Tulsa

The commercial pilot was conducting an instrument approach following a 3.5-hour cross-country instrument flight rules (IFR) flight in a single-engine turboprop airplane. About 1.6 miles from the runway threshold, the airplane began a climb consistent with the published missed approach procedure; however, rather than completing the slight left climbing turn toward the designated holding point, the airplane continued in an approximate 270° left turn, during which the airplane's altitude varied, before entering a descending right turn and impacting terrain. Tree and ground impact signatures were consistent with a 60° nose-low attitude at the time of impact. No distress calls were received or recorded from the accident flight. A postimpact fire consumed a majority of the cockpit and fuselage. Weather information for the time of the accident revealed that the pilot was operating in IFR to low IFR conditions with gusting surface winds, light to heavy snow, mist, cloud ceilings between 700 and 1,400 ft above ground level with clouds extending through 18,500 ft, and the potential for low-level wind shear and clear air turbulence. The area of the accident site was under AIRMETs for IFR conditions, mountain obscuration, moderate icing below 20,000 ft, and moderate turbulence below 18,000 ft. In addition, a winter storm warning was issued about 6 hours before the flight departed. Although the pilot received a weather briefing about 17 hours before the accident, there was no indication that he obtained updated weather information before departure or during the accident flight. Examination of the airframe and engine did not reveal any preimpact anomalies that would have precluded normal operation; however, the extent of the fire damage precluded examination of the avionics system. The airplane was equipped with standby flight instruments. An acquaintance of the pilot reported that the pilot had experienced an avionics malfunction several months before the accident during which the airplane's flight display went blank while flying an instrument approach. During that occurrence, the pilot used ForeFlight on his iPad to maneuver back to the northeast and fly the approach again using his own navigation. During the accident flight, the airplane appeared to go missed approach, but rather than fly the published missed approach procedure, the airplane also turned left towards to northeast. However, it could not be determined if the pilot's actions were an attempt to fly the approach using his own navigation or if he was experiencing spatial disorientation. The restricted visibility and turbulence present at the time of the accident provided conditions conducive to the development of spatial disorientation. Additionally, the airplane's turning flight track and steep descent profile are consistent with the known effects of spatial disorientation.

The 69-year-old commercial pilot was making a personal cross-country flight in the newly purchased airplane. When the airplane was on final approach to the destination airport in night visual meteorological conditions, airport surveillance video showed it pitch up and roll to the right. The airplane then descended in a nose-down attitude to impact in a ravine on the right side of the runway. During the descent over the ravine the right wing came in contact with a powerline that briefly cut power to the airport. Postaccident examination of the airframe, engines, and their components revealed no evidence of mechanical anomalies or malfunctions that would have precluded normal operation. The pilot's toxicology findings identified five different impairing medications: clonazepam, temazepam, hydrocodone, nortriptyline, and diphenhydramine. Although the results were from cavity blood and may not accurately reflect antemortem levels, the hydrocodone, temazepam, and diphenhydramine levels were high enough to likely have had some psychoactive effects. While the exact effects of these drugs in combination are not known, it is likely that the pilot was impaired to some degree by his use of this combination of medications, which likely contributed to his failure to maintain control of the airplane.

The pilot reported that, during the postmaintenance test flight, the turboprop engine lost power. The airplane was unable to maintain altitude, and the pilot conducted a forced landing, during which the airplane was substantially damaged. The engine had about 9 total flight hours at the time of the accident. A teardown of the fuel pump revealed that the high-pressure drive gear teeth exhibited wear and that material was missing from them, whereas the driven gear exhibited little to no visible wear. A metallurgical examination of the gears revealed that the damaged drive gear was made of a material similar to 300-series stainless steel instead of the harder specified M50 steel, whereas the driven gear was made of a material similar to the specified M50 steel. Subsequent to these findings, the airplane manufacturer determined that the gear manufacturer allowed three set-up gears made from 300-series stainless steel to become part of the production inventory during the manufacturing process. One of those gears was installed in the fuel pump on the accident airplane, and the location of the two other gears could not be determined. Based on the evidence, it is likely that the nonconforming gear installed in the fuel pump failed because it was manufactured from a softer material than specified, which resulted in a loss of fuel flow to the engine and the subsequent loss of engine power. The manufacturer subsequently inspected its stock of gears and issued notices to customers that had engines with fuel pumps installed with the same part number gear set as the one installed on the accident airplane. The manufacturer also issued a service information letter and service bulletins regarding the fuel pump gear set for engines used in civilian and military applications. As of the date of this report, the two remaining gears have not been located.

