were unsuccessful. The instructor stated that he looked for a suitable place to land, but there was none. He stated that he elected to land in the trees. During the forced landing, the airplane struck trees separating the right tip tank and left wing. The instructor stated that the airplane is normally tied down outside, and that the airplane was topped off with 14.5 gallons of fuel six days before the accident. He stated that he had completed his preflight inspection which included draining the fuel sump (gascolator), "...however, I do not recall draining the individual fuel drains on the mains. These drains sometimes drip after checking...so I drain them every other time I fly." There were several witnesses who saw and heard the airplane as it came over the trees. One of the witnesses reported hearing the engine sputtering before it struck a tree. The accident occurred during the hours of daylight, at 39 degrees 10 minutes North and 77 degrees and 10 minutes West. PERSONNEL INFORMATION The pilot held a commercial pilot certificate with single and multiengine land ratings. The pilot reported over 2268 hours of total flight time including 1268 hours in type. AIRCRAFT INFORMATION The 1952 year model Beech C35 airplane, serial no. D-3323 was equipped with a Continental E225-8 engine, serial no. 36321-D-9- 8R. According to the engine log book, the airplane had accumulated over 3155 hours of total time including 48 hours since the last 100 hour inspection. This inspection was completed on July 29, 1993. METEOROLOGICAL INFORMATION The 0850 hours surface weather observation for Dulles Airport, about 15 miles south of the accident site was as follows: Sky condition, 25,000 feet thin scattered; visibility, 12 miles; temperature, 41 degrees (F); dew point, 33 degrees (F); wind condition, 190 degrees at 9 knots; and altimeter, 30.50 inches. WRECKAGE AND IMPACT INFORMATION The airplane struck trees on a magnetic heading of 040 degrees and came to rest on the propeller spinner 50 feet from the initial impact point. Examination of the accident site revealed that during the impact sequence with the trees the left wing, and the right wing tip tank separated. The wreckage came to rest oriented on a magnetic heading of 270 degrees. The main wreckage was oriented on a magnetic heading of 270 degrees and the tail section was braced against some trees. The fuselage and empennage area remained intact while the left wing with its respective landing gear, and the right wing tip tank were located in the rear section of the house. A 7 foot section of the right wing with the aileron was located about 10 feet from the main wreckage. The left wing separated from the aircraft at the root. The left wing tip tank remained attached to the wing. About 4 gallons of fuel was found in the left main tank. The right wing with the flap remained attached to the fuselage while the outboard section of the wing and aileron separated. The right fuel tank was ruptured and the fuel was leaking out onto the ground. The right main tip tank separated and was destroyed. The right side ruddervator separated and was found hanging from the tail section. The left side ruddervator remained attached to the empennage. The elevator trim tab when measured corresponded to a trim setting of zero trim according to Beech Aircraft engineering data. The landing gear actuator corresponded to the retracted position. The flap actuator measured 2 3/8 inches which corresponded to the flap up position. The fuel selector for the main fuel selector was in the right main position and the tip tank was in between the both and left tip tank position. The engine was removed from the accident site and transported to Alphin Aviation, Hagerstown, Maryland for further examination on February 22, 1994. The top spark plugs were removed and were grayish in color. Compression was obtained in all six cylinders. The liquid contents from the main fuel selector and the finger screen from the carburetor were removed and tested with a water paste. The paste changed color from green to pink revealing the presence of water. The examination did not reveal any pre- existing defects that would have precluded operation. The engine was removed and transported to Continental Engines in Mobile, Alabama, where it was test run. TESTS AND RESEARCH The engine was examined and placed on a test stand under the supervision of the NTSB on May 17, 1994. In order to test run the engine, a wooden test propeller was installed and secured to the crankshaft. The engine was pre-oiled and the start up was immediate. The engine ran, and after warm up the engine power was increased to 1700 rpm for a magneto check. The magneto drop of the individual magnetos was within specifications. The engine attained a maximum of 1800 rpm at 28 inches of manifold pressure. This examination revealed no pre-existing deficiencies that would preclude operation. ADDITIONAL INFORMATION The wreckage was released to the owner, William Canda on July 15, 1994.