# NTSB NYC99LA146: Hiller UH-12C, N57CR, Delphos, OH, June 16, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 16, 1999, 15:30 local (19:30 UTC) - Place: Delphos, OH - Coordinates: 40.839466, -84.329605 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.8395&lon=-84.3296&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 4, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 46708 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC99LA146 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/46708/pdf - Page: https://openairdocs.org/ntsb/NYC99LA146 ## Probable cause A blocked fuel line, from an unknown object, that resulted in fuel starvation, and total loss of engine power. A factor in the accident was the pilot's failure to maintain rotor rpm during the autorotation. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, cruise - fuel system,line - blocked(total) (cause) - fluid,fuel - starvation - Forced landing, descent - emergency - Hard landing, emergency descent/landing - terrain condition - open field - rotor rpm - not maintained, pilot in command (contributing factor) ## Analysis After maintenance was completed to change an engine, the pilot conducted a test flight, paid the bill, and departed. About 30 minutes into the flight, the pilot felt the helicopter shutter, and noticed a partial loss of power, accompanied by engine surges. The pilot executed an autorotation to an open field, followed by a hard landing. No pre impact failures or malfunctions were identified with the engine or engine accessories. After the accident the helicopter had approximately 25 gallons of fuel onboard. Power was applied to the auxiliary fuel pump, it rotated, but no fuel was expelled. The pump was examined, and no failures or malfunctions were identified. Also, no breaks in the fuel system were identified. The engine driven fuel pump, and auxiliary fuel pump share a common fuel filter, and plumbing from the fuel tanks. ## Factual narrative On June 16, 1999, about 1530 eastern daylight time, a Hiller UH-12C helicopter, N57CR, was substantially damaged during a forced landing to a field near Delphos, Ohio. The certificated commercial pilot was not injured. Visual meteorological conditions prevailed. No flight plan was filed for the ferry flight conducted under 14 CFR Part 91, that departed Sidney, Ohio, destined for Defiance, Ohio. According to the pilot, the helicopter had under gone maintenance for an engine change in Sidney. The pilot arrived at the maintenance facility about 1415, to conduct a test flight, and then ferry the helicopter home. He added that the replacement engine was manufactured from new parts by an individual in Texas. After conducting a preflight, the pilot started the helicopter's engine on the first attempt. He allowed the engine to warm-up, then brought the helicopter to a hover. The pilot hovered the helicopter for approximately 15 minutes then executed a takeoff. He climbed to 500 feet agl, and entered an autorotation to check rotor rpm. After recovering from the autorotation at 200 feet agl, the pilot preformed a "normal" approach, terminating at a 5 foot hover. While at hover, the pilot performed a left pedal turn to verify tailrotor rigging, and hovering characteristics with a tailwind. The flight lasted about 30 minutes, and the pilot noticed no anomalies. After a 2 minute cool down, the pilot secured the engine, and paid the bill for the installation of the replacement engine. The helicopter was then fueled for the non-stop flight back to Defiance. The pilot, with the assistance of the mechanic, conducted another preflight flight, and no engine oil leaks, or discrepancies were identified. The pilot boarded the helicopter, and once again, the engine started on the first attempt. He checked the magnetos, and observed a drop of 75 to 100 rpm for both sides. The pilot departed to the northeast to avoid some structures, and powerlines. Once clear of the powerlines, he established the helicopter on a northwest course, and climbed to a cruise altitude of 500 feet agl. About 30 minutes into the flight, the pilot felt the helicopter shutter, and noticed a partial loss of power, accompanied by engine surges. With the only open area to the helicopter's 6 o'clock position, the pilot executed a left turn. When the helicopter completed the turn, it was about 100 feet agl, and indicating 30 knots of airspeed. With rotor rpm decaying, and the helicopter yawing left and right, the pilot lowered the collective, and entered an autorotation, leaving the throttle open. The pilot said the engine was behaving like the, "key was being turned on and off." About 25 feet agl, the helicopter experienced a total loss off power. The pilot felt rotor rpm was slower then "normal" when he initiated the flare. When the helicopter was about 8 to 10 feet agl, the collective was full up, and the helicopter was traveling forward about 10 knots. When the helicopter touched down the main rotor flexed, and severed the tailboom. The helicopter slid about 15 feet, and rotated about 30 degrees to the left before coming to a stop. The pilot secured the magnetos, electrical master, and unplugged the battery before walking to a house. According to a Federal Aviation Administration Inspector, on June 21, 1999, he examined the helicopter at a recovery facility in Ohio. He removed both magnetos, rotated their drive shafts by hand, and observed spark on all magneto leads. He removed the carburetor bowl, and observed approximately one teaspoon of fuel. While still connected to the helicopter's fuel and electrical systems, power was applied to the auxiliary fuel pump. The pump rotated, but no fuel was expelled. The Inspector then rotated the engine drive fuel pump's drive shaft by hand, and detected no anomalies. In addition the engine driven fuel pump, and auxiliary fuel pump share a common fuel filter, and plumbing. The Inspector estimated the helicopter had 25 gallons of fuel onboard during the examination. ## Aircraft - Registration: [N57CR](https://openairdocs.org/deregistered/N57CR-2014-06-13), registration cancelled 2014-06-13, S/N 909, built 1956 (OpenAirDocs) - Reported make and model: Hiller UH-12C - Registry model: [Hiller UH-12C](https://openairdocs.org/model/hiller-uh-12c) (registry code 4360116) (OpenAirDocs) - Registry engine: [Franklin 6VS-335 series](https://openairdocs.org/engine/franklin-6vs-335-series) (registry code 27040, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 909 - Airframe hours: 4952 - Engines: Franklin 6VS-335 210 horsepower reciprocating - Damage: Substantial damage - Flight: Ferry, Part 91 - Registered owner: William Miller - Airworthiness certificate: Standard, Normal - Last inspection: Annual, December 30, 1998, 36 hours before - Departed: I12, SIDNEY, OH - Destination: DFI, DEFIANCE, OH ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 33; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: center; flight hours: 750 total, 170 in this make and model, 690 as pilot in command, 75 in the last 90 days, 40 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 50° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 70 °F, dew point 45 °F - Altimeter: 30.00 inHg - Observed at: DAY, 65 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 19990616007139A](https://openairdocs.org/incident/19990616007139A), Jun 16, 1999: Hiller UH12C, Delphos, OH, Destroyed. 1956 Hiller-world helicopters UH-12C helicopter lost power, and the pilot auto-rotated the acft, the main rotor flexed on landing and severed the tail of the… ## Other investigations on N57CR (1) 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. - [NTSB FTW81FPD31](https://openairdocs.org/ntsb/FTW81FPD31), Jul 15, 1981: Hiller Acft UH-12C (N57CR), Burleson, TX, substantial damage 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.