NTSB Factual Report

HISTORY OF FLIGHT

On May 11, 1997, at 2108 hours Pacific daylight time, a Beech A-36TC, N6174N, en route to San Jose, California, collided with terrain immediately after takeoff from Truckee, California. The aircraft was destroyed by impact and subsequent fire, and the pilot and four passengers received fatal injuries. The aircraft was being operated as a personal flight by the pilot/owner when the accident occurred. Visual meteorological conditions prevailed and no flight plan was filed.

Four witnesses stated that they observed the aircraft taxi to the takeoff end of runway 28 and delay for what they thought was sufficient time to accomplish an engine and flight controls checkout. On takeoff, the witnesses observed the aircraft liftoff at the midfield point on the 7,000-foot runway and begin a shallow climb. Near the departure end of the runway, at an estimated altitude of 100 to 150 feet agl, the witnesses observed the aircraft enter a turn to the left and begin to lose altitude. The aircraft was observed to continually lose altitude throughout the turn until it impacted the ground. Evidence at the crash site indicated that the aircraft had turned through a total of 220 degrees from the runway heading impacting the ground on a magnetic heading of 060 degrees.

A witness, located in a building approximately 300 feet from the crash site, reported hearing a loud "pop" similar to a rifle report which was followed immediately by the sound of the engine "revving up". These sounds were followed 3 to 4 seconds later by the sound of the aircraft impact with the ground.

PILOT INFORMATION

The pilot's logbook and other credentials were destroyed by fire. FAA records indicated that he was the holder of a private pilot certificate with airplane ratings for single engine land and instrument. He also held a current third-class medical certificate with a restriction to wear corrective lenses while piloting an aircraft. At the time of his last flight physical examination on April 2, 1997, he reported a total flight time of 4,000 hours with 72 hours in the last 6 months. During an interview with the family, his relatives stated that he had about 1,000 hours in the Beech A-36 model aircraft.

The pilot's wife, who occupied the right front seat, also held a private pilot certificate with an airplane single engine land rating, and had reported a total flight time of 1930 hours with 28 in the last 6 months at her last flight physical examination on April 2, 1997.

AIRPLANE INFORMATION

Relatives of the pilot reported that the aircraft maintenance records were carried onboard the airplane. Review of records from the FAA Aircraft Registry and manufacturing documents from Beech Aircraft revealed that the aircraft was a 1981 model and powered by a normally aspirated 285 horsepower reciprocating engine. Records available at the engine overhaul facility where the engine was last overhauled indicated an engine total time of 2,169 hours with 109 hours since last overhaul.

WRECKAGE AND IMPACT INFORMATION

The aircraft was found approximately 1,000 feet left of the runway 28 centerline and 100 feet short of the runway's departure end. The median wreckage distribution and ground scars from the initial point of impact were oriented on a magnetic bearing of 060 degrees. Initial wreckage debris in the field included left wing and engine compartment components. A detailed wreckage distribution diagram is attached.

The engine and main cabin had come to rest on a magnetic heading of approximately 340 degrees in an inverted attitude. The tail section was in an upright attitude and was located 20 feet behind the main fuselage. The right wing was found 10 feet to the right of the fuselage lying on its bottom side, while the left wing was approximately 100 feet to the left of the fuselage lying on its top side.

Two of the three propeller blades were still attached to the hub, with the third blade located approximately 225 feet to the right of the fuselage. All three blades exhibited torsional twisting, aft bending, and chordwise striations. Examination of the engine and propeller controls revealed that the throttle was full open, the prop was in low pitch (high RPM), and the mixture was mid-range between full rich and idle cutoff. It was not possible to determine flight control system or engine controls continuity due to the extreme damage incurred during impact and the subsequent fire.

The landing gear and wing flap actuators were both in the retracted position. The retaining pins for both front cabin doors were extended and had impact damage. The forward utility door had separated from the airframe and its locking handle was found in the locked position. The rear half of the utility door was consumed by fire and could not be inspected

METEOROLOGICAL INFORMATION

At the time of departure from Truckee, the weather was reported by the airport AWOS to be clear with ceiling and visibility unlimited. The free air temperature and dew point were 68 and 20 degrees Fahrenheit, respectively. The wind was from 275 degrees magnetic at 5 knots and the altimeter setting was 30.24 inHg. With a field pressure altitude of 5,800 feet and a free air temperature of 68 degrees, the density altitude was calculated to be 7,800 feet. Although the sun had set behind the local mountains at the time of takeoff, photographs taken immediately after the crash indicate a clear and easily discernible visual horizon when looking to the west in the direction of takeoff. However, when looking east, the visual horizon was not so evident and other ground references, such as lights were minimal.

TESTS AND RESEARCH:

On May 12, 1997, a fuel sample was obtained from the Truckee airport refueling facility and analyzed by the United Testing Group of Sparks, Nevada. Their report stated that the fuel sample analyzed was the proper grade of aviation fuel and that it contained less than 0.05 percent water by volume and no particulate matter

An engine teardown inspection was performed on May 22, 1997, with the assistance of a Continental Engine technical representative. The representative stated in his report that "nothing was noted that would have precluded the engine from developing power prior to impact."

Because one propeller blade was located a considerable distance from the rest of the prop assembly, the McCauley propeller and hub were shipped to the Safety Board's laboratory in Washington, D.C. for teardown inspection and lab analysis. The lab results indicated that there was no evidence of fatigue failure in the prop elements, and that all three blades appeared to have been in the hub and positioned at the same angle of attack at the time of impact. A McCauley technical representative assisted in the teardown inspection.

MEDICAL AND PATHOLOGICAL INFORMATION

On May 16, 1997, the Institute of Forensic Sciences in Oakland, California, performed an autopsy on the pilot and all four passengers. The toxicological analysis stated that all occupants had approximately 0.04 percent ethanol in their heart blood and less than 2.0 percent saturation of carbon monoxide.

ADDITIONAL INFORMATION

After completion of the engine and propeller teardown inspections, the remains of the airframe and engine were released on June 27, 1997, to Mr. A. D. Llorente who was a certified representative of Ewert's Photo-Scientific, Inc., the registered owner of the aircraft. The aircraft remains were located at the Plain Parts, Pleasant Grove, California, at the time of release.

NTSB Probable Cause

failure of the pilot to maintain altitude and clearance above the terrain, while turning (for an unknown reason) back toward the airport after takeoff. Factors relating to the accident were: the environmental conditions (light conditions at dusk and high density altitude) and lack of visual cues, while turning toward darker conditions; and spatial disorientation of the pilot.