Aviation Accident Summaries

Aviation Accident Summary FTW97FA049

TUCUMCARI, NM, USA

Aircraft #1

N48PD

Beech A36TC

Analysis

Due to en route weather, the noninstrument-rated pilot decided to land at an en route airport. During the descent to the airport, the pilot reported a loss of engine power. The passenger stated that the airplane 'appeared to be gliding down toward a field and then it started to spin out of control.' A witness observed the airplane at 150 to 200 feet AGL with the left wing low, then perpendicular to the sky, followed by a nose low impact' short of the runway in flat terrain. Maintenance records did not reveal any uncorrected maintenance defects. Flight control continuity was confirmed. The right rear forward facing seat was found detached from the cabin floor where the nut plates pulled through the floor. Prescription and nonprescription drugs were found in the aircraft, and the toxicology was positive for Verapamil, a high blood pressure medication that may be approved by FAA for use by pilots; however, the FAA records did not indicate that the pilot had requested approval to use the drug. An engine test that was run to full throttle did not reveal any discrepancies that would have contributed to a total loss of engine power.

Factual Information

HISTORY OF FLIGHT On November 27, 1996, at 1224 mountain standard time, a Beech A36TC airplane, N48PD, was substantially damaged following a loss of control during a forced landing near Tucumcari, New Mexico. The non-instrument rated private pilot was fatally injured and his two passengers received serious injuries. The airplane, registered to and operated by Desert Aero Inc., was operating under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the personal cross country flight for which a flight plan was not filed. The airplane departed Addison, Texas, at approximately 0936. During interviews conducted by the investigator-in-charge, and on the enclosed statements, local authorities and witnesses reported the following information. The final destination of the flight was Sante Fe, New Mexico, with a planned en route stop at Albuquerque, New Mexico. After the pilot obtained an in flight weather update for New Mexico, he elected to land at Tucumcari and monitor the weather before continuing his flight to Albuquerque. At 1215, prior to entering the traffic pattern at Tucumcari, the pilot requested and received an airport advisory of "winds 5 to 10 knots from the west favoring runway 26." About 10 minutes later, the pilot reported entering the pattern on a left downwind. Two minutes later the pilot transmitted "engine quit coming in." The unicom operator observed the airplane at an estimated altitude of 150 to 200 feet AGL. The witness observed the airplane "with the left wing low, then perpendicular to the sky, followed by a nose low impact." Local authorities were notified and rescue personnel responded to the scene. PERSONNEL INFORMATION During interviews, conducted by the investigator-in-charge, the fixed base operator (FBO) manager and the flight instructor, who had previously flown with the pilot, reported the following information. The airplane was topped with fuel on November 26, 1997. With full fuel tanks, the pilot "would fly with the left fuel tank selected for one hour and then the right fuel tank for one hour of flight time. With the main tanks 1/2 full, the pilot would select the tip tank crossfeed position and fuel would flow simultaneously from both tip tanks. The before landing checklist states "fuel selector - MOST FULL" and the pilot would select the fullest (left) tank prior to the landing." During interviews, conducted by the investigator-in-charge, and on the enclosed passenger statement, the pilot's spouse stated the following information. The en route weather was fine until the flight crossed the New Mexico border and then the weather was foggy. The non instrument rated pilot called Albuquerque for an en flight weather report and due to weather in the vicinity of Albuquerque, the pilot decided to land at Tucumcari and recheck the weather before proceeding to Albuquerque. There were no problems with the airplane prior to the loss of engine power during the descent to the Tucumcari airport. Following the loss of engine power, the airplane "appeared to be gliding down toward a field and then it started to spin out of control." A review of the pilot flight records and the FAA records, by the investigator-in-charge, revealed that the pilot's first flight in the BE35 was on January 16, 1994, when he received 0.5 hour of dual instruction in a BE35 aircraft. The pilot's first flight in N48PD was on March 30, 1995, and at the time of the accident, the pilot's total flight experience in this make and model of airplane was 128.7 hours of which 92.6 hours was in N48PD. AIRCRAFT INFORMATION The maintenance records were reviewed by the investigator-in-charge. The