Nacogdoches, TX, USA
N2966B
Beech D35
Night visual meteorological conditions prevailed for the personnel cross-country flight. The pilot reported that the single-engine airplane was in cruise flight when the engine lost power. The pilot stated that he performed the emergency procedures including the wobble pump (manual fuel pump); however, the engine did not restart. During the emergency descent to a road, the airplane struck trees, went to an inverted attitude, descended, and came to rest in a creek bed. Maintenance records indicated that in April 1993, at the accumulated engine time of 4,110.0 hours, the engine was removed, overhauled and reinstalled. On June 10, 1983, the wobble pump and fuel system were checked. On November 4, 2001, the last annual inspection was performed at the accumulated airframe time of 8,117 hours, and 100 hour inspection performed at the accumulated engine time of 980.15 hours since major overhaul (TSMOH). The airplane had accumulated 27.1 hours since the last annual inspection. Flight control continuity was confirmed. The auxiliary (wobble pump) handle was found in its stowed position. When the engine driven fuel pump was removed from the engine, the splines that engage the pump into the engine accessory section were intact; however, the pin that engages the drive coupling to the fuel pump drive shaft was found separated. The Thompson Ramo Woolridge Incorporated engine drive fuel pump (model TF1900, S/N TF45071), and splined drive were examined by the NTSB metallurgist. The housing for the fuel pump contains a rotor. The hollow end of this rotor is exposed to the outside surface of the pump. In the installed condition, the shaft end of the driver is partially inserted into the hollow shaft end of the rotor. The shaft ends of both parts are attached to each other by a pin. Visual examination of the pump pieces revealed that a pin was installed on the shaft end of the driver. The ends of the pin were severely worn. The length of the pin measured approximately 0.310 inch. The spline gears showed no evidence of wear. The mounting flange was disassembled from the pump housing to expose a portion of the hollow shaft end of the rotor. The end of the shaft portion of the rotor has two sets of holes (a total of 4 holes). The holes are spaced equally around the circumference of the shaft. Continental Motors Corporation Service Bulletin (SB) ESD 182D indicated that the diameter of these holes should be measured in the circumferential and axial directions of the shaft. If the diameter in the circumferential direction exceeds the diameter in the axial direction by more that 0.015 inch, the rotor must be replaced. The rotor can be reused if either set of holes is worn less than 0.015 inch and the drive pin is installed in the unworn set of holes. According to the SB, the rotor should be discarded and the pump should be overhauled if both sets of holes are worn beyond 0.015 inch. The wall of the holes exhibited severe wear and was elongated in the circumferential direction. The diameter of the worn hole in the circumferential direction measured 0.1500, 0.1430, 0.1510, and 0.1730 inch. The diameter of the hole in the axial direction measured 0.1185, 0.1250, 0.1255, and 0.1225 inch, respectively. The diameter of the holes in the circumferential direction exceed the 0.015 wear limits specified in the SB. The inside diameter of the hollow end of the rotor measured approximately 0.313 inch, which was greater than the measured length of the worn pin (0.310 inch). Utilizing an exemplary engine driven fuel pump, et al, the post-accident engine run sustained 2,450 rpm's and 28 inches manifold pressure. The accident airplane fuel selector valve/auxiliary fuel pump (wobble pump) was plumbed into the test stand fuel system. The exemplary engine driven fuel pump was removed from the engine, and the engine was started with the auxiliary fuel pump (wobble pump). Utilizing the wobble pump, the engine sustained 2,450 rpm's and 28 inches of manifold pressure with only the wobble pump supplying fuel to the engine with the fuel selector valve (left and right) positions. Examination and flow testing of the carburetor revealed that a four tube discharge nozzle was found installed in the carburetor. According to the manufacturer’s representative, the correct nozzle has six discharge tubes for the carburetor. Auto gas was evident inside the carburetor. During the flow test, no external leaks were noted. Test points 1,3,4,5, and 11 were under the minimum limits, and all other test points were within specifications.
