Minden, NV, USA
N14GQ
PIPER PA34
The instrument-rated airline transport pilot was maneuvering the airplane from about 14,500 ft mean sea level (msl) while descending to the destination airport. Throughout the flight, the pilot was communicating with his son via text messaging to ask about the weather conditions at the destination airport, near where his son was located. The pilot's son described a broken cloud layer and advised the pilot that, if the airplane stayed above the clouds, he could then "drop in over the valley." About 2 minutes before the accident, the pilot told an air traffic controller, "I'm going to orbit here to the south…south over the airport I can see it, maneuvering through a hole," GPS data showed that, as the airplane continued to turn to the right, its airspeed increased rapidly, and the right turn tightened. After completing a full revolution, the airplane exceeded its maximum structural cruising speed and never-exceed speed. The airplane's flight load increased throughout the turn, exceeding the airplane's maximum flight load factor. Immediately afterward, the flight data became unreliable; this point was likely when an in-flight breakup occurred. The location of the separated components in the debris field and the damage to the components were consistent with a tail-first in-flight breakup. The airplane flight path before the in-flight breakup were consistent with a graveyard spiral caused by spatial disorientation. The pilot's statement to the controller regarding his intent to maneuver through a hole in the cloud layer indicated operation near instrument meteorological conditions (IMC). The airplane's excessive bank, pitch, and load factor coincided with the height of the reported cloud tops (13,000 ft), further indicating that the pilot was likely flying in and out of the clouds as he was attempting to spiral down to the airport. Given the reports of ceilings at 9,500 feet, the in-flight breakup likely occurred in IMC or within seconds of the airplane exiting IMC, precluding the pilot from taking recovery action upon reentering visual meteorological conditions. The investigation could not determine whether the pilot was using supplemental oxygen while operating the airplane above 14,000 ft msl, as required by federal regulations. However, the communications between the controller and the pilot revealed that the pilot had no appreciable change in speech rate, coherence, or response time, indicating that the pilot was not experiencing hypoxia while in contact with air traffic control. Although the pilot's coronary artery disease placed him at an increased risk for a sudden cardiac event, no evidence indicated that such an event occurred. Toxicology testing identified diphenhydramine, a sedating antihistamine, in the pilot's cavity blood and liver specimens. Because experienced instrument-rated pilots should be able to identify spatial disorientation, the pilot's use of diphenhydramine likely contributed to this accident by degrading his judgment and slowing his responses.
On February 19, 2018, about 1125 Pacific standard time, a Piper PA-34-200T airplane, N14GQ, was destroyed when it impacted the ground about 4 miles northwest of Minden-Tahoe Airport (MEV), Minden, Nevada. The commercial pilot was fatally injured. The airplane was operated by the pilot as a Title 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological conditions prevailed, and a flight plan was not filed for the cross-country flight, which originated from Meadows Field Airport (BFL), Bakersfield, California, about 0900. According to GPS data and a recording of communications between the pilot and air traffic control (ATC), the pilot was in contact with a controller at the Northern California Terminal Radar Approach Control. At 1119:41, the pilot reported that the airplane was at an altitude of 14,500 ft mean sea level (msl) and about 10 miles southwest of and inbound to MEV. At 1121:16, when the airplane was about 7 miles west of MEV, the controller asked, "how much further north are you going to go or is it for clouds?" The controller then attempted to contact the pilot twice more, at 1122:33 and 1122:39; the pilot responded, at 1122:43, "ah, one four golf Quebec." Three seconds later, the controller asked the pilot again, "how much further north you want to go?" At 1122:50, the pilot asked the controller to please speak up, indicating "I can't hear you." Five seconds later, the controller repeated the question with emphasis. At 1123:07, the pilot responded, "I'm going to orbit here to the south…south over the airport I can see it, maneuvering through a hole," which was the last transmission from the pilot. About that time, the pilot started a wide right turn toward MEV. The GPS data showed that the airplane was at an altitude of 14,210 ft msl and on a heading of about 50°. About 24 seconds later, the airplane was at an altitude of 14,462 ft msl and was on a heading of about 122°. Shortly afterward, as the airplane continued south, it appeared to enter a descending spiraling pattern. Specifically, GPS data showed that, at 1124:20, the airplane began a spiral turn of about 360° and descended to 13,410 ft msl; 9 seconds later, the airplane's altitude was 12,493 ft msl. At 11:24:49, the airplane began a spiral turn of about 580° and descended to an altitude of 9,750 ft msl, which was the last reliable altitude recorded. Figure 1 shows the flight track above the accident site. Figure 1. Aerial View of the Flight Track and Wreckage Debris Field The pilot and his son were communicating throughout the flight, via text messaging, about the weather conditions near MEV. The pilot's son described a broken cloud layer and indicated