# NTSB MIA96LA088: Bell 206L4, N6248X, Chiefland, FL, March 1, 1996 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 1, 1996, 15:15 local (20:15 UTC) - Place: Chiefland, FL - Coordinates: 29.469404, -82.85958 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=29.4694&lon=-82.8596&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report February 18, 1997 - Report: Approved by Office Director - NTSB case key (mKey): 37986 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA96LA088 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/37986/pdf - Page: https://openairdocs.org/ntsb/MIA96LA088 ## Probable cause Improper cyclic and collective input by the pilot-in-command resulting in the hard landing during the autorotative landing. Contributing to the accident was the total loss of engine power due to undetermined reasons. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, cruise - normal - reason for occurrence undetermined (contributing factor) - Hard landing, emergency descent/landing - cyclic - improper, pilot in command (cause) - collective - improper, pilot in command (cause) ## Analysis The pilot stated that during cruise flight about 400 feet mean sea level he heard the engine decelerate then heard the engine-out audio. He maneuvered the helicopter for an autorotative landing in a clearing, but after observing uneven terrain he elected to zero his forward airspeed. After a hard landing the helicopter rocked forward causing the main rotor blades to contact the tailboom. Fuel quantity was sufficient to sustain engine operation and visually no contaminants were noted. The helicopter was recovered and the engine was started several times using the fuel supply in the fuel tank with no discrepancies noted. The engine was removed from the helicopter and tested at the manufacturers facility with no discrepancies noted. The power turbine governor (PTG) and the main fuel control and engine driven fuel pump were removed for bench testing. The only discrepancy noted was a failed roll pin for the throttle level stop in the PTG. The PTG manufacturer states that the failed roll pin would not effect operation of the unit. ## Factual narrative On March 1, 1996, about 1515 eastern standard time, a Bell 206L4, N6248X, registered to the Bell Helicopter Textron, Inc., experienced total loss of engine power during cruise flight and was substantially damaged during an autorotative landing near Chiefland, Florida. Visual meteorological conditions (VMC) prevailed at the time and no flight plan was filed for the 14 CFR Part 91 business flight. The commercial-rated pilot, the sole occupant, was not injured. The flight originated about 1300 central standard time from the Marianna Municipal Airport, Marianna, Florida. The pilot stated that during cruise flight about 400 feet mean sea level, in VMC, he first heard the engine decelerate then heard the engine out audio announcement. He verified that the throttle was full open then lowered the collective control for an autorotative landing. He observed a clearing and initiated a 180-degree turn but when the flight was near the ground, he observed uneven terrain and elected to zero his forward speed. The helicopter then landed hard and rocked forward, causing the main rotor blades to contact the tailboom. The helicopter had been operated for about 1.3 hours since fueling and a total of 74.8 hours since manufacture. Postaccident examination of the helicopter by an FAA airworthiness inspector revealed sufficient fuel to sustain engine operation. Visual examination of a sample of fuel obtained from the fuel tank revealed no evidence of contamination. The helicopter was recovered and the engine was started and operated several times using the fuel supply in the fuel tank with no discrepancies noted. Vacuum test of the fuel system revealed no evidence of preimpact failure or malfunction. The engine was removed from the helicopter for further tests. The engine was placed in a test stand at the manufacturer's facility and operated with no discrepancies noted. The engine-driven fuel pump with attached main fuel control and the power turbine governor (PTG) were removed and sent to the manufacturer's facility for bench tests which revealed no failure or malfunction that would have prevented normal engine operation. The only discrepancy noted was a sheared PTG throttle lever stop roll pin. According to Allied Signal personnel, failure of the roll pin has previously been determined to occur due to over torque of the outer lever attachment nut. The failure did not affect operation of the throttle input from the cockpit. Review of the helicopter historical records revealed that the power turbine governor was installed on 12/15/95, and had accumulated 70.5 hours since new. ## Aircraft - Registration: N6248X (not matched to a registry record) - Reported make and model: Bell 206L4 - Category: Helicopter - Serial number: 52162 - Airframe hours: 72 - Engines: Allison 250-C30P 650 horsepower turbo shaft - Damage: Substantial damage - Flight: Business, Part 91 - Registered owner: Bell Helicopter Textron, Inc. - Airworthiness certificate: Standard, Normal - Departed: MAI, MARIANNA, FL - Destination: LAL, LAKELAND, FL ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 56; commercial; airplane ratings: single-engine land; instrument ratings: airplane, helicopter; medical: class 2, valid medical--w/ waivers/lim; seat: right; flight hours: 9,600 total, 2,000 in this make and model, 9,300 as pilot in command, 34 in the last 90 days, 12 in the last 30 days, 7 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 50° at 7 knots - Visibility: 2.5 statute miles - Lowest ceiling: 300 ft overcast - Temperature: 48 °F, dew point 48 °F - Altimeter: 29.00 inHg - Observed at: GNV, 34 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 19960301004449A](https://openairdocs.org/incident/19960301004449A), Mar 1, 1996: Bell 206L4, Chiefland, FL, Substantial damage. Lost power en route. Autorotated to clearing. Rocked landing. Rotors chopped tailboom. No anomalies found. 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.