HISTORY OF FLIGHT On March 29, 2002, approximately 2130 central standard time, a Beech D-35, N2966B, single-engine airplane, sustained substantial damage during a forced landing following a total loss of engine power near Nacogdoches, Texas. The airplane was owned and operated by the pilot under 14 Code of Federal Regulations Part 91. The private pilot received serious injuries, the passenger in the right front seat received fatal injuries, and the passenger in the right rear seat received minor injuries. Night visual meteorological conditions prevailed for the cross-country flight, and a flight plan was not filed. The personal flight originated from the Louisiana Regional Airport (L38) Gonzales, Louisiana, approximately 1920, with a planned destination of the Cherokee County Airport (JSO), Jacksonville, Texas. Prior to the departure from Gonzales, the pilot requested a weather briefing from the DeRidder Flight Service Station for a flight from Baton Rouge, Louisiana, to Henderson, Texas, and received a partial weather briefing due to an inadvertent telephone disconnect. During the flight, the pilot requested and received VFR flight following from air traffic control facilities. A review of the air traffic controller data rerecording by the NTSB investigator-in-charge (IIC) revealed that the pilot contacted the Baton Rouge (BTR) Air Traffic Controller, reported the airplane climbing through 1,800 feet msl for 6,500 feet, msl and requested flight following. The flight was assigned a transponder squawk of 0235, and the pilot was instructed to report reaching 6,500 feet msl. Subsequently, the pilot reported the flight was level at 6,500 feet msl; however, there were strong headwinds and the pilot requested to cruise at 4,500 feet msl The controller cleared the flight to descend at pilot's discretion to 4,500 feet msl and contact the Lafayette (LFT) Approach Controller on radio frequency 121.1 MHz. The pilot reported to the LFT controller that the flight was descending to 4,500 feet msl. The controller issued the altimeter settings of 29.93 inches Mercury, and later 29.94 inches Mercury. Subsequently, the pilot was instructed to contact the Houston Air Route Traffic Control Center Controller on radio frequency 134.8 MHz. Subsequently, the flight descended to 3,000 feet msl and flight following services were terminated. Following the accident, the pilot reported that the airplane was in cruise flight at 3,500 feet msl when the engine lost power. The pilot stated that he performed the emergency procedures including the wobble pump (manual fuel pump); however, the engine did not restart. During the emergency descent to FM 343, the airplane struck trees approximately 20-30 feet agl, went to an inverted attitude, descended, and came to rest in a creek bed. the pilot and rear seat passenger exited the airplane, walked to FM 343, where they were transported by local citizens to a store. A citizen at the store called 911, and the occupants were transported via ground ambulance to the local hospital Two witnesses reported observing the airplane's green and red light flashing at approximately "tree top height." Both witnesses stated that they did not hear the engine. PERSONNEL INFORMATION The pilot holds the FAA private pilot certificate with the airplane single-engine land rating. The pilot was issued a second class medical certificate on May 12, 1999, without limitations. On the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) the pilot reported his accumulated time of 521.4 hours (325.9 in the accident make and model) of which 162.8 hours were at night. The pilot's biennial flight review was performed on May 7, 2001, in a Cessna 172 single-engine airplane. AIRCRAFT INFORMATION N2966B, a Beech D-35, serial number D-3607, was manufacturer in 1995 and issued a FAA airworthiness certificate on March 26, 1956. Registration to the current owner/pilot had not been received/recorded by the FAA aircraft registration branch in Oklahoma City, Oklahoma. The airplane was equipped with the Continental engine model E-225-8 ( serial number 30619-D-5-8) with the Precision Aircraft Corporation carburetor model PS-5C ( part number 39131810, serial number 794347) installed. The Hartzell propeller model HC-A2V20-4A1 (serial number AK-564) was installed. The airplane was equipped with the Air Map 100 model unit (serial number 70003979). Maintenance records indicated that the wobble pump and fuel system were checked on June 10, 1983. On November 4, 2001, the last annual inspection was performed at the accumulated airframe time of 8,117 hours. In April 1993, at the accumulated engine time of 4,110.0 hours, the engine was removed, overhauled and reinstalled. At the last 100 hour inspection performed on November 4, 2001, the accumulated engine time since major overhaul (TSMOH) was 980.15 hours. On the date of the accident, the accumulated airframe time was 8,144.10 hours (27.1 hours since the last inspection) and the accumulated engine time was 1,007.25 hours. WRECKAGE AND IMPACT INFORMATION The Global Positioning System (GPS) location of the accident site was 31 degrees 39.99 minutes North; 94 degrees 42.84 minutes West at an elevation of 347 feet in a creek bed, approximately 15 feet deep with approximately 1-2 feet of water. The main wreckage came to rest inverted on a measured magnetic heading of 011 degrees approximately 54 feet north of FM 343. The distance to the A. L. Mangham Jr. Regional Airport, Nacogdoches, Texas, was approximately 5 nautical miles. The outboard portion of the left wing was folded over the cabin, and the outboard portion of the right wing was separated from the airframe. The engine came to rest inverted in approximately 2 feet of water. Oil was found along the entire lower surface of the fuselage. Local authorities, who responded to the site, reported fuel leakage. Examination of the airplane at the accident site revealed chordwise crushing along the leading edges of both wings and deformation consistent with the diameter of the trees along the wreckage distribution path on a measured magnetic heading of 270 degrees. The fuselage was intact with compression to the occupiable space. Both front seats were found separated from their attachment points, both lap belts were found buckled, and the webbing on the right front lap belt was found cut. The rear left seat lab belt was found buckled. Shoulder harnesses were not installed. The integrity of the fuel system was compromised. The right main fuel tank and the fuselage fuel tank were found