Radar and air traffic control communications indicated that the Mitsubishi MU-2B-25 was operating normally and flew a nominal flightpath from takeoff through the beginning of the approach until the airplane overshot the extended centerline of the landing runway, tracking to the east and left of course by about 0.2 nautical mile then briefly tracking back toward the centerline. The airplane then entered a 360-degree turn to the left, east of the centerline and at an altitude far below what would be expected for a nominal flightpath and intentional maneuvering flight given the airplane's distance from the airport, which was about 5 miles. As the airplane was in its sustained left turn tracking away from the airport, the controller queried the pilot, who stated that he had a "control problem" and subsequently stated he had a "left engine shutdown." This was the last communication received from the pilot. Witnesses saw the airplane spiral toward the ground and disappear from view. Examination of the wreckage revealed that the landing gear was in the extended position, the flaps were extended 20 degrees, and the left engine propeller blades were in the feathered position. Examination of the left engine showed the fuel shutoff valve was in the closed position, consistent with the engine being in an inoperative condition. As examined, the airplane was not configured in accordance with the airplane flight manual engine shutdown and single-engine landing procedures, which state that the airplane should remain in a clean configuration with flaps set to 5 degrees at the beginning of the final approach descent and the landing gear retracted until landing is assured. Thermal damage to the cockpit instrumentation precluded determining the preimpact position of fuel control and engine switches. The investigation found that the airplane was properly certified, equipped, and maintained in accordance with federal regulations and that the recovered airplane components showed no evidence of any preimpact structural, engine, or system failures. The investigation also determined that the pilot was properly certificated and qualified in accordance with applicable federal regulations, including Special Federal Aviation Regulation (SFAR) No. 108, which is required for MU-2B pilots and adequate for the operation of MU-2B series airplanes. The pilot had recently completed the SFAR No. 108 training in Kansas and was returning to Tulsa. At the time of the accident, he had about 12 hours total time in the airplane make and model, and the flight was the first time he operated the airplane as a solo pilot. The investigation found no evidence indicating any preexisting medical or behavioral conditions that might have adversely affected the pilot's performance on the day of the accident. Based on aircraft performance calculations, the airplane should have been flyable in a one engine-inoperative condition; the day visual meteorological conditions at the time of the accident do not support a loss of control due to spatial disorientation. Therefore, the available evidence indicates that the pilot did not appropriately manage a one-engine-inoperative condition, leading to a loss of control from which he did not recover. The airplane was not equipped, and was not required to be equipped, with any type of crash resistant recorder. Although radar data and air traffic control voice communications were available during the investigation to determine the airplane's altitude and flight path and estimate its motions (pitch, bank, yaw attitudes), the exact movements and trim state of the airplane are unknown, and other details of the airplane's performance (such as power settings) can only be estimated. In addition, because the airplane was not equipped with any type of recording device, the pilot's control and system inputs and other actions are unknown. The lack of available data significantly increased the difficulty of determining the specific causes that led to this accident, and it was not possible to determine the reasons for the left engine shutdown or evaluate the pilot's recognition of and response to an engine problem. Recorded video images from the accident flight would possibly have shown where the pilot's attention was directed during the reported problems, his interaction with the airplane controls and systems, and the status of many cockpit switches and instruments. Recorded flight data would have provided information about the engines' operating parameters and the airplane's motions. Previous NTSB recommendations have addressed the need for recording information on airplane types such as the one involved in this accident. Recorders can help investigators identify safety issues that might otherwise be undetectable, which is critical to the prevention of future accidents.

According to the cockpit voice recorder (CVR), during cruise flight, the unqualified pilot-rated passenger was manipulating the aircraft controls, including the engine controls, under the supervision and direction of the private pilot. After receiving a descent clearance to 3,000 feet mean sea level (msl), the pilot told the pilot-rated passenger to reduce engine power to maintain a target airspeed. The cockpit area microphone subsequently recorded the sound of both engines spooling down. The pilot recognized that the pilot-rated passenger had shutdown both engines after he retarded the engine throttles past the flight idle stops into the fuel cutoff position. Specifically, the pilot stated "you went back behind the stops and we lost power." According to air traffic control (ATC) radar track data, at the time of the dual engine shutdown, the airplane was located about 18 miles southwest of the destination airport and was descending through 6,700 feet msl. The pilot reported to the controller that the airplane had experienced a dual loss of engine power, declared an emergency, and requested radar vectors to the destination airport. As the flight approached the destination airport, the cockpit area microphone recorded a sound similar to an engine starter spooling up; however, engine power was not restored during the attempted restart. A review of the remaining CVR audio did not reveal any evidence of another attempt to restart an engine. The CVR stopped recording while the airplane was still airborne, with both engines still inoperative, while on an extended base leg to the runway. Subsequently, the controller told the pilot to go-around because the main landing gear was not extended. The accident airplane was then observed to climb and enter a right traffic pattern to make another landing approach. Witness accounts indicated that only the nose landing gear was extended during the second landing approach. The witnesses observed the airplane bounce several times on the runway before it ultimately entered a climbing right turn. The airplane was then observed to enter a nose low, rolling descent into a nearby residential community. The postaccident examinations and testing did not reveal any anomalies or failures that would have precluded normal operation of the airplane. Although the CVR did not record a successful engine restart, the pilot was able to initiate a go-around during the initial landing attempt, which implies that he was able to restart at least one engine during the initial approach. The investigation subsequently determined that only the left engine was operating at impact. Following an engine start, procedures require that the respective generator be reset to reestablish electrical power to the Essential Bus. If the Essential Bus had been restored, all aircraft systems would have operated normally. However, the battery toggle switch was observed in the Standby position at the accident site, which would have prevented the Essential Bus from receiving power regardless of whether the generator had been reset. As such, the airplane was likely operating on the Standby Bus, which would preclude the normal extension of the landing gear. However, the investigation determined that the landing gear alternate extension handle was partially extended. The observed position of the handle would have precluded the main landing gear from extending (only the nose landing gear would extend). The investigation determined that it is likely the pilot did not fully extend the handle to obtain a full landing gear deployment. Had he fully extended the landing gear, a successful single-engine landing could have been accomplished. In conclusion, the private pilot's decision to allow the unqualified pilot-rated passenger to manipulate the airplane controls directly resulted in the inadvertent dual engine shutdown during cruise descent. Additionally, the pilot's inadequate response to the emergency, including his failure to adhere to procedures, resulted in his inability to fully restore airplane systems and ultimately resulted in a loss of airplane control.

The airplane was substantially damaged during an in-flight encounter with weather, in-flight separation of airframe components, and subsequent impact with the ground near Wells, Texas. The private pilot, who was the sole occupant, was fatally injured. The airplane sustained impact and fire damage to all major airframe components. The aircraft was registered to H-S Air LP and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a business flight. Instrument meteorological conditions prevailed for the flight, which operated on an instrument flight rules (IFR) flight plan. The flight originated from the West Houston Airport (IWS), Houston, Texas, about 2040 and was bound for the Richard Lloyd Jones Jr. Airport (RVS), Tulsa, Oklahoma. Witnesses near the accident site reported hearing an explosion and then seeing a fireball descending through the clouds to the ground. Radar track data for the last portion of the flight depicted the airplane on a 7720 transponder code. The track showed the airplane initially on a heading of about 20 degrees at 23,000 feet. The track continued in this direction until 2120:03.73 when the airplane began a right turn. The right turn continued for about 30 seconds during which time the altitude remained constant and the heading changed to about 90 degrees. After 2120:45.86, the track showed an erratic steep descent that continued to the end of the data. The final data location was received at 2122:15.53 at an altitude of 2,800 feet. The accident location was 0.86 miles and 94 degrees from the last recorded radar position.

During the 3.5-hour flight preceding the accident flight, the airplane used about 156 gallons of the 196 gallons of usable fuel. After landing, the airplane was topped off with 156 gallons of fuel for the return flight. During the preflight inspection, a line serviceman at the fixed based operator observed the right main fuel tank sump become stuck in the open position. He estimated 5 to 6 gallons of fuel were lost before the sump seal was regained, but the exact amount of fuel lost could not be determined. The lost fuel was not replaced before the airplane departed. Data from an on board GPS unit indicate that the airplane flew the return leg at an altitude of about 4,500 feet mean sea level for about 4 hours. About 4 minutes after beginning the descent to the destination airport, the pilot requested to divert to a closer airport. The pilot was cleared for an approach to runway 18R at the new destination. While on approach to land, the pilot reported to the air traffic control tower controller, “we exhausted fuel.” The airplane descended and crashed into a forested area about 1/2 mile from the airport. Post accident examination of the right and left propellers noted no leading edge impact damage or signatures indicative of rotation at the time of impact. Examination of the airplane wreckage and engines found no malfunctions or failures that would have precluded normal operation. The pilot did not report any problems with the airplane or its fuel state before announcing the fuel was exhausted. His acceptance of the approach to runway 18R resulted in the airplane flying at least 1 mile further than if he had requested to land on runway 18L instead. If the pilot had declared an emergency and made an immediate approach to the closest runway when he realized the exhausted fuel state, he likely would have reached the airport. Toxicological testing revealed cyclobenzaprine and diphenhydramine in the pilot’s system at or above therapeutic levels. Both medications carry warnings that use may impair mental and/or physical abilities required for activities such as driving or operating heavy machinery. The airplane would have used about 186 gallons of fuel on the 4-hour return flight if the engines burned fuel at the same rate as the previous flight. The fuel lost during the preflight inspection and the additional 30 minutes of flight time on the return leg reduced the airplane’s usable fuel available to complete the planned flight, and the pilot likely did not recognize the low fuel state before the fuel was exhausted due to impairment by the medications he was taking.

The commercial pilot departed on a night instrument flight rules flight in actual instrument meteorological in-flight conditions. Less than 2 minutes after the airplane departed the airport, the controller observed the airplane in a right turn and instructed the pilot to report his altitude. The pilot responded he thought he was at 3,500 feet and he thought he had lost the gyros. The pilot said he was trying to level out, and when the controller informed the pilot he observed the airplane on radar making a 360-degree right turn , the pilot said "roger." Three minutes and 23 seconds after departure the pilot said "yeah, I'm having some trouble right now" and there were no further radio communications from the flight. The on scene investigation disclosed that both wings and the tail section had separated from the airframe. All fractures of the wing and wing skin were typical of ductile overload with no evidence of preexisting failures such as fatigue or stress-corrosion. The deformation of the wings indicated an upward failure due to positive loading. No anomalies were noted with the gyro instruments, engine assembly or accessories

Prior to the accident flight, the pilot obtained a preflight weather briefing and filed an instrument flight rules flight plan. The briefer noted no adverse weather conditions along the route. The airplane departed the airport at 0853, and climbed to FL190. The first two hours of the flight was uneventful, and the aircraft was handed off to Jacksonville Air Route Traffic Control Center (ZJX ARTCC) at 1053. The pilot contacted ZJX Crestview sector at 1054:45 with the airplane level at FL190. At 1102, the Crestview controller broadcasted an alert for Significant Meteorological Information (SIGMET) 32E, which pertained to thunderstorms in portions of Florida southwest of the pilot's route. At 1103, the controller cleared to the airplane to descend to 11,000 feet and the pilot again acknowledged. At 1110:21, the pilot was instructed to contact Tyndall Approach. The pilot checked in with the Tyndall RAPCON North Approach controller at 1110:39. The pilot was told to expect a visual approach. Shortly thereafter, the pilot transmitted, "...we're at 11,000, like to get down lower so we can get underneath this stuff." The controller told the pilot to stand by and expect lower [altitude] in 3 miles. About 15 seconds later, the controller cleared to pilot to descend to 6,000 feet, and the pilot acknowledged. At 1112:27, the pilot was instructed to contact Tyndall Approach on another frequency. The airplane's position at that time was just northwest of REBBA intersection. The Panama sector controller cleared the pilot to descend to 3,000 feet at his discretion, and the pilot acknowledged. There was no further contact with the airplane. The controller attempted to advise the pilot that radar contact was lost, but repeated attempts to establish communications and locate the airplane were unsuccessful. A witness, located approximately 1 mile south of the accident site, reported he heard a "loud bang," looked up and observed the airplane in a nose down spiral. The witness reported there were parts separating from the airplane during the descent. The witness stated it was raining and there was lightning and thunder in the area. Local authorities reported that the weather "was raining real good with lightning and the thunderstorm materialized very quickly." The main wreckage came to rest near the edge of a swamp in tree covered and high grassy terrain. The left wing, left engine, and the left wing tip tank were located in a wooded area approximately 0.6 miles northwest of the main wreckage. The left wing separated from the airplane inboard of the left engine and nacelle. Examination of the fracture surfaces indicated that both the front and rear spars failed from "catastrophic static up-bending overstress..." The airplane flew through an intense to extreme weather radar echo containing a thunderstorm. Although the controllers denied that there was any weather displayed ahead of the airplane, recorded radar and display data indicated that moderate to extreme precipitation was depicted on and near the route of flight. During the flight, the pilot was given no real-time information on the weather ahead. The airplane was equipped with a weather radar system and the system provided continuous en route weather information relative to cloud formation, rainfall rate, thunderstorms, icing conditions, and storm detection up to a distance of 240 miles. No anomalies were noted with the airframe and engines.

The 2,100-hour instrument-rated private pilot stated that prior to departure for a 507 nautical mile cross-country flight, the fuel gauges indicated approximately 800 pounds of fuel on each side for a total of 1600 pounds; however, he did not visually check the amount of fuel that the tanks contained. During his approach to the destination airport, the right engine started to "sputter" before it finally quit. The pilot then "looked over at the fuel gauges and both tanks were showing empty." The left engine quit just a few moments later. The auto ignition installed in the airplane attempted to restart the engines. The engines restarted momentarily and then shut-off once more. The pilot declared an emergency and executed a forced landing onto a street below. After a hard landing onto the street, the right wing hit a telephone pole, and the left wing then hit several tree limbs before the airplane impacted a hill and came to a stop. The Federal Aviation Administration (FAA) inspector, who responded to the accident site, found the fuel transfer switch in the "right-crossfeed" position. The fuel system was examined and no leaks or anomalies were found. Approximately three-quarters of a gallon of unusable fuel was found in the right engine nacelle. Approximately four gallons (28 pounds) of usable fuel was found in the left engine nacelle.