# NTSB ERA12LA226: Michael S/Michael K Safari, N105KM, Middle Valley, TN, March 13, 2012 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: March 13, 2012, 17:45 local (21:45 UTC) - Place: Middle Valley, TN - Coordinates: 35.190277, -85.183891 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.1903&lon=-85.1839&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: Serious injuries - Injuries: 1 serious, 1 uninjured - Status: Completed, report May 21, 2014 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: CHR International, Inc., FAA/FSDO - NTSB case key (mKey): 83141 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA12LA226 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/83141/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=83141 - Page: https://openairdocs.org/ntsb/ERA12LA226 ## Probable cause A partial loss of engine power for reasons that could not be determined due to the postaccident condition of the airframe and engine. ## 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: [Michael S/Michael K SAFARI, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=056273W), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Michael S/Michael K SAFARI, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=056273W), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Autorotation: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Michael S/Michael K SAFARI, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=056273W), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) - [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Michael S/Michael K SAFARI, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=056273W), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot of the experimental amateur-built helicopter reported that the engine shuddered twice momentarily shortly after takeoff and then lost power. After observing the engine rpm drop from about 2,700 to 1,500, the pilot initiated an autorotation and subsequently landed the helicopter on top of a tree, which began to lower toward a creek. The helicopter came to rest partially submerged in the creek and was partially consumed by a postcrash fire. Postaccident examination of the wreckage did not reveal any preimpact malfunctions or failures that would have precluded normal operation; however, impact and fire damage precluded the ability to functionally check the engine and fuel system. Review of engine monitor data, which was recorded at 5-second intervals, did not reveal any drops in engine rpm or any other anomalies consistent with the pilot's statement. ## Factual narrative On March 13, 2012, about 1745 eastern daylight time, an experimental amateur-built, CHR Safari helicopter, N105KM, operated by a private individual, was substantially damaged during an autorotation in Hixson, Tennessee. The private pilot was not injured and a passenger was seriously injured. Visual meteorological conditions prevailed and no flight plan was filed for the local personal flight that was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. The two seat helicopter was co-owned and co-built by the pilot. It was powered by a non-certified Superior XP IO-360 series, 380-horsepower engine and issued an experimental airworthiness certificate on September 23, 2009. The pilot stated he flew about 1 mile from his home to reach the passenger's property. He landed in an open field and secured the helicopter before assisting the passenger on board. The helicopter was started and lifted off without incident. At an airspeed of approximately 45 knots, and between 100 and 150 feet above the ground, "the engine shuttered for an instant and came back to normal." The pilot stopped the climb, confirmed that all engine instruments were "in the green" and began a left turn back toward the takeoff area. About halfway into the 180-degree turn, the engine shuttered again. The pilot applied full throttle with no engine response and observed the engine rpm drop from about 2,700 to about 1,500, with the rotor speed in the middle of the green indicator. He then entered an autorotation and landed on top of a tree, which began to bend over, and lowered the helicopter toward a creek below. As the helicopter reached the water, it rolled on to its side and fell about 3 feet into the creek. The pilot was able to assist the passenger out of the helicopter during the time in which a fire erupted from the engine compartment. The fire was contained with water from the creek until it was extinguished by the local fire department. Examination of the helicopter by a Federal Aviation Administration inspector did not reveal any preimpact mechanical malfunctions that would have precluded normal operation. The engine crankshaft rotated freely, compression was obtained on all cylinders and proper magneto function was noted. Fuel mixed with water was found in the gascolater; consistent with being submerged in the creek. Damage sustained to the engine during the impact and postaccident fire prevented the ability to have it operationally test run. Additional detailed examinations of the helicopter, which included examinations of the engine, clutch and transmission systems by the helicopter kit manufacturer, did not reveal any preimpact failures. In addition, the kit manufacturer conducted a series of test flights utilizing a