# NTSB CEN15LA231: Robinson Helicopter R44 II, N165RV, Columbia, IL, May 13, 2015 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 13, 2015, 17:30 local (22:30 UTC) - Place: Columbia, IL - Coordinates: 38.412776, -90.223335 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.4128&lon=-90.2233&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: No injuries - Injuries: 1 uninjured - Status: Completed, report May 24, 2018 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA - NTSB case key (mKey): 91166 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN15LA231 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/91166/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=91166 - Page: https://openairdocs.org/ntsb/CEN15LA231 ## Probable cause A total loss of engine power while maneuvering at low altitude for reasons that could not be determined during postaccident examination. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Robinson Helicopter R44 II, 24 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=7640122), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) - [Runway/land/takeoff/taxi surface: soft surface](https://openairdocs.org/ntsb-findings/03023020): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Robinson Helicopter R44 II, 4 cases](https://openairdocs.org/ntsb-findings/03023020/cases.md?model=7640122), [All aircraft, 264 cases](https://openairdocs.org/ntsb-findings/03023020/cases.md) - [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Not specified; cases with it: [Robinson Helicopter R44 II, 4 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=7640122), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md) - [Misc hardware: hoses and tubes](https://openairdocs.org/ntsb-findings/01071410): Aircraft › Fluids/misc hardware · Incorrect use/operation; cases with it: [Robinson Helicopter R44 II, 2 cases](https://openairdocs.org/ntsb-findings/01071410/cases.md?model=7640122), [All aircraft, 40 cases](https://openairdocs.org/ntsb-findings/01071410/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: [Robinson Helicopter R44 II, 20 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=7640122), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Maneuvering-low-alt flying: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Robinson Helicopter R44 II, 24 cases](https://openairdocs.org/ntsb-events/060/sequence.md?model=7640122), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Robinson Helicopter R44 II, 26 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=7640122), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The helicopter experienced a loss of engine power during an agricultural application flight at low altitude. The commercial pilot lowered the collective and increased the throttle but was unable to reestablish engine power, so he made a run-on landing to a field. During landing, the right skid sunk into the mud/wheat, which caused a "slight hop," and the main rotor struck the tailboom. Postaccident examination of the oil filter revealed no signs of contamination. No mechanical anomalies were noted with the fuel system and the fuel from the carburetor was light blue, typical of 100 low-lead aviation fuel. An unidentified sticky substance, likely agricultural spray, coated the lower half of the throttle flap and the bottom half of the fuel injector body. However, the observed buildup of the substance was not sufficient to restrict the throttle flap from actuating. The refueling station used for the spraying operations consisted of a large storage tank attached to a trailer, a filtering unit, and a supply hose, which was connected to the refueling tank. The supply hose had been purchased from a farm supply store, and its exterior was stamped with "farm fuel transfer hose w/static wire." According to the manufacturer's packaging label, the supply hose was not designed to dispense aviation fuel. Samples of fuel were collected from inside the refueling tank and the supply hose; the sample from the hose was pale green, indicating that some type of contamination was present, and the sample from the tank was light blue. Laboratory analysis of the fuel samples from the refueling tank and supply hose showed that they were substantially identical; however both had a high "unwashed gum" content from different sources; the unwashed gum content in the hose sample was consistent with an additive used in plastics and rubber hoses; whereas, the unwashed gum content in the fuel tank was consistent with a stabilizing additive common in fuels. However, it could not be determined whether the unwashed gum content from the hose would have affected engine operation. ## Factual narrative On May 13, 2015 about 1845 central daylight time, a Robinson Helicopter R-44, N165RV, impacted terrain following a loss of engine power during an aerial application flight near Columbia, Illinois. The helicopter was substantially damaged, and the commercial pilot was uninjured. Visual meteorological conditions prevailed at the time of the accident and a flight plan was not filed for the Title 14 Code of Federal Regulations Part 137 local flight. The pilot reported he had made 2-4 passes over the field with spray when he heard the Low Rotor RPM horn and the engine "went silent." He estimated he was approximately 5-10 feet above ground level (agl) when the loss of engine power occurred. The pilot lowered the collective and increased throttle but there was no reaction from the engine. He then slowed the helicopter's ground speed as much as possible and performed a run-on-landing to the field. The pilot reported that as the helicopter touched down the right skid sunk into the mud/wheat, which caused a "slight hop" to the right and the main rotor impacted the tail boom. On June 11, 2015, Federal Aviation Administration (FAA) inspectors provided oversight of an examination of the helicopter at a maintenance facility in Cahokia, Illinois. The throttle, mixture and fuel shutoff controls were checked for correct freedom-of-movement and condition with no anomalies noted. The oil filter was removed, cut open and revealed no contaminants. A sample of fuel from the fuel strainer assembly revealed a blue colored liquid that was consistent with uncontaminated 100 low-lead aviation fuel. The contents of the fuel strainer bowl was poured through a clean white paper towel and no debris was observed. The fuel filter showed no signs of particulate contamination. The engine inlet air filter element exhibited a sticky residue on the exterior side of filter; however, the filter element looked clean and free of debris. Upon removal of the air filter, it was discovered that an unknown sticky substance coated the lower half of throttle flap and the bottom half of the fuel injector body. The buildup of residue was less than 1/32 inch at the thickest point, located at the base of the inlet portal. Despite the presence of the unknown sticky substance, the throttle flap was able to rotate normally. The refueling station used for the spraying operation consisted of a large storage tank attached to a trailer. The tank was equipped with a filtering unit and supply hose. The supply hose was purchased from a farm supply store and contained a stamp on the exterior of the hose indicating "farm fuel transfer hose w/static wire." The supply hose was subsequently identified as an non-aviation refueling hose that was intended to dispense gasoline, diesel, and oil, according to the manufacturers packaging label. According to FAA Advisory Circular 150/5230-4B, "Aircraft Fuel Storage, Handling, Training, and Dispensing on Airports," the FAA has adopted standards used in National FirePrevention Agency (NFPA) 407, Standard for Aircraft Fuel Servicing. NFPA 407 provides a standard for the storage and delivery of aviation fuel; it specified a refueling hose shall conform to American Petroleum Institute (API) Standard (STD) 1529. It could not be determined whether the supply hose connected to the re-fueling tank met API STD 1529 because of the limited information able to be collected on the hose. The FAA stated the filter connecting the supply hose to the re-fueling tank was discolored; however, the aviation fuel in the tank appeared clear. Two fuel samples from the re-fueling tank were collected by the FAA, one sample obtained from the supply hose and another from inside the tank. The sample from the hose was pale green in color, clear and bright with no water or particulate observed. The sample from the tank was light blue in color, clear and bright with no water or particulate observed. Typical 100 low-lead aviation fuel is light blue in color. These two samples were sent to an independent laboratory for testing to evaluate the abnormal color of the fuel sample collected from the hose. Both samples collected were submitted to the laboratory in the same type of glass container. The test results determined the samples were substantially identical, with both having a high "unwashed gum" content appearing to be from different sources. The unwashed gum content in the hose sample was almost double that found in the tank sample and appeared consistent with an additive that is used in plastics and rubber hoses. The unwashed gum content in the tank was consistent with a stabilizing additive common in fuels. ## Aircraft - Registration: [N165RV](https://openairdocs.org/deregistered/N165RV-2018-09-21), registration cancelled 2018-09-21, S/N 10165, built 2003 (OpenAirDocs) - Reported make and model: ROBINSON HELICOPTER COMPANY R44 II (II) - Registry model: [Robinson Helicopter R44 II](https://openairdocs.org/model/robinson-helicopter-r44-ii) (registry code 7640122) (OpenAirDocs) - Registry engine: [Lycoming IO-540 series](https://openairdocs.org/engine/lycoming-io-540-series) (registry code 41530, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 10165 - Year built: 2003 - Engines: LYCOMING IO-540 SER reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Joshua Shiver, doing business as Prairie State Helicopters - Registered owner: Moats Jesse R - Airworthiness certificate: Special, Restricted (Special) - Destination: Columbia, IL - Flight plan: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 33; injuries: none; commercial; instrument ratings: helicopter; medical: class 1, without waivers/limitations; last flight review December 13, 2014; seat: right; restraint: 3-point; flight hours: 990 total, 717 in this make and model, 925 as pilot in command, 56 in the last 90 days, 17 in the last 30 days, 6 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 90° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 70 °F, dew point 46 °F - Altimeter: 30.29 inHg - Observed at: KCPS, 10 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 20150513007699A](https://openairdocs.org/incident/20150513007699A), May 13, 2015: Robinson Helicopter Company R44 II, Columbia, IL, Substantial damage. On may 13, 2015, at 1845 hours local, at 9475 d road, Columbia, Illinois, the pilot was conducting agricultural spraying in R-44 ii, N165RV. As the aircraft… ## Docket (5 files) The files NTSB released with the investigation on March 20, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=91166. 8.8 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 566 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461104&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Laboratory Report for Fuel Testing (item 2, .PDF, 109 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461105&FileExtension=.PDF&FileName=Laboratory%20Report%20for%20Fuel%20Testing-Master.PDF - FAA FSDO Inspector's Statements (item 3, .PDF, 834 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461106&FileExtension=.PDF&FileName=FAA%20FSDO%20Inspector%27s%20Statements-Master.PDF - Information for Fuel Refilling Hose (item 4, .PDF, 7.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461107&FileExtension=.PDF&FileName=Information%20for%20Fuel%20Refilling%20Hose-Master.PDF - Interview with Land Owner/Chemical Refiller (item 5, .PDF, 246 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461108&FileExtension=.PDF&FileName=Interview%20with%20Land%20Owner%2FChemical%20Refiller-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.