WPR14FA132

The pilot’s delayed decision to initiate a course-reversal turn when the airplane was unable to attain sufficient altitude to cross a mountain range, which resulted in the airplane exceeding its critical angle of attack and entering an aerodynamic stall during the turn. Contributing to the accident was the pilot’s selection, for undetermined reasons, of a route different than his normal route.

The owner/pilot regularly made roundtrip flights between his home airport and another airport located about 25 miles to the northwest. A north-south mountain range, with peaks ranging between 8,300 and 9,400 ft above mean sea level (msl), separated the two airports. Due to the limited climb capability of the airplane, on each leg, the pilot would climb parallel to the mountain range until he gained sufficient altitude and then turn to cross the range. Thus, the pilot's normal westbound (outbound) crossing segment was situated well north of his eastbound (return) crossing segment. The pilot typically crossed the mountain range at an altitude of 8,500 to 9,000 ft msl, which provided limited terrain clearance. After successfully completing the outbound trip in the morning, the pilot departed on the 30-minute return trip in the late afternoon likely about 1 hour before sunset. The pilot did not return home, and the airplane was reported missing on the following day about the same time that another pilot who was overflying the mountain range spotted the wreckage. The accident site was located at an elevation of about 6,200 ft msl about 7 miles north of the pilot's normal return trip crossing location, likely indicating that the pilot had turned early to cross the mountain range. Examination of the accident site indicated that the airplane impacted a hillside in a steep descent with a nose-down attitude. The airplane heading at the time of impact was about opposite of that required for the intended flight. The impact trajectory and attitude, airplane heading, and accident location are consistent with the airplane exceeding the critical angle of attack and entering an aerodynamic stall during the pilot's execution of a course reversal turn. It is unknown why the pilot attempted to cross the mountain range at a different location than the one he normally used. It is possible that he turned early in order to cross before nightfall. Because he made the attempt to cross significantly closer to the departure airport than normal, there was a reduced amount of time and distance for the airplane to climb to an altitude sufficient to clear the mountain range. Propeller damage signatures indicated that the engine was developing power at the time of impact. Except for the engine primer handle, which was found in the unlocked and partially extended position, no pre-impact mechanical anomalies or deficiencies were noted with the engine or airframe. If the engine primer was unlocked during the flight, the engine would likely have been running rich, possibly resulting in reduced power and climb capability. However, the investigation was unable to determine whether the engine primer was unlocked during the flight or became unlocked during the accident sequence. A pilot report from earlier in the day indicated turbulence and downdrafts in the vicinity, which, if present during the accident flight, could have reduced the airplane's ability to clear rising terrain. The premature eastbound turn, possibly in combination with reduced climb capability due to reduced engine power, downdrafts, or both, placed the airplane in a situation that prevented a successful crossing and that the pilot failed to respond to until it was too late to escape. The pilot's decision to reverse course may have been delayed because he had made many previous successful crossings and had a habit of crossing the range with limited terrain clearance. The delayed decision resulted in the pilot attempting the course-reversal turn without sufficient airplane performance capability to successfully complete it.

