# NTSB ERA10LA383: Hiller UH-12E, N104HH, Holly Hill, SC, July 29, 2010 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: July 29, 2010, 09:30 local (13:30 UTC) - Place: Holly Hill, SC - Coordinates: 33.305557, -80.433052 - Nearby events: https://openairdocs.org/map.md?lat=33.3056&lon=-80.4331&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed, report September 19, 2011 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 76792 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA10LA383 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/76792/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=76792 - Page: https://openairdocs.org/ntsb/ERA10LA383 ## Probable cause Maintenance personnel's improper inspection and cleaning of the fuel nozzle, which resulted in a total loss of engine power. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine fuel and control: fuel injector nozzle](https://openairdocs.org/ntsb-findings/01057313): Aircraft › Aircraft power plant · Inadequate inspection (probable cause); cases with it: [Hiller UH-12E, 1 case](https://openairdocs.org/ntsb-findings/01057313/cases.md?model=4360122), [All aircraft, 20 cases](https://openairdocs.org/ntsb-findings/01057313/cases.md) - [Maintenance: scheduled/routine maintenance](https://openairdocs.org/ntsb-findings/02062010): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Hiller UH-12E, 3 cases](https://openairdocs.org/ntsb-findings/02062010/cases.md?model=4360122), [All aircraft, 320 cases](https://openairdocs.org/ntsb-findings/02062010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Hiller UH-12E, 5 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=4360122), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Hiller UH-12E, 4 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=4360122), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Emergency descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Hiller UH-12E, 14 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=4360122), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot stated that as he approached a tree line for aerial application his chemical ran out. As he turned back to reload the chemical, the engine experienced a total loss of power. The pilot quickly conducted an autorotation and collided with trees before coming to rest on the ground. A postaccident examination of the engine revealed that the combustion chamber fuel spray nozzle was clogged with carbon and soot deposits, which is likely the result of the nozzle not being properly inspected and cleaned during the last 100-hour inspection. A review of the engine maintenance logbooks revealed that the last 100-hour inspection was completed 41 days prior to the accident. According to the aircraft Hobbs time, the engine accumulated 40 hours since the 100-hour inspection. ## Factual narrative On July 29, 2010, at 0930 eastern daylight time, a Hiller UH-12E, N104HH, registered to and operated by Haddock Flying Service Inc., collided with a tree during an autorotation following a total loss of engine power near Holly Hill, South Carolina. The aerial application flight was operated under the provisions of 14 Code of Federal Regulations Part 137, with no flight plan filed. Visual meteorological conditions prevailed. The certificated commercial pilot received serious injuries, and the helicopter was substantially damaged. The flight departed from a landing pad in Holly Hill, South Carolina, at 0925. The pilot stated that as he approached a tree line for aerial application, his chemical ran out. As he turned back to reload chemical the engine experienced a total loss of power. Due to the low operating altitude he quickly conducted an autorotation and collided with trees before coming to rest on the ground. Examination of the wreckage by a Federal Aviation Administration inspector revealed that the helicopter collided with a tree during the autorotation which resulted in substantial damage to the fuselage and the main rotor assembly. Flight control continuity was confirmed from the cockpit through the tail rotor system, and from the cockpit cyclic and collective controls through the main rotor head. Further examination of the helicopter revealed that fuel was present in the fuel tank. The helicopter was recovered for further examination. An examination of the engine revealed that the combustion chamber fuel spray nozzle was clogged with carbon and soot deposits. A review of the engine maintenance logbooks revealed that the most recent 100-hour inspection was completed 41 days prior to the accident. According to the aircraft Hobbs time, the engine accumulated 40 hours since the 100-hour inspection. A review of the engine logbooks did not reveal documentation of the inspection or the cleaning of the fuel spray nozzle. A review of the Rolls Royce 250-C20 series operation and maintenance schedule inspection pages revealed that at the 100-hour inspection, item 21.A states: "remove, inspect and clean the fuel nozzle. If no airframe mounted fuel filter is installed, inspect the fuel nozzle filter." It also noted that operators may find it necessary to inspect and clean the fuel nozzle more often depending on past experience or operating conditions. ## Aircraft - Registration: [N104HH](https://openairdocs.org/aircraft/N104HH), registered now, S/N 2062, built 1960 (OpenAirDocs) - Reported make and model: HILLER UH-12E - Registry model: [Hiller UH-12E](https://openairdocs.org/model/hiller-uh-12e) (registry code 4360122) (OpenAirDocs) - Registry engine: [Allison 250 series](https://openairdocs.org/engine/allison-250-series) (registry code 03014, turbo-prop) (OpenAirDocs) - Category: Helicopter - Serial number: 2062 - Airframe hours: 10099 - Engines: ALLISON 250 SERIES 300 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Haddock Flying Service Inc - Registered owner: Haddock Flying Service Inc - Airworthiness certificate: Standard, Utility - Last inspection: 100 hour, May 19, 2010, 40 hours before - Departed: Holly Hill, SC - Destination: Holly Hill, SC ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 59; injuries: serious; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review March 10, 2010; seat: right; flight hours: 19,890 total, 5,700 in this make and model, 19,790 as pilot in command, 150 in the last 90 days, 12 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 260° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 82 °F, dew point 77 °F - Altimeter: 30.01 inHg - Observed at: DYB ## 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 20100729042709A](https://openairdocs.org/incident/20100729042709A), Jul 29, 2010: Hiller UH-12E, Holly Hill, SC, Substantial damage. On July 29, 2010, at approximately 0930 eastern standard time, a Hiller UH-12E helicopter, N104HH, registered to haddock flying, inc., operating as a 14 CFR… ## Docket (8 files) The files NTSB released with the investigation on June 29, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=76792. 3.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 703 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40348117&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Correspondence-Record of Conversation (item 2, .PDF, 43 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40348118&FileExtension=.PDF&FileName=Correspondence-Record%20of%20Conversation-Master.PDF - Other Pertinent Forms and Reports-Airframe Logbook Pages (item 3, .PDF, 959 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40349062&FileExtension=.PDF&FileName=Other%20Pertinent%20Forms%20and%20Reports-Airframe%20Logbook%20Pages-Redacted.PDF - Other Pertinent Forms and Reports-Engine Logbook Page (item 4, .PDF, 646 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40348122&FileExtension=.PDF&FileName=Other%20Pertinent%20Forms%20and%20Reports-Engine%20Logbook%20Page-Redacted.PDF - Other Pertinent Forms and Reports-RR 250-C20 Engine Inspection Checklist (item 5, .PDF, 768 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40348123&FileExtension=.PDF&FileName=Other%20Pertinent%20Forms%20and%20Reports-RR%20250-C20%20Engine%20Inspection%20Checklist-Master.PDF - Correspondence-Haddock Flying Service (item 6, .PDF, 15 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40348124&FileExtension=.PDF&FileName=Correspondence-Haddock%20Flying%20Service-Redacted.PDF - Photo 1: Fuel Nozzle (item 7, .PDF, 43 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40348125&FileExtension=.PDF&FileName=Photo%201%3A%20Fuel%20Nozzle-Master.PDF - Photo 2: Helicopter (item 8, .PDF, 189 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40348127&FileExtension=.PDF&FileName=Photo%202%3A%20Helicopter-Master.PDF 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.