NTSB Factual Report

HISTORY OF FLIGHT

On January 11, 1996, at 1518 mountain standard time, a Beech 35, N3052V, was destroyed when it impacted terrain while maneuvering 8 miles southwest of Allenspark, Colorado. The private pilot and a passenger were fatally injured. Visual meteorological conditions prevailed. No flight plan was filed for the business flight being conducted under Title 49 CFR Part 91. The flight originated at Longmont, Colorado, on January 11, 1996, at 1502.

There was no record of the pilot obtaining a weather briefing or filing a flight plan. When the airplane failed to arrive at Page, Arizona, family members became concerned and notified the Federal Aviation Administration. An Alert Notice (ALNOT) was issued on January 12, 1996, at 2358. According to the ALNOT, the route of flight was to have been from Longmont to Pueblo, Colorado, direct to Farmington, New Mexico, then direct to Page, Arizona, a distance of approximately 605 nm. An air and ground search was initiated, but was later suspended with negative results. On February 14, 1996, members of the Rocky Mountain Search and Rescue ski patrol sighted wreckage of an airplane approximately 23 nm west of Longmont, or about 6 nm south-southwest of Allenspark, Colorado. On February 18, 1996, rescuers were able to reach the scene, confirmed it was the wreckage of N3052V, and removed the bodies of the two occupants. On the same date, the investigative team also attempted to reach the accident site but was turned back by adverse weather, rough terrain, and avalanche hazards. The on-scene investigation finally commenced and terminated on June 25, 1996.

PERSONNEL INFORMATION

The pilot's flight logbook was never located. According to FAA, the pilot was issued a private pilot certificate, with an airplane single-engine land rating, on September 12, 1977. This was the last recorded certificate action. When the pilot made application for his most recent medical certificate on May 24, 1995, he indicated he had logged a total of 800 flight hours, 80 hours of which were accrued in the previous six months.

AIRCRAFT INFORMATION

The airplane maintenance records were never located. According to the Beech Aircraft Corporation, the airplane was manufactured in 1947 and was equipped with a Continental E-185-8 engine and a variable pitch propeller. It was equipped with standard fuel tanks with a total capacity of 40 gallons (34 gallons usable). According to the Federal Aviation Administration, a 10 gallon auxiliary fuselage fuel tank was installed in the airplane as allowed by an STC (Supplemental Type Certificate).

Longmont Airport records indicate the airplane was serviced to capacity prior to its departure (see TESTS AND RESEARCH).

METEOROLOGICAL INFORMATION

There were no SIGMETs (significant meteorology) or PIREPs (pilot reports) in effect for the route of flight flown by N3052V. Two AIRMETs (airman meteorology), however, were in effect: AIRMET Sierra forecast mountains to be occasionally obscured in clouds and precipitation. AIRMET Tango 1 forecast moderate updrafts and downdrafts over the mountains due to developing mountain wave activity, with occasional moderate turbulence below 20,000 feet, and isolated severe turbulence below 15,000 feet. There was also the potential for low level wind shear over the eastern slopes of the Rockies due to strong gusty west-northwesterly low level flow near the surface. Also forecast was occasional moderate turbulence between 28,000 and 40,000 feet due to jet stream wind shear, with conditions moving eastward.

On the day of the accident, a Rocky Mountain Search and Rescue team was searching for a lost skier 10 miles south of the accident site. He told investigators that surface winds in the area were approximately 60 mph with "a lot of debris blowing along the ground."

WRECKAGE AND IMPACT INFORMATION

Using a Global Positioning System receiver (GPS), the wreckage was fixed at a location of 40 degrees, 07 minutes, 33.5 seconds north latitude, and 105 degrees, 35 minutes, 22.3 seconds west longitude, less than one-half mile from the last radar position of the VFR target. Mountains in the area reach 12,300 feet.

The main body of wreckage -- consisting of the engine, propeller, cockpit and cabin area -- was located on the side of a mountain at the 10,300-foot level. The slope was approximately 35 degrees. The cockpit and cabin had been gutted by fire. The fire had melted part of the engine and propeller, and globules of molten metal had run downhill for about 24 inches. Extending from the right side of the wreckage was a faint ground scar. At the end of this scar were green lens fragments. This was the only discernible ground interruption noted. Equidistant on the opposite side of the wreckage were pieces of red lens. The right wing had been destroyed by fire and the spar was next to the wreckage.

The left wing was located approximately 200 feet down the mountain. According to rescuers who accompanied the investigative team to the accident site, the wreckage had been disturbed and they surmised it had been displaced by wind and melting snow. Nearby were the inboard portions of both wings, including the filler caps and shredded portions of the fuel bladders. The empennage lay close by. On some portions of the empennage, the paint was blistered; on other portions, the paint was obliterated. Whereas all major structural components were located and identified within an area of about 5,000 square, control continuity could not be established due to the degree of airframe destruction. No baggage was found at the accident site. Rescuers said they had previously removed several pieces of personal items that were returned to the various estates.

MEDICAL AND PATHOLOGICAL INFORMATION

Autopsies were performed on the pilot (96A-14) and passenger (96A-15) by pathologists with the Boulder County Coroner's Office. Toxicological screening was performed by FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma. No evidence of alcohol or drugs were found. Carbon monoxide and cyanide tests could not be performed due to the unsuitability of specimens.

TESTS AND RESEARCH

The wreckage was located by utilizing CDR List 3 radar data from the Denver Air Route Traffic Control Center (ARTCC). The data was electronically transmitted to a California Civil Air Patrol member's computer equipped with a Radar Viewpoint program.

According to this data, a VFR target with a transponder code of 1200 was detected at the Platteville, Colorado, antenna site. The target departed Longmont Airport's runway 11 at 1502, made a left turn, and took up a westerly heading. At 1513, the target made a complete left turn, climbing from 10,700 feet to 10,900 feet, then continued westward, climbing to 11,200 feet, which was the last recorded altitude. Radar contact was lost at 1518. At that time, the target was at a position of 40 degrees, 07 minutes, 47 seconds north latitude, and 105 degrees, 35 minutes, 21 seconds west longitude.

Using the nearest official weather observation recorded at Jeffco Airport, Broomfield, Colorado, at 1552 (or 34 minutes after the accident), the pressure altitude at the accident site was estimated to be 10,020 feet MSL (30.20 - 29.92 = 0.28, or 10,300 - 280). Using the standard adiabatic lapse rate of 2 degrees Celsius per 1,000 feet, the temperature at the accident site was estimated to be -3.6 degrees C. (10,300 - 5,671 = 4,629; 4.6 x 2 = 9.2; 5.6 - 9.2). Density altitude at the accident site was computed to be approximately 10,168 feet msl. According to the Beech Climb Performance Chart, if the airplane was at maximum gross weight under these conditions, its rate of climb would be approximately 500 feet per minute and the climb gradient would be 5.0%. In addition, the airplane has a service ceiling of 18,000 feet and a stall speed (clean configuration) of 53 knots.

Longmont Airport records indicate the airplane was serviced to capacity prior to its departure (50 gallons). Radar data indicates the airplane had been aloft for 16 minutes. According to the Beech Aircraft Corporation, fuel consumption was approximately 10 gallons per hour. In the time it would take to start the engine, taxi, takeoff, and proceed to a point 23 nm west of the airport while at the same time climbing to 11,500 feet, the engine would have consumed approximately 3 gallons of fuel. Estimated fuel on board at the time of the accident was 47 gallons.

ADDITIONAL INFORMATION

The wreckage was released to the owner's representative on June 25, 1996.

NTSB Probable Cause

Aircraft control not maintained by the pilot in command for reasons undetermined.