Review of advertisement information for the airplane, and discussions with the pilot's girlfriend, indicated that the airplane was not equipped with any navigation aids except a compass. Two closed, expired San Francisco sectional navigation charts, whose coverage area includes CXP and NV33, were recovered in the wreckage. There were no known radio communications to or from the airplane during the accident flight. According to FAA Airport/Facilities Directory information, the departure airport (CXP) was equipped with a single paved runway, designated 9/27, and airport elevation was 4,705 feet above mean sea level (msl). The airport was not equipped with an air traffic control tower (ATCT). A dedicated Common Traffic Advisory Frequency (CTAF) was specified for radio communications use by arriving and departing aircraft. The CTAF communications were not recorded. NV33 was situated at an elevation of 4,848 feet msl. The airport was not equipped with an ATCT. CXP was located about 25 miles northwest of NV33. A north-south mountain range, with peaks ranging between approximately 8,300 and 9,400 feet msl, was situated between, and separated, the two airports. That range extended continuously from south of NV33 to north of CXP. Date and Time of Accident Several information sources were utilized in an unsuccessful attempt to positively establish the date and time of the accident. Searches of Federal Aviation Administration (FAA) radio communications and radar data did not reveal any evidence of the accident flight. A non-NTSB examination of Fallon Naval Air Station (NFL) Fallon, Nevada, radar target data did not yield any targets that could be associated with the accident flight. A receipt from the Carson City Home Depot store was located in the wreckage. That receipt bore a date/time stamp of March 8, 2014, at 2:12 pm. Two different witnesses at CXP, both of whom were pilots, reported that they observed the airplane depart CXP on the afternoon of March 8. One witness observed an airplane that matched the description of the accident airplane depart runway 9 about 1400 on Saturday, March 8. He observed the airplane from his hangar, which was situated about 4,000 feet down, and on the south side of, runway 9. He reported that the engine sounded "awful," and that when the airplane was abeam his hangar, it was about the height of his hangar, and "just was not climbing." Another witness, who owned and operated a maintenance facility at CXP, observed an airplane that matched the description of the accident airplane land earlier in the day, and watched it depart from runway 9 about 1700 on Saturday, March 8. He noted that the airplane departed prior to sunset, but he did not note the departure direction after takeoff. Those two CXP witness reports each appeared internally consistent and credible, but the investigation was unable to reconcile the apparent discrepancy regarding the departure time between the two reports. The reported departure time (1400) of the first report was inconsistent with the time and date stamp on the Home Depot receipt. Review of the available March 8 text and email messages to or from the pilot indicated that the pilot's last message was sent to his girlfriend at 1538. The pilot was known to text while in flight, but the topic of the 1538 text (product selection assistance for the shopping errands in Carson City) was inconsistent with the text being sent after the pilot was airborne, when he was on his way home after the shopping was completed. The pilot's girlfriend was not certain whether the pilot planned to return on March 8 or on the morning of March 9. On the morning of March 9, when the pilot had not returned, and the girlfriend had not heard from him despite a texted query, she initiated an unsuccessful telephone search among their friends. Subsequent to that effort, she conducted an aerial search of his normal routes, which was also unsuccessful. She then filed a missing persons report sometime in the mid afternoon of March 9. Pilot's Flight Routes and Habits The pilot's girlfriend, who was also a certificated pilot, reported that they owned two other airplanes, a Cessna 150 and a Piper Seneca. She stated that he made the round trip flights from NV33 to CXP approximately once every week, usually in one of the Cessna airplanes, and that when she accompanied him, they typically flew in the Cessna 150. She reported that he was familiar enough with the route that he did not need or use navigation charts. The pilot's girlfriend stated that the pilot normally navigated the trip legs by visual means. However, she stated that when he conducted the flight at night, he took the C-150 because of its greater engine power, and the fact that it was equipped with a VOR navigation receiver, in order to avoid the need to rely solely on visual navigation. She reported that when he crossed the mountains at night, he climbed higher than normal to ensure sufficient terrain clearance. According to the pilot's girlfriend, the accident site was not along the pilot's normal route of flight between the two airports. She explained that due to the north-south mountain range that separated NV33 from CXP, the route that the pilot followed to CXP was different from the route that he followed on the return trip. The rationale was that the pilot would climb parallel to the mountain range until he gained sufficient altitude, and then he would turn to cross the range. Because CXP was northwest of NV33, on the outbound (NV33 to CXP) leg, the pilot's typical westbound range-crossing segment was north of his typical eastbound, return trip crossing segment. The pilot's girlfriend reported that the pilot's normal return trip crossing segment was located east of Minden, Nevada. Minden was located about 12 miles to the south of CXP. In contrast, the impact site was located about 5 miles to the south of CXP, which was approximately 7 miles north of (prior to) the point where the pilot normally conducted his eastbound crossing of the mountain range. An interview with the pilot's daughter, who was not a pilot, revealed that she had flown with the pilot in both the C-150 and the Piper Seneca. She had seen the C-120, but told the pilot that she would not fly in that airplane with him. The pilot's daughter stated that she had flown in the C-150 with the pilot. It was her opinion that he flew "uncomfortably close" to the terrain when he was crossing the mountains between CXP and NV33, and estimated that the terrain clearance was "hundreds of feet." When she expressed concern to him about the terrain proximity, he informed her that "we're catching the lift." The pilot's daughter also reported that the pilot would text from his cell phone while flying/airborne. She witnessed him texting while she was in the airplane with him, and she also received text messages from him when he was airborne and inbound to meet her. Engine Primer Information The engine primer was a manually-powered pump system, which provides unmetered fuel to the engine cylinders to facilitate engine start. The primer handle was designed to lock in the closed position; for engine start it was to be unlocked, pumped a specified number of times, and then stowed and re-locked for the remainder of the flight. According to the airplane manufacturer's Operation Manual (OM) recovered from the wreckage, "The primer is not required except at winter temperatures." FAA Advisory Circular AC 20-105B (Reciprocating Engine Power-Loss Accident Prevention and Trend Monitoring) stated the following, "if the primer pump handle is not locked in the closed position, raw fuel will continue to be drawn into the cylinders by the suction created in the affected cylinders during the intake cycle. The engine will run rough at low RPM, mimicking magneto problems, but will smooth out above 1700 RPM." Chapter 10 of the FAA Airplane Flying Handbook (FAA-H-8081-3A) stated the