HISTORY OF FLIGHT On August 4, 1997, at 1515 central daylight time (cdt), a Beech 76, N18960, was destroyed when it impacted terrain in a residential area in New Richmond, Wisconsin. Witnesses reported the airplane was turning left base to the New Richmond Airport. The aircraft was observed to roll to the right, descend and impact the terrain. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91, local, multiengine commercial instructional flight originated from Downtown Holman Field in St. Paul, Minnesota, sometime after 1400 cdt. There was no flight plan on file. The commercial rated flight instructor and single engine commercial rated student pilot were fatally injured. WITNESSES Numerous witnesses stated the aircraft was approximately 200 feet above the ground, heading in a southerly direction when they took notice of the aircraft. Many witnesses reported the aircraft was in a left downwind for runway 32. The witnesses stated the aircraft was in a left turn as it went below the tree line. Other witnesses who saw the aircraft hit the ground, reported that the aircraft was attempting to make a left turn onto the street, but hit with the right wing low. Several of the witnesses stated that the aircraft sounded as if it was developing full power. A couple of the witnesses reported hearing a "missing" sound as the airplane was descending. One witness who was at a park two blocks north of the crash site stated the aircraft appeared to be in level flight, at a constant speed, and heading south/southeast. He stated that the engines sounded like they were at full power and much louder than "normal." The witness stated that there was noise coming from the engines, but that the noise was not a "missing" sound. The witness stated the sound was "...like he was trying to match the engines... ." The witness said the wings rocked right and left and then the aircraft began a left turn below the tree line. A second witness who was delivering mail at the time of the accident said that she had just come around the corner when she heard an airplane engine that "...sounded very close." The witness said she looked up and could not locate the airplane until "...it seemed to come out of the treetops directly over me." She said she saw it "...tilt to the side as if it was going down..." whereupon she ran up the street and "...immediately heard and felt it crash." A third witness, who is a private pilot, stated he saw the airplane at 150 to 200 feet, "...running with both engines running at full power and gear and flaps up." The witness said the airplane was "...definitely behind the power curve... nose up, mushing along." Another pilot witness said: The aircraft he observed was a T tail twin engine aircraft and his mental thought was "someone is practicing single engines." He also stated the propellers were out of sync and he head power added to one of the engines. PERSONNEL INFORMATION The right seat pilot, the CFI instructor, was born on April 24,1974, and possessed a commercial pilot certificate with an instrument airplane, single engine land and multiengine land ratings, issued on July 3, 1996. His certified flight instructor certificate with an airplane single and multiengine/CFI was issued on February 24, 1997. According to the PIC's last medical taken on January 15, 1997, he had 400 hours total flight time. Records obtained from his place of employment indicated he flew approximately 125 hours in the preceding month and a half. The multiengine commercial student in the left seat of the aircraft was born on September 30, 1970, and possessed a commercial pilot certificate with an instrument airplane, single engine land rating. According to his reported total time at the time of his last medical taken four days prior to the accident on August 1, 1997, he had 250 hours total time. AIRCRAFT INFORMATION The airplane was a Beechcraft BE-76 Duchess, manufactured in 1978, serial number ME-10, registered to an individual and issued on June 22, 1989. The airworthiness certificate was issued on May 30, 1978. The airplane was being used by Wing, Inc. at Downtown Holman Field, St. Paul, Minnesota. According to the aircraft logbook, the last recorded inspection of the airplane in accordance with 14 CFR Part 43, Appendix D, was performed on June 24,1997. At the 100 hour inspection, the left engine times were as follows: the left engine tachometer was 5,565.74 hours, the engine total time was 4,911.72 hours and the total time since major overhaul was 1,589.36 hours. At the 100 hour inspection, the right engine times were as follows: the right engine tachometer was 5,586.36 hours, the engine total time was 4,905.48 hours, and the total time since major overhaul was 1,554.48 hours. Replacement of the Hobbs meter on the airplane on July 19, 1997, showed the airplane had 5645.74 hours total time. According to the Wings, Inc. dispatch release form for the previous flight, the aircraft had a tachometer reading of 5,658.74 hours (right engine tachometer). The aircraft had flown approximately 72 hours since the last 100 hour inspection. Both propellers had 1577.36 hours total time at the last recorded inspection. The total time since major overhaul on the left engine was approximately 1,661 hours and approximately 1,626 hours on the right engine at the time of the accident. St. Paul Flight Center fueled N18960 at approximately 1330 cdt with 26.4 gallons of 100LL fuel. N18960 burned 13.5 gallons of fuel per hour per engine. WRECKAGE AND IMPACT INFORMATION The airplane wreckage was located between the curb and a house at the corner of East Green Avenue and South 2nd Street in New Richmond, Wisconsin. All major aircraft components were accounted for in the wreckage. The right outboard wing had separated from the fuselage and was in front of the aircraft. The right engine was separated and inverted just in front of the left wing tip. The empennage had broken free and was resting right behind the fuselage. The cabin door and left and right propellers were all separated from the aircraft. The main wreckage was oriented on a 340 degree magnetic heading. The post-impact fire consumed much of the fuselage and empennage. Most of the other aircraft parts had fire damage. All of the gear were in the UP position. Flaps were in the UP position. All of the aircraft instruments were destroyed by the post-impact fire. The right fuel selector was set from right tank to right engine. The left fuel selector was destroyed. Flight control continuity was confirmed. The initial ground contact was with a tree across the street from where the aircraft ended up. A telephone pole alongside the road had an impact mark 7 feet 4 inches from the base. There was 21 feet 6 inches to the initial ground scar. Twenty three feet five inches from the initial ground scar was the first prop marks from the right engine. Twenty eight feet eight inches from the beginning of the right prop marks were the left prop marks. Twenty three feet nine inches from the left prop marks was a tree with slashes and missing bark. Twenty nine feet from this tree was the center of the wreckage. From the first tree contact to the center of the wreckage was a 222 degree magnetic heading. A wreckage diagram is attached to this file. MEDICAL An autopsy performed by the Ramsey County, Minnesota, coroner's office revealed no pre-existing medical conditions. Toxicology tests found no evidence of drugs or alcohol. TESTS AND RESEARCH The on-scene engine investigation revealed no preimpact anomalies. The left engine tear down revealed the following information: The dual magneto on the left engine was internally destroyed by the fire and would not rotate. All spark plugs were found secure in the cylinders with the ignition wires attached. The spark plugs displayed gray combustion coloration and were dry. The vacuum pump was destroyed by fire. The vacuum pump drive coupling was found melted into the accessory housing. All oil system components were destroyed by fire. The propeller governor was attached and was observed in the full forward/high RPM position. The carburetor heat valve was observed open. The throttle valve was noted about 3/4 open. The mixture control position was found about 3/4 rich. The #1 and #2 cylinders were removed at which point the crankshaft would rotate completely. Thumb compression was confirmed to the #3 and #4 cylinders. The left propeller blades displayed torsional bending of the blade tips, chordwise scratching and leading edge gouges. The street pavement revealed four propeller strike marks from the left propeller. These marks measured about 16 inches apart. The right engine tear down revealed the following information: The dual magneto was found attached and secure. The impulse coupling would rotate by hand. The spark plugs remained attached and were secure with all ignition wires intact. All spark plugs displayed gray combustion coloration. The vacuum pump was destroyed by fire, but remained attached to the accessory mount pad. All oil system components were fired damaged. The engine had separated from the right nacelle and came to rest inverted. The crankshaft rotated by hand. Thumb compression was confirmed on all cylinders. Engine continuity was noted. The right propeller blades displayed torsional bending of the blade tips, chordwise scratching and leading edge gouges. The street pavement revealed four propeller strike marks from the right propeller. These marks measured about 18 inches apart. Based on the measurements of the prop strikes on the road and plugged into the prop slash marks formula to determine ground speed, the left engine indicates a ground speed of 119 knots. The right engine prop marks indicate a ground speed of 135 knots.