SEA02GA053

The aircraft was cleared direct and to climb to 14,000 feet. During the climb out, the controller inquired several times as to the flights altitude. The pilot's response to the controllers queries were exactly 10,000 feet lower than what the controller was indicating on radar. Eventually the controller instructed the pilot to stop altitude squawk, which he did. During the last communication with the pilot, he reported that he was level at 14,000 feet. During the next approximately 45 minutes, the aircraft was observed proceeding generally in the direction of its destination. When the controller observed the flight track turn approximately 45 degrees to the right and headed generally northwest, he attempted to contact the pilot without a response. The tracking then turned about 90 degrees to the left for a few minutes, then turned 180 degrees to the right. The aircraft dropped from radar coverage shortly thereafter. On site investigation revealed that the aircraft broke-up in flight as the wreckage was scattered generally east-to-west over the mountainous terrain for approximately .3 nautical miles. Further investigation revealed that the right wing separated at the wing root in an upward direction. Separation points indicated features typical of overload. The right side horizontal stabilizer separated upward and aft. The left side horizontal stabilizer remained attached however, it was twisted down and aft. The aft fuselage was twisted to the left. Both engines separated in flight from the wings. Post-crash examinations of the airframe and engines did not reveal evidence of a mechanical failure or malfunction. Both altimeters were too badly damaged to test. Autopsy and toxicology results indicated that the pilot had severe coronary artery disease with greater than 95% narrowing of the left anterior descending coronary artery by atherosclerotic plaque. The coroner also reported that superimposed upon this severe narrowing was complete occlusion of the lumen by brown thrombus. Toxicology results indicated a moderate level of diabetes. The pilot's actions leading up to the accident were consistent with an incapacitation due to hypoxia. The role of a possible heart attack was unclear, since it is possible that it occurred as a result of the hypoxia

History of flight

On March 12, 2002, approximately 1437 mountain standard time, the Federal Aviation Administration (FAA) Air Route Traffic Control Center (ARTCC) at Salt Lake City, Utah (Salt Lake Center), lost contact with a Piper PA-31 airplane, N2336V, which was on a public-use flight under instrument flight rules (IFR) from Idaho Falls, Idaho, to Boise, Idaho. At the time contact was lost, the aircraft, which was owned by the Idaho State Aeronautics Division, was transporting a juvenile offender to a commitment facility, with the commercial pilot-in-command (a part-time pilot for the Idaho State Aeronautics Division), an Idaho State Department of Juvenile Corrections transport officer, and the juvenile offender aboard. Search-and-rescue (SAR) forces subsequently acquired an emergency locator transmitter (ELT) signal from the missing aircraft, and located the wreckage of N2336V the following day. The substantially damaged aircraft wreckage was dispersed over mountainous terrain at elevations between 8,900 feet and 9,600 feet in the Sawtooth Wilderness, near the last recorded radar position, approximately 10 nautical miles north-northeast of Atlanta, Idaho. A ground party that reached the wreckage on March 15, 2002, found all three aircraft occupants to have been fatally injured. At 1450 marginal visual flight rules (MVFR) conditions (scattered clouds at 1,000 feet, ceiling 2,300 feet broken, visibility 15 statute miles) were reported at Friedman Memorial Airport, Hailey, Idaho, the closest weather reporting station to the accident site.

After the pilot checked in with the air traffic controller, the aircraft's radar track proceeded generally toward Boise for the next 45 minutes with no further radio communication with the aircraft. About 1425, the track turned approximately 45 degrees to the right and headed generally northwest. The controller then attempted to contact the aircraft at about 1426, but did not receive a response. The track turned about 90 degrees to the left, to a west-southwesterly track, about 1433. About 1436, the track initiated an approximate 180 degree turn to the right, heading northeast. The last recorded radar position was at 1437:01, at 43 degrees, 57 minutes, 28 seconds North latitude; 115 degrees, 03 minutes, 40 seconds West longitude. Following the aircraft's disappearance from radar, the Salt Lake Center controller continued to attempt radio contact with the aircraft and made a number of other efforts to locate the aircraft without success.

Personnel information

At the time of the accident, the pilot held commercial and flight instructor certificates. Ratings included single-engine land and sea, multi-engine land and instrument airplane. A representative from Idaho Division of Aeronautics reported that the pilot's flight logbook was not located, however, total flight time derived from company records indicated that the pilot had accumulated approximately 20,647 hours, with 338 hours in the accident aircraft make and model. The pilot had accumulated approximately 1,000 hours of actual instrument flight time. The pilot held a second class medical certificate dated December 18, 2001, with a limitation for corrective lenses.

On the day of the accident, the daily aircraft flight log located in the wreckage indicated that the pilot began his first flight of the day at 0800 from Boise, to Lewiston, Idaho with three passengers on board. The duration of the flight was logged as one hour and ten minutes. The aircraft then took off with two passengers at 0925 and landed in Coeur d'Alene, Idaho at 1000. At 1030 the flight departed with four passengers and landed in Idaho Falls at 1240. The flight log indicated that the accident flight took off from Idaho Falls with two passengers at 1310 en route to Boise.

Aircraft information

The accident aircraft was manufactured in 1968, as a non-pressurized Piper PA-31-310 Navajo, serial number 31-135. State of Idaho Division of Aeronautics purchased this aircraft in 1995. The original Lycoming TIO-540-A2B engines were replaced in January 1978, with the installation of Colemill Enterprises, Inc. "Panther" engine conversion, Lycoming model TIO-540-J2BD, engines which developed 350 horsepower each. These engines use the Hartzell four-bladed Q-tip propellers.

Maintenance records indicated that the last Annual/100 hour inspection was accomplished on February 4, 2002, at a recording tachometer time of 976.0 hours, and an aircraft total-time of 7,940.3 hours. Approximately 27 hours had been accumulated on the aircraft since the last inspection.

The pilot's side Aerosonic Corp. altimeter part number: 101635-0197, serial number: C124847, and the co-pilot's side United Instruments altimeter part number: 5934PA-1, serial number 8D729, were both tested to 35,000 feet and signed off as serviceable on September 6, 2001. Both altimeters were equipped with three points to indicate 100 feet, 1,000 feet and 10,000 feet.

Communications

According to FAA air traffic control (ATC) information from Salt Lake City, ARTCC, the aircraft took off from Idaho Falls (airport elevation of 4,741 feet) about 1308. At 1309, the pilot checked in with Salt Lake Center, Sector Radar 08 (R8) and reported that he would like to go from his present position, direct at 14,000 feet. The R8 controller responded that he had radar contact with the aircraft two miles southwest of Idaho Falls VOR. At 1310, the R8 controller contacted the pilot and asked if he copied that radar contact was now four miles southwest of Idaho Falls VOR, and wanted the pilot to verify that he was leaving 6,400 feet. The pilot responded that he was now at 6,500 feet, and asked the controller if he was cleared to go direct to Boise. The R8 controller responded that he was cleared via area navigation (RNAV) direct to Boise.

At 1319, the R8 controller contacted the pilot and asked him to say assigned altitude. The pilot responded 14,000. The R8 controller then informed the pilot that radar was showing the aircraft at 15,300 feet. The pilot responded that he was, "just going through 5,600 for right now..." The controller then stated to the pilot that it was not a problem, but wanted to know if he was correcting back to 14,000 feet. The pilot responded, "No I'm climbing to 14,000 and I'm just going through 6,300 now..." The controller responded to the pilot that he might need to check his altimeter as he was showing the aircraft at 16,200 feet. The pilot stated that he would see what he could do and reported "I'm gonna go off line just a moment." The R8 controller acknowledged this and reported the Idaho Falls altimeter as 29.87.

At 1321, the pilot informed the R8 controller that "...both my altimeters say I'm going through 7,000." At 1322, the R8 controller asked the pilot what altitude he was going through. The pilot responded that he was going through 8,500. The R8 controller acknowledged this and asked the pilot if he had ground contact. The pilot responded affirmative.

At 1324, the R8 controller asked the pilot to verify that his altimeter setting was 29.92 and not just 992. The pilot responded "okay 29.92 and we're just going through 9,800." The controller then asked the pilot to reset to Idaho Falls altimeter of 29.87. The pilot acknowledged this and reported that they were reading 10,700. The controller responded that he was showing the aircraft "exactly 10,000 feet higher than what you're showing." The pilot responded "okay, if I got to go VFR, I need to do it now." The R8 controller then asked the pilot to verify that he had ground contact. The pilot responded that he had ground contact to his left and thought that he could descend and go VFR. At 1325, the R8 controller asked the pilot to stop altitude squawk. The pilot acknowledged that it was stopped. The R8 controller then asked the pilot to report level at 14,000, and then told the pilot that when he got