# NTSB LAX97LA179: Hiller UH-12E, N7082D, Truckee, CA, May 14, 1997 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: May 14, 1997, 11:59 local (18:59 UTC) - Place: Truckee, CA - Coordinates: 39.330444, -120.239707 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.3304&lon=-120.2397&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed, report April 10, 1998 - Report: Approved by Office Director - NTSB case key (mKey): 29787 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX97LA179 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/29787/pdf - Page: https://openairdocs.org/ntsb/LAX97LA179 ## Probable cause A loss of engine power for undetermined reasons. A factor in the accident was the unsuccessful attempt to release the long line from the belly hook after it became entangled in a tree. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, takeoff - initial climb - reason for occurrence undetermined (cause) - Forced landing, emergency landing after takeoff - In flight collision with terrain/water, emergency landing after takeoff - external load cable/hook - entangled (cause) - object - tree(s) (contributing factor) - emergency procedure - restricted, pilot in command (contributing factor) - diverted attention, pilot in command (contributing factor) ## Analysis The pilot reported that the purpose of the accident flight was to move a 200-foot long line to a new clearing area. After takeoff from the dirt strip, the pilot heard a change in the sound of the engine. He stated that he was turning back to make an emergency landing and attempted to release the long line; however, it became entangled around a tree and the helicopter impacted the ground. FAA inspectors examined the helicopter and the long line, but could not make a determination of when the long line became entangled in the tree; during takeoff or upon returning to land. Examination of the engine revealed continuity throughout, with no preexisting malfunctions noted. ## Factual narrative On May 14, 1997, about 1159 hours Pacific daylight time, a Hiller UH-12E, N7082D, crashed during an emergency landing 7 miles northeast of Truckee, California. The helicopter was substantially damaged, and the commercial instrument rated pilot was seriously injured. Visual meteorological conditions existed for the 14 CFR Part 133 external load operation, and no flight plan was filed. The flight was originating from a private dirt helipad in Truckee at the time for the purpose of moving a 200-foot long line to a work site. The pilot stated that after physically "hooking up the long line to the belly hook, I climbed back in and started the aircraft." He stated that the primary mission for this flight was to drop off the long line at a new site and pick up the woodcutters. The pilot reported that the preflight and engine start appeared normal. After lifting to a hover, he repositioned the aircraft over the long line. He said that "As I transitioned to forward flight, I experienced a left yaw and decreasing aircraft noises." The pilot then picked out a place to make an emergency landing and then moved his attention back inside the aircraft, trying to switch his radio from FM to VHF to transmit on the Truckee Unicom. Prior to trying to switch the radio frequency ". . .the RPM rapidly increased causing the aircraft to yaw to the right and increase in forward speed." The pilot reported that corrective action was taken and he then attempted to release the long line; however, it became entangled around a tree and the helicopter impacted the ground. FAA inspectors from the Reno, Nevada, Flight Standards District Office responded to the accident site and examined both the long line and the helicopter. According to their report, they could not make a determination of when the long line became entangled in the tree; during takeoff or upon returning to land. The wreckage was removed to the operator's home base in White City, Oregon, where an engine inspection was accomplished. An FAA inspector from the Hillsboro, Oregon, Flight Standards District Office was present at the engine inspection. Engine continuity was established and no preexisting malfunctions were noted. See attached report. ## Aircraft - Registration: [N7082D](https://openairdocs.org/deregistered/N7082D-1998-12-01), registration cancelled 1998-12-01, S/N 5193 (OpenAirDocs) - Reported make and model: Hiller UH-12E - Registry model: [Hiller UH-12E](https://openairdocs.org/model/hiller-uh-12e) (registry code 4360122) (OpenAirDocs) - Category: Helicopter - Serial number: 5193 - Airframe hours: 2802 - Engines: Allison 250-C20B 420 horsepower turbo shaft - Damage: Substantial damage - Flight: Positioning, Part 133 - Registered owner: Croman Corporation - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, April 24, 1997, 60 hours before - Airport: Private Dirt Strip ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 37; military, commercial; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 3,878 total, 855 in this make and model, 2,934 as pilot in command, 169 in the last 90 days, 27 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 220° at 8 knots, gusting 18 - Visibility: 30 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 37 °F - Altimeter: 30.00 inHg - Observed at: TRK, 7 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 19970514010989A](https://openairdocs.org/incident/19970514010989A), May 14, 1997: Hiller UH12E, Truckee, CA, Substantial damage. 200FT line caught in tree causing helecopter to collide with ground. 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.