aircraft was issued the FAA airworthiness certificate on March 18, 1980. Desert Aero, Inc., Certificate of Incorporation in the State of Texas, was issued on January 11, 1996, with the aircraft registered to that corporation on June 6, 1996. Aircraft airframe, propeller, and engine logbooks did not reveal any anomalies or uncorrected maintenance defects. COMMUNICATIONS A review of air traffic control data revealed the following summary information. All times are converted to central mountain standard time unless otherwise indicated. At 0836, the pilot of N48PD, called and received a full weather briefing for a VFR flight from Addison, Texas, to Albuquerque, New Mexico. En route to Albuquerque, the pilot of N48PD called the Albuquerque Flight Specialists and reported that his flight was encountering MVFR conditions with broken cloud layers in the area forming IFR conditions. The pilot reported that he needed to remain VFR and requested the weather for climbing above the cloud layers and continuing the flight to Albuquerque. The pilot was briefed on the current airmet for IFR conditions along and north of the route to Albuquerque for the next 2 hours. Subsequently, the pilot stated that he would land at Tucumcari and obtain an update on the weather after the next hourly sequence report. WRECKAGE AND IMPACT INFORMATION The airplane impacted the terrain (an unobstructed, flat, level milo field that had been harvested and disk-plowed) approximately 1/2 mile east of the approach end of runway 26. Forward of the left wing, a ground scar 17' 6" in length was found. The propeller was buried in the ground at one end of the ground scar and the left wing fuel tip tank near the other end of the ground scar. According to the manufacturer representative, the horizontal span of the airplane from wing tip to wing tip is 33' 6." The airplane came to rest on a measured magnetic heading of 210 degrees. See the enclosed diagram for additional details. The left wing section, outboard of the fuel tank, separated from the wing. The fuel tank split spanwise exposing the baffle zipper and the outlet screen. No fuel was found in the tank, the zipper was closed and the outlet screen was clear of debris. The forward end of the left wing fuel tip tank was crushed aft and the tank was separated from the wing. The aileron was found aft of the wing and the separation points at the bellcrank exhibited surface deformation and roughness. Skin buckling and wrinkling was found on the outboard lower surface of the right wing that remained attached to the fuselage. The right wing aileron remained attached at the right wing attachment points; however, the left wing aileron was separated from the left wing and lying on the ground aft of the left wing. Both of the flaps remained attached to the respective wings and the actuator extension measurement placed the flaps in the retracted position. Flight control continuity was established. The fuel system integrity of all the fuel tanks was compromised; however 17.5 gallons of fuel was recovered from the right wing fuel tank. The fuel selector valve shaft fractured through the fuel selector handle; however, with the fractured surfaces matched, the pointer was positioned to the left main fuel tank with the shaft in the detent position. Fuel drained from the left main fuel tank line where the line attached to the fuel selector. Approximately 1% of the fuel selector fuel screen was covered with debris. The cockpit was destroyed and the cabin roof was crushed aft and inward. The instrument panel separated from the cockpit and part of the avionics were found aft of the right wing. The aircraft doors were separated from the fuselage; however there was no physical evidence supporting an in flight opening of the doors. The inboard doors for the main landing gear were closed, the gear was extended, and the gear actuator was in the extended position. All the seats remained in the airplane; however, the forward support for the left front seat was found detached from the carrythrough spar. The right rear forward facing seat (P/N 106-530056-2 manufactured in March 1980 was found detached from the cabin floor where the nut plates pulled through the floor. The only attachment point to remain secure on the left forward facing seat was the left rear point. The Continental engine TSIO-520-U-MB, S/N 515609 was recovered from the site and was examined at a hangar at the Tucumcari Municipal Airport under the surveillance of the investigator-in-charge. The cooling fins on the number 6 cylinder, the #4 and # 6 rocker covers, the induction and exhaust system tubes, the vacuum pump support pad and the magneto drive received impact damage. The crankshaft rotated and hand compression and continuity was noted at all the cylinders and the engine accessory case. The turbocharger compressor drive shaft rotated and the drive coupling was intact. The fuel pump drive coupling