N777TZ – Bell/tsirah 209AH-1FT – 1996-08-20 NTSB Accident Report

History of Flight

On August 20, 1996, at 1624 hours Pacific daylight time, the main rotor blades of an experimental certificated Bell/Tsirah 209AH-1FT helicopter, N777TZ, struck a rock outcropping and crashed near Palmdale, California. The pilots were conducting a local area visual flight rules filming flight. The helicopter, registered to Tsirah Corporation, Westlake Village, California, and operated by West Coast Helicopters, Van Nuys, California, was destroyed. The certificated airline transport first pilot sustained minor injuries; one ground person sustained serious injuries, and the certificated commercial second pilot sustained fatal injuries. Visual meteorological conditions prevailed. The flight originated at the accident site about 1610.

The helicopter was engaged in filming for a commercial. The director told Safety Board investigators that his producer contracted the operator to provide the helicopter for the filming sequence. He said that he discussed the flight with the pilot and that the pilot surveyed the flight path area on the ground before the flight. He said that the helicopter was to fly over and between two rock outcroppings and descend toward a moving ground vehicle. After the helicopter and vehicle departed the area, a series of buried pyrotechnics (a.k.a. squibs) were to be detonated.

The director said that the helicopter made three flights. The first flight was an overview of the proposed flight path and was not filmed. On the first filming flight, the helicopter hovered south of the rock outcroppings. When the filming action started, the helicopter came over the rock outcroppings on a northerly heading and descended toward the moving chase vehicle. He said that the timing between the helicopter and the chase vehicle was insufficient. He also said that the blowing sand made by the helicopter when it was hovering necessitated a retake of the action sequence.

The director instructed the pilot through the ground coordinator via a two-way radio to orbit further south of the outcroppings. He also instructed the driver of the chase vehicle to begin moving about 5 seconds earlier; he did not instruct the pilot to fly at a lower altitude.

The director and other ground witnesses reported that on the accident flight, the helicopter came between and slightly above the rock outcroppings while in a left turn. When the helicopter nosed over, the main rotor blades struck the west side rock. Pieces of the main rotor blades separated and the helicopter began to oscillate about its longitudinal axis. The helicopter assumed a momentarily level flight attitude and flew in a northerly direction. The main rotor rpm began to decrease and the helicopter entered into a nose high, tail low attitude. The helicopter struck the ground maintaining a nose high attitude. After the initial ground impact, the helicopter bounced and struck a parked truck and trailer.

A representative of Tsirah Corporation, the registered owner of the helicopter (herein referred to as the owner), confirmed the director's statement. He said that he was communicating with the pilot via the two-way radio.

The owner's representative also said that he and the second pilot of the accident flight flew the helicopter on the day of the accident to the filming location. The flight departed Van Nuys Airport about 1444 hours and arrived at the filming location about 1509 hours. He said that he deplaned the helicopter at the filming location. He said that he was not aware of the particulars of the proposed filming flight, but that the pilot had discussed the flight with the director.

The owner's representative said in a written statement that he was acting as the ground coordinator and relaying messages to the first pilot. He said that the helicopter made a non-filmed practice run. After the practice run, the director told him to tell the first pilot to get into position because he was going to film the second pass.

At the director's direction, the helicopter began the second pass. Due to the faulty timing and the dust cloud, the director said that another pass was required. The first pilot suggested to the director, through the owner's representative, that because of timing problems, that the owner's representative should give him a 5 second advance cue so that he could ". . .fly around without hovering. . . ." The owner's representative relayed this information to the first assistant director who relayed it to the director. The director agreed with the 5 second delay.

After he relayed the director's action cue to the flight, the first pilot said, ". . .you're going to like this one. . . . " The owner's representative said he saw the helicopter go through the natural V-shaped channel of the rock outcroppings. He said that the helicopter appeared to be lower and then the helicopter made a left banking turn. The helicopter's main rotor blades repeatedly struck the western side rock outcropping and began to disintegrate. The helicopter appeared to level off momentarily and the main rotor blades began to breakup. The helicopter crashed shortly thereafter.

The owner's representative was the first person to arrive at the helicopter. The helicopter was lying on its lower fuselage with the engine still running. The side of the helicopter had struck a stake bed truck. He climbed to the rear seat and the first pilot was apparently dazed. He reached over the first pilot and shut down the engine. He aided the first pilot in exiting the helicopter and then went to the second pilot.

The second pilot was motionless. The owner's representative said that the second pilot was not wearing his helmet and that both shoulder harnesses were lying unattached to the left of his body. The lap belt was properly secured.

A Los Angeles County Sheriff's deputy confirmed that the owner's representative told him that before commencing the accident flight, the pilot said over the radio that, ". . .you're going to like this one. . . ."

The following are sworn statements taken at the National Transportation Safety Board, Southwest Regional Office, Gardena, California:

First Pilot:

Safety Board investigators interviewed the pilot on September 4, 1996. The pilot said that the director called about a week before the accident and asked him to make a flyby over the set. The flyby was scheduled for the accident date. The helicopter was not going to be in the filming sequence. About 4 days before the accident, the director told him that the helicopter was going to be filmed. The helicopter was to reveal itself and then fly over the camera.

The day before the accident the pilot scouted the filming area. On the day of the accident he arrived at the filming set via ground vehicle about 1200 hours. In a brief conversation, the director pointed to the rock outcroppings as the initial point where the helicopter was to reveal itself. He did not review the story boards or the script. The pilot said that the helicopter was not to fly between the rock outcroppings. The camera angle would make it appear as if the helicopter was flying between the rocks. The pilot said that he told the director that the helicopter would need to come up from the back [south] side of the rocks. The director told the pilot that the helicopter was to be as low as possible over the rocks.

When the helicopter arrived, the owner's representative deplaned from the rear seat. The pilot briefed the owner's representative as to the filming sequence and told him to stand next to the first assistant director (AD). The owner's representative assumed the aerial/ground coordinator's duties.

The pilot, on the advice of his attorney, claimed his fifth amendment rights, and refused to acknowledge if he was the pilot-in-command during the accident flight. He also refused to state if he or the second pilot was piloting the helicopter at the time of the accident.

On the rehearsal flight before the first filming, the pilot said that ". . .we flew the route higher, much higher than we were intending to do it. . . ." The director told him (through the ground coordinator via the hand-held radio) that the flight path was too high. The first pilot said he did the rehearsal flight because the winds were "intensifying." He said that the winds were out of the west between 20 and 30 knots.

The initial filming sequence went very smooth. The helicopter was positioned further back and approached the rocks with some horizontal speed. He said that this would eliminate developing a dust cloud. He also said that he did not receive any instructions regarding the first flight and that he was not apprised of why the second [accident] flight was required. He said that retakes are often made for artistic purposes. He did recall receiving instructions to reveal the helicopter more slowly. He did not recall receiving instructions to reposition the helicopter further south of the rocks because of blowing dust.

The pilot said that he thought the ground squibs (to simulate bullets being fired from the helicopter) were going to be fired during the filming flight. They were not.

The pilots discussed the wind conditions and the high hover to eliminate the dust cloud. The first pilot said that the discussions also included that the second pilot was going to watch the left side because the main rotor blades were closer to the rocks. He also said that he had a line on the camera and that he was trying to maintain the helicopter's direction toward the camera. He reiterated that the helicopter was going to fly over the rocks and not between them. He said there was some blowing sand, but not enough to reduce the in-flight visibility.

There were no major turns made during the filming sequence; there were some slight corrections made. Most of the corrections were made with the cyclic. He was unaware if the second pilot was wearing his shoulder harness; he was sure that the second pilot was wearing his helmet.

First Assistant Director (first AD):

Safety Board investigators interviewed the first AD on September 16, 1996. The first AD said that he was retained by the filming company about 8 or 9 days before the accident. He became aware that a helicopter was going to be used about a week before the accident. He said that the original story boards received from the advertising agency were generic. The story boards showed a helicopter was to be in the filming. The story boards provided by the film company contained additional writings made by the director.

The first AD said that about a week before the accident, he and the director walked up to the top of the rock outcroppings. The director showed him where he wanted the helicopter to come from. He said the director wanted the helicopter to fly over the rocks.

On the day of the accident, he walked the site with the director and the pilot. He said that the pilot told him he was going to fly the helicopter. He was not aware that a second pilot was going to be used until the helicopter departed on the accident flight.

The commercial was filmed by two cameras. One camera was equipped with wide angle lenses and the other camera used close-up lenses. The cameras were positioned next to each other. The close-up camera was positioned to the right (viewing toward the south) of the wide angle camera. The helicopter was to fly over the rock outcroppings and continue until it flew over the left camera. The lighting trucks were parked to the east of the cameras.

The first AD held a safety meeting with the filming crew; neither of the pilots attended the safety meeting. He instructed all of the nonessential persons to remain to the right (west) of the helicopter's proposed flight path.

The helicopter made two non-filming rehearsal flights over the set; the flights were made between 75 and 100 feet above the ground. He said that on the first filming flight the dust cloud created by the helicopter and the timing between the helicopter and the ground chase vehicle was not correct. During the discussions about the first filming flight, the helicopter was relocated south and behind the rocks.

The first AD instructed the ground coordinator to have the helicopter back up from its initial hovering position (move south of the area). He discussed the timing with the pilot (through the ground coordinator) and they agreed that they would move about 100 yards south of the initial hovering position.

Shortly thereafter, he commenced the filming action. The first AD directed his view toward the ground vehicle and began a 5-second count. He could hear the helicopter and then he heard several "popping" sounds. He thought the special effects technician had ignited the buried squibs and then he heard the helicopter sound change. He looked at the helicopter and saw that something happened and that it was about to crash. He did not have a clear view of the helicopter hitting the ground, but he saw part of it; the helicopter was partially obscured by the stake bed of the parked truck.

During the filming sequence, the director did not order the helicopter to get lower.

The weather conditions consisted of clear skies and the temperature was about 92 degrees (F). The surface winds were breezy with occasional gusts. He said the wind velocity was ". . .under 10 miles per hour. . . ." Other than on the initial filming sequence, he did not notice any blowing sand during the accident sequence.

The first AD said that safety bulletins were not attached to the call sheets. This is not normally done during filming of commercials. Safety bulletins pertaining to helicopter operations are normally provided by the Alliance of Motion Picture and Television Producers (AMPTP) organization for television and feature film productions. The filming company, however, must be members (signatories) of the AMPTP.

The first AD said that had the accident not occurred, another flight would have been taken and the buried squibs would have been ignited.

On-Site Paramedic (Hall Ambulance Service, Bakersfield, California):

The paramedic said that his company was retained for emergency standby by the filming company. He said that sometime before noon, he learned through conversations with other persons that a helicopter was going to be used. Initially, he was only told that a stunt person was going to be repelled from a tower into a moving jeep. He did not attend the safety meeting concerning the helicopter operation; he did attend a safety meeting involving the stunt person being lowered into a moving jeep.

He said that after the accident, he and his partner, also a certified emergency medical technician, responded to the helicopter. He said that he saw the second pilot's helmet lying about 15 feet in front of the helicopter. When he arrived at the helicopter he observed that the second pilot had expired. He said that he did not see any shoulder harness or lap belt around the second pilot.

The paramedic said that he saw both filming flights. On the first flight, the helicopter came over the rocks. On the second flight the helicopter flew between the rocks and it appeared to be closer to the western side rocks and then he heard a popping noise. He then saw the main rotor begin to disintegrate and he ran for safety and ". . .dove behind a truck. . . ."

Pilot Information

Both pilots held a letter of authorization (LOA) to act as pilot-in-command in the accident helicopter make and model. In addition to other restrictions, the LOA requires that each pilot, within the preceding 180 days, make at least three takeoffs and landings in ". . .one of the models authorized or a comparable model. . . ." The pilots received the LOA on December 4, 1995.

The first pilot's attorney submitted a partially completed Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1) on September 9, 1996. He indicated in the form that the second pilot was the copilot. The first pilot did not sign or date the form.

The first pilot holds an Airline Transport Pilot Certificate with a rotorcraft - helicopter rating; the certificate is endorsed for private pilot privileges in an airplane with a single engine land rating. He also held an unrestricted second-class medical certificate which was issued on July 31, 1996.

Safety Board investigators did not examine the pilot's flight hours logbook. The first and second pilots flight hours reflected on page 3 and Supplement E, respectively, of this report were obtained from the accident report.

The first pilot indicated in the report that he accrued 11,000 flight hours, of which 70 hours were as pilot-in-command in the accident helicopter. He also indicated that he had accrued all of the flight hours in the accident helicopter make and model within the preceding 90 days, and that he accrued 25 hours within 30 days preceding the accident. He indicated that he successfully completed the required biennial flight review on June 8, 1996.

The second pilot held a commercial pilot certificate with an airplane single engine land and a rotorcraft - helicopter ratings. He also held an unrestricted second-class medical certificate which was issued on October 2, 1995.

The second pilot's family could not provide the Safety Board with his personal flight hours logbook. The accident report shows that the second pilot accrued 6,600 flight hours, of which 35 hours were in the accident helicopter make and model. The second pilot, however, indicated on his last medical certificate application form that he had accrued 4,800 flight hours. The form indicated that the second pilot accrued 35 flight hours within 90 days preceding the accident, and that he accrued 11 hours within 30 days preceding the accident.

In a telephone interview, the first pilot said that the second pilot last flew the accident helicopter on February 27, 1996, to Las Vegas, Nevada. He said that a company employee accompanied the second pilot. The company employee confirmed the first pilot's statement concerning this flight. The first pilot also said that the second pilot last flew the accident helicopter make and model on a film production sometime in December 1995. Within the preceding 180 days of the accident, the second pilot made only one takeoff and landing.

The owner's representative is authorized by the FAA, West Chicago Flight Standards District Office, Dupage, Illinois, to administer flight tests in the accident helicopter make and model. He stated that he gave the appropriate flight tests to the first and second pilot in December 1995.

In a written statement, the owner's representative said that he was told by the owner and the second pilot in separate telephone conversations that he was to ferry the accident helicopter to the filming location on August 20, 1996. The second pilot was going to assume copilot duties during the filming. He said that he was the pilot-in-command during the ferry flight because the second pilot's LOA had expired and that he did not have time to give the second pilot the required recurrency flight check. He said that the second pilot occupied the front seat.

After taking off from Van Nuys Airport, the owner's representative relinquished the flight controls to the second pilot. When the flight approached the filming location, the first pilot (of the accident flight), while standing on the ground and communicating through a hand-held radio, instructed the second pilot to make a low pass over the location. After the second pilot completed the low pass, he asked the owner's representative to make the landing saying, in part, ". . .I have been out of the seat too long. . . ."

Aircraft Information

According to the manufacturer, the helicopter was initially delivered to the U.S. Army in 1975. In 1985, the helicopter was involved in a class A aircraft accident, and was retired from military operations. The helicopter airframe accrued 651 hours at the time it was retired from military operations. The owner purchased the helicopter at a U.S. Department of Defense surplus aircraft sale and restoration was initiated on March 22, 1992. The helicopter received its special airworthiness certificate on July 28, 1993.

The owner provided the Safety Board with all of the airplane's maintenance records (civilian). A review of the records disclosed that all new or "0" time remanufactured parts were used during the restoration process. The required life limited parts were well within their scheduled replacement times. The flight hours reflected on page 2 of this report were derived from the maintenance records examination and the helicopter's Hobbsmeter.

The owner's representative, a certificated aircraft mechanic with airframe and powerplant ratings, performed the last airframe and engine 100-hour inspection on April 18, 1996. The helicopter accrued 95.6 hours at the time of the inspection and the engine accrued 56.1 hours since overhaul.

At the time of the accident, the helicopter accrued 97.9 hours since it was rebuilt and 748.9 hours from the date of manufacture. The engine accrued 457.1 hours since new.

Safety Board investigators calculated the helicopter's weight and balance at the time of the accident. The flight crew members' weights were obtained from their FAA pilot records. The fuel quantity was estimated at 1,224 pounds (180 gallons at 6.8 lbs/gallon). The weight & balance calculations determined that at the time of the accident, the airplane weighed 8,102.0 pounds and the center of gravity was at 197.77 inches aft of the datum. The maximum allowable gross weight is 10,000 pounds. At the accident weight, the center of gravity limits were between 192.2 to 201.0 inches.

According to the U.S. Army Flight Manual, the pilot-in-command occupies the rear seat.

Fire

There was no pre- or postimpact fire

Wreckage and Impact Information

The crash site is an open desert area at 2,520 feet mean sea level (msl). The terrain slopes upward to about 2,660 feet msl about 100 yards north of the accident site. There are two rock formations, separated by about 45 feet at the crest of the upward sloping terrain. The helicopter's flight path was between and slightly above the rock formation.

The east side of the west side rock formation displayed a blade impact signature. The scrape marks contained black paint transference signatures. The main rotor blades are painted black. Scattered main rotor blade honeycomb particles and blade skin were found between the rock formation and the main wreckage site.

Ground scars, ground witness statements, and the wreckage examination disclosed the helicopter struck the ground in a tail low attitude while on a 346-degree heading. After initial ground contact, the helicopter bounced and then struck a truck on about a 300-degree heading. The truck was displaced about 6 feet after it was struck. The helicopter came to rest on its right side with the forward section facing 288 degrees.

All of the helicopter's major components were found at the main wreckage site. Scattered main rotor blade debris was found between the rock formation and the main wreckage.

Safety Board investigators conducted a detailed wreckage examination on August 23, 1996, at Aircraft Recovery Service, Compton Airport, Compton, California. The parties listed in this report participated in the examination.

The hydraulic boosted flight controls were jammed and could not be operated: however, continuity of the transmission assembly was established; the output drive shaft rotated upon rotation of the mast assembly. The transmission assembly support frame was found fractured near the rear attach points. The assembly was found resting against the left forward bulkhead.

The main rotor blades remained attached at the mast assembly, but its two pitch change links were broken and displayed bending and compression signatures. The blades exhibited external object impact signatures and were delaminated; less than 1/2 of the blades were remaining. The left lateral and the collective hydraulic servos push/pull tubes were broken at their respective attach points. The right fore and aft cyclic push/pull tube was found attached to its respective hydraulic servo and its attach plate (a.k.a. ladder assembly). All of the fractured surfaces noted above displayed torsional, tensile, and compression overload signatures.

The tail boom separated at tail boom station 41.33 and was found resting against a trailer. The tail rotor blades remained attached at the 90-degree gear box. The blades were bent about 90 degrees about 1/3 the distance of the blade from the tip ends. The tail rotor 45- and 90-degree gearboxes were intact. The number one and two drive shaft sections were found broken and the fracture surface displayed torsional overload signatures; the drive shaft cover in this area displayed rotational scoring and tearing signatures. Continuity of the tail rotor drive shaft was established aft of the broken sections to the tail rotor assembly. Continuity of the elevator and tail rotor pitch change push/pull tubes were also established.

The engine was intact and displayed some external impact damage. The right engine mount was bent downward and the left engine mount was fractured. The engine assembly was turned to the right about 10 degrees and had dropped about 2 inches toward the compartment deck. A 3-inch diameter hole was found on the left side of the plenum, near the forward flange. The hole was adjacent to the separated left engine mount.

The transmission to engine shaft (a.k.a. short shaft) was disengaged and found wedged between the engine and firewall. Extensive grease and oil from the transmission was found on the firewall. Some of the grease was ingested by the engine; the grease was also deposited on the left side of the engine through the hole in the plenum.

Safety Board investigators established continuity of the rotating group. The power turbine rotated smoothly through 360 degrees and continuity through the output coupling was established. Continuity from the N2 shaft through the N2 tachometer was established. The engine chip detector displayed minor fuzz particles and the engine oil filter showed minor particulate matter. The manufacturer's representative said that the particles were normal with a recently overhauled engine.

The fuel filter was free of contaminates. The oil tank dipstick indicated that the tank was full. No fluid leaks were noted from the engine.

Medical and Pathological Information

The Los Angeles County Coroner's Office conducted the post mortem and toxicological examinations on the second pilot. According to the Coroner's investigator, the toxicology examinations were negative for alcohol or drugs. The FAA, Civil Aero Medical Institute, Oklahoma City, Oklahoma, also conducted toxicological examinations on the second pilot. These tests were also negative for all screened drugs and alcohol.

Safety Board investigators visually examined the second pilot's body at the accident site. The examination revealed no evidence of any shoulder harness bruising. There was extensive lap belt bruising around the waist area.

The first pilot was admitted to the Antelope Valley Hospital, Palmdale, California, on the evening of the accident. At the request of the Los Angeles County Sheriff's Department (LASD), Antelope Valley Hospital medical personnel performed toxicological examinations on the pilot about 4 hours after he was admitted. The pilot volunteered for these tests. According to a LASD deputy, the examinations were negative for alcohol or drugs.

Tests and Research

Film Examination:

The production company provided Safety Board investigators with a copy of the film showing the helicopter filming sequence. A frame-by-frame examination was conducted at Aerospace Corporation, Law Enforcement Technology Center, El Segundo, California, and at Warner Brothers Studios, Burbank, California. Before the flight commenced, a helicopter blade was observed south and below the west side rock formation. The helicopter was hovering as depicted by the blowing sand. Shortly thereafter, the helicopter flew over the west side rock formation and began a slight left turn after it crossed over the rocks. This was the initial filming sequence. The helicopter's actual height above the rock outcroppings was not determined.

On the accident sequence, the helicopter approached the rock formation from the south-southwest. The helicopter's height above the rock out cropping appeared to be lower. When the helicopter was between the east and west rock outcroppings, it made a left turn. During the turn, the main rotor blades struck the west side rock out cropping three times. The rotor blades began to shed its outer skin and inner core composition.

The helicopter then established a main rotor blades' level attitude and one of the pitch change links broke. The second pilot was wearing his helmet and he rapidly moved forward and to the right; only portions of his left shoulder could be seen. Moments later, the main rotor blades began to decelerate and the helicopter went into a nose high attitude. At this point, the filming of the accident sequence stopped with the camera pointed toward the sky.

Stability Augmentation System

The Stability Augmentation System sensor amplifier modules were examined at the Bell Helicopter Textron test facility on October 25, 1996. The examination was supervised by an NTSB investigator from the Fort Worth (Arlington) South Central Regional Office. The pitch and roll modules functionally tested normal. The yaw module failed in test point 22. This test point checked a beep input, but is not utilized on the accident helicopter make and model. Disassembly examination of the yaw module revealed that the connector had a bent pin. A Bell Helicopter technician straightened the pin and the unit then functioned normally.

Additional Information

The helicopter was released to the owner on August 23, 1996. The helicopter wreckage was located at Aircraft Recovery Service, Compton Airport, Compton, when it was released. The Safety Board did not retain any original helicopter records or components.