NTSB Factual Report

HISTORY OF FLIGHT

On August 4, 1998, between 0600 and 0700 mountain daylight time, a Mooney M20J, N5698L was destroyed when it impacted terrain at 10,400 feet above sea level, during cruise flight approximately 15 miles northwest of Centennial, Wyoming. The private certificated, non-instrument rated, pilot received fatal injuries. The flight was a cross-country operating under Title 14 CFR Part 91 and no flight plan was filed. Instrument meteorological conditions prevailed in the accident area. The flight originated from Longmont, Colorado, with a destination of Buchanan Field, Oakland, California. The aircraft was found on August 7, 1998, by the Civil Air Patrol following a 3-day search.

At 0451 on August 4, 1998, the pilot contacted Denver Flight Service via telephone and received a weather brief for a flight from Longmont (2V2) to Oakland (CCR) via Salt Lake City, Utah (SLC), Battle Mountain, Nevada, (BAM), and Reno, Nevada, (RNO). The pilot did not file a flight plan. The weather brief provided information that visual flight through the Rocky Mountain States was not recommended due to mountainous terrain being obscured by clouds.

At 0614, the pilot of N5698L contacted flight watch by radio and received a weather update. Again, visual flight for westbound flights was not recommended due to weather. When the flight did not arrive at its destination, concerned family members contacted flight service and an Alert Notice (ALNOT) for an overdue aircraft was issued through flight service.

Radar track information developed by Denver Air Route Traffic Control Center (ARTCC), provided a flight path which began on the north side of Fort Collins, Colorado, and extended north midway between Laramie and Cheyenne, Wyoming. The track then showed a westward path north of Laramie to a point northwest of Centennial (See attached charts and maps.)

Because of the radar track, on August 6, 1998, at about 0905, the Carbon County Wyoming, Sheriff's Department, was notified that an aircraft might be down in an area northwest of Centennial, Wyoming. Since a county boundary ran through the area in question, the Albany County Sheriff was also notified. Both counties activated their search and rescue plan. The Civil Air Patrol and an Army reserve helicopter were coordinated into the search effort and on August 7, 1999, at 1205, a Civil Air Patrol aircraft spotted a burned area and ground investigation provided evidence that it was the missing aircraft.

PERSONNEL INFORMATION

According to Federal Aviation Administration (FAA) Airmen Records, the pilot was born on July 19, 1935. He held a private pilot certificate with a rating in airplane single engine land issued July 8, 1997. He did not possess an instrument rating and his medical application provided information that he had 230 hours of flight experience as of June 5, 1997. No pilot log was found during the course of the investigation.

The pilot held a third class medical certificate issued June 5, 1997, with the limitation that he wear glasses for distant vision and possess glasses for near vision. Two birth dates appeared on different FAA medical records. One was July 19, 1935, and the other was November 24, 1929. His California issued drivers license provided a birth date of July 19, 1940. A relative provided verbal information that his correct birth date was the 1935 date.

AIRCRAFT INFORMATION

The aircraft, a Mooney M20J, was built in 1983. It had accumulated 1,526 hours of time and the last inspection was an annual completed on August 1, 1997. Time accumulated between the inspection and the accident is unknown.

The M20J is a low wing semimonocoque constructed airplane that incorporates electrically operated, tricycle type, retractable landing gear. It is powered by a Lycoming IO-360-A36D reciprocating engine, which normally drives a two-bladed, constant speed, McCauley B2D34C214HB-16E propeller. This aircraft had been modified in accordance with a supplemental type certificate (STC), and a Hartzell three-bladed constant speed propeller (HC-C3YR-1RF/F7282) was installed. In this application, the rated horsepower at 2,700 revolutions per minutes at sea level is 200.

The aircraft had a maximum certified gross weight of 2,740 pounds and a total fuel capacity of 66.5 gallons of which 64 gallons is usable. The published service ceiling at the maximum certified gross weight was 18,700 feet, and the average endurance was between 6 and 7 hours.

METEOROLOGICAL INFORMATION

Witnesses camping in the area said they heard an aircraft but could not see it due to low clouds and rain. They said the mountaintops were obscured and there were thunderstorms in the area at the time they heard the aircraft. The witnesses characterized the engine sounds as normal. Laramie, Wyoming, was the nearest weather reporting facility to the accident site. The city was located approximately 30 miles east of the accident site. At 0651, Laramie was reporting light rain and hail with scattered clouds at 800 feet, broken clouds and 3,000 feet, and overcast skies at 4,000 feet. Laramie was 7,276 feet above sea level.

WRECKAGE AND IMPACT INFORMATION

Witness marks provided evidence that the aircraft impacted the side of mountain, wings level, at 10,450 feet above mean sea level (msl). The wreckage scatter was up slope on a track of 278 degrees magnetic heading and the slope was measured at 36 degrees. Terrain at the accident site consisted of small (less than 10 feet high) pine trees, rock covered ground and downed old timber. According to the Forest Service ranger who managed the area, the accident site was in an old timber cutting area and was under a regrowth program.

The wreckage and trees throughout the wreckage scatter were scorched but long term fire evidence was not present.

The aircraft disintegrated upon impact and the scatter pattern extended 72 feet up slope from the initial impact point, which contained one propeller blade. All portions of the aircraft were identified in the wreckage scatter.

The remaining two blades and propeller hub were located approximately midway through the wreckage scatter. Both of these blades exhibited low pitch twisting and chordwise scarring. The spinner was peeled back around the hub and exhibited a corkscrew pattern opposite the direction of rotation. The separated blade broke free of the hub approximately 2 inches outboard of the blade cuff and the outer 3 inches of the blade tip was missing. The fracture point exhibited a jagged surface and the blade was imbedded in an 8-inch diameter pine deadfall.

The propeller hub separated from the engine at the mounting flange and was crushed rearward. Damage prevented recording blade angle at impact.

Approximately 3 feet of the inboard left wing remained intact. This portion of the wing contained the inner section of the left flap, which was faired with the trailing edge of the wing. The landing gear in the left wing was in the up position.

The fuselage, right wing and empennage were destroyed. Due to damage, flight control integrity could not be established.

The cockpit area was destroyed by impact and fire and no instrument panel remained. The artificial horizon was found in the scatter pattern. The face was broken free of the case and no useful reading could be obtained. No other instruments were recovered in a condition to provide useful information.

The emergency locator transmitter (ELT) was found in the wreckage. The antenna separated from the unit and the switch was in the off position. The ELT was a Dorne and Margolin type 8.1. The replacement date for the alkaline battery was September 1999.

Part of the engine case containing three cylinders, a portion of one piston and the camshaft were still connected together. The crankshaft was in three pieces scattered throughout the wreckage and all the valves were accounted for in the wreckage scatter. One valve was found stem up on a grass tuft and the grass under the valve face was scorched. Both magnetos were destroyed and could not be tested, as was the vacuum pump, fuel pump, and induction system.

MEDICAL AND PATHOLOGICAL INFORMATION

According to the Wyoming Medical Examiner, no autopsy or toxicological examination was performed due to unavailability of samples.

ADDITIONAL DATA/ INFORMATION

Other than the Federal Aviation Administration, (FAA), there were no parties to the investigation.

The wreckage was released to Beegles Aircraft Services, Greeley, Colorado, on August 8, 1998. No parts were retained.

NTSB Probable Cause

The pilot's disregard of information provided in weather briefs, and his flight into known adverse weather in mountainous terrain which resulted in an in-flight collision with a mountain. Factors were rain and low ceiling/visibility.