# NTSB LAX00LA055: Bell 206B, N6624N, Apache Junction, AZ, October 7, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 7, 1999, 10:15 local (17:15 UTC) - Place: Apache Junction, AZ - Location: 33.4150° N, 111.5496° W: Placed by OpenAirDocs: center of Apache Junction, AZ, within about 6 miles (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=33.4150&lon=-111.5496&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report May 16, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 48367 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX00LA055 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/48367/pdf - Page: https://openairdocs.org/ntsb/LAX00LA055 ## Probable cause Oil starvation and seizure of the engines Nos. 6 and 7 bearings due to a clogged oil jet, which resulted in a total loss of engine power. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, cruise - lubricating system,oil port/passage,internal - blocked(partial) (cause) - fluid,oil - starvation (cause) - Forced landing, emergency descent/landing - autorotation - performed, pilot in command - On ground/water encounter with terrain/water, landing - flare/touchdown - terrain condition - high vegetation - landing gear,skid assembly - separation ## Analysis While in cruise flight about 600 feet agl, the pilot noticed that the engine oil pressure was high and the torque gauge was exceeding the high limits. The engine chip light became illuminated. As the pilot descended to make an immediate landing, the engine quit about 75 to 100 feet agl. The pilot autorotated to the ground. The main rotor blades severed the tail cone aft of the horizontal stabilizer after the toe of the left skid became entangled in a large bush and separated. A teardown examination of the engine was conducted. The mechanic reported that the Nos. 6 and 7 bearings displayed evidence of heat distress and oil starvation. When he blew through the oil jet for the Nos. 6 and 7 bearings, he heard something pop out. He opined that it might have been a piece of carbon, which could have prevented the flow of oil into the turbine. He stated that all other components of the lubrication system were intact and functional. No other discrepancies were found. ## Factual narrative On October 7, 1999, at 1015 hours mountain standard time, a Bell 206B, N6624N, experienced a loss of engine power and collided with high vegitation during a forced landing near Apache Junction, Arizona. The helicopter, operated by Arizona HeliServices, Inc., of Chandler, Arizona, sustained substantial damage. The commercial pilot and two passengers were not injured. The local personal flight, conducted under the provisions of 14 CFR Part 91, originated from the Cochise County Airport, Willcox, Arizona, about 0905, and was en route to Falcon Field, Mesa, Arizona. Visual meteorological conditions prevailed and no flight plan was filed. The pilot reported that while in cruise flight about 600 feet agl, he noticed that the engine oil pressure was "exceedingly high," and the torque gauge was exceeding the high limits (120+). The engine chip light became illuminated. The pilot lowered the collective with no apparent effect on the torque gauge reading. As he descended to make an immediate landing, the engine quit about 75 to 100 feet agl. The pilot autorotated to the ground with a slight aft skid touchdown and minimum forward airspeed. The left skid toe became embedded in a creosote bush and the helicopter turned left 90 degrees. The left skid separated from the crossmember and the left side of the nose dipped. The main rotor blades severed the tail cone aft of the horizontal stabilizer. The right skid separated but the helicopter remained upright. A teardown examination of the engine was conducted. The mechanic reported that the Nos. 6 and 7 bearings displayed evidence of heat distress and oil starvation. He blew through the oil jet for the Nos. 6 and 7 bearings and thought it seemed to be partially blocked. He then blew compressed air through the oil jet and heard something pop out. He opined that it might have been a piece of carbon, which could have clogged the jet and blocked the flow of oil. He stated that all other components of the lubrication system were intact and functional. No other discrepancies were found. ## Aircraft - Registration: N6624N (not matched to a registry record) - Reported make and model: Bell 206B - Category: Helicopter - Serial number: 3169 - Airframe hours: 6335 - Engines: Allison 250-C20B 420 horsepower turbo shaft - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Arizona Heliservices Inc. - Registered owner: Bell Ford, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, March 31, 1999, 93 hours before - Departed: P33, WILLCOX, AZ - Destination: FFZ, MESA, AZ ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 52; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 5,800 total, 2,300 in this make and model, 5,700 as pilot in command, 20 in the last 90 days, 20 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 43 °F - Altimeter: 29.00 inHg - Observed at: PHX, 23 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 19991007036939A](https://openairdocs.org/incident/19991007036939A), Oct 7, 1999: Bell 206B, Apache Junction, AZ, Substantial damage. (.19) On October 7, 1999, at 1015 hours mountain standard time, a Bell 206B, N6624N, experienced a loss of engine power and force landed in Apache Junction,… 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.