Springfield, OH, USA
N453WB
WRIGHT B FLYER INC WRIGHT B FLYER
The experimental amateur-built replica airplane was on a test flight with two pilot-rated occupants. Another pilot heard a radio transmission from the accident airplane indicating that they were going to land in a field about 5 miles north of the departure airport. Witnesses reported that the airplane’s engine rpm varied while it was flying at a low altitude. The airplane was then observed in a spiraling descent to the ground. Postaccident examination of the airplane’s left propeller shaft revealed a broken weld, which would have prevented the left propeller from being driven by the engine. Further examination of the joint identified incomplete weld penetration during welding, thus about 25 to 35 percent of the through thickness of the propeller shaft tube was not welded to the propeller shaft end. This incomplete weld penetration occurred in the inner areas of the joint. Visible defects, such as pores and voids, were observed in the welded areas. The part’s engineering drawing specifies complete weld penetration. The on-scene accident examination of the wreckage did not reveal any other preimpact anomalies. Despite the resultant partial loss of thrust, the flight crew should have been able to maintain control of the airplane during the forced landing attempt.
HISTORY OF FLIGHT On July 30, 2011, about 1045 eastern daylight time, a Wright B Flyer Inc. Wright B Flyer experimental amateur-built airplane, N453WB, impacted terrain during a forced landing near Springfield, Ohio. The two commercial pilots sustained fatal injuries. The airplane sustained substantial wing and fuselage damage. The airplane was registered to and operated by Wright B Flyer Inc. under the provisions of 14 Code of Federal Regulations Part 91 as a test flight. Visual flight rules (VFR) conditions prevailed for the flight, which did not operate on a VFR flight plan. The local flight originated from the Springfield-Beckley Municipal Airport (SGH), near Springfield, Ohio, approximately 1008. The operator’s accident report, in part, stated: This experimental airplane was involved in the initial phases of flight testing. Flying qualities, stability and control and performance were being tested. Depending on the weather conditions test points were selected from a flight test matrix. The pilots, always two in the aircraft, would brief the flight, fly the test points and document the results. Depending on how well the test conditions were met the pilots would show that test point as complete and select another test to fly. The morning of the accident the pilots brief was not attended by any other person; exactly what points they were testing is not known. According to statements given by witnesses in the area, the airplane's engine sounded like its rpm varied. The airplane was observed to be flying slow and to bank to the left and right. One witness reported that the airplane spiraled downward. PERSONNEL INFORMATION The pilot in the right seat, age 64, held a commercial pilot certificate with an airplane single engine land, multi-engine land, and instrument airplane ratings. He was issued a second-class airman medical certificate on March 23, 2011, with a limitation for corrective lenses. According to the operator, he accumulated 3,078 hours of total flight time and 235 hours of flight time in the same make and model airplane as the accident airplane. The pilot in the left seat, age 73, held a commercial pilot certificate with an airplane single engine land, multi-engine land, airplane single engine sea, and instrument airplane ratings. He was issued a second-class airman medical certificate on March 09, 2011, with a limitation for corrective lenses. According to the operator, he accumulated 955 hours of total flight time and 68 hours of flight time in the same make and model airplane as the accident airplane. AIRCRAFT INFORMATION N453WB, serial number 002, was a Wright B Flyer Inc. plans-built antique replica Wright B Flyer experimental amateur-built airplane. According to the builder’s web site, the airplane had modern airfoils, conventional ailerons, steel tube structure, and modern aircraft fabric. A four-cylinder, 205-horsepower Lycoming HIO-360-C1B engine, with serial number L-13374-51A, powered the airplane. The airplane was equipped with two chain-driven, counter-rotating, two-blade Sensenich pusher propellers. The airplane had seating for two occupants. The airplane was equipped with dual controls. The airplane had a wingspan of 33 feet 6 inches, a height of 7 feet 8 inches, and a length of 26 feet. The airplane’s empty weight was 1,876 pounds and its gross weight was 2,650 pounds. The demonstrated takeoff speed was listed as 55 mph. The airplane had accumulated 58 hours of total time at the time of the accident and had accumulated 28.8 hours of Phase I flight time. METEOROLOGICAL INFORMATION At 1056, the recorded weather at SGH, located about three miles and about 295 degrees from the accident site, was: wind 110 degrees at 4 knots, visibility 5 statute miles with mist, sky condition few clouds at 1,000 feet above the ground, temperature 26 degrees C, dew point 24 degrees C, and altimeter 30.14 inches of mercury. COMMUNICATIONS According to a pilot flying inbound to SGH, he made a position report on the SGH common traffic advisory frequency (CTAF) and a pilot representing the Wright B Flyer answered back on the CTAF indicating the Wright B Flyer was in a racetrack pattern at 3,100 feet above mean sea level about three to four miles south of SGH making east - west circuits. The inbound pilot practiced a touch and go at SGH and subsequently heard a call that indicated the Wright B Flyer was landing in