Aviation Accident Summaries

Aviation Accident Summary LAX01FA199

Big Bear City, CA, USA

Aircraft #1

N5413S

Piper PA-28-180

Analysis

The student pilot lost control of the single engine airplane during the takeoff initial climb with a tailwind and collided with trees while descending in the crosswind turn. The student departed with an 8-knot tailwind. The UNICOM frequency was reported to be in operation; however, no one reported hearing the accident airplane request departure information or make a position report. According to a pilot witness, the airplane was unable to gain altitude after leaving ground effect and the nose pitched up and to the left, and began to "oscillate back and forth as if it was having difficulty in trying to climb." The witness added the airplane made a shallow left-hand turn and the nose began to pitch up, then the airplane "stalled and the aircraft went nose down." The student pilot was a paraplegic and had obtained approximately 74 total hours of flight time, of which approximately 25 hours were accumulated in the same make and model as the accident airplane. The student had accumulated approximately 6 hours of solo flight time prior to the accident flight. The aircraft utilized a rudder hand control, which allowed the pilot to operate the rudder pedals manually. The student had performed a demonstrated ability flight utilizing the hand control 5 days before the accident. A post accident examination of the wreckage revealed the propeller had sliced through 4-inch thick tree branches. The right magneto would not operate following the accident and it was noted that the breaker points would not open, oil and dirt were found in the magneto housing, and the magneto's drive was excessively loose. At the time of the last annual inspection, the engine's magneto timing was checked. A service bulletin issued for the affected magneto required an inspection of the magnetos every 500 hours. At the time of the accident, the magneto had accumulated a total time in service of 1,256.36 hours, and there was no entry indication the service bulletin had been complied with. No other anomalies were noted with the airplane and engine. The density altitude was computed to be 8,400 feet.

Factual Information

HISTORY OF FLIGHT On June 4, 2001, at 0855 Pacific daylight time, a Piper PA-28-180 single engine airplane, N5413S, collided with a tree while turning crosswind after takeoff at Big Bear City, California. The airplane was destroyed and the student pilot, who was the sole occupant, received fatal injuries. The airplane was registered to and operated by Aero Haven, Inc., Big Bear City, and the instructional solo flight was conducted under 14 CFR Part 91 when the accident occurred. The flight was originating from the Big Bear City Airport at the time of the accident. Visual meteorological conditions prevailed at the time of the accident and no flight plan had been filed for the local flight. A flight instructor was standing near midfield as the airplane departed. The winds were from 080 degrees at 8 knots. Before the accident airplane departed, another airplane took off on runway 08, flying directly over the accident airplane. The UNICOM was reported to be in operation; however, no one reported hearing the accident airplane request departure information or make a position report. The airplane took off from runway 26, initiating the departure from the approach end. At midfield, the pilot rotated and the airplane began what was described as a normal climb out. After gaining about 250 agl, the attitude of the airplane leveled and began to sink, losing about 50 to 75 feet of altitude. The pilot then began a 45-degree banked turn to the left. After about 90 degrees of turn, the airplane began approaching some 200-foot-tall pine trees that were growing along the left side of the departure path. As the airplane neared the trees, the bank angle steepened and the nose of the airplane suddenly dropped as the right wing contacted several branches near the top of one of the trees. The right wing separated from the airplane and both it and the airplane impacted the ground within a few feet of the base of the tree. According to anther pilot-rated witness, he was at the airport and observed the accident airplane taxi for takeoff on runway 26. The witness thought it was "odd because the winds were out of the east and the Piper was preparing to takeoff to the west, which would be a downwind takeoff." The witness added that a Cessna 150 had departed from runway 08 and overflew the Piper just before it departed. The witness stated the Piper took off, but was "unable to gain altitude." He observed the aircraft pitch nose up and to the left, and began to "oscillate back and forth as if it was having difficulty in trying to climb." The witness added the airplane made a shallow left-hand turn and the nose began to pitch up. He then reported the airplane "stalled, the aircraft went nose down." PERSONNEL INFORMATION The student pilot was a paraplegic and was issued a third-class medical certificate on April 19, 2001, with a limitation to wear corrective lenses. He had obtained approximately 74 total hours of flight time, of which approximately 25 hours were in the same make and model as the accident airplane. The student had accumulated approximately 6 hours of solo flight time prior to the accident flight. The student was issued a Statement of Demonstrated Ability on May 30, 2001, which required a special flight test. The student had completed a demonstrated ability flight with a Federal Aviation Administration (FAA) inspector on June 1, 2001. The flight lasted 0.3 hours. According to the demonstrated ability flight requirements, the pilot must demonstrate "the ability to reach and operate effectively all controls which would normally require the use of that extremity (or those extremities)." As the pilot demonstrates his flying ability, the inspector is to "note any unusual body position the applicant may use to compensate for the defect and what effect that position has on the applicant's field of vision." The pilot is also supposed to demonstrate the "ability to satisfactorily perform emergency procedures relative to flight, such as recovery from stalls..." AIRCRAFT INFORMATION The airplane was equipped with a 180-horsepower Textron Lycoming O-360-A1A engine. The aircraft utilized a "Blackwood" rudder hand control, which allowed the pilot to operate the rudder pedals manually. The rudder hand control was installed via a supplemental type certificate (STC SA1741WE). The control utilized a handle, that, when installed, would be moved forward (downward force) by the pilot to apply left rudder and aft (upward force) to apply right rudder. The hand control was positioned just aft of the throttle/mixture positions. During takeoff, the pilot applies full throttle and tightens the friction lock. The pilot then repositions his right hand to the rudder hand control to maintain directional control of the airplane during the takeoff sequence. Review of the aircraft's maintenance records revealed the engine was overhauled on June 6, 1999, at a tachometer time of 6,078.3 hours. Since its overhaul, the engine had accumulated a total of 1,374.06 hours. On July 30, 1999, the right magneto was installed new at an engine tachometer time of 6,196.0 hours. The engine was removed, disassembled, inspected, reassembled, and reinstalled as a result of a propeller strike dated September 29, 1999, at a tachometer time of 6,363.6, at which time the engine had accrued 285.1 hours of operation since the June 1999 field overhaul. The engine maintenance record included a FAA Airworthiness Approval Tag for a repaired cylinder assembly dated April 9, 2001. The cylinder was placed in the number 3 cylinder position on April 11, 2001, at an aircraft tachometer time of 7,350.41 hours. The airplane/engine underwent its last annual inspection on May 9, 2001, at a tachometer time of 7,396.74 hours. At the time of the annual inspection, the engine's magneto timing was checked. Maintenance worksheets from Calaway Aviation, (a local maintenance facility utilized to maintain N5413S) were reviewed. On May 25, 2001, mechanics removed and cleaned the bottom spark plugs, replaced the induction pipe gaskets, and replaced the valve cover gaskets. On May 29, 2001, the engine cowling was removed and the bottom spark plugs were cleaned and reinstalled at a tachometer time of 7,434.55 hours, and a compression check of the number 4 cylinder was checked. The result of the compression check was not reported on the worksheet. On May 31, 2001, a compression check was conducted with the following results: No. 1 70/80, No. 2 78/80, No. 3 79/80, No. 4 79/80, and the bottom spark plugs were cleaned and reinstalled. On June 1, 2001, the No. 2 and No. 4 spark plugs were cleaned after lead fowling. None of the aforementioned work was depicted or endorsed in the engine's maintenance records. METEOROLOGICAL INFORMATION At 0900, the weather observation facility at the Big Bear City Airport reported the wind from 080 degrees at 8 knots; visibility 10 statute miles; sky clear; temperature 17 degrees Celsius; dew point -08 degrees Celsius; and altimeter setting of 29.99 inches of Mercury. The observation also reported a density altitude of 8,400 feet msl. AERODROME INFORMATION The Big Bear City Airport (L35) elevation is 6,748 feet msl, and is positioned a latitude and longitude of 34 degrees 15.82 minutes north and 116 degrees 51.27 minutes west. The airport utilizes one runway, 08-26. The total length of the runway is 5,850 feet, and runway 26 has a 600-foot displaced threshold. The remarks section of the airport facility directory indicates that mountains are present in all quadrants. A noise abatement procedure exists at the airport that indicates after "takeoff, make 10-degree left turn at end of runway to avoid...elementary school to the west of airport." WRECKAGE AND IMPACT INFORMATION The airplane came to rest at a latitude and longitude position of 34 degrees 