N91TDTextron Aviation T240 · 2016

On November 8, 2009, about 1130 central standard time, a Beech A36, N91TD, was lost from radar contact and impacted the ground approximately one mile northwest of Kestrel Airpark (1T7), Spring Branch, Texas. The pilot and the two passengers were fatally injured. The airplane was substantially damaged. The airplane was registered to Gold Cup Pawn Shop Inc., and operated by the private pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Instrument meteorological conditions (IMC) prevailed for the flight, which operated on a instrument flight rules flight plan. The flight originated from Kerrville Municipal Airport/Louis Schreiner Field (ERV), Kerrville, Texas, about 1110 and was en route to Pearland Regional Airport (LVJ), Pearland, Texas.

According to transcripts and radar data provided by the Federal Aviation Administration (FAA), the airplane was in radar contact and the pilot was in voice communications with San Antonio air traffic control tower (ATCT) approach control. At 1118, the airplane was level at 5,000 feet mean sea level (msl) and with a clearance to climb to 9,000 feet msl. At 1121, the pilot acknowledged the San Antonio altimeter setting. At 1127, the airplane was level at 9,000 feet msl. At 1129, radar and radio contact with the airplane was lost. No distress call was received.

A review of the radar data, obtained from the FAA, illustrated the flight was at about 9,000 feet msl on a meandering course generally eastbound. Radar data depicted the airplane began a shallow turn to the left at 1127:20 and then began turning to the right at 1128:44. A radar contact at 1129:32 showed the airplane in a right turn at 8,900 feet msl. The last radar contact at 1129:46 showed the airplane in a descending right turn at 6,400 feet msl.

Two witnesses reported hearing a noise like an “airplane in a dive”, and then looked out their window and saw something very large with lots of smaller pieces falling out of the clouds. Several witnesses reported hearing the loud sounds of high engine rpms and then the sounds of impact. One witness heard an airplane flying “ridiculously low” over her house, and then heard a loud crashing noise. She ran out of her garage and saw debris flying in the air.

The pilot, age 60, held a private pilot certificate with an airplane single-engine land rating. An instrument airplane rating was added to that pilot certificate after the pilot passed a practical test on December 8, 2007. The pilot held a third-class airman medical certificate issued July 30, 2009, with limitations.

One pilot logbook, marked logbook number 2, was available for examination. It covered the period beginning on November 2, 2003, until the last logbook entry on October 7, 2009. That logbook showed that the pilot had 885 hours of total pilot experience, including more than 500 hours in a Beech model J35, and a total of 84 hours in instrument flying conditions. The most recent entry in the logbook for instrument flight experience was on December 15, 2007. Based on witness information, the pilot flew about 4 hours in the accident airplane on November 6, 2009.

A certified flight instructor (CFI) provided a statement that he gave 44 periods of flight instruction to the pilot during a 14 month period in 2005 and 2006 when the pilot was preparing for his instrument airplane rating. The CFI perceived the pilot had developed an over reliance on the autopilot, was reluctant to read the flight manual, and not normally use a cockpit checklist. Consequently, the pilot would forget to complete required tasks and was easily distracted, sometimes at critical points in the flight. The CFI’s opinion was that the pilot had lost, or had never developed, basic instrument skills. In addition, the CFI thought that the pilot had good basic visual flight rules (VFR) flying skills and was generally cautious in his flying, but at times, was over confident in his flying ability. .

A second CFI said he had given about 34 hours of flight instruction to the pilot during the three month period before the pilot successfully passed his instrument check ride in December 2007. The CFI said the pilot was flying an older V tail Bonanza which he flew very well and the pilot was proficient in all operations of the aircraft.

The second CFI reported that he had flown N91TD with the pilot only once, when he gave a single 1.2 hour period of flight instruction on November 6, 2009. The CFI recalled the pilot flew the new airplane well, but struggled with the different autopilot and avionics in the new airplane. The CFI had told the pilot that he did not believe he was ready to fly the airplane in IMC until the pilot had gained more experience and received more instruction in the new airplane.

The six-seat, low-wing, retractable-gear airplane, serial number E-2624, was manufactured in 1991. It was powered by a Continental IO-550-B(6) 300 horsepower engine and equipped with a Hartzell 3-blade, constant speed, aluminum alloy propeller. A review of the maintenance logbook records showed an annual inspection was completed on November 3, 2008, at an airframe total time of 2744.8 hours, an engine total time of 1705.0 hours, and engine time since major overhaul of 233.7 hours. The last entry in the aircraft maintenance logbook showed a “pre buy” inspection was completed on November 4, 2009, at an airframe total time of 3065.4 hours. Damage sustained to the Hobbs hour-meter during the accident precluded obtaining the airplane’s current reading.

The airplane was equipped with a Bendix/King KFC-150 autopilot with KAS-297B altitude preselect, a Garmin MX20 multifunction display, and a Garmin GNS 430W navigation and communications unit. It was also equipped with a Ryan TCAD ATS-8000 collision avoidance system, and a WX-1000 stormscope.

FAA aircraft registry records show that the airplane was registered to the owner on October 22, 2009.

The closest weather reporting station to the accident site was from San Antonio International Airport (KSAT), San Antonio, Texas, located approximately 18 miles south of the accident site at an elevation of 809 feet msl. The airport was equipped with an Automated Surface Observation System (ASOS) and was augmented by NWS certified weather observers. A thunderstorm with heavy rain had been reported at San Antonio between 1008 and 1039 and had moved northwestward. Rain continued at the time of the accident, when the following conditions were reported:

San Antonio special weather observation at 1137, wind from 120 degrees at 4 knots, visibility 2 miles, runway 12R visual range 3,000 feet variable 6,000 feet, heavy rain and mist, ceiling broken at 300 feet, broken at 1,600 feet, and overcast at 2,200 feet, temperature 19 degrees C, dew point temperature 18 degrees C, and an altimeter setting of 30.05 inches of mercury. Remarks: automated observation system, ceiling 200 variable 800 feet, hourly precipitation 0.33 inches.

The closest upper air sounding or rawinsonde observation (RAOB) was from the NWS Corpus Christi (KCRP), Texas, location approximately 130 miles southeast of the accident site at an elevation of 43 feet msl. The 0600 sounding depicted a surface based temperature inversion, where temperature increased with height to 254 feet above ground level (agl) before decreasing. The sounding was also characterized as being a moist low-level environment from the surface to 16,000 feet with a lifted condensation level (LCL) at 338 feet agl, a convective condensation level (CCL) at 3,324 feet agl, and a level of free convection (LFC) at 4,473 feet agl. The precipitable water content was 1.65 inches. The expected top of convective clouds was estimated by the equilibrium level (EL) to be 30,058 feet, with the tropopause height identified at 55,664 feet. The freezing level was identified at 13,332 feet. The sounding stability parameters indicated a Lifted Index (LI) of -0.5, with the most unstable LI of -2, indicating a conditional to unstable environment was favorable for thunderstorm development. The K-index of 31.3 indicated an approximately 60 percent chance of air mass type thunderstorms. The storm character and category was for weak ordinary cell formation, capable of producing surface hail to 0.25 inch, with wind gusts to approximately 21 knots.

The Austin/San Antonio (KEWX),WSR-88D radar, approximately 22 miles east of the accident site, recorded a base reflectivity image for a 0.5 degree elevation scan completed at 1132. with the aircraft’s flight track overlaid which provided with a resolution of 0.5 X 0.25 kilometers. The track of N91TD proceeded through an area of light intensity echoes immediately after the airplane departed ERV and entered a small area of echoes of 40 to 50 dBZ or heavy intensity echoes (VIP Level 3 to 5) when the aircraft upset occurred. The area of echoes was organized in a northeast to southwest band of embedded echoes.

A convective SIGMET 3C issued at 1055 was current over the accident site for an area of embedded thunderstorms moving from 190 degrees at 25 knots, with tops to 33,000 feet.

AIRMET Sierra update 3 was current for IFR conditions with ceilings below 1,000 feet and visibility below 3 miles in mist. The IFR conditions were expected to end over the area between 0900 through 1200 CST.

NEXRAD radar data indicated the presence of precipitation in the area, but it is unknown whether that precipitation was being displayed to the air traffic control (ATC) controller on the ATC radar display.

The pilot contacted the Fort Worth, Texas, FAA contract Automated Flight Service Station (AFSS) between 0918 and 0937 to file an IFR flight plan and obtain a weather briefing. The AFSS briefer provided airmen’s meteorological information (AIRMET) for IFR and icing conditions above 13,000 feet for the route, and then proceeded to provide the current ERV weather which had an overcast ceiling at 1,200 feet and provided a pilot report of cloud tops near 3,600 feet. The enroute forecast conditions were briefed as overcast clouds at 2,000 feet with tops to 6,000 feet, visibility 3 to 5 miles in mist, and then after 1200, ceilings broken at 4,000 feet and overcast at 15,000 feet with cloud tops to 8,000 feet. The briefer indicated that thunderstorms were likely after 1500. The pilot of N91TD then indicated that’s why he was trying to get there and back before the thunderstorms were expected. The briefer provided the forecast weather conditions near the destination for marginal visual flight rules (MVFR) conditions and for thunderstorms in the vicinity of the destination after 1200. T The briefer relayed the current radar and indicated that rain showers were developing just south of the planned route of flight, which was moving northward and indicated that northerly deviations would be preferred to avoid any activity.

At 1116, N91TD contacted the San Antonio ATCT approach radar west (APW) controller and advised he was at five thousand and proceeding “direct to SEEDS”. The APW controller responded.

At 1118, the APW controller cleared N91TD to climb and maintain nine thousand. N91TD responded.

At 1120, the APW controller asked N91TD to expedite his climb through eight thousand. N91TD responded.

At 1122, the APW controller instructed N91TD to change radio frequency to San Antonio approach. N91TD responded.

At 1122, N91TD contacted the San Antonio ATCT approach radar north (APN) controller and advised he was climbing to nine thousand.

At 1122, the APN controller responded and gave the current altimeter setting as “three zero zero four”.

At 1122, N91TD responded with: “three zero zero four for nine one tango delta”.

At 1129:29, the APN controller asked N91TD if he was “turning south for weather”. There was no response.

At 1129:36, the APN controller called N91TD. There was no response.

At 1129:41, the APN controller called N91TD and said “if you hear me ident”.

At 1129:46, the APN controller called N91TD and said “I have ident observed”.

At 1129:57, the APN controller called N91TD. There was no response.

At 1130:05, the APN controller called N91TD. There was no response.

The accident site was on relatively flat pasture area with grazing cattle. It was adjacent to a barn and residence at an estimated elevation of about 1,260 feet msl. The main wreckage of the airplane impacted terrain on a southerly course. Most major portions of the airplane had separated before impact and were widely dispersed in an area about 500 feet in diameter.

The main wreckage consisted of the engine, propeller assembly, the left flap, and the lower forward fuselage. All portions had impact damage. A handheld compass showed the direction from the initial impact hole to the main wreckage was 196 degrees at a distance of about 40 feet. The right wing was observed about 200 feet to the east from the main wreckage. The left wing was about 40 feet to the southwest from the main wreckage. A portion of the aft fuselage with the vertical stabilizer and part of the rudder was about 80 feet north from the main wreckage. The right aileron was observed about 165 feet northeast from the main wreckage. The left aileron was observed about 300 feet northwest from the main wreckage. The left aileron was observed about 300 feet northwest from the main wreckage. Portions of the forward top skin and the upper aft fuselage were observed about 325 feet northwest from the main wreckage.

All primary and secondary flight control surfaces with their appropriate trim tabs were observed and accounted for at the accident scene. Continuity of all primary control cables were confirmed from the cockpit to their respective flight control surface via cable separation. Continuity of the elevator and aileron trim control cables were confirmed from the cockpit to the respective flight control surfaces via cable separation. The primary and secondary control cables that were separated had signatures consistent with tension overload.

The left flap actuator exposed rod extension was measured and found to be approximately 1 3/4 inches, which corresponds to approximately a 0 degree flap up position. The right flap actuator exposed rod extension was measured and found to be approximately 2 5/8 inches, which corresponds to approximately a 4 degree flap position.

The landing gear actuator was examined and found in the landing gear retracted position. The left main landing gear push rod was separated from the left main landing gear. The right main landing gear push rod was separated from the landing gear actuator. The left main landing gear and the nose landing gear were separated from the airplane. The right main landing gear was attached to the separated right wing in the extended position.

The engine exhibited an extensive amount of impact related damage. All of the engine accessories had separated free of the engine. The number 1, 3, and 5 cylinder heads separated free from their respective cylinder barrels. The cylinders on the opposite side remained attached to the crankcase and exhibited heavy impact damage. One exhaust manifold was recovered and visually appeared to have been perpendicularly compressed.

The propeller assembly was observed separated from the engine crankshaft flange attachment bolts. One propeller blade had an aftward bend approximately six inches from the tip. One blade was straight and no damage was observed. One blade was buckled in a ‘U’ shape figure.

The other separated wreckage components were laid out corresponding to their normal location on the airplane. Both ailerons, aileron trim tab, both wings, both wing tips, both flaps, all three tail surfaces, both elevators, elevator trim tab, both elevator counter weights, rudder and rudder counter weight, cabin door, utility door, both main landing gear, the nose gear, engine, propeller, engine cowling, all six seats from the cockpit and cabin area, and most portions of the fuselage skin were observed in the debris field and were recovered and laid out.

The examination of the wreckage did not reveal any preimpact anomalies that would have prevented normal operations.

An autopsy was performed on the remains of the pilot on November 9, 2009, by the Deputy Chief Medical Examiner, at the Travis County Forensic Center, Austin, Texas. The autopsy concluded that the cause of death was due to blunt force injuries.

Forensic toxicology was performed on specimens from the pilot by the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The toxicology report stated: tests for CARBON MONOXIDE were not performed; tests for CYANIDE were not performed; NO ETHANOL detected in Vitreous; Amlodipine detected in Liver; Amlodipine detected in Kidney, Diphenhydramine detected in Liver; and Diphenhydramine detected in Kidney. No blood was available for analysis.

Amlodipine was reported as a treatment for high blood pressure on the pilot’s most recent application for an airman medical certificate. Diphenhydramine is a common over the counter sedating antihistamine with impairing effects. It is used in the treatment of the common cold and hay fever.

The wreckage was recovered from the accident scene and relocated to the facilities of Air Salvage of Dallas, Lancaster, Texas. On November 11 and 12, 2009, investigators from the Safety Board, Hawker Beechcraft Corporation (HBC), and Teledyne Continental Motors, Inc. (Continental) examined the wreckage at that location.

The engine was removed from the wreckage and examined separately. The other separated wreckage components were laid out corresponding to their normal location on the airplane. Both ailerons, aileron trim tab, both wings, both wing tips, both flaps, all three tail surfaces, both elevators, elevator trim tab, both elevator counter weights, rudder and rudder counter weight, cabin door, utility door, both main landing gear, the nose gear, engine, propeller, engine cowling, all six seats from the cockpit and cabin area, and most portions of the fuselage skin were observed in the debris field and were recovered and laid out.

The examination of the wreckage did not reveal any preimpact anomalies that would have prevented normal operations.

On December 4, 2009 investigators from the FAA, HBC, and Continental examined portions of the wreckage at the Continental facilities in Mobile, Alabama. Examined were the engine, propeller governor, exhaust system, and portions of wiring harnesses, hoses, tubing and control cables. The engine was disassembled and examined.. The crankshaft and counterweight assembly was undamaged and exhibited normal operating signatures. Crankshaft to camshaft timing could not be verified due to impact damage on the aft crankshaft gear. The connecting rods, connecting rod journals, main journals and thrust surfaces were undamaged and showed no signs of abnormal wear or lubrication distress. The crankshaft counterweight pins, plates and snap-rings were intact. The counterweights were undamaged and had free and unrestricted movement on the hanger blades.

The examination of the engine did not reveal any preimpact anomalies that would have prevented normal operations.

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The FAA “Instrument Flying Handbook”, FAA-H-8083-5A, chapter 1, Human Factors, lists some of the illusions leading to spatial disorientation:

The leans - An abrupt correction of a banked attitude, which has been entered too slowly to stimulate the motion sensing system in the inner ear, can create the illusion of banking in the opposite direction. The disoriented pilot will roll the aircraft back into its original dangerous attitude, or if level flight is maintained, will feel compelled to lean in the perceived vertical plane until this illusion subsides.

Elevator illusion - An abrupt upward vertical acceleration, as can occur in a helicopter or an updraft, can shift vision downwards (visual scene moves upwards) through excessive stimulation of the sensory organs for gravity and linear acceleration, creating the illusion of being in a climb. The disoriented pilot may push the aircraft into a nose low attitude.

False horizon - Sloping cloud formations, an obscured horizon, a dark scene spread with ground lights and stars, and certain geometric patterns of ground light can create illusions of not being aligned correctly with the actual horizon. The disoriented pilot will place the aircraft in a dangerous attitude.

According to the FAA Advisory Circular AC 60-4A, "Pilot's Spatial Disorientation," tests conducted with qualified instrument pilots indicated that it can take as long as 35 seconds to establish full control by instruments after a loss of visual reference of the earth's surface. AC 60-4A further states that surface references and the natural horizon may become obscured even though visibility may be above VFR minimums and that an inability to perceive the natural horizon or surface references is common during flights over water, at night, in sparsely populated areas, and in low-visibility conditions.