# NTSB ATL94LA180: Bell UH-1B, N41870, Ozark, AL, September 29, 1994 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: September 29, 1994, 18:40 local (23:40 UTC) - Place: Ozark, AL - Coordinates: 31.43062, -85.640808 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=31.4306&lon=-85.6408&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor, 1 uninjured - Status: Completed, report May 9, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 3452 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL94LA180 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/3452/pdf - Page: https://openairdocs.org/ntsb/ATL94LA180 ## Probable cause THE FAILURE OF THE ENGINES' MAIN BEARINGS BECAUSE OF A LACK OF LUBRICATION. A FACTOR WAS THE HEAVILY WOODED TERRAIN. ## 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 - engine assembly,bearing - failure,total (cause) - fluid,oil - starvation (cause) - Forced landing, emergency descent/landing - In flight collision with object, emergency descent/landing - object - tree(s) (contributing factor) ## Analysis WHILE IN CRUISE, DURING A POSITIONING FLIGHT, THE ENGINE CHIP DETECTOR ILLUMINATED. A FEW SECONDS LATER IT EXTINGUISHED. SINCE THE TERRAIN WAS HEAVILY WOODED, AND THE DESTINATION AIRPORT WAS ABOUT THREE MILES AWAY, THE PILOT ELECTED TO CONTINUE TOWARD THE AIRPORT. SHORTLY AFTERWARDS, THE CHIP LIGHT RE-ILLUMINATED, AND THE PILOT BEGAN LOOKING FOR A LANDING SITE. THEN THE LOW ROTOR SPEED WARNING HORN SOUNDED AND THE PILOT BEGAN AN AUTOROTATION. HE WAS UNABLE TO REACH AN OPEN FIELD, AND COLLIDED WITH TREES ON THE EDGE OF THE FIELD. DURING THE POST ACCIDENT EXAMINATION OF THE ENGINE, THE NUMBER ONE, THREE, AND FOUR MAIN BEARINGS WERE FOUND TO HAVE FAILED BECAUSE OF A LACK OF LUBRICATION. ## Factual narrative On September 29, 1994, about 1840 central daylight time, a Bell UH-1B, N41870, collided with trees during a forced landing near Ozark, Alabama. The helicopter was operated by Summit Helicopters, Inc. under the provisions of 14 CFR Part 91, and visual flight rules. A flight plan was not filed for the positioning flight. There were no injuries to the commercial pilot, minor injuries to a passenger, and substantial damage to the aircraft. Origination of the flight was Brantley, Alabama, about 1615, on the same day. The pilot reported that while in cruise flight, the engine chip light illuminated. About five seconds later it extinguished. Since the helicopter was about three miles from the Blackwell Airport, Ozark, Alabama, he elected to continue toward the airport. The chip light re-illuminated and the pilot began searching for a landing site in the heavily wooded terrain. About the same time, the low rotor speed warning horn sounded. An autorotation was established to an open field. The helicopter could not reach the field and collided with trees. Metal debris was found in the accessory gearbox during a post accident, on-site inspection of the engine. Subsequently, a teardown and inspection of the engine was performed. The number one, three, and four bearings had failed because of a lack of lubrication. ## Aircraft - Registration: [N41870](https://openairdocs.org/deregistered/N41870-2007-09-18), registration cancelled 2007-09-18, S/N 65-12853, built 1965 (OpenAirDocs) - Reported make and model: BELL UH-1B - Registry model: [Bell UH-1B](https://openairdocs.org/model/bell-uh-1b) (registry code 1181410) (OpenAirDocs) - Registry engine: [Lycoming T-53 series](https://openairdocs.org/engine/lycoming-t-53-series) (registry code 41549, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 65-12853 - Airframe hours: 8119 - Engines: LYCOMING T53-L-11C 1100 horsepower turbo shaft - Damage: Substantial damage - Flight: Positioning, Part 91 - Registered owner: Summit Sales And Leasing, Inc - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Continuous airworthiness, September 5, 1994, 84 hours before - Departed: NONE, BRANTLEY, AL - Destination: 71J, AL ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 47; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane, helicopter; medical: class 2, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 8,300 total, 500 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 7 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 63 °F - Altimeter: 29.00 inHg - Observed at: DHN, 12 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 19940929035369A](https://openairdocs.org/incident/19940929035369A), Sep 29, 1994: Bell UH1B, Ozark, AL, Substantial damage. Chip light on. Low rotor RPM. Autorotated to field but struck trees. Metal in gearbox. Bearing failure. Lacked lube 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.