that parts of the Sierra Mountain Range were either below or obscured by clouds. The pilot asked if the clouds were broken over Lake Tahoe, to which his son replied, "yes." The pilot then stated, "is clearing up over there, might stop in Stockton." The pilot's son replied, "there's many holes over Carson Valley," and "you should be able to stay above and drop in over the valley." A witness, who was located outside her residence about 2 miles north of the accident site, reported that she heard a loud noise that sounded similar to a "sonic boom." She looked up and saw an airplane "nose-diving down" with trailing smoke. The witness stated she did not see any flames. PERSONNEL INFORMATION The pilot held an airline transport pilot certificate with a rating for airplane multiengine land, commercial privileges for airplane single-engine land and single-engine sea, and private privileges for glider. The pilot was also a flight instructor with airplane single- and multiengine ratings and held an airframe and powerplant certificate (A&P) with inspection authorization. His most recent second-class medical certificate was issued September 24, 2017. On his medical certificate application, the pilot reported that he had accumulated 6,000 hours of total flight experience, of which 50 hours were in the previous 6 months. The pilot's logbooks indicated that he had accumulated 5,945 hours of total flight experience, of which 4.9 hours were in the Piper PA-34-200T airplane during the previous 6 months. The pilot successfully completed his most recent flight review on September 24, 2017. AIRCRAFT INFORMATION The airplane was manufactured in 1978. It was powered by a Continental LTIO-360-EB-1B (right) and a TIO-360-EB-1B (left) engine, both of which were rated at 200 horsepower. The engines were equipped with Hartzell two-bladed, controllable-pitch propellers. According to maintenance logbooks, the airplane's last annual inspection was on August 1, 2017, with a total time of 3,948 hours, and both engines had a total time of 1,960 hours since new. The airplane had a full-span flaps and spoiler system in accordance with the Robertson Aircraft Corporation supplemental type certificate (STC) SA154NW. This system incorporated the functions of both flaps and ailerons by removing the ailerons and changing the deployment route of the flaps. The spoilers were mounted above the flaps for roll control, and conical cambered wing tips were installed per the STC. The airplane was equipped with a supplemental oxygen system. The maintenance logbooks indicated that the oxygen bottle was hydrostatic checked and certified on April 13, 2012, and that the bottles were filled to 1,800 psi with aviation breathing oxygen. The next hydrostatic check was due in March 2017. No evidence indicated that the check occurred at that time, and no other maintenance on the oxygen system was recorded in the maintenance logbooks. METEOROLOGICAL INFORMATION The nearest weather reporting station was MEV, located about 4 miles south of the accident site. The recorded weather at 1115 indicated wind from 350°at 15 knots gusting to 29 knots, visibility 10 statute miles or greater, sky clear, temperature -2°C, dew point -13°C, and an altimeter setting of 29.82 inches of mercury. Satellite imagery taken 30 minutes before the accident revealed extensive cloud coverage over the region, as shown in figure 2, but also significant breaks in the cloud coverage, through which the ground could be seen. A pilot report about 30 minutes after the accident indicated clouds between 9,500 and 13,000 ft msl about 10 miles east of the accident site. Weather radar also showed snow showers moving through the area about the time of the accident with some light icing in the clouds. WRECKAGE AND IMPACT INFORMATION Initial examination of the airplane revealed that the airplane impacted the ground in an inverted, wings-level, slightly nose-down attitude. No debris was located near the main wreckage. The nose cone assembly, empennage, right wing outboard full-span flap assembly, and left outboard wing section separated from the airplane. A debris field located about 0.5 mile south of the main wreckage contained the separated airplane parts. The debris field was about 800 ft wide and 3,200 ft long and was on a 167o magnetic heading from the main wreckage to stabilator trim tab, the last airplane part found in the debris field. The airplane wreckage was relocated to a secure facility for further examination. The examination revealed that the stabilator separated in a downward and aft direction and that the wing sections separated in a downward direction. The lower fuselage showed areas of damage and black transfer marks consistent with wing contact. There was no evidence of any pre-existing corrosion or cracking on any of the fracture surfaces. The fracture surfaces exhibited a dull, grainy appearance consistent with overstress separation. The oxygen system was found loose in the cabin area at the accident site. Examination of the system could not determine whether the pilot was using supplemental oxygen during the flight. MEDICAL AND PATHOLOGICAL INFORMATION The Washoe County Regional Medical Examiner's Office, Reno, Nevada, performed an autopsy on the pilot. His cause of death was multiple blunt force injuries. The autopsy revealed that the pilot had moderate coronary artery disease with 50% to 75% stenosis of the proximal and mid-segments of the left anterior descending coronary artery and 10% to 20% stenosis of the right coronary artery. Toxicology testing performed at the Federal Aviation Administration (FAA) Forensic Sciences Laboratory identified diphenhydramine in the pilot's cavity blood (0.305 µg/mL) and