LAX95FA033
LAX95FA033

HISTORY OF FLIGHT

On November 11, 1994, at 1540 Pacific standard time, a Schweizer 269C, N60TA, operated by Pacific Shore Aviation, Van Nuys, California, crashed into an open field about 6 miles west of Valencia, California. Visual meteorological conditions prevailed at the time, and no flight plan was filed for the solo instructional flight. The helicopter was destroyed by impact forces and postimpact fire, and the student pilot was fatally injured. The flight originated from the Van Nuys airport at 1508.

The student pilot's certified flight instructor (CFI) stated that his student had blocked the accident helicopter for use between 1500 and 1700. The student was authorized to fly to the "Pico Plateau" training area, where he had previously performed maneuvers in both dual and solo flight. The National Transportation Safety Board has not received information that anyone witnessed the accident.

PERSONNEL INFORMATION

The pilot's personal flight record logbook was not located. A reconstruction of the pilot's flight time/experience revealed the pilot had a total of about 90 hours of rotorcraft flight time. This flight time included initially about 25 instructional flight hours in the Bell 47 and Robinson R-22 helicopters, and then about 65 instructional flight hours in the Schweizer 269 helicopter.

The pilot performed his first solo flight on September 11, 1994. The flight was in a Schweizer 269 helicopter. At that time, his total rotorcraft flight experience was approximately 73 hours.

On November 12, 1994, during a face-to-face interview with the accident pilot's CFI, he reported that he had authorized his student to practice normal and vertical takeoffs and landings, hovering, and normal approaches. No emergency-type maneuvers were to be practiced solo. The student was authorized to fly the helicopter from Van Nuys to the practice area where the crash occurred.

The CFI further reported that the student's previous five solo flights were made to the accident site area, which he called the "Pico Plateau." The CFI stated that, in his judgement, the pilot had demonstrated good technique and was very conscientious.

The CFI provided the Safety Board with a copy of his student's primary flight training records. The CFI reported that the records encompassed the students entire training at Pacific Shore, and were from June 29, 1994, to November 8, 1994.

In part, the records itemized each dual and solo flight, and grades indicating the student's performance flying specific maneuvers. Each flight lesson was dated, and each dual lesson bore the CFI's initials. The flight records contained over an estimated 250 separate entries which the CFI stated he made by hand. The records showed the respective flight dates, maneuvers, grades, and the CFI's initials (see attached record).

During the interview, the CFI indicated that he had produced the entire flight school record after being notified of his student's fatal accident.

The record was examined by the Federal Aviation Administration (FAA) in concert with the regulatory solo flight requirements for student pilots (reference 14 CFR Part 61.87(d)). The FAA reported to the Safety Board that its record review did not indicate the CFI had provided the student pilot with presolo flight training involving crosswind takeoffs and landings, wake turbulence avoidance, and emergency procedures/equipment malfunctions.

HELICOPTER INFORMATION

The operator reported that the helicopter was maintained by Rotorcraft Support, Van Nuys, California. According to Rotorcraft Support, the helicopter was equipped with a main transmission chip detector. Schweizer reported that, by design, the chip detector was not electrically wired to any cockpit warning light.

1. Logbook Review.

A review of the helicopter's logbooks indicated that on August 5, 1994, the helicopter underwent maintenance by a company called Rotorcraft Support, Inc. In part, the maintenance involved removing the fuel servo and the R.P.M. limiter box. The maintenance was related to an unspecified "engine problem." No record was found in the rotorcraft or engine logbooks indicating that the R.P.M. limiter box had been replaced in the helicopter before it was "APPROVED FOR RETURN TO SERVICE." At the time of the maintenance, the engine logbook indicated that the helicopter's time was 1,164.8 hours.

On August 18, 1994, at 1,196.0 hours, Rotorcraft Support personnel indicated in the engine logbook that a 100-hour inspection was performed.

On August 29, 1994, at 1,204.8 hours, Rotorcraft Support personnel indicated in the engine logbook that a new starter and alternator were installed in the helicopter. Also, the alternator mount bracket was found worn and was replaced. On November 2, 1994, at 1,313.1 hours, Rotorcraft Support personnel indicated in the rotorcraft logbook that the helicopter had received a 100, 200, 300, and 1,200-hour inspection and was "DETERMINED TO BE AIRWORTHY."

