Hawthorne, CA, USA
N618MW
RAYTHEON AIRCRAFT COMPANY G36
While on final approach during the accident landing, the pilot informed air traffic control tower personnel that he was going to perform a go-around but gave no explanation for the maneuver. Witnesses observed the airplane climbing westbound ”belching” black smoke, then the engine stopped. When the airplane was about midfield, they saw it turn left and then back to the right and descend out of sight. The airplane impacted the roof and a vertical wall of a five-story building before coming to rest in an adjacent parking lot. Postaccident examination of the engine’s spark plugs and cylinders indicated that the engine was running with an overly rich fuel/air mixture, which was also evident from the witness statements of the black exhaust emanating from the airplane. The electric fuel boost pump switch is located next to the landing gear selection handle. According to the G36 Pilot Operating Handbook, the engine’s electric boost pump provides pressure for starting and emergency operation only. The handbook cautions that use of the electric boost pump during normal operations can result in an overly rich fuel/air mixture, possibly flooding the engine. If either pilot inadvertently activated the fuel boost pump while attempting to retract the landing gear during the go-around, it could have resulted in a temporarily rich fuel/air mixture, reducing the available engine power and possibly distracting the pilots during the go-around. Although, the examination revealed that the electric fuel boost pump system switch was in the “OFF” position and that the pump was not operating at the time of impact, it is possible that the pilots recognized that the electric fuel boost pump system was on during the go-around and switched it off before the crash. The position of the switch and the reduced engine power likely distracted the pilot, who did not maintain adequate airspeed during the go-around, which resulted in a loss of control.
HISTORY OF FLIGHT On July 15, 2009, about 1620 Pacific daylight time, a Raytheon Aircraft Company (Hawker Beechcraft Company, HBC) G36, N618MW, struck a building and crashed into a parking lot near Hawthorne Municipal Airport (HHR), Hawthorne, California. Carpet Pros, Inc., was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The airline transport pilot with a certified flight instructor (CFI) certificate, the private pilot under instruction (PUI), and one passenger were killed; the airplane sustained substantial damage by impact forces. The local personal demonstration flight departed Hawthorne about 1550. Visual meteorological conditions prevailed, and no flight plan had been filed. During a personal local demonstrational flight, the CFI and the PUI had taken off, landed, and taxied back for another takeoff. During the second takeoff, the CFI reported to a controller in the air traffic control tower that the airplane had an open door, and successfully aborted the takeoff. The last takeoff was uneventful; while on final, the pilot advised the controller that they were going around, but gave no explanation. Witnesses reported that, as the airplane was climbing upwind during the go-around, it made a left turn midfield towards the south followed by a hard right turn back towards the west. A witness observed the airplane trailing black smoke and the wings were rocking. The airplane’s right wing tip struck on top of a rooftop adjacent to a parapet and a secondary impact occurred against a vertical wall approximately 45 feet high. The third impact mark was found within a parking lot 35 feet below west of the initial impact points. PERSONNEL INFORMATION Pilot in Command-(CFI) A review of Federal Aviation Administration (FAA) airman records revealed that the 38-year-old pilot held an airline transport pilot certificate with a rating for airplane multiengine land, and a commercial pilot certificate with ratings for airplane single-engine land and instrument airplane. The pilot held a certified flight instructor (CFI) certificate with ratings for airplane single-engine land, multi-engine land, and instrument airplane. The pilot held a first-class medical certificate issued on May 27, 2008. It had the limitations that the pilot must wear corrective lenses. No personal flight records were located for the pilot. The IIC obtained the aeronautical experience listed in this report from a review of the FAA airmen medical records on file in the Airman and Medical Records Center located in Oklahoma City, Oklahoma. The pilot reported on his medical application that he had a total time of 3,500 hours with 520 hours logged in the last 6 months. The pilot reported to the insurance company on a pilot experience form that as of May 7, 2008, he had a total flight time of 2,830 hours, with 638 hours in the last 12 months. Pilot Under Instruction-(PUI) A review of Federal Aviation Administration (FAA) airman records revealed that the 40-year-old pilot held a private pilot certificate with ratings for airplane single-engine land and instrument airplane. The pilot held a second-class medical certificate issued on April 6, 2007. It had the limitations that the pilot must wear corrective lenses. No personal flight records were located for the pilot. The IIC obtained the aeronautical experience listed in this report from a review of the FAA airmen records on file in the Airman Records Center located in Oklahoma City. The pilot reported on his application for an additional rating of instrument airplane that he had a total time of 207 hours, as of June 3, 2009. The PUI had completed two other demonstration flights in the accident make and model airplane with