Aviation Accident Summaries

Aviation Accident Summary LAX95FA079

LOS ANGELES, CA, USA

Aircraft #1

N2209P

BELL 206B

Analysis

THE PILOT REQUESTED AND RECEIVED A SPECIAL VFR CLEARANCE OUT OF THE CLASS C AIRSPACE AND PROCEEDED SOUTHBOUND FROM THE BURBANK AIRPORT. THE AIRPORT PREVAILING WEATHER WAS 300 FT BROKEN; VISIBILITY 2-1/2 MI WITH FOG AND LIGHT RAIN. THE HELICOPTER CONTINUED SOUTHBOUND UNTIL IT COLLIDED WITH HIGH VOLTAGE TRANSMISSION WIRES ABOUT 150 FT AGL. RADAR DATA SHOWED THAT THE HELICOPTER DID NOT CLIMB MORE THAN 300 FT ABOVE THE GROUND AFTER DEPARTURE. GROUND WITNESSES REPORTED THAT DUE THE PREVAILING RAIN SHOWERS, CLOUD OBSCURATION, AND A 1/4-MI VISIBILITY, THE HELICOPTER WAS BARELY DISTINGUISHABLE. THE HELICOPTER BECAME ENTANGLED WITH THE SECOND SET OF WIRES UNTIL THE MAIN ROTOR ASSEMBLY SEPARATED AND THEN IT PLUNGED TO THE GROUND. THE PILOT DID NOT OBTAIN A WEATHER BRIEFING FROM THE FSS, NOR FILE A FLIGHT PLAN. HE DID RECEIVE THE CURRENT ATIS BEFORE DEPARTING.

Factual Information

History of Flight On January 14, 1995, at 1945 hours Pacific standard time, a Bell 206B helicopter, N2209P, collided with a high-voltage transmission wire and crashed next to State Highway 101 (aka Hollywood Freeway), Los Angeles, California. The pilot was conducting a visual flight rules (VFR) air taxi flight to the TransAmerica Building in downtown Los Angeles. He did not file a flight plan. The pilot was operating under the provisions of Title 14 CFR Part 135. The helicopter, registered to Fleet Management, Pasadena, California, and operated by Wolfe Air Aviation Ltd., Burbank, California, was destroyed. The certificated airline transport pilot and the left front seat passenger sustained fatal injuries; the two rear seat passengers sustained serious injuries. Instrument meteorological conditions prevailed. The flight originated at Burbank Airport at 1939 hours. According to the Federal Aviation Administration (FAA) Burbank Airport Traffic Control Tower recorded communications media, the pilot initially contacted the local controller at 1938:28 hours and requested a special vfr clearance " . . . southeast bound . . . ." The local controller responded, " . . . will that be to the special flight rules aah correction aah to cahuenga pass . . . ? The pilot responded, "Aah I'll tell you we'll head towards cahuenga pass, but Im gonna assume we'll have to follow the Ventura Freeway from there eastbound then." The local controller issued the pilot a special VFR clearance out of the Class C airspace and instructed the pilot to remain at or below 1,500 feet mean sea level (msl). At 1742:06 hours, the local controller instructed the pilot to maintain special VFR south of the Ventura Freeway and said that a Boeing 737 will be departing toward the southwest under instrument flight rules (IFR). The pilot achkowledged the instructions. The local controller then asked the pilot to advise him if he needed to go on a different direction other than south. At 1744:06 hours, the pilot reported that he was south of the airport and clear of the Class C airspace. The local controller acknowledged the pilot's report and cleared him for a frequency change. At 1744:11 hours, the pilot acknowledged the controller's instruction. There were no further communications between the pilot and any other FAA air traffic facilities. The available recorded radar data showed that the helicopter departed Burbank in a southerly direction and initially climbed to 900 feet msl (about 225 feet above the ground). At 1942:35 hours, the helicopter climbed to 1,000 feet msl and maintained that altitude until 1944:12 hours (the last radar acquisition target). The available radar data showed that the helicopter maintained a southerly course. The last radar target was about 7 miles south of Burbank Airport. The operator's vice-president/chief pilot (herein called the chief pilot) responded to the accident site. He told National Transportation Safety Board investigators that the company was contracted to provide the flight about a week before the accident. The pilot was to fly the passengers to the TransAmerica building for dinner and then fly them on a sightseeing tour of the city. After the passengers had dinner, the pilot was scheduled to return to Burbank Airport. The chief pilot said that the pilot checked the weather with the FAA Hawthorne [California] Flight Service Station, before departing on the accident flight. He also said that he told the Media Aviation dispatcher that he checked Burbank Airport terminal information service (ATIS) and decided that the weather was good enough for the flight. In an interview conducted on January 17, 1994, the chief pilot repeated his statement given to Safety Board investigators at the accident site on January 14, 1994. Additionally, he said that he dispatched the flight about an hour before the accident. He said that the company does not list the passengers names or addresses in the load manifest; the company does require that the lead passenger (the passenger who books the flight) be listed in the manifest. Safety Board investigators recovered the flight's load manifest at the accident site. The load manifest did not contain any of the passengers' names. The Media Aviation dispatcher was interviewed by Safety Board investigators on January 19, 1995, via telephone. The dispatcher said that the accident operator based their aircraft at Media Aviation. She said that the pilot arrived at the Media Aviation terminal 45 minutes before the flight departed (about 1847 hours), and engaged in a casual conversation with the pilot. At the pilot's request, she gave him the Burbank Airport ATIS telephone number. The pilot called the ATIS telephone number and obtained the Burbank Airport weather information. The pilot told her that the weather was satisfactory for the flight. He said, however, that he would like to cancel the flight because he was concerned about the passengers' comfort and not because of the weather. He said the weather might frighten the passengers. The pilot also told her that he was going to fly around Griffith Park (about 3 miles east of the accident site) to the TransAmerica building, instead of the normal routing over the Cahuenga Pass (the accident site). When the passengers arrived at the terminal, the pilot repeated his routing statement to the lead passenger, the co-owner of the limousine service. He also told the lead passenger that he was not going to fly over Universal Studios (on the northeast side of Cahuenga Pass), as customary. The lead passenger concurred. A Los Angeles Sheriff's Department deputy reported that he observed a blue and white helicopter circling over Universal Studios between 200 and 300 feet above the ground. The helicopter then flew toward the Hollywood Freeway. Safety Board investigators interviewed several other ground witnesses. The consensus of the ground witnesses was that clouds and ground fog obscured wires, light to moderate rain conditions prevailed, and that the ground visibility was between 1/4 and 1/2 mile. A passenger in an automobile driving south on the Hollywood Freeway said she observed a helicopter entangled in the transmission wires between 5 and 10 seconds before it fell to the ground. The helicopter was "jarring up and down." Moments later, she observed a "bright blue and white blinding explosion." She said that she saw "something fall" from the helicopter and then it plunged downward as their automobile approached the wires. The helicopter struck some trees as it nosed-down to the ground. The witness said their automobile was next to the helicopter when it struck the ground. The passenger's husband told Safety Board investigators that he did not see the helicopter until it crashed. He thought the wire explosion was a transformer failure. Another witness driving south on the Hollywood Freeway said that the helicopter was "hovering" over the freeway. He said he thought that it was a police helicopter because he saw what appeared to be a searchlight shining from the helicopter. The witness also said that the helicopter's lights were distinguishable, but the rest of the helicopter was not due to the inclement weather. Other Damage Safety Board investigators contacted the Los Angeles Department of Power and Water Company on January 16, 1994. The principal engineer described the wires that cross the freeway as two sets of three vertical high-voltage wires and one ground conductor wire that spans the freeway (about 1,242 feet). The helicopter severed the southern set of wires. The horizontal distance between the two sets of wires is 23.08 feet. The wires are connected to a transmission tower on the top of the hills east and west of the freeway (#581 & #582, respectively). The tops of the transmission towers are about 300 feet above the ground, and the wires slope downward to their lowest point (about 135 feet above the ground) near the middle of the freeway. Each set of vertical wires is connected to the northern and southern arms of each transmission tower and is about 25 feet apart (horizontally). The ground conductor wire is 20 feet above the top high-voltage transmission wire and contains international orange colored balls. The high-voltage transmission wires are 1.802 inches in diameter and transmit 230KV (kilovolts) of power. Each wire contains a 0.047-inch steel core, with 19 aluminum wire strands wrapped around the core. The breaking strength of the wire/core is 56.7 1000-foot pounds. The top transmission wire is named A Phase, the middle wire is B Phase, and the lower wire is C Phase, with a clearance between each phase of about 15 feet. The helicopter struck the B phase wire about 150 feet above the ground midway between #581 and #582 transmission towers. Pilot Information The pilot held an airline transport pilot certificate with airplane multiengine land, CE-500, Lear Jet, and N-B25 type ratings; the B-25 type rating is valid for VFR flights only. The certificate was endorsed for commercial privileges with airplane single engine land and rotorcraft-helicopter ratings. He also held a first class medical certificate issued by an FAA designated airman medical examiner on July 27, 1994; the certificate contained a "must wear corrective lenses" limitation endorsement. Safety Board investigators did not find the pilot's personal flight hours' logbook. The flight information reflected on page 3 of this report were obtained from the operator. The total helicopter times listed in the report were valid until January, 1994. The operator estimates the pilot accrued 500 hours in helicopters. As of January 1, 1994, the records show that the pilot accrued 389 total helicopter flight hours, of which 311 hours were accrued as pilot-in-command. The pilot accrued 59 total flight hours during the 90 days preceding the accident. He accrued 5 flight hours in the accident helicopter make and model 30 days preceding the accident. The pilot's last instrument proficiency flight check was conducted by an FAA operations inspector on July 6, 1994. This flight check satisfied the requirements of Title 14 CFR 135.297 (IFR proficiency), 14 CFR 135.299 (line check), and 14 CFR 61.58 (biennial flight review). The chief pilot said that the pilot was not salaried and is paid on a per flight basis. The pilot is also a qualified captain in the company's Lear 25B. Aircraft Information The operator, Wolfe Aviation, Ltd., leased the helicopter from the registered owner, Fleet Unlimited, Inc. The lease requires the operator to maintain the helicopter. The operator contracted the maintenance to Rotorcraft Support, Inc. (herein called Rotorcraft Support), Van Nuys Airport, Van Nuys, California. Safety Board investigators reviewed the helicopter's maintenance records at Rotorcraft Support on January 17, 1994. The records' examination showed that Rotorcraft Support maintenance personnel accomplished an annual inspection on the airframe and engine on October 28, 1994; the helicopter and engine accrued 3,200 hours at the time of the inspection. The helicopter accrued 3,255.4 hours at the time of the accident. The examination also revealed that there were no deferred maintenance discrepancies noted, and that all applicable airworthiness directives were complied with. According to the Bell representatives, the height of the helicopter from the skids to the top of the rotor mast is 11 feet 6 inches; the main rotor blades diameter is 33 feet. Meteorological Information There is no official weather observation facility at the accident site. Burbank Airport is the closest official weather observation facility. The weather data reflected on page 3 of this report were the obtained from the ground witnesses, including California Highway Patrol and Los Angeles Police officers who responded to the accident site. The following is the Burbank Airport ATIS 1930 hours information and the 1946 hours surface weather observation. Clouds - partially obscured, 300 feet broken, 900 feet overcast; visibility - 2 1/2 miles with fog and light rain; temperature - 56 degrees Fahrenheit; dew point 56 degrees Fahrenheit; surface winds - 120 degrees at 8 knots. Burbank Airport is 5 miles north of the accident site and its elevation is 775 feet msl. The crash site elevation is about 676 feet msl. The FAA Hawthorne [California] Flight Service Station personnel told Safety Board investigators that there is no record of the pilot obtaining a weather briefing. The pilot did not file a VFR flight plan. According to their respective watch commanders, the Los Angeles Sheriff's Department Aero Bureau and the Los Angeles Police Department Air Support Division ended their flight operations after 1600 hours due to poor weather in the Los Angeles basin. Their flight operations did not resume until January 15, 1995. Wreckage and Impact Information The crash site is beneath the wires that span the freeway and is surrounded by palm and other coniferous trees. Witness statements, broken wires and tree limbs, and the wreckage examination revealed the helicopter became entangled in the south set of wires, fell down tail first, struck a palm tree, and rotated to a nose-down attitude before striking the ground. The helicopter struck the ground in about a 60-degree nose-down and about a 45-degree right banking attitude. The helicopter came to rest on its right side with its nose facing 088 degrees. A 6-inch diameter tree limb impaled the right side of the cockpit next to the pilot's seat. All of the helicopter's major components were found at the main wreckage area. Safety Board investigators found the main rotor mast and its two attached rotor blades about 166 feet north of the main wreckage. The tail rotor assembly separated from the tailboom and was found about 10 feet west of the main wreckage. Safety Board investigators conducted a detailed wreckage examination at Aero Retrieval, Compton Airport, Compton, California, on January 15, 1995. The flight control tubes beneath the pilot's seats at the mixing bellcrank were broken. The control tubes in the "broom closet" were found connected; some tubes displayed impact crushing and bending. The right and center hydraulic servos' push/pull tubes were broken. The center servo also exhibited many electrical arcing burn marks. All of the fractured surfaces displayed overload characteristics. The upper cabin area bearing housing upper shield displayed tearing from the swash plate attach arms. The main rotor mast was broken about 2 inches below the static stop and displayed many electrical arcing burn marks. The fractured surfaces displayed extensive torsional overload signatures. Continuity of the rotating group to the tail rotor drive shaft was established. Investigators found no binding when the rotor mast was rotated. All of the drive shaft's Thomas couplings displayed extensive rubbing and open areas between their plates. According to a Bell Helicopter's representative, the spreading is consistent with sudden stoppage of the drive shaft. The tail rotor drive shaft Thomas' couplings displayed extensive rubbing on the tail rotor drive shaft cover. The tail rotor drive shaft separated at two places, and from its respective attach points; the drive shaft also displayed numerous electrical arcing burn marks. The electrical wiring next to the drive shaft was found melted. The tail rotor 90-degree gearbox drive shaft and its associated Thomas coupling exhibited extensive electrical arcing burn marks. Continuity of the 90-degree gearbox was established. Both tail rotor blades sustained extensive impact damage, but remained attached to the hub assembly. Palm frons were found impinged against the right horizontal stabilizer and the tail boom. The lower vertical stabilizer displayed wire strikes and electrical arcing burn marks on its leading edge. One of the tail light's filaments was found bent in the impact direction; however, no discernable stretching of the filaments was observed. Continuity of the engine's rotating group was established. The power turbine rotated freely

Probable Cause and Findings

THE PILOT'S CONTINUED VFR FLIGHT INTO INSTRUMENT METEOROLOGICAL CONDITIONS. FACTORS WHICH CONTRIBUTED TO THE ACCIDENT WERE: THE PILOT'S AND OPERATOR'S FAILURE TO FOLLOW THEIR ESTABLISHED DISPATCH PROCEDURES, THE PILOT'S POOR JUDGMENT IN INITIATING THE FLIGHT, AND THE EXISTING WEATHER CONDITIONS.

 

Source: NTSB Aviation Accident Database

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