The next entry in the helicopter logbooks was dated November 8, 1994, at 1,340.00 hours. Rotorcraft Support personnel indicated in the rotorcraft logbook that they removed the over speed limiter for repair, tightened the cylinder head temperature probe, and repaired the compass mount. No logbook entry was found indicating that the over speed limiter had been reinstalled in the helicopter prior to the helicopter being "APPROVED FOR RETURN TO SERVICE."

The next (and final) entry in the helicopter logbooks was found dated November 10, 1994, at 1,341.01 hours, by Rotorcraft Support. The entry indicated that a 25-hour inspection was performed in accordance with Schweizer requirements. In part, the following was also written in the logbook: "TORQUE CHECKED TAIL DRIVE SHAFT PINION NUT, AND ADJUSTED IDLER PULLEY TENSION. AIRCRAFT APPROVED FOR RETURN TO SERVICE."

The flight school operator, Pacific Shore Aviation, completed the National Transportation Safety Board's "Aircraft Accident Report" Form 6120.1/2. Pacific Shore Aviation reported that the helicopter had been operated for 2.1 hours since last receiving an inspection on November 10, 1994, and the helicopter's total airframe time at the accident flight was 1,343.2 hours.

2. Complaints Related to Maintenance.

The Safety Board received a letter from a commercial rotorcraft pilot in which he reported his recent experiences associated with the accident helicopter, and with the accident pilot's CFI with whom he was taking instruction to become a flight instructor. In part, the commercial rotorcraft pilot indicated that:

A. On November 2, 1994, the CFI picked up N60TA from Rotorcraft Support immediately following maintenance. At the conclusion of the 0.7-hour-long flight between Rotorcraft Support and Pacific Shore, the CFI heard "a vibration from the tail area." The CFI was not able to locate the source of the vibration. However, during the flight the CFI detected "a different problem with the helicopter" and had returned it to Rotorcraft Support for (unspecified) "additional work."

B. Later during November 2, the helicopter was delivered to Rotorcraft Support and was available for rental. During his subsequent preflight inspection, he observed that "the eight bolts which secured the vertical stabilizer to the tail boom were loose."

C. The CFI requested that Rotorcraft Support repair the helicopter. Several minutes later, personnel from Rotorcraft Support tightened the loose bolts. He and the CFI then took off for the instructional flight.

D. Passing the Los Angeles International Airport, the odor of "burning oil" was smelled, and a prompt landing was made at the Hawthorne Airport.

E. The CFI exited the helicopter and examined the running engine. The CFI reported observing "a small amount of oil leaking from around the magneto area." The CFI "assumed pilot-in-command control authority of the helicopter." The helicopter was flown back to the Van Nuys Airport.

F. As a result of the November 2, 1994 incident, the pilot wrote a letter to the fixed-base operator. In the letter, he expressed his concern for safety and for the maintenance deficiency in N60TA (see attached letter).

G. On November 5, in preparation for his next scheduled lesson in N60TA, the CFI reported to him that the "problem was fixed." When further questioned about the incident, the CFI reported that: (1) "The oil had leaked from around a seal at the dip stick filler neck tube;" (2) "It was tightened;" (3) "It would continue to leak;" (4) "We are watching it;" and (5) It was OK to leak."

H. During his preflight inspection on November 5, he observed "several nickel-size drops of oil" on the pavement below the helicopter's engine. He informed the CFI of his observation. The CFI responded by saying "it was OK." The flight lesson commenced.

I. At the completion of the lesson during the engine shutdown procedure, the engine "cut out briefly above 100 RPM." The CFI expressed concern about the engine having briefly died, and he said "that's not normal."

J. At the commencement of his next flight lesson on November 8, the CFI reported that he desired to perform the takeoff because "we've been having some trouble with the engine cutting out." During the flight lesson, the helicopter operated without incident.

METEOROLOGICAL INFORMATION

Responding sheriff department personnel reported that, a few minutes after the crash upon their arrival at the site, the wind was from the north at 5 to 8 knots.

COMMUNICATION

The FAA reported that all services provided to N60TA by the Van Nuys Air Traffic Control Tower were normal. No communications occurred with the accident helicopter following its departure from the airport.

WRECKAGE AND IMPACT INFORMATION

From an examination of the accident site and helicopter wreckage, the helicopter was found to have crashed into an estimated 10-foot-high dirt embankment which was adjacent to an open dirt field. No evidence of skid marks was observed in the field adjacent to the main wreckage area.

The accident site elevation was estimated at 1,080 feet mean sea level, and at geographic coordinates of approximately 34 degrees 24.0 minutes north latitude, by 118 degrees 40.0 minutes west longitude. This location was about 14.4 nautical miles and 308 degrees (magnetic) from the Van Nuys Airport.

The helicopter came to rest partially on the embankment and partially in the open field (see photographs and the accident site diagram). The helicopter was found generally pointed in a southeasterly direction. The skids were found in about a 90-degree nose-down pitch attitude.

The entire cockpit was destroyed by fire. Most of the control linkages between the cockpit and the rotor blades, the transmission, the mast, and portions of the engine were observed destroyed by fire. The preimpact continuity of the flight control system was not established.

Several components were found in the open field and were not fire damaged. For example, one main rotor blade was found about 147 feet west-northwest (303 degrees magnetic) from the main wreckage. The tail rotor gear box, tail rotor, and the tail stinger were found between 93 feet and 126 feet west-northwest of the main wreckage. Additional components, including the emergency locator transmitter (ELT), the horizontal stabilizer, and a tail rotor blade pitch link were found in the field to the south and west of the main wreckage at distances between 5 and 36 feet. The left rear landing gear damper was found on the inclined slope several yards east of the main wreckage.

The main transmission and the tail rotor gearbox housing were found broken open. The main transmission housing was observed partially destroyed by fire. No main transmission chip detector plug was located. The tail rotor gear box was found impact- damaged.

The tail rotor gear box's chip detector was removed from the gearbox, and it was examined. No metallic particles were found. A pinhead size ball of brown dirt-like material was observed on the detector.

Crushed areas in the separated tail rotor blade and blade spar were found to match the curvature of the leading edge of the main rotor blade, which was found separated from the main wreckage. (See photograph and the investigation report submitted by the Schweizer participant for additional information regarding observations of structural deformation, and evidence of main rotor speed.)

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy was performed on the pilot by the Los Angeles County Coroners Office. Results of toxicology tests performed on the pilot by the Armed Forces Institute of Pathology were negative for ethanol and drugs.

TESTS AND RESEARCH

On November 14, 1994, the engine and airframe were re-examined at the Santa Paula, California, storage facilities of H.L.M. Air Services. The following observations were noted:

1. Engine.

A. Visual Examination.

The engine had sustained extensive heat and fire damage. A hole, exposing the camshaft and several tappets, was observed near the front of the case. A portion of the oil sump and the left side of the accessory case had been consumed by the fire. One cylinder intake push rod and a tappet were located in a pile of debris which had been recovered from the crash site.

The engine was equipped with an over speed governor control (Hartzell anti-over-speed kit). The governor was found attached to the engine. The governor was removed and visually examined. The governor had sustained heat damage and could not be tested. The drive gear was found intact.

The engine was equipped with a light weight starter. According to the Schweizer Aircraft participant, the manufacturer did not authorize installation of a light weight starter because of insufficient clearance between the starter housing and the impeller shroud.

B. Ignition System.

The left magneto was not found attached to the engine. Several fire-damaged components were found in a pile of engine-related debris.

The right magneto was found attached to the engine. The magneto was removed and visually examined. It was found heat damaged and could not be functionally tested.

All eight spark plugs were found attached to the engine. The harness assembly was destroyed by fire. The spark plugs were removed and visually examined. The Lycoming engine participant opined that all spark plugs exhibited normal appearing electrode wear.

C. Fuel System.

The fuel servo unit was found attached to the engine and was observed heat damaged. The vernier-type mixture control cable was found attached and was observed in the full rich position. The throttle arm linkage was found in an intermediate position. The throttle cable and the over-speed governor linkage were destroyed and not attached to the servo.

The flow divider assembly was not found attached to the servo. It was observed safety wired to the servo unit, but had sustained heat damage and had separated from the servo unit. All four fuel lines and the top cap assembly were found attached to the flow divider assembly. The fuel inlet line and fitting were found heat damaged and had separated from the fuel servo. The inlet fuel screen was found with the servo unit. The screen was removed and visually examined. The screen had sustained heat damage. No fuel contamination was noted.

The diaphragm-type fuel pump was found destroyed by heat and was not attached to the engine. Several pieces of the pump were found in the engine debris.

D. Lubrication System.

The oil filter adaptor and canister were found separated from the engine and were heat damaged. The canister assembly was cut open and the element was visually examined. The element had sustained heat damage. No metal contamination was observed.

The oil suction screen was removed and visually examined. The screen exhibited heat damage and was mostly dry. No metal contamination was observed.

E. Valve, Gear Train, Cylinders, and Crankcase.

According to the Lycoming Engine participant, the continuity of the valve and gear train could not be confirmed because of the fire damage to the engine. All four cylinders were found attached to the engine. All cylinder valve covers were removed and no preimpact discrepancies were noted. Lubrication was present under the No. 3 cylinder cover. The other three cylinders were found mostly dry due to heat. Because of the extent of the fire damage, no compression values could be obtained. The crankshaft could not be rotated because of the extent of postimpact fire damage to the engine.

At the conclusion of the November, 1994, engine examination, the Lycoming Engine participant reported that he did not observe evidence of preimpact mechanical failures to any rotating or reciprocating engine component.

2. Airframe.

According to information received from the Schweizer Aircraft Corporation, when the helicopter was manufactured it was equipped with a Hartzell anti-over-speed kit, and a RPM limiter (a.k.a. startup limiter control). Regarding the installation of other optional equipment, no electronic engine throttle governor control unit was installed by the factory. The Schweizer Aircraft participant additionally reported that during the examination of the fire-damaged wreckage, no electronic engine throttle governor control unit was observed.

A. Visual Examination.

The left, forward, skid strut assembly was found bent in a downward direction. The forward crossbeam was found broken. The landing gear skids were found deformed in an upward direction and were both observed fractured.

The main rotor blade, which was found farthest from the main wreckage, was found with a smear of red paint on its leading edge near its tip end. The blade was observed coned upward about a 30-degree angle over approximately the outboard 5-foot-long portion of its span. Compressive buckles were observed in the blade's trailing edge.

Compressive buckles were observed in the spar of the second main rotor blade, and in the trailing edge of the blade over its entire span. The third main rotor blade was found with about a 4-foot-long outboard portion of its span broken off in a fire damaged area. Both the second the third blades were found attached to the helicopter.

The red and white colored tail rotor blade assembly was observed with two crushed/impacted areas. One area was in the spar (between the blades), and another area was in a blade. The tail rotor blade was placed against the leading edge of the separated main rotor blade. As previously stated, the curved shape of the main rotor blade's leading edge was observed to match the depressions in the tail rotor blade assembly (see photographs).

The tail boom was found severed in several locations near the vertical stabilizer attachment point. (See the "Wreckage Diagram" drawn in the Service Training Manual extract).

The Schweizer Aircraft participant reported that the starter was found assembled to the airframe in a manner which varied from the design prescribed by Schweizer. Required mounting hardware was not found installed.

B. Metallurgical Examination.

The main transmission was found fire damaged, and a tooth from the ring gear was missing. The ring gear and associated pinion shaft were examined by the Safety Board's Materials Laboratory. The examination showed that the fracture surface where the gear tooth had been located, had "coarse features indicative of a single or very few shock load applications. Further examination showed no evidence of excessive local deformation or wear on any on the teeth surfaces."

C. Structural Deformation Report.

The Schweizer Aircraft participant compared the observations made of deformed structural components in the accident helicopter with the structure of an (undamaged) production helicopter. Based upon the examination, the Schweizer participant reported in pertinent part that the major buckling in the left corner of the accident helicopter's fuselage frame and the fracture of the forward cross beam at the left side ". . . indicated a considerable impact in this area. . . . This can only happen if a sizable forward airspeed component existed. . . . The lack of damage to the aft crossbeam and structure confirms little vertical velocity transmitted to the gear and frame assembly."

At the conclusion of the airframe examination, the Schweizer Aircraft participant reported, in pertinent part, that the power train appeared to have been functioning at the time of impact. The separation of the main rotor blade near its root indicated that the rotor system was at normal RPM and energy levels. No evidence was found of preimpact mechanical failures in any airframe component.

ADDITIONAL INFORMATION

The entire helicopter wreckage was verbally released to the operator's assigned insurance adjuster in c/o H.L.M. Air Services, Inc., Santa Paula, California, on April 24, 1994. All components which had been examined by the Safety Board's laboratory, and all maintenance records associated with the helicopter (received from the FAA Van Nuys Flight Standards Office on July 17, 1995) were sent to the owner's assigned insurance adjuster in c/o H.L.M. Air Services, Inc., around August 8, 1995. The Safety Board has not retained any records or components.

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