15.581 minutes north, and 116 degrees 52.423 minutes west. The airplane came to rest on a heading of 120 degrees, adjacent to a tree that was positioned along side Baker's Pond. The accident site was approximately 0.7 miles on a magnetic bearing of 234 degrees from the departure end of runway 26. Several branches (approximately 4 inches and 10 inches in diameter) were found lying adjacent to the aircraft wreckage. Some of the 4-inch branches displayed jagged fracture surfaces, and a couple displayed diagonal smooth cuts. The airplane's left wing remained attached to the fuselage, but displayed considerable leading edge damage along its entire span. The right wing was separated from the fuselage and was fragmented into several sections. The right wing displayed a 10-inch diameter semicircular indentation on the outboard leading edge section of the wing tip. The empennage remained attached to the fuselage and the vertical stabilizer and rudder surface were destroyed. The elevator trim tab actuator was examined and it was noted that 10 threads were visible equating to a trailing edge down position. The right aileron control cable was found separated, and the rudder and elevator control cables remained intact between the fuselage and the control surface. There was no apparent malfunction of the Blackwood rudder hand control. The device was found in place; however, it sustained significant bending damage. The engine remained attached to the airframe and sustained damage to the bottom forward section. The propeller remained attached to the crankshaft flange, which was bent. The propeller blades displayed leading edge gouging, torsional twisting, chordwise striations, and trailing edge "S" bending. The exhaust system pipes and carburetor assembly were displaced aft. The bent crankshaft flange was removed, via a circular saw, because it was impinging on the crankcase. The top spark plugs were removed and examined. The vacuum pump was removed and the crankshaft was rotated manually through the vacuum pump drive pad. The crankshaft rotated freely and easily and thumb compression was obtained in the proper order on all four cylinders. Valve operation was also confirmed during the crankshaft rotation. The cylinders were examined utilizing a lighted borescope. No mechanical damage was noted in the combustion chambers. The spark plugs displayed intact electrodes, and coloration consistent with normal operation when compared to the Champion Spark Plugs Check-A-Plug chart AV-27. The engine carburetor was fractured and displaced from the engine; however, its mounting pad remained securely attached to the engine. The throttle and mixture controls were found securely attached to the carburetor and their continuity was confirmed to the cockpit. All of the engine fuel lines were found in place and secure. The carburetor's fuel inlet filter screen was free from visible contaminates. The carburetor was disassembled and the float assembly was found secured; however, the float's left pontoon exhibited signatures of hydrodynamic deformation. No obstructions were noted. The engine driven fuel pump was disassembled and examined. The fuel pump was free of internal mechanical defects and obstructions. The left magneto was displaced from its mounting pad. Portions of the magneto flange remained securely clamped to the engine accessory section. The magneto-to-engine timing could not be ascertained. The impulse coupling was found intact and secure. The magneto drive functioned during manual rotation, and the magneto produced a spark at all four leads. The right magneto was also displaced from its mounding pad and portions of the magneto flange remained clamped to the engine. The magneto-to-engine timing could not be ascertained. The magneto drive was manually rotated and no spark was noted in either of the leads. There was no evidence of carbon tracking or electrical arcing observed in the distributor cap. Initial examination revealed the magneto's contact (breaker) points were not opening, and the steel drive gear was excessively loose around the drive shaft. The internal cavity of the magneto housing contained significant amounts of dirt and oil. The magneto was retained by the Safety Board investigator-in-charge for further examination. Investigators noted that the magneto flanges were situated in the clamps at their maximum travel in the counterclockwise direction. TESTS AND RESEARCH The right magneto, a Bendix S4LN-205, S/N 1149832ER, Model 10-163045-3, was examined on June 13, 2001. Further examination revealed the breaker points would not open when the magneto shaft was rotated. The portion of the magneto where the points are located appeared to have recently been cleaned as well as the breaker assembly itself. The screws attaching the breaker point assembly were tight. The remainder of the interior magneto assembly was covered with oil and dirt. The oil seal itself showed evidence of leakage. The steel drive gear was loose both radially and axially on the main shaft and could be rotated back and forth about 10 degrees. The drive gear and the distributor gear were properly mated to each other. The cam retaining screw was found to be loose. Upon removal of the cam, bearing race, shims and drive gear, it was noted that the rear face of the drive gear and its keyway showed evidence of wear. The wear on the drive gear allowed the shims and the bearing race to move toward the center of the shaft and to void the bearing preload. The magneto was reassembled with the exception of the adjusting the breaker points to open 0.015 inches. Upon rotation of the magneto main shaft, in a counter-clockwise direction the magneto then produced a spark. The airplane reportedly had a magneto problem repaired on or about June 1, 2001. According to an FAA airworthiness inspector, no corresponding entry was found in the airplane maintenance records. None of the maintenance personnel, where the airplane had been maintained, claimed knowledge of any work being performed on the magneto. According to Textron Lycoming Mandatory Service Bulletin 515, dated May 27, 1994, which references Teledyne Continental Motors Service Bulletin 643, dated February 8, 1994, magnetos must be inspected every 500 hours as outlined in the periodic maintenance section of the applicable Service Support Manual, Paragraph 6.2.3. At the time of the accident, the magneto had accumulated a total time in service of 1,256.36 hours, and there was no entry indicating that either Service Bulletin had been complied with. PATHOLOGICAL INFORMATION An autopsy on the pilot was performed at the San Bernardino County Coroner's Office. According to the autopsy report, the pilot died as a result of multiple blunt force injuries. A toxicological test was performed and was negative for carbon monoxide, cyanide, volatiles, and drugs. ADDITIONAL INFORMATION It is unknown whether the student performed a magneto check during an engine run-up. Review of an informational flyer regarding Lycoming engines revealed there could be "a power loss of approximately 3 percent with a single dead magneto or running on one mag." The flyer continues by indicating, "In fixed wing aircraft, if the pilot lost a magneto in flight, it might not be a serious situation to complete the flight safely provided other power robbers didn't begin to add to the problem."

Probable Cause and Findings

the student pilot's selection of a takeoff runway conducive to a tailwind weather condition and his failure to maintain airspeed and his inadvertent stall during takeoff initial climb. Factors in the accident were the partial loss engine power resulting from the inoperative right magneto and the high density altitude weather condition.

 

Source: NTSB Aviation Accident Database

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