liver specimens. In addition, amlodipine and atorvastatin were detected in the pilot's cavity blood and kidney specimens. No ethanol was detected. Diphenhydramine is a sedating antihistamine used to treat allergy symptoms and aid sleep. It is available over the counter under the names Benadryl and Unisom. Diphenhydramine carries the following warning: may impair mental and/or physical ability required for the performance of potentially hazardous tasks (e.g., driving and operating heavy machinery). Compared with other antihistamines, diphenhydramine causes marked sedation; it is also classified as a central nervous system depressant. Altered mood and impaired cognitive and psychomotor performance may also be observed. For example, during a driving simulator study, a single dose of diphenhydramine impaired driving ability more than a blood alcohol concentration of 0.1%. The range of blood levels expected to cause effects with routine use is between 0.025 and 0.112 ug/ml. Diphenhydramine undergoes postmortem redistribution; postmortem central blood levels may thus increase by about three times. Amlodipine is a prescription blood pressure medication. Atorvastatin is a prescription cholesterol medication. Neither medication is considered impairing. TESTS AND RESEARCH Airplane Performance Study Data used in the performance study were from the airplane's Appareo Stratus PRX V2 device, which recorded GPS position and attitude and heading reference system information in its nonvolatile memory. For the accident flight, the GPS recorded data from 0926:40 to 1125:15. According to the recorded flight data, the accident flight proceeded without incident until the final minutes of the flight as the airplane approached its intended destination. The airplane's maximum structural cruising speed (VNO) is listed in the Piper Aircraft Pilots Operating Manual as 190 mph or 165 knots calibrated airspeed. The never exceed speed (VNE) is 224 mph or 194 knots calibrated airspeed. At 11:24:37 the estimated airspeed peaks at 220 kt. The airplane exceeded VNO and VNE after completing about one revolution of the turn, at 1124:44 and 1124:49, respectively. The airplane's maximum positive flight load factor (flaps up) is listed as 3.8 G. The airplane's recorded flight vertical load increased steadily when the right turn began. The airplane's flight load reached a maximum of 3.95 G before the Appareo data became unreliable. The unreliability of the data after the airplane exceeded the maximum load indicated that the airplane broke up at 1124:49 at an altitude of about 9,500 ft msl, (4,900 ft above ground level). ADDITIONAL INFORMATION Supplemental Oxygen Requirements The flight data indicated that the airplane was operating above 12,500 ft msl for about 37 minutes, including about 15 minutes between 14,000 and 14,462 ft. According to regulations, the pilot should have been using supplemental oxygen after reaching 14,000 ft msl. Spatial Disorientation The FAA Civil Aeromedical Institute's publication, "Introduction to Aviation Physiology," defines spatial disorientation as a loss of proper bearings or a state of mental confusion as to position, location, or movement relative to the position of the earth. Factors contributing to spatial disorientation include changes in acceleration, flight in instrument meteorological conditions (IMC), frequent transfer between VMC and IMC, and unperceived changes in aircraft attitude. The FAA Airplane Flying Handbook describes some hazards associated with flying when the ground or horizon are obscured. The handbook states, in part: "The vestibular sense (motion sensing by the inner ear) in particular tends to confuse the pilot. Because of inertia, the sensory areas of the inner ear cannot detect slight changes in the attitude of the airplane, nor can they accurately sense attitude changes that occur at a uniform rate over a period of time. On the other hand, false sensations are often generated; leading the pilot to believe the attitude of the airplane has changed when in fact, it has not. These false sensations result in the pilot experiencing spatial disorientation." These illusions include the graveyard spiral, about which, "Medical Facts for Pilots" (AM-400-03/1)," describes, in part, as the following: The Graveyard Spiral…is associated with a return to level flight following an intentional or unintentional prolonged bank turn. For example, a pilot who enters a banking turn to the left will initially have a sensation of a turn in the same direction. If the left turn continues (~20 seconds or more), the pilot will experience the sensation that the airplane is no longer turning to the left. At this point, if the pilot attempts to level the wings this action will produce a sensation that the airplane is turning and banking in the opposite direction (to the right). If the pilot believes the illusion of a right turn (which can be very compelling), he/she will reenter the original left turn in an attempt to counteract the sensation of a right turn. Unfortunately, while this is happening, the airplane is still turning to the left and losing altitude. Pulling the control yoke/stick and applying power while turning would not be a good idea–because it would only make the left turn tighter. If the pilot fails to recognize the illusion and does not level the wings, the airplane will continue turning left and losing altitude until it impacts the ground.
The pilot's loss of airplane control due to spatial disorientation while maneuvering in instrument meteorological conditions. Contributing to the accident was the pilot's impairment from the use of a sedating antihistamine.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports
