# NTSB FTW96LA285: Hiller UH12, N14637, Franklin, LA, July 1, 1996 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 1, 1996, 09:30 local (14:30 UTC) - Place: Franklin, LA - Coordinates: 29.800724, -91.510658 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=29.8007&lon=-91.5107&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): 19891 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW96LA285 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/19891/pdf - Page: https://openairdocs.org/ntsb/FTW96LA285 ## Probable cause loss of engine power for undetermined reasons, and the pilot's failure to maintain rotor RPM. A factor was the unsuitable terrain available for the precautionary landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, cruise - reason for occurrence undetermined (cause) - Hard landing, landing - flare/touchdown - terrain condition - none suitable (contributing factor) - rotor rpm - not maintained, pilot in command (cause) ## Analysis The pilot reported that he heard a 'bang' and the engine started 'running rough' while the helicopter was operating at about 100 feet AGL. The pilot elected to execute a precautionary landing to 'investigate the source of the engine problems.' The pilot stated that during the precautionary landing the 'rotor RPM started to bleed and sufficient RPM could not be maintained for a successful landing.' During the low rotor RPM landing touchdown to a muddy grass area, the front cross tube collapsed and the aft skid settled into the mud. Examination of the airframe revealed that the tailboom, tailrotor gearbox, and a portion of the vertical stabilizer were severed from the helicopter as result of impact with the main rotor blades. The reason for the partial loss of engine power could not be determined. ## Factual narrative On July 1, 1996, at 0930 central daylight time, a Hiller UH12E helicopter, N14637, was substantially damaged while executing a precautionary landing following a partial loss of engine power near Franklin, Louisiana. The helicopter, owned and operated by a private owner, was being operated under Title 14 CFR Part 91. Visual meteorological conditions prevailed and a flight plan was not filed. The commercial pilot, sole occupant of the aircraft, was not injured. The local business flight originated from Patterson, Louisiana, at 0815. During personal interviews, conducted by the FAA inspector, the pilot reported that he heard a "bang" and the helicopter engine started "running rough" while the helicopter was operating at about 100 feet AGL en route between Patterson and Franklin. The pilot further stated that he elected to execute a precautionary landing to "investigate the source of the engine problems." The pilot further stated that during the precautionary landing the "rotor RPM started to bleed and sufficient RPM could not be maintained for a successful landing." During the low rotor RPM landing touchdown to a muddy grass area, the front cross tube collapsed and the aft skid settled into the mud. Examination of the airframe revealed that the tailboom, tailrotor gearbox, and a portion of the vertical stabilizer were severed from the helicopter as result of impact with the main rotor blades. The reason for the partial loss of engine power could not be determined. The pilot did not complete any of the several Pilot/Operator Reports (NTSB Form 6120.1/2) that were mailed to him. ## Aircraft - Registration: [N14637](https://openairdocs.org/aircraft/N14637), registered now, S/N 1577, built 1993 (OpenAirDocs) - Reported make and model: Hiller UH12 - Registry model: [Hiller UH-12E](https://openairdocs.org/model/hiller-uh-12e) (registry code 4360122) (OpenAirDocs) - Registry engine: [Lycoming VO-540 series](https://openairdocs.org/engine/lycoming-vo-540-series) (registry code 41534, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 1577 - Engines: Lycoming VO-540 225 horsepower reciprocating - Damage: Substantial damage - Flight: Business, Part 91 - Registered owner: Dewayne C. Davis - Airworthiness certificate: Standard, Normal - Departed: PTN, PATTERSON, LA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: right; flight hours: 3,500 total ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none ## 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 19960701015659A](https://openairdocs.org/incident/19960701015659A), Jul 1, 1996: Hiller UH12E, Franklin, LA, Substantial damage. On spotting flight. Engine running rough, made emergency landing, tail rotor section cut off by main rotor blades. (-23) on July 1, 1996, at approximately 0930… 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.