similarly equipped and configured helicopter in an attempt to determine if clutch slippage could be induced under normal flight conditions. According to the kit manufacturer, clutch slippage could only be induced under conditionswhich were well outside the helicopter's normal operating parameters and standard procedures, such as allowing the rotor rpm to decay below 450 rpm and rapid application of the collective or throttle controls. The helicopter was equipped with a Dynon EMS-D10 engine monitor which was configured to record information at 5 second intervals to non-volatile-memory. The engine monitor was successfully downloaded at the NTSB Vehicle Recorder Laboratory, Washington, DC. Review of the data did not reveal any drops in engine rpm or any other anomalies consistent with the pilot's statement. The data during about 30 seconds prior to the autorotation showed consistent fuel flows, fuel pressures, and manifold pressures, with rpm mostly in the 2,700-2,740 range and never dropping below about 2,600 rpm. At the time of the accident, the helicopter had been operated for about 130 total hours, and about 75 hours since its most recent condition inspection, which was performed on June 20, 2011. The pilot/co-owner reported 1,230 hours of total flight experience, which included about 380 hours in helicopters, and approximately 147 hours in the same make and model as the accident helicopter. In addition, he had flown the accident helicopter 26 hours and 3 hours, during the 90 and 30 days that preceded the accident; respectively. ## Aircraft - Registration: [N105KM](https://openairdocs.org/deregistered/N105KM-2017-09-18), registration cancelled 2017-09-18, S/N 2008005-S2172 (OpenAirDocs) - Reported make and model: MICHAEL S/MICHAEL K SAFARI - Registry model: [Michael S/Michael K SAFARI](https://openairdocs.org/model/michael-s-michael-k-safari) (registry code 056273W) (OpenAirDocs) - Registry engine: [Superior IO-360 series](https://openairdocs.org/engine/superior-io-360-series) (registry code 59251, reciprocating) (OpenAirDocs) - Category: Helicopter, amateur-built - Serial number: 2008005-S2172 - Year built: 2009 - Airframe hours: 126 - Engines: SUPERIOR IO-360 180 horsepower reciprocating - Damage: Substantial damage - Fire: On-Ground - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, June 20, 2011, 74 hours before - Departed: Hixson, TN - Destination: Hixson, TN ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 57; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review September 29, 2011; seat: left; flight hours: 1,229 total, 146 in this make and model, 1,229 as pilot in command, 26 in the last 90 days, 3 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 10 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 48 °F - Altimeter: 30.12 inHg - Observed at: CHA, 11 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 20120313004159A](https://openairdocs.org/incident/20120313004159A), Mar 13, 2012: Michael S/Michael K SAFARI, Hixson, TN, Substantial damage. On 3-13/2012, an experimental home built helicopter departed from a private helicopter pad at the owner's home, landing 1MILE away, to pick up a passenger at… ## Docket (13 files) The files NTSB released with the investigation on March 28, 2014, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=83141. 7.3 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40410806&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Pilot Statement (item 2, .PDF, 378 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40410807&FileExtension=.PDF&FileName=Pilot%20Statement-Redacted.PDF - Excerpt -Pilot Logbook (item 3, .PDF, 742 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40410808&FileExtension=.PDF&FileName=Excerpt%20-Pilot%20Logbook-Redacted.PDF - Weather Observations (item 4, .PDF, 57 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40410809&FileExtension=.PDF&FileName=Weather%20Observations-Master.PDF - Excerpt – Maintenance Records (item 5, .PDF, 818 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40410810&FileExtension=.PDF&FileName=Excerpt%20%E2%80%93%20Maintenance%20Records-Redacted.PDF - Airplane Bill of Sale (item 6, .PDF, 198 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40410811&FileExtension=.PDF&FileName=Airplane%20Bill%20of%20Sale-Redacted.PDF - Airworthiness Certificate and Information (item 7, .PDF, 655 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40410812&FileExtension=.PDF&FileName=Airworthiness%20Certificate%20and%20Information-Redacted.PDF - Cockpit Electronic Display Report (item 8, .PDF, 288 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40410813&FileExtension=.PDF&FileName=Cockpit%20Electronic%20Display%20Report-Master.PDF - Attachment 1 to Cockpit Electronic Display Report (item 9, .CSV, 6 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40410814&FileExtension=.csv&FileName=Attachment%201%20to%20Cockpit%20Electronic%20Display%20Report-Master.csv - NTSB Materials Laboratory Factual Report (item 10, .PDF, 191 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40410815&FileExtension=.PDF&FileName=NTSB%20Materials%20Laboratory%20Factual%20Report-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 11, .PDF, 329 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40410816&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.PDF - