WPR09FA320

The pilot's failure to maintain terrain clearance during descent for undetermined reasons.

Radar data indicated that the airplane departed for a cross-country flight, climbed to a cruise altitude of 9,700 feet msl, and maintained a northeasterly course of 050 degrees magnetic direct to its destination. About 11 minutes after takeoff, the airplane entered a 1,000 foot-per-minute descent. The airplane continued to descend at this rate until it impacted terrain at an elevation of 4,734 feet. Examination of the accident site revealed that the airplane was still on its northeasterly course towards the destination at impact. Ground scars at the initial point of impact were consistent with the airplane being wings level in a slight nose-down pitch attitude. No mechanical anomalies with the airplane or engine were identified during the airplane wreckage examination. A postimpact fire destroyed all cockpit instrumentation, and no recorded or stored flight data could be recovered. Weather conditions at the time were clear, and light winds. The pilot had some moderate heart disease that was noted during the autopsy. He also had a history of stress and insomnia, which was documented in his FAA medical records. Toxicology findings noted the use of a sedating and impairing over-the-counter medication (chlorpheniramine) that was taken at some undetermined time prior to the accident. The investigation could not conclusively determine whether the pilot’s conditions or medication use were related to the accident. The reason for the airplane’s descent to ground impact could not be determined.

HISTORY OF FLIGHT On June 30, 2009, at 0708 mountain daylight time, a Piper PA-46-350P, N927GL, collided with mountainous terrain 16.3 miles west of St. George, Utah. The airplane was operated by the private pilot under the provisions of Title 14 Code of Federal Regulations Part 91. The pilot was killed and the airplane was substantially damaged. Visual meteorological conditions prevailed, and a VFR (visual flight rules) flight plan had been filed. The flight originated at North Las Vegas Airport, Las Vegas, Nevada, at 0651, and the intended destination was Cedar City, Utah. Radar data indicated that the airplane departed North Las Vegas and climbed to an altitude of 9,700 feet mean sea level (msl) on a northeasterly course of 050 degrees magnetic. At 0656, the pilot checked in with Los Angeles Center, stating he was at 9,200 feet VFR to Cedar City. At 0702, the data showed the target entering an approximately 1,000-foot-per-minute (fpm) rate of descent. The target continued to descend at this rate until radar contact was lost. The last radar return was at 0707, at an altitude of 5,400 feet msl, 5.5 miles southwest of the accident location. The course of the target was along a northeasterly line of 050 degrees, consistent with a direct course to Cedar City. There were no other radio communications with the pilot by Los Angeles Center other than the initial check in. The airplane wreckage was located by the Civil Air Patrol and Washington County Search and Rescue in the late afternoon of June 30. The initial impact point was just below the crest of a small hill at 4,734 feet msl, and the main wreckage was located on a 30-degree slope of a large hill, approximately 384 feet northeast of the initial impact point. The bearing from the initial impact point to the main wreckage was 054 degrees (northeast direction). Cedar City lays on a 049 degree bearing and is 60 miles from the accident site. PERSONNEL INFORMATION The pilot, age 54, held a private pilot certificate for airplane single-engine land, and an airplane instrument rating, issued on September 14, 2006. A second-class medical certificate was issued on October 24, 2007, with the restriction that he have glasses available for near vision. The family provided a copy of the pilot’s flight logbook. The last entry in the logbook was dated September 18, 2008, with a recorded total flight time of 782.7 hours. The son of the pilot stated that his father stopped logging flight time in his pilot log, and started using an electronic log that was available in the airplane. On November 27 and 28, 2007, the logbook recorded two flights where the pilot practiced instrument procedures with a certified flight instructor (CFI), and logged 12 instrument approaches. The pilot’s wife stated that they had spent the weekend in Arizona visiting their son, and returned to Las Vegas Monday night, June 29. The pilot had a normal night’s sleep of 6 hours and was up around 0500 Tuesday morning. He walked the dogs and decided to fly to Cedar City. He most likely did not eat breakfast, which was consistent with his normal morning routine. He was in the process of selling the airplane and this would have been his last flight in it before he turned it over to the buyer. He was considering purchasing a smaller airplane for his future use. She said that he was healthy and fit with no serious health concerns. He did take medication for high cholesterol, and she thought he had hypoglycemia, but a doctor had never diagnosed him with that condition. He sometimes would experience tiredness, low energy, or weakness, but he never lost consciousness. He normally carried a soda pop or candy bar that he could eat if he felt those symptoms. She also stated that he was not under any unusual emotional stress, and there had been no change in their financial situation. AIRCRAFT INFORMATION The six seat, low-wing, retractable landing gear, single engine airplane, serial number (S/N) 4636400, was manufactured in 2006. It was powered by a Lycoming TIO-540-AE2A, 350-hp engine and equipped with a Hartzell, 3-bladed constant speed propeller, model HC-I3YR-1E. A review of copies of the maintenance logbooks showed an annual inspection was completed on March 6, 2009, at a recorded Hobbs meter reading of 306.4 hours, total airframe hours of 306.4, and engine total time since new of 306.4 hours. The records showed that the primary flight display (PFD) was removed, rebuilt and reinstalled on May 29, 2008; the multifunction display (MFD) was removed and replaced on October 26, 2008; and the copilot’s PFD was removed and replaced on June 17, 2009. The son of the pilot related that the airplane had a history of electrical problems with the PFDs, MFDs, autopilot, and pitot system. Fueling records from the North Las Vegas Terminal document that the airplane was last fueled on June 30, 2009, at 0622, with 47.7 gallons of 100LL avgas. The pilot operating handbook (POH) describes the flight control system as follows, “The primary flight controls are conventional and are operated by dual control wheels and rudder pedals. The control wheel operates the ailerons and elevator. The rudder pedals actuate the rudder and nose wheel steering. The toe brakes, which are an integral part of the pedals, operate the wheel brakes. The ailerons and rudder are interconnected through a spring system, which is activated only when controls are out of harmony. In normal coordinated flight, the system is inactive. All flight control systems are operated by closed circuit cable systems.” The autopilot was an S-TEC 55X two-axis automatic flight guidance system with trim monitor. The autopilot was integrated with the Avidyne PFD and MFD, and the Garmin GNS430W GPS (global positioning system) systems. The S-TEC 55X pilot operating handbook (POH) states the following regarding the Vertical Speed Mode capability. “The vertical speed mode can only be engaged if a roll mode (HDG, NAV, NAV APR, REV, REV APR, NAV GPSS) is already engaged. With a roll mode engaged and the aircraft at the desired vertical speed, press the VS mode selector switch to engage the vertical speed mode. The VS annunciation will appear…to acknowledge that this mode is engaged, along with the current vertical speed. The latter appears as a number in units of FPM x 100, prefixed by either a "+" to indicate a climb, or a "-" to indicate a descent (i.e., for example, +5 indicates 500 FPM climbing, if within the aircraft's capabilities). The autopilot will hold the aircraft at its current (captured) vertical speed. This vertical speed may be modified by rotating the Modifier Knob. In a climb, rotating the Modifier Knob clockwise (CW) increases the climb rate, whereas rotating it counterclockwise (CCW) decreases the climb rate. In a descent, rotating the Modifier Knob CCW increases the descent rate, whereas rotating it CW decreases the descent rate. Each detent equals 100 FPM, and the range is ±1600 FPM from the original captured vertical speed.” The autopilot can be disconnected by pressing the remote autopilot disconnect switch on the control wheel, or pressing either forward or aft on both segments of the remote manual electric trim switch on the control wheel, or setting the autopilot master switch to the OFF position, or by pulling the autopilot circuit breaker. The MFD had a Terrain Awareness and Warning System (TAWS) Mode, which is normally ‘on’ and can be ‘inhibited’ by the pilot. If the pilot engages the ‘TERR INHIB’ button, all terrain alerting functions are inhibited. The TAWS provides the following visual warnings on the Terrain Awareness Control Unit: red annunciator light for terrain warnings, amber annunciator light for terrain cautions, and white annunciator light for terrain inhibit. The TAWS also provides aural warnings and advisory call outs. The advisory call out “Five Hundred” occurs at 500 feet above gr