representatives from HBC. The flights were conducted on April 30, 2009, and May 8, 2009. AIRCRAFT INFORMATION The airplane was a Raytheon Aircraft Company G36, N618MW, serial number E-3643. A review of the airplane’s logbooks revealed that the airplane had a total airframe time of 387.7 hours at the last annual inspection. The logbooks contained an entry for an annual inspection dated February 11, 2009. The Hobbs hour meter read 387.7 hours at the last inspection. The Hobbs hour meter read 469.9 hours at the accident site. The engine was a Teledyne Continental Motors (TCM) IO-550-B, serial number 687084. Total time recorded on the engine at the last inspection was 387.7 hours. The airplane was manufactured and delivered with a TCM 10-550-B engine, which was normally aspirated. At the time of the accident, the engine contained an aftermarket installation of a Tornado Alley Turbo, Inc., (TATI) (Ada,Oklahoma) “Whirlwind System II” turbo normalizing system covered under STC SA5223NM that was installed on June 11, 2008. Fueling records at Hawthorne Municipal Airport established that the airplane was last fueled on July 15, 2009, with the addition of 9.5 gallons of 100LL-octane aviation fuel. METEOROLOGICAL INFORMATION The closest weather reporting station was located at KHHR, which was approximately 0.1 mile north of the accident location. The routine weather reported 10 statute miles visibility and clear of clouds. The winds were reported at 13 knots from 260° magnetic; temperature was 23 degrees C (Celsius), 73.4 degrees F (Fahrenheit); and the dew point was 15 degrees C, 59 degrees F. WRECKAGE AND IMPACT INFORMATION Investigators examined the wreckage at the accident scene. The initial impact point was located on a rooftop within the Vought Aircraft Industries facility, adjacent to a parapet, which was approximately two stories high. Red and black (wingtip colors) paint transfer marks were located adjacent to the indentation in the roof, and beige (rooftop paint color) transfer marks were observed on the right wingtip. The secondary impact occurred against a vertical wall, approximately 45 feet high. The wall exhibited paint transfer marks (red and black) from the left wingtip, and two propeller slash marks were visible approximately 15 feet below and to the right of the wingtip marks. A third impact mark was observed within an asphalt parking lot, approximately 35 feet from the secondary impact with the vertical structure. The ground scar was approximately 10 inches deep by 24 inches wide. The airplane came to rest upright at Global Positioning System (GPS) coordinate of N33°55.235' W118°20.299', which was approximately 50 feet from the ground scar, adjacent to a parked car, and on an approximate heading of 030° magnetic. A strong odor of fuel consistent with 100LL-type fuel was present at the accident site. The outboard half of the right wing remained on the rooftop, adjacent to the parapet. The right elevator counterweight was recovered from the interior of an office. The office was located inside the vertical structure of a building, which was adjacent to the rooftop. The right wing exhibited leading edge compression buckling (forward to aft direction,) and was separated approximately 20 inches outboard of the right wing fuel filler cap. The right fuel tank was breached. The right aileron was intact, buckled, and attached to the separated outboard wing. The flap was separated approximately 12 inches outboard of the inboard track. The left wing remained intact throughout its length and remained attached to the fuselage. The left wing exhibited leading edge compression buckling (forward to aft direction). The left fuel tank was breached. The left aileron was intact, buckled, and remained attached to the wing. The flap was intact, buckled, and remained attached to the wing via the flap tracks. The nose section was compressed aft, the windshield was shattered, and the nose keel was collapsed. The engine separated from its mounts, and remained attached via control cables and hoses. The forward fuselage was intact and contained smooth linear cuts at the base of the pilot's window frame, which were consistent with first responder cuts. The upper forward fuselage (cabin roof) was peeled back by the first responders to facilitate the occupant extraction. The fuselage (cabin) sides exhibited skin tearing, crushing, and compression buckling signatures. The aft fuselage remained attached to the fuselage via a portion of skin aft of the utility doors, flight control cables, and electrical wiring. The horizontal and vertical stabilizers remained attached to the aft fuselage. The aft fuselage and tail exhibited compression buckling. The right elevator and horizontal stabilizer were displaced upward and aft, and their skins exhibited compression signatures and were torn. Blue paint transfer marks were visible at the right horizontal stabilizer tip, which corresponded to the color of the parapet upper surface. The left horizontal stabilizer was intact, and the left elevator remained attached to the same. The left elevator counterweight remained attached to its surface, but was displaced to the right, and exhibited skin tearing at the outboard mounting surface. During the on-scene investigation, it was observed that the turbocharger separated from the engine, and had impact damage. The turbine shaft rotated through, and several compressor blades were bent. MEDICAL AND PATHOLOGICAL INFORMATION PILOT-IN-COMMAND -(CFI) The Los Angeles County Coroner completed an autopsy on July 18, 2009. The cause of death was determined to be a result of multiple traumatic injuries. The FAA Civil Aerospace Medical Institute (CAMI), Oklahoma City, performed toxicological testing of specimens of the pilot. Analysis of the specimens contained no findings for carbon monoxide, cyanide, volatiles, and tested drugs. PILOT UNDER INSTRUCTION -(PUI) The Los Angeles County Coroner completed an autopsy on July 18, 2009. The cause of death was determined to be a result of multiple blunt force injuries. The FAA Civil Aerospace Medical Institute (CAMI), Oklahoma City, performed toxicological testing of specimens of the pilot. Analysis of the specimens contained no findings for carbon monoxide, cyanide, volatiles, and tested drugs. TESTS AND RESEARCH Investigators examined the wreckage at the Aircraft Recovery Service facility, Chino, California, on July 17, 2009. The airframe, engine, and turbo-normalizing system were examined with no mechanical anomalies identified that would have precluded operation. The upper spark plugs were removed during the on-site inspection of the engine. According to the Champion AV-27 chart, the electrodes showed (worn out - normal) erosion, indicating a normal service life. The number 1 spark plug electrode had dark sooty deposits in the electrode area. The remaining spark plug electrode areas had light gray deposits. At the follow-up inspection of the engine, the lower spark plugs were removed. According to the Champion AV-27 chart, the electrodes showed (worn out - normal) erosion, indicating a normal service life. The number 1 lower spark plug electrode had a substance consistent with a carbon based material that was observed bridging the gap between one of the ground electrodes and center electrode. The remaining spark plug electrode areas had light gray deposits. Investigators removed the cylinders from the crankcase. The combustion chambers were undamaged, and had small amounts of thick light grey deposits covered by dark sooty deposits. The piston heads also had a layer of dark sooty deposits. The turbo charger suffered major impact damage, but the turbo had no signs of impeller damage due to FOD. The impeller was free to turn slightly, but would not rotate completely due to the housing damage. HBC EXEMPLAR TEST The NTSB requested that HBC perform a ground run on a production G36 Bonanza with the boost pump in the OFF, LO, and HI positions. The throttle was to be retarded from full throttle to the idle position for each of the boost pump operating positions, and the results recorded. The tests were conducted with the brakes set with the airplane on the ground in a static condition. The propeller control was set at high rpm, and the mixture control was in the full rich position. The full test plan and results are found in the docket of this accident. The first data set (test 1) was recorded with a FULL forward throttle position. The auxiliary fuel pump switch was actuated from OFF, then LO, then HI, then back to OFF, allowing engine parameters to stabilize during each interval. The flight test engineer (onboard, visually) recorded the incremental data. The throttle was closed, allowing for stabilization at idle. In order to collect the second data set (test 2), the throttle was placed in the full forward position, and the auxiliary fuel pump switch was positioned at LO. The throttle was retarded in 3" Hg manifold pressure (MAP) increments. The flight test engineer (onboard, visually) recorded the incremental data once again. The auxiliary fuel pump was placed in the OFF position and the fuel flow stabilized. The last data set (test 3) was accomplished by placing the throttle in the full forward position, and positioning the auxiliary fuel pump switch to HI. The throttle was retarded in 3" Hg MAP increments. The flight test engineer (onboard, visually) recorded the incremental data. The engine ceased operating at approximately 23" Hg MAP. An outside observer noted that there were two “puffs” of black smoke “as the engine was winding down.” There was no smoke noted during any of the previous conditions. In addition, there was no hesitation or “stumbling” indicated or noted audibly (inside or outside the airplane) when the engine ceased operation. TATI EXEMPLAR TEST The NTSB requested that TATI perform a ground run on a turbo-normalized A36 or G36 Bonanza (with the same TATI STC installation as the accident airplane) with the boost pump in the OFF, LO, and HI positions. The throttle was to be retarded from full throttle to the idle position for each of the boost pump operating positions and the results recorded. TATI submitted a completed test plan, and the results are included in the docket for this accident. ADDITIONAL INFORMATION According to the G36 POH, the pump provides pressure for starting and emergency operation only. The manual cautions that use of the pump during normal operations can cause excessive fuel flows with an overly rich mixture, and possible flooding of the engine. The Fuel Boost Pump switch is located left of the landing gear selection handle. The switch is a three position lock switch with positions for high, low, and off. The normal position for landing or balked landing is “Off”. On July 28, 2009, the investigation team met at the Dukes, Inc., manufacturing facility in Northridge, California. The auxiliary fuel pump was disassembled and examined. It was determined that the pump was “OFF” at the time of impact, and exhibited normal operating signatures.
The pilot’s failure to maintain an adequate airspeed during a go-around, which resulted in a loss of airplane control. Contributing to the accident was the inadvertent activation of the fuel boost pump during the attempted go-around.
Source: NTSB Aviation Accident Database
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