NTSB Factual Report

HISTORY OF FLIGHT

On June 29, 2002, about 2124 mountain standard time, a Beech C35, N5856C, experienced an uncontrolled descent and in-flight breakup following a departure from cruise flight. The accident occurred about 20 nautical miles (nm) south-southeast (153 degrees, magnetic) of Chambers, Arizona. The airplane impacted desert terrain and was destroyed. The commercial pilot, the sole occupant, was fatally injured. Visual meteorological conditions prevailed in the vicinity, and no flight plan had been filed. The nighttime personal flight was performed under the provisions of 14 CFR Part 91. The flight originated from near Albuquerque, New Mexico, approximately 1 hour earlier, at an estimated time of 2022.

According to the Federal Aviation Administration's (FAA) quality assurance staff at the Albuquerque Air Route Traffic Control Center (ARTCC), the pilot had requested, and was receiving, visual flight rules (VFR) radar flight following service for his flight to Buckeye, Arizona. The airplane was initially radar identified about 9 nm southwest of the Double Eagle II (uncontrolled) Airport, near Albuquerque. At the time, the airplane was climbing through 8,400 feet. The pilot informed the radar controller that he intended to climb to 10,500 feet. The radar track indicated that the airplane proceeded in a westerly direction while climbing between 10,900 and 11,000 feet, as indicated by the airplane's altitude reporting (Mode C) transponder. At no time during the flight did the pilot indicate he was experiencing any difficulties or request assistance.

The last communication with the accident airplane occurred at 2031. At this time, the Albuquerque ARTCC controller issued the pilot the Albuquerque altimeter setting, which was 30.04 inches of mercury (inHg). The pilot acknowledged the information.

The airplane's average ground speed from 2045:12 to 2121:12 was about 134 knots. During the last 19 seconds of radar recorded flight (between 2123:08 and 2123:27), the airplane's average ground track changed from a west-southwesterly (241 degrees) to a southerly direction (170 degrees), while its altitude increased from 10,900 to 11,000 feet. There were no further altitude readouts from the airplane's transponder on any of the following four final radar hits, which were at 2123:36, 2123:46, 2123:56, and 2124:05.

The main wreckage was found about 0.4 nm south of the airplane's last known position (LKP). No witnesses reported having observed the airplane's descent and/or ground impact.

PERSONNEL INFORMATION

The pilot held a commercial pilot certificate with an airplane single engine land rating. He was not instrument rated. The pilot also held an airframe and powerplant mechanic certificate. The pilot's total flight time and flying experience in the accident model of airplane was about 12,581 and 192 hours, respectively.

When the pilot was not performing agricultural pilot operations for an Arizona-based company, he was employed as a contract pilot and flew for the United States Forest Service (USFS) and the Bureau of Indian Affairs (BIA).

USFS personnel reported to the National Transportation Safety Board investigator that on the accident day the pilot had reported for work about 0750, and he performed his first flight about 1100. By the end of the day, the pilot had flown on five contract flights dispersing fire retardant chemicals on wildfires for a total of 7.4 flight hours.

At the end of the workday, the pilot informed a BIA associate that he intended to spend the night in a local New Mexico hotel rather than flying home to Arizona. He planned to fly home the following morning.

The BIA associate reported to the Safety Board investigator that the pilot had experienced difficulty completing the required end of day paperwork. The pilot was observed making arithmetic errors regarding calculating his flight and duty times for the day's work. The associate subsequently reported to the Safety Board investigator that he thought the pilot was tired and was "mentally exhausted."

Upon completing his last firefighting contract flight the pilot was overheard stating to another associate "we had a tough one today." He then laid his head down on the airplane's wing and said something like "dang I'm tired." Thereafter, the pilot departed on the accident flight.

AIRPLANE INFORMATION

The airplane's maximum never exceed speed was 177 knots indicated airspeed (KIAS). Its maneuvering speed was 114 KIAS.

The airplane was maintained on an annual inspection basis. It was not equipped with an autopilot.

METEOROLOGICAL INFORMATION

National Oceanic and Atmospheric Administration radar summary and weather depiction charts, along with surface observation data for the accident site vicinity indicated that the sky was generally clear. High pressure prevailed in the region and there were no reported radar echoes.

Five aviation weather reporting facilities were located between 22 and 72 nm, circumferentially around the accident site. A review of the reported surface weather at these facilities from approximately 30 minutes before to 30 minutes after the time of the accident revealed a clear sky condition, with surface wind at or less than 10 knots. The barometric pressure varied from 30.08 to 30.24 inches of mercury.

The closest aviation weather reporting facility to the accident site was St. Johns, Arizona (SJU). At 2054, SJU reported the following weather: Wind from 260 degrees at 9 knots; visibility 7 miles; sky clear; temperature/dew point 26/00 degrees Celsius, respectively; and altimeter 30.13 inches of mercury.

AIDS TO NAVIGATION

The FAA reported that all electronic aids to navigation pertinent to, and in the vicinity of, the accident site were operating normally.