intact. Approximately 9 gallons of fuel was drained from the right main fuel tank, and approximately one gallon of fuel was drained from the fuselage tank. The fuel selector valve was found in the left main tank position. The auxiliary (wobble pump) handle was found in its stowed position. At the cockpit control quadrant, the throttle, mixture, and propeller controls were in the full forward position. A Lowrance AirMap 100 hand held GPS was recovered from the wreckage. The landing gear was in the extended position, and the flaps were found in the UP position. The empennage remained attached to the aft fuselage. Flight control continuity was confirmed. The engine was found partially attached to the airframe and partially submerged in water at the accident site. Both tip tank fuel transfer pumps and the magneto switch were found operational. The Thompson Ramo Woolridge Incorporated engine drive fuel pump, model TF1900 (serial number TF45071) was removed from the engine. The splines that engage the pump into the engine accessory section were intact; however, the pin that engages the drive coupling to the fuel pump drive shaft was found sheared. The fuel pump was retained for further examination by the Board. Subsequently, when the engine crankshaft was rotated, thumb compression and valve action was noted at all the cylinders, and continuity to the accessory case was confirmed. Impact damage (hole) was found in the #6 cylinder valve cover and in the carburetor. The propeller and spinner were found attached to the engine. The spinner exhibited aft crushing. One propeller blade was bent aft near the propeller hub, and the second propeller blade was straight. . The airplane was recovered from the accident site by Air Salvage of Dallas (ASOD), Lancaster, Texas, for further examination by the Board. METEOROLOGICAL INFORMATION At 2115, the local weather observation facility at Nacogdoches reported the wind from 190 degrees at 11 knots, visibility 10 statute miles, ceiling broken clouds at 1,600 feet, temperature 23 degrees Celsius, dew point 20 degrees Celsius, and the altimeter setting 29.81 inches Mercury. MEDICAL AND PATHOLOGICAL INFORMATION Toxicology was not performed for the pilot. TEST AND RESEARCH In November 2002, the Thompson Ramo Woolridge Incorporated engine drive fuel pump, model TF1900 (serial number TF45071) and splined drive were examined at the NTSB Materials Laboratory. The housing for the fuel pump contains a rotor. The hollow end of this rotor is exposed to the outside surface of the pump. In the installed condition, the shaft end of the driver is partially inserted into the hollow shaft end of the rotor. The shaft ends of both parts are attached to each other by a pin. Visual examination of the pump pieces revealed that a pin was installed on the shaft end of the driver. The ends of the pin were severely worn. The length of the pin measured approximately 0.310 inch. The spline gears showed no evidence of wear. The mounting flange was disassembled from the pump housing to expose a portion of the hollow shaft end of the rotor. The end of the shaft portion of the rotor has two sets of holes (a total of 4 holes). The holes are spaced equally around the circumference of the shaft. Continental Motors Corporation Service Bulletin (SB) ESD 182D indicated that the diameter of these holes should be measured in the circumferential and axial directions of the shaft. If the diameter in the circumferential direction exceeds the diameter in the axial direction by more that 0.015 inch, the rotor must be replaced. The rotor can be reused if either set of holes is worn less than 0.015 inch and the drive pin is installed in the unworn set of holes. According to the SB, the rotor should be discarded and the pump should be overhauled if both sets of holes are worn beyond 0.015 inch. The wall of the holes exhibited severe wear and was elongated in the circumferential direction. The diameter of the worn hole in the circumferential direction measured 0.1500, 0.1430, 0.1510, and 0.1730 inch. The diameter of the hole in the axial direction measured 0.1185, 0.1250, 0.1255, and 0.1225 inch, respectively. The diameter of the holes in the circumferential direction exceed the 0.015 wear limits specified in the SB. The inside diameter of the hollow end of the rotor measured approximately 0.313 inch, which was greater than the measured length of the worn pin (0.310 inch). On April 11, 2002, the engine was examined at ASOD under the supervision of the NTSB and prepared/examined during an engine run sequence. Due to impact damage, the crankcase breather tube and the carburetor air box were removed. The ends of the #3 and #5 top and bottom spark plug leads of the ignition harness were replaced. An exemplary engine driven fuel pump, carburetor, and propeller were installed. The magnetos were removed, disassembled, cleaned, dried, reassembled, and reinstalled. The accident airplane fuel selector valve/auxiliary fuel pump (wobble pump) was plumbed into the test stand fuel system. During the engine run, the engine sustained 2,450 rpm's and 28 inches of manifold pressure. The exemplary engine driven fuel pump was removed from the engine. The engine was started with the auxiliary fuel pump (wobble pump) and the engine sustained 2,450 rpm's and 28 inches of manifold pressure with only the wobble pump supplying fuel to the engine with the fuel selector valve (left and right) positions. O n May 28, 2002, the Lowrance AirMap GPS unit was examined at Lowrance Electronics, Inc., Tulsa, Oklahoma. Impact and water damage precluded a retrieval of any data from the unit. On May 29, 2002, the carburetor was examined at Precision Engines Corporation, Everett, Washington, under the supervision of the NTSB. A four discharge nozzle was found installed in the carburetor. According to the manufacturer’s representative, the correct nozzle has six discharge tubes for the carburetor. Auto gas was evident inside the carburetor. During the flow test, no external leaks were noted. Test points 1,3,4,5, and 11 were under the minimum limits, and all other test points were within specifications. ADDITIONAL INFORMATION The airplane was released to the owner's representative.
The failure of the engine driven fuel pump drive pin resulted in a total loss of engine power. Contributing factors were inadequate maintenance, the pilot's inadequate use of the manual auxillary fuel pump (wobble pump), and the night conditions.
Source: NTSB Aviation Accident Database
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