Texas

The twin engine aircraft, owned by Lawrence R. Liptack, crashed in flames in an open field located northeast of Bowie, Texas. The pilot and owner, aged 51, was killed with his son aged 10. The multi-engine airplane was about 500 ft above ground level (agl) and on a left base landing approach when a witness saw the airplane suddenly point straight down, begin spinning, and make three complete rotations before impacting terrain in a partially nose-down attitude. The airplane came to rest upright, and was mostly consumed by an immediate post impact fire. A post accident examination of the wreckage revealed no evidence of preimpact mechanical malfunctions or failures that would have precluded normal operation. A pilot operating another pipeline patrol airplane in the vicinity reported frequent severe-to-extreme turbulence about 1,000-2,000 ft above ground level. Data from an on-board GPS unit indicated that, while on the base leg of the airport traffic pattern for landing, the accident airplane's airspeed decayed 10 knots below the manufacturer's recommended approach speed for turbulent conditions. An autopsy performed on the pilot found significant existing atherosclerotic disease (60 to 80 percent) and described evidence of an acute, premortem, nonocclusive thrombosis of the left anterior descending coronary artery. The medical examiner's conclusion stated it "appears the decedent likely suffered an acute cardiac event while piloting his aircraft" and "died primarily due to hypertensive and atherosclerotic cardiovascular disease and that his multiple blunt force injuries likely contributed to his death." It is likely that the pilot was incapacitated due to the acute cardiac event and lost control of the airplane during the approach to land.

The private pilot was conducting a personal flight during day, instrument flight rules (IFR) conditions. The pilot checked in with an air route traffic control center, and, after radar data showed multiple changes in altitude that were not in accordance with the assigned altitudes, an air traffic controller queried the pilot about the altitude changes. The pilot reported an autopilot problem and then later requested clearance to deviate around weather at a higher altitude. The airplane passed through several sectors and controllers, and it was understood that the pilot was aware of the adverse weather due to the deviation information in the flight strip. The air traffic controller did not provide additional adverse weather information and updates to the pilot, as required by a Federal Aviation Administration order; however, general broadcasts of this weather information were recorded on the frequency the pilot was using before the accident. Multiple weather resources showed rapidly developing multicellular to supercell-type convective activity with cloud tops near 48,000 ft. Forecasts and advisories warned of potential strong to severe thunderstorms with the potential for moderate-to-severe turbulence, hail, lightning, heavy rains, and high wind. Radar data indicated that the pilot turned into the intense weather cells instead of away from them as he had requested. The pilot declared a "mayday" and reported that he had lost visual reference and was in a spin. Damage to the airplane and witness marks on the ground were consistent with the airplane impacting in a level attitude and a flat spin. No mechanical anomalies were noted that would have precluded normal operation before the loss of control and impact with the ground. The investigation could not determine if there was an anomaly with the autopilot or if the rapidly developing thunderstorms and associated weather created a perception of an autopilot problem. The autopsy identified coronary artery disease. Although the coronary artery disease could have led to an acute coronary syndrome with symptoms such as chest pain, shortness of breath, palpitations, or fainting, it was unlikely to have impaired the pilot's judgment following a preflight weather briefing or while decision-making en route. Thus, there is no evidence that a medical condition contributed to the accident. The toxicology testing of the pilot identified zolpidem in the pilot's blood and tetrahydrocannabinol and its metabolite in the pilot's cavity blood, which indicated that he was using two potentially impairing substances in the days to hours before the accident. It is unlikely that the pilot's use of zolpidem contributed to the accident; however, the investigation could not determine whether the pilot's use of marijuana contributed to the cause of the accident.

The non-instrument-rated pilot departed on a cross-country flight in a twin-engine turboprop airplane on an instrument flight plan. As the pilot neared his destination airport, he received heading and altitude vectors from air traffic control. The controller cleared the flight for the approach to the airport; shortly afterward, the pilot radioed that he was executing a missed approach. The controller then issued missed approach instructions, which the pilot acknowledged. There was no further communication with the pilot. The airplane collided with terrain in a near-vertical angle. About the time of the accident, the automated weather reporting station recorded a 300-foot overcast ceiling, and 5 miles visibility in mist. Examination of the wreckage did not reveal any anomalies that would have precluded normal operation. Additionally, both engines displayed signatures consistent with the production of power at the time of impact. The pilot's logbook indicated that he had a total of 1,281.6 flight hours, with 512.4 in multi-engine airplanes and 192.9 in the accident airplane. The logbook also revealed that he had 29.7 total hours of actual instrument time, with 15.6 of those hours in the accident airplane. Of the total instrument time, he received 1 hour of instrument instruction by a flight instructor, recorded about 3 years before the accident. The accident is consistent with a loss of control in instrument conditions.

The pilot reported that he had added fuel at the previous fuel stop and that he was using a fuel totalizer to determine the quantity of fuel onboard. After climbing to a cruise altitude of 14,000 feet above ground level, he discovered that the fuel mixture control was frozen and that he was unable to lean the mixture to a lower fuel flow setting. The pilot reported that because of the increased fuel consumption, he briefly considered an en route stop for additional fuel but decided to continue. During descent, the airplane experienced a complete loss of power in both engines, and the pilot made an emergency off-field, gear-up landing about 7 miles from the destination. The airplane impacted terrain and thick scrub trees, which resulted in substantial damage to both wings, both engine mounts, and the fuselage. A postaccident examination found that only a trace of fuel remained. The pilot also reported that there was no mechanical malfunction or failure and that his inadequate fuel management was partly because he had become overconfident in his abilities after 50 years of flying.