rotated, the mixture control was in the full rich position, and the adjusting shaft was bent. The throttle control was found in the mid throttle position and the throttle body was crushed. No physical evidence of internal engine failure was noted. Engine mounts were broken and the starter was separated from its mounting pad. All internal components of the vacuum pump were found intact. The spark plugs had "moderate wear and light deposits in the electrode areas." The propeller was found separated from the engine and the propeller governor actuating head was separated from the governor. The propeller spinner was crushed and deformed in a rearward direction. The propeller mounting flange was measured with a dial micrometer. The face of the propeller flange had 0.250 inch distortion and 0.210 inch radial distortion. Circumferential cracks approximately 180 degrees around the crankshaft were found in the aft area of the propeller mounting flange. Two of the propeller blades were loose in the hub and bent aft approximately 20 degrees and the third blade remained fixed in the hub. The engine and the propeller were shipped to Mobile, Alabama, for further examination by the Board. The baggage was found aft of the cabin seats, was removed from the airplane and weighed for a total baggage weight of 104 pounds. Prescription and non prescription drugs were found in the baggage. The non prescription drugs consisted of 5 Malox tablets, 10 Dimatap, 3 Sudafed remaining in a 10 pack package, 1 Sinutab, 10 Imodium, 19 Claritan, 1 unopened package of Ex Lax, 6 Pepto Bismo, 20 Tylenol, 4 Drixoral, and 10 unidentified white tablets. The prescription drugs consisted of 16 tablets of 240 mg Verapamil from a 30 tablet prescription and 19 tablets of 10 mg Accupil from a 60 tablet prescription. MEDICAL AND PATHOLOGICAL INFORMATION The autopsy was performed by the Office of the Medical Examiner, University of New Mexico at Albuquerque, New Mexico. Aviation toxicological testing was performed by the FAA Civil Aeromedical Institute (CAMI) at Oklahoma City, Oklahoma. The CAMI toxicological non quantified findings were positive for Verapamil and Norverapamil. See the enclosed toxicological report for details. According to G. J. Salazar, M. D., Regional Flight Surgeon FAA Southwest Region, Verapamil and Norverapamil may be approved by the FAA for use while flying, though a cardiovascular evaluation must be performed or reviewed by the FAA Airman Medical Examiner. There was no documentation in the FAA pilot records requesting approval for using the drug while flying. SURVIVAL ASPECTS A tractor driver and a driver of a highway vehicle were the first to arrive at the site. The pilot was found secured in the left front seat with the seat belt and shoulder harness still fastened. One passenger was found in the left rear seat and the other passenger, who had occupied the right rear seat, was found lying outside the cabin along the right rear cabin door. The passengers were transported to the hospital at Tucumcari and later airlifted to Albuquerque. TEST AND RESEARCH On March 20, 1997, the airframe was examined at El Paso, Texas. The right wing flap was crushed and the lower surface of the aileron was crushed upward. Wing skin outboard of the right wing fuel tank was buckled and wrinkled. The right wing fuel screen and fuel lines were clear of debris. The fuel bladder was removed from the right wing and subsequently leak checked by filling the bladder with water. The bladder contained leaks near the areas where fuel had been observed dripping from the right wing prior to removal of the fuel bladder and in the areas where the wing was crushed toward the bladder area. The left wing leading edge skin area exhibited outward buckling and the center wing area was crushed aft of the main spar with the leading edge of the wing where the fuel cell was installed separated along the rivet line along the main spar. The fuel cell liner was pushed upward toward the upper wing skin and outward toward the lower wing skin. The tip fuel tanks were crushed aft. The fuel boost pump operated when test powered by a battery. On March 24, 1997, engine serial number 515609, and the propeller were examined at Mobile, Alabama, under the surveillance of an NTSB investigator. The engine was run on a production test cell to full throttle and no discrepancies were found that would have contributed to a total loss of engine power. There were no indications of any type of propeller failure prior to impact. Physical evidence indicated that the propeller was being operated under conditions of low power at impact. ADDITIONAL INFORMATION The airplane was released to the owner's representative.

Probable Cause and Findings

the total loss of engine power for undetermined reasons and the pilot's failure to maintain airspeed.

 

Source: NTSB Aviation Accident Database

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