a field five miles north of SGH. He said the pilot sounded calm. He asked the Wright B Flyer if he could be of any assistance and got no reply. He then heard two garbled transmissions that said something about a "chase car". He flew three to seven miles north of SGH to look for the aircraft based on the radio call. FLIGHT RECORDERS The airplane was equipped with an engine monitor. The airplane's engine monitor and a recovered global positioning system (GPS) device were shipped to the National Transportation Safety Board Recorder Laboratory (NTSB) for readout. A secure data (SD) memory chip from an on-board Contour video camera was located on-scene following the recovery of the wreckage and that SD chip was also shipped to the NTSB Recorder Lab for readout. The recovered engine monitor was a Dynon EMS-D10 model, serial number 001502, which was a cockpit instrument that graphically displayed engine information to the pilot using a six-inch liquid crystal display. The unit can display engine rpm, cylinder head temperature (CHT), exhaust gas temperature (EGT), oil pressure, oil temperature, battery voltage, fuel flow, engine manifold pressure (MAP), fuel pressure, and aircraft fuel quantity. The unit can record that data on a flash memory chip located on its main printed circuit board. This data is typically recorded at a rate of once per second. The recovered GPS device was a Garmin GPSMAP 196 model, serial number 65410637, which was a portable GPS unit equipped with a detachable antenna, and a 320 x 240 12-level grayscale liquid crystal display. The unit was capable of storing date, route of flight, and flight time information for up to 50 individual flights in the form of a flight log. Flight logging began when the GPS unit senses a speed increase to greater than 30 knots together with an altitude gain of greater than 500 feet. Recorded flight log data was saved when the speed is sensed to decrease to below 30 knots, and a new log is started if more than 10 minutes passes from this time. All recorded data was stored in non-volatile flash memory. The Contour high definition (HD) Video camera was a consumer grade HD adventurer recorder which was ruggedized and water resistant. It was powered by an internal rechargeable battery and recorded the video and audio information to a removable mini-SD memory card. The camera can record at various resolution, frame rates, and recording duration prior to using the camera. Additionally, the camera had a three-position selection switch which permitted the user to select one of three pre-defined recording resolutions at the time of use. There also was a recorder power switch and a switch to start and stop the recording. The camera buffers approximately 10 to 20 seconds of data prior to writing it to the memory card. During normal shutdown, this buffer gets flushed and no loss of data occurs. During an abnormal shutdown, the memory buffer’s information is lost. Depending on when the recording ends in relation to this buffer cycling, you may lose some portion of the recording when the unit does not have a chance to write the contents of the buffer to the SD memory card. This camera was connected to the airplane’s audio/intercom panel and it could record audio alarms, radio conversations, and pilot-to-pilot intercom conversations. WRECKAGE AND IMPACT INFORMATION The airplane was located by first responders in a field about one-half mile northwest of the intersection of South Pitchin Road and North River Road. The airplane had a resting magnetic heading of about 210 degrees. The top wing was found displaced forward and deformed downward over the forward portion of the lower wing and engine. The lower forward empennage tubing was buckled and the empennage was bent downward. An on-scene examination of the wreckage was conducted. A liquid consistent with the smell of aviation gasoline was found in the bottom of the left fuel tank. The right fuel tank and the header tank were compromised and no fuel was found in those tanks. The fuel tank selector valve had the right fuel tank selected. When electric power was applied, the electric fuel pump emitted drops of a liquid consistent with the smell of aviation gasoline. Flight control cables and linkages were traced and all breaks were consistent with overload. Engine control cables were traced and all breaks were consistent with overload. The left magneto sustained damage and was not able to be tested. The right magneto sustained damage and it produced spark from its center electrode when it was rotated. The top spark plugs were removed. The sparkplugs were gray in color and no anomalies were detected. The engine driven fuel pump was torn off its base. A disassembly of the engine driven fuel pump revealed no pre-impact anomalies. The fuel injection distribution valve was disassembled and no anomalies were detected. The engine exhibited a thumb compression at all cylinders. The fuel servo sustained damage and its mixture control shaft had separated outboard of its mixture control stop. The hose to the fuel servo screen contained drops of a liquid consistent with the smell of aviation gasoline. The fuel servo screen was free of debris. The oil filter canister was removed and no debris was observed. Subsequent to the on-scene examination, the propeller shafts were examined by FAA inspectors and the left propeller shaft tube exhibited a separation at its aft weld. The left and right propeller shafts were shipped to the NTSB Materials Laboratory for detailed examination. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on both pilots by the Montgomery County Coroner's Office. The cause of death for both pilots was listed as blunt force injuries. The FAA Civil Aerospace Medical Institute prepared a Final Forensic Toxicology Accident Report on both pilots. The report on the left seat pilot was negative for the tests performed. The report on the right seat pilot indicated that the pilot’s toxological sample was putrefied, and, in part, stated: 11 (mg/dL, mg/hg) ETHANOL detected in Muscle NO ETHANOL detected in Brain Metoprolol detected in Liver Metoprolol detected in Kidney The FAA Forensic Toxicology Web Drugs website description of Metoprolol, in part, stated that Metoprolol “is a beta-adrenergic receptor antagonist, ‘beta blocker,’ used in the treatment of hypertension and certain arrhythmias.” TESTS AND RESEARCH Dynon EMS-D10 According to a NTSB Vehicle Recorder Laboratory Recorded Data Factual Report, the Dynon EFIS-D100 unit sustained major damage from impact forces. An internal inspection was performed and it was determined that the unit could not be rebuilt for download. The Dynon stores recorded data in non-volatile memory. This particular model stores recorded data on a flash memory device mounted to the main printed circuit board (PCB). The main printed circuit board was removed and cleaned using methanol and Cirozane electronic component cleaner. The flash memory device was removed from the PCB and raw-data binary readout of the chip was obtained using a Xeltek SP-3000u Electrically Erasable Programmable Read-Only Memory (EEPROM) programmer. Recorded data is stored in a proprietary format, and cannot be easily interpreted directly from the stored data. Recorded engine data was identified and converted to engineering units using an in-house software program. Garmin GPSMAP 196 According to a NTSB Vehicle Recorder Laboratory Recorded Data Factual Report, the Garmin GPSMAP 196 unit sustained major damage from impact forces and it was determined that the unit could not be rebuilt for download. This model stores recorded data on a flash memory chip mounted to the main PCB. The flash memory chip was removed from the PCB and raw-data binary readout of the chip was obtained using a Xeltek SP-3000u EEPROM programmer. Recorded data is stored in a proprietary format and recorded tracklog data was identified and converted to engineering units using an in-house software program. The GPS unit’s data revealed the accident airplane’s flight path and it recorded data until 1044:57 where the last recorded groundspeed was 55 knots. The NTSB Vehicle Recorder Laboratory Recorded Data Factual Report is appended to the docket associated with this investigation. Contour HD Video Camera The SD memory card was placed in a memory card reader. A two megabyte file was recovered from the SD memory card. The recovered file would not play using either the manufacturer’s supplied software or any third-party playback software. It was suspected that the normal file closeout and shutdown process had not occurred consistent with an abrupt stoppage of the recorder. However, several third-party software file recovery programs were used to reconstruct the normal movie file structure. This reconstruction yielded a 51 minute 33 second video and audio file. The reconstructed file revealed that during the accident flight, none of the co-pilot’s intercom conversations were audible on the recording. The co-pilot’s voice was however heard when he was talking on the aircraft’s radio. The pilot’s voice appeared to be recorded normally during the flight. The video showed that the airplane yawed near the end of the recorded video. Both pilots were observed to manipulate the controls following the yaw. The video showed that airplane was controllable after the yaw. The video ended in flight near the location of the accident site. The NTSB Vehicle Recorder Laboratory CVR Study is appended to the docket associated with this investigation. Propeller Shafts According to NTSB Materials Laboratory Factual Report No. 12-074, the left propeller shaft had completely separated at its aft weld. The majority of the contact areas of both mating separation surfaces had been obliterated by smearing and which was consistent with rotational rubbing of the fractured faces. The outer tube surface near the left tube’s aft separation exhibited paint spalling and general discoloration. These features were not observed on the right propeller shaft tube. A magnified edge view of the tube separation revealed that approximately 25 to 35 percent of the through thickness of the propeller shaft tube had not been welded to the propeller shaft end. This incomplete weld penetration occurred in the inner areas of the joint. Visible defects, such as pores and voids, were observed in the welded areas. Other propeller shaft welds from the accident airplane were examined and they exhibited incomplete weld penetrations. The Materials Laboratory Report is appended to the docket associated with this investigation. ADDITIONAL INFORMATION The operator’s accident report recommendation section indicated: The pilot's pre and post flight brief should be recorded. If the airplane had been equipped with a ballistic parachute the pilots would have had one more option. USEFUL OR EFFECTIVE INVESTIGATION TECHNIQUES Review of the cockpit video revealed that the airplane yawed near the end of the recorded video. This observation precipitated a follow up examination of the propeller shafts, which revealed the weld failure.
The flight crew’s failure to maintain airplane control following a partial loss of engine thrust during cruise flight. Contributing to the accident was the failed weld as a result of incomplete welding on the left propeller shaft, which led to the partial loss of engine thrust.
Source: NTSB Aviation Accident Database
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