The instrument-rated pilot obtained a weather briefing prior to departure that contained surface observations along the route of flight, as well as significant meteorological (SIGMET) and airman's meteorological (AIRMET) information. The briefing also included convective weather advisories, a convective outlook, the area forecast, pilot reports, radar summary, and winds aloft information. The area forecast included overcast ceilings at 1,500 feet mean sea level (msl) with cloud tops at 6,000 feet msl, visibility between 3 and 5 miles, light rain and mist, and isolated thunderstorms with cumulonimbus tops to 35,000 feet msl. After the pilot departed, he established contact with air traffic control; the airplane was initially observed on radar heading toward the destination airport. An analysis of radar from the day of the accident indicated that isolated thunderstorms existed and that, almost 4 minutes after departing, the airplane encountered an area of developing rain showers and vertical updrafts. The airplane began a descending right turn followed by a brief climb, then another descent; its ground speed slowed from 202 knots to 110 knots before the data ended. At that time, the airplane was at 4,500 feet msl. A witness said he heard the airplane but was unable to see it due to the low cloud layer. A few moments later, he saw the airplane exit the cloud layer in a spin before it impacted the ground. A postaccident examination revealed no mechanical deficiencies that would have precluded normal operation of the airplane and engine.

During the cross-country instrument flight rules flight, the pilot was in contact with air traffic control personnel. The controller cleared the airplane to flight level 210 and gave the pilot permission to deviate east of the airplane's route to avoid weather and traffic. A review of radar data showed the airplane heading southward away from the departure airport and climbing to an altitude of about 14,800 feet mean sea level (msl). Shortly thereafter, the airplane turned north, and the controller queried the pilot about the turn; however, he did not respond. The airplane wreckage was located on ranch land with sections of the airplane's outer wing, engines, elevators, and vertical and horizontal stabilizers separated from the fuselage and scattered in several directions, which is consistent with an in-flight breakup before impact with terrain. A review of the weather information for the airplane's route of flight showed widely scattered thunderstorms and a southerly surface wind of 30 knots with gusts to 40 knots. An AIRMET active at the time advised of moderate turbulence below flight level 180. Three pilot reports made within 50 miles of the accident site indicated moderate turbulence and mountain wave activity. An assessment of the humidity and freezing level noted the potential for clear, light-mixed, or rime icing between 10,700 and 17,300 feet msl. Postaccident airplane examination did not reveal any mechanical malfunctions or anomalies with the airframe and engines that would have precluded normal operation. It's likely the airplane encountered heavy to extreme turbulence and icing conditions during the flight, which led to the pilot’s loss of control of the airplane and its subsequent in-flight breakup.

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.

The commercial pilot was distracted by the nose cargo door popping open during takeoff; the airplane stalled and collided with trees off the end of the runway. The pilot said there were no mechanical problems with the airplane or engines and that he was fixated on the cargo door and lost control of the airplane. He also said that due to stress, he was not mentally prepared to handle the emergency situation.

Before the flight, the pilot did not obtain a weather briefing and departed without approval from company personnel. The airplane departed the airport about 0230 and climbed to 14,500 feet mean sea level. The pilot obtained visual flight rules (VFR) flight following services from air traffic control (ATC) personnel during the flight. While the airplane was en route, ATC personnel advised the pilot that an area of moderate precipitation was located about 15 miles ahead along the airplane’s flight path. The pilot acknowledged the transmission and was then directed to contact another controller. About 3 minutes later, the new controller advised the pilot of an area of moderate to extreme precipitation about 2 miles ahead of the airplane. The pilot responded that he could see the weather and asked the controller for a recommendation for a reroute. The controller indicated he didn’t have a recommendation, but finished by saying a turn to the west (a right turn) away from the weather would probably be better. The pilot responded that he would make a right turn. There was no further radio contact with the pilot. Flight track data indicated the airplane was in a right turn when radar contact was lost. A review of the radar data, available weather information, and airplane wreckage indicated the airplane flew through a heavy to extreme weather radar echo containing a thunderstorm and subsequently broke up in flight. Postaccident examination revealed no mechanical malfunctions or anomalies with the airframe and engines that would have precluded normal operation. During the VFR flight, the pilot was responsible for remaining in VFR conditions and staying clear of clouds. However, Federal Aviation Administration directives instruct ATC personnel to issue pertinent weather information to pilots, provide guidance to pilots to avoid weather (when requested), and plan ahead and be prepared to suggest alternate routes or altitudes when there are areas of significant weather. The weather advisories and warnings issued to the pilot by ATC were not in compliance with these directives. The delay in providing information to the pilot about the heavy and extreme weather made avoiding the thunderstorm more difficult and contributed to the accident.

The pilots reported that the cargo airplane was about 60 pounds over its maximum takeoff weight. Because their taxi to the assigned runway was long, they decided to reduce weight by using higher-than-normal engine power settings to burn fuel before takeoff while using the wheel brakes to control the airplane’s speed while taxiing. During the taxi, a fire ignited in the right wheel housing. The pilots brought the airplane to a stop on the taxiway, evacuated, and attempted to extinguish the fire with two handheld fire extinguishers. Airport firefighting personnel arrived on scene and extinguished the fire using foam suppressant. Although the fire damage was extensive, postaccident examination of the airplane did not show evidence of mechanical malfunctions or failures with the wheel and brake system that could have caused the fire. The right and left main landing gear tires deflated when the fusible plugs in the wheels blew due to overheating. The fusible plugs are designed to “fail” if the wheels overheat, and those plugs functioned as designed. The pilots stated that they had been trained to not ride the brakes while taxiing. However, the captain stated that he did not realize that he was in danger of blowing the tires much less causing a fire, otherwise he would not have attempted to bum off excess fuel while taxiing.