ATL07FA083

While executing an approach in mountainous terrain, the instrument-rated private pilot requested help due to a malfunctioning directional gyro. The controller initiated giving the pilot vectors for a no-gyro approach to the airport, which included a climb. Shortly thereafter, the pilot advised the controller that the attitude indicator had failed. The controller continued to provide guidance to the pilot until radar contact was lost less than 2 minutes later. The airplane impacted a mountain about 2,300 feet below the last assigned altitude. Evidence at the scene indicated that the airplane had entered an uncontrolled descent prior to impact. Examination of the vacuum system revealed that the vacuum inlet line "B-Nut" fitting to the attitude indicator was loose and that contamination had entered the instrument. This indicated there was a leak in the vacuum system, and insufficient vacuum for the associated instruments.

History of flight

On May 4, 2007, at 1058 eastern standard time, a Cessna 182Q, N735DP, registered to and operated by a private individual, was destroyed when it struck a mountain during a missed approach at Asheville Regional Airport (AVL), Asheville, North Carolina. Instrument meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91, and an instrument flight rules (IFR) flight plan had been filed. The private pilot-in-command, commercial-certificated pilot-passenger, and another passenger were fatally injured. The cross-country flight originated from the W. H. "Bud" Barron Airport (DUB), Dublin, Georgia, at 0815, and was en route to AVL.

A representative of the fixed base operator at Dublin Airport said the airplane had been fueled to capacity, and he watched the occupants as they boarded the airplane. He said the private pilot was in the left seat and the commercial pilot was in the right seat. He watched the airplane as it taxied out to the end of the runway and, after an engine run-up, watched it take off.

One of the pilots made initial contact with Asheville approach control at 10:27:43. At 10:45:45, approach control cleared the pilot to descend and maintain 4,600 feet. At 10:46:45, approach control instructed the pilot to turn to a heading of 160 degrees. At 10:47:15, approach control advised the pilot that he was over the initial approach fix, Junoe, and to maintain 4,600 feet until established on the localizer. The pilot was then cleared for the ILS (instrument landing system) runway 16 approach. At 10:50:53, approach control advised the pilot to contact the tower and at 10:51:09, the pilot was cleared to land on runway 16.

At 10:55:03, the controller advised the pilot that he was off the localizer and to immediately climb to and maintain 5,000 feet. Shortly thereafter, the pilot reported his directional gyro was "messed up." At 10:55:42, the controller advised the pilot to turn right to a heading of 300 degrees. The pilot requested help due to his malfunctioning directional gyro. The controller said he would give the pilot no-gyro vectors. At 10:56:41, the controller instructed the pilot to climb and maintain 5,100 feet. The pilot then reported, "We've just lost the attitude indicator." The controller continued to provide guidance, and at 10:58:26, the tower controller, who was handling the airplane, advised approach control he had lost radar contact. The Asheville Department of Public Safety was notified, and a ground search for the downed airplane was initiated. At 1258, the wreckage was located at the 2,800-foot level of Bald Mountain.

Witnesses in the vicinity of the accident site said they saw an airplane flying low in the direction of the airport. Shortly thereafter, they heard a loud crash. They said there was dense fog in the area.

Personnel information

The pilot-in-command was issued a private pilot certificate, dated July 31, 1971, with airplane single/multiengine land, and instrument ratings. He also held a third class airman medical certificate, dated March 16, 2005, with a restriction for corrective lenses. His most recent logbook began on March 11, 2001, and revealed that he had logged a total of 117.6 flight hours. His last flight review was dated November 28, 2005.

Aircraft information

The accident airplane was manufactured by the Cessna Aircraft Company in 1977. It was equipped with a Continental O-470-U engine rated at 230 horsepower. The engine was equipped with a McCauley C2A3402040 2-blade, all-metal, constant speed propeller.

A review of the aircraft maintenance records revealed the last annual/100 hour inspection was done on June 8, 2006, at a tachometer time of 683.0 hours and a Hobbs meter time of 95.5 hours.

Meteorological information

The AVL terminal area forecast (TAF), effective at 1501, forecast the wind to be 180 degrees at 7 knots, 5 statute miles visibility and mist, overcast ceiling at 200 feet, temperature 14 degrees Celsius (C.), dew point 12 degrees C., and an altimeter setting of 30.18 inches of Mercury.

Aids to navigation

There were no reported difficulties with aids to navigation. The runway 16 localizer was flight checked shortly after the accident by the Atlantic Operation Control Center. It was re-certified with no anomalies noted.

Airport information

AVL is located 9 miles south of the City of Asheville, North Carolina, at an elevation of 2,165 feet msl. It is served by one grooved runway, 16-34, which is 8,001 feet long and 150 feet wide.

Wreckage and impact information

Examination of the accident site revealed a wreckage path 150 feet long, and aligned on a magnetic heading of 250 degrees. All primary and secondary flight control surfaces were identified. The engine was torn away from the engine mounts and the propeller was separated from the propeller flange. The cockpit, cabin, baggage, and empennage sections were destroyed. Fragments of the left and right wing were strewn along the wreckage path. Both fuel bladders were compromised, and there was a strong odor of fuel. The crushed vertical and horizontal stabilizers were partially separated from the empennage.

Medical and pathological information

An autopsy was performed on the private pilot on May 7, 2007, by the Wake Forest University School of Medicine, Department of Pathology, Medical Center, Winston-Salem, North Carolina, as authorized by the Buncombe County medical examiner. The cause of death was reported as "blunt trauma."

Forensic toxicology was performed on specimens from the pilot by the Federal Aviation Administration (FAA) Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The toxicology report stated no ethanol was detected in the liver or muscle, and no drugs were detected in the liver.

Tests and research

The heading indicator (directional gyro), artificial horizon (attitude indicator), and vacuum system including the regulator, relief valve, filter and vacuum lines were removed and forwarded to the National Transportation Safety Board's Materials Laboratory in Washington, D.C. for further examination. Examination of the vacuum pump showed no evidence of precrash failure or malfunction. Examination of the attitude indicator showed that the "B-Nut" fitting on the vacuum inlet line was loose and black material,containing copper zinc oxide of micron sized particles, was observed on the flare fitting end of the ADI. Examination of the vacuum regulator showed that a hose remained connected to its 5/8 inch diameter tube via a clamp. After removing the hose, corrosion was observed on the tube. Examination of the saddle connection, for the shutoff valve, found that the clamp securing the hose to the saddle tube appeared to be over tightened and there was evidence of RTV like material found on the end of the tube and over one area of the clamp. After removing the hose from the saddle tube, corrosion was observed on the exterior surface of the tube.