COMMUNICATION

Albuquerque ARTCC's quality assurance staff reported that all services for the airplane had been normal.

WRECKAGE AND IMPACT INFORMATION

The accident site is located at the following global positioning satellite (GPS) coordinates: 34 degrees 52.4 minutes north latitude by 109 degrees 19.7 minutes west longitude. Wreckage fragments and structural components from the airplane's wings, tail, and all the flight control surfaces were located in the accident site area. The main wreckage was found on flat, desert terrain, at an approximate elevation of 6,200 feet mean sea level (msl).

Components from the fragmented right wing and fragmented right ruddervator/stabilizer were located near the northern end of an approximate 1,650-foot-long wreckage distribution path. The main wreckage, consisting of the fuselage and its attached left wing, and the engine, were located near the southern portion of the distribution path. The principal axis of the wreckage distribution path was about 195 degrees, magnetic. The specific locations where 19 components were found were documented using a GPS receiver. (See the wreckage distribution diagram for their locations.) There was no evidence of fire.

MEDICAL AND PATHOLOGICAL INFORMATION

On July 2, 2002, the Pima County Office of the Medical Examiner, Forensic Science Center, 2825 East District, Tucson, Arizona, performed an autopsy on the pilot. The autopsy was performed at the request of the Apache County Sheriff's Office, in whose jurisdiction the accident occurred. In addition, toxicological specimens of blood and urine were analyzed by the University Medical Center, Tucson. No evidence of ethanol or drugs was found.

The FAA's Toxicology and Accident Research Laboratory, Oklahoma City, Oklahoma, also analyzed toxicological specimens of blood and urine. No evidence of ethanol or drugs was found.

Family members and acquaintances of the pilot reported that he had been in excellent health. No drug usage history was acknowledged.

TESTS AND RESEARCH

Duty Time Requirements.

According to the USFS's regional safety manager, the pilot was not allowed to fly over 8 revenue hours during a 24-hour period. Also, the pilot's duty day could not be longer than 14 hours long. An examination of the pilot's work schedule indicated that the pilot had complied with the agency's policy.

Work and Rest History.

A family member reported that on June 28, 2002, the pilot awoke at 0600, and he went to work. The pilot returned to his hotel about 2100, whereupon he had dinner. He retired for the night about midnight.

On June 29, 2002, the pilot awoke at 0600, and he went to work. The pilot's last flight was completed about 1900, and he departed on the accident flight about 2022 (estimated time).

Wreckage Examination, Instruments.

The airplane's altimeter was found with its face broken. The barometric pressure set in the Kollsman window was 30.04 inHg. The engine's tachometer indicated 1,500.03 hours at 200 rpm.

Circumferential score marks were observed on the directional gyroscope's rotor. Corresponding score marks were observed in its case.

Wreckage Examination, Airframe.

The left wing, the left stabilizer, and the left ruddervator were found attached to the fuselage and empennage.

The right wing and the right stabilizer were found separated from the airframe. The right wing spar in the vicinity of its attachment fittings to the fuselage was found bent and broken in an upward and aft direction, as evidenced by the buckled appearance of the upper wing skins. Also, the upper and lower portions of the front spars were bent up. No evidence of corrosion was observed in the bent and separated surfaces. The fracture surfaces appeared as bright metal with no discoloration of the faces. There was a granular appearance in the fractured areas.

The top of the right wing was found with scrape-like marks on its surface (see photograph #11). Corresponding scrape-like marks were found on the separated right stabilizer (see photograph #12). The right stabilizer's leading edge was observed deformed in an upward and aft direction.

Flight control cable continuity was confirmed with all of the control cables located with the wreckage. Separated ends of cables exhibited a broomstraw appearance.

Engine, Accessories and Controls.

The impact-damaged engine, serial number 21773-D-2-11, was found with one propeller blade attached to the crankshaft. The other propeller blade was found nearby. No evidence of preimpact oil leakage or case rupture was observed. A puddle of oil was observed in the soil beneath the engine. Oil was also observed inside the engine. The upper case was found cracked. The crankshaft was rotated, and the continuity of the valves and gear train was confirmed.

The throttle control was found in the full forward position. The mixture control was in the full rich position. The terminating ends of both control cables were found attached to the engine.

The carburetor's fuel filter was found devoid of foreign objects. The fuel selector was positioned to the left main fuel tank. The magneto switch was set to the "Both" position, and the key was bent.

The vacuum pump drive gear and vanes were found intact. All of the spark plug leads were found separated from the bottom plugs. The magnetos' drive gears were rotated. Spark was observed from all terminal leads.

ADDITIONAL INFORMATION

The airplane wreckage was released to its owner on July 2, 2002. No parts or records were retained.

NTSB Probable Cause

The pilot's loss of airplane control after falling asleep due to fatigue, which resulted in a structural failure of the airframe during a high speed descent after the design stress limits of the aircraft were exceeded.