# NTSB LAX02LA218: Bell 47G-2, N2483B, Compton, CA, July 7, 2002 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 7, 2002, 11:45 local (18:45 UTC) - Place: Compton, CA - Coordinates: 33.883335, -118.233329 - Nearby events: https://openairdocs.org/map.md?lat=33.8833&lon=-118.2333&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report September 29, 2004 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 55154 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX02LA218 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/55154/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=55154 - Page: https://openairdocs.org/ntsb/LAX02LA218 ## Probable cause the failure and separation of a fan belt for the engine cooling system. A factor in the accident was the inadequate annual inspection 14 hours prior to the accident. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(partial) - mech failure/malf, cruise - cooling system - disconnected (cause) - maintenance,annual inspection - inadequate, other maintenance personnel (contributing factor) - Forced landing, emergency descent/landing - In flight collision with object, emergency descent/landing - object - wire,transmission ## Analysis The helicopter experienced a partial loss of engine power during cruise flight, and collided with power lines during a precautionary landing. The pilot felt a severe vibration and noted a drop in the helicopter's rotor rpm. As the vibrations continued, he manipulated the flight controls in an effort to maintain a controlled descent and began an autorotation. While searching for a suitable landing area, about 200 feet agl, he noticed that power lines were in the helicopter's path. He maneuvered the helicopter in a unsuccessful effort to avoid the power lines, and landed hard in a dirt field. A mechanic with inspection authorization (IA), who regularly worked on the helicopter, conducted an examination after the accident. He stated that a fan belt used in the integral system for cooling the engine had either broken or come loose. As a result, the belt wrapped around the pulley, which caused the transmission to drag. He noted that the engine ran fine after the accident, and the fuel system was free of particulates and contaminates. He said that he completed the annual inspection for the helicopter about 14 hours prior to the accident, at which time he believed that he examined the belts. He further stated the helicopter was stored outside, in a corrosive environment. ## Factual narrative On July 7, 2002, about 1145 Pacific daylight time, a Bell 47G-2, N2483B, experienced a partial loss of engine power during cruise flight and collided with power lines during a forced landing near Compton, California. The pilot/owner was operating the helicopter under the provisions of 14 CFR Part 91. The pilot and one passenger were not injured; the helicopter sustained substantial damage. Visual meteorological conditions prevailed, and a flight plan had not been filed. The personal local flight originated at the Compton/Woodley Airport about 1100. In a written statement, the pilot reported that about 45 minutes after departure, the helicopter was about 1,000 feet above ground level (agl), and moving in an easterly direction with an airspeed of 70 knots. He felt a "severe" vibration and noted a drop in the helicopter's rotor rpm. As the vibrations continued, he manipulated the flight controls in an effort to maintain a controlled descent. While searching for a suitable landing area, he verified that the engine rpm indicated zero. About 200 feet agl he noticed that power lines were in the helicopter's path, and turned the helicopter in a unsuccessful effort to avoid them and an accompanying pole. The helicopter came to rest in a dirt field on the corner of the 91 freeway and Alondra Blvd. During a telephone interview with a National Transportation Safety Board investigator, the brother of the pilot, a mechanic with inspection authorization (IA) who regularly worked on N2483B, examined the helicopter after the accident. He stated that a fan belt used in the integral system for cooling the engine had either broken or come loose. As a result, the belt wrapped around the pulley, which caused the transmission to drag. The pilot autorotated the helicopter into power lines and impacted terrain. The IA further noted that the engine ran fine after the accident, and the fuel system was free of particulates and contaminates. He said that he completed the annual inspection for the helicopter about 14 hours prior to the accident, at which time he believed that he examined the belts. He further stated the helicopter was stored outside, in a corrosive environment. ## Aircraft - Registration: [N2483B](https://openairdocs.org/deregistered/N2483B-2011-02-07), registration cancelled 2011-02-07, S/N 1459, built 1956 (OpenAirDocs) - Reported make and model: Bell 47G-2 - Registry model: [Bell 47G-2](https://openairdocs.org/model/bell-47g-2) (registry code 1181008) (OpenAirDocs) - Registry engine: [Lycoming VO-435 series](https://openairdocs.org/engine/lycoming-vo-435-series) (registry code 41525, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 1459 - Engines: Lycoming VO-435-AIF 260 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: John Ochwatt - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, January 16, 2002, 14 hours before - Departed: CPM, Compton, CA - Destination: CPM, Compton, CA - Airport: CPM, Compton/Woodley Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 36; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 3, valid medical--no waivers/lim.; last flight review May 31, 2002; seat: left; flight hours: 300 total, 140 in this make and model, 263 as pilot in command, 10 in the last 90 days, 3 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 190° at 8 knots - Visibility: 4 statute miles - Lowest ceiling: none - Temperature: 73 °F, dew point 63 °F - Altimeter: 29.95 inHg - Observed at: LGB, 6 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20020707017329A](https://openairdocs.org/incident/20020707017329A), Jul 7, 2002: Bell 47G2, Compton, CA, No damage. (-23) On 07-07-2002 at approximately 1250 PDT, a Bell 47G-2 helicopter (N2483B) experienced vibration and a loss of power which resulted in its autorotation to… ## Other investigations on N2483B (5) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB LAX98LA001](https://openairdocs.org/ntsb/LAX98LA001), Oct 3, 1997: Bell 47G-2 (N2483B), Burbank, CA, substantial damage. Probable cause: A loss of engine power for undetermined reasons. - [NTSB SEA76FYG53](https://openairdocs.org/ntsb/SEA76FYG53), Jun 9, 1976: Bell 47G-2 (N2483B), Eltopia, WA, destroyed - [NTSB SEA71FWG17](https://openairdocs.org/ntsb/SEA71FWG17), Sep 9, 1970: Bell 47G-2 (N2483B), Wenatchee, WA, substantial damage - [NTSB SEA65A0047](https://openairdocs.org/ntsb/SEA65A0047), Mar 13, 1965: Bell 47G-2 (N2483B), Wenatchee, WA, destroyed - [NTSB UNK64X3325](https://openairdocs.org/ntsb/UNK64X3325), Aug 11, 1964: Bell B-47G2 (N2483B), Monitor, WA, incident, no damage ## Docket (2 files) The files NTSB released with the investigation on August 14, 2004, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=55154. 349 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 318 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461159&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Record of Conversation-IA (item 2, .PDF, 32 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40216331&FileExtension=.PDF&FileName=Record%20of%20Conversation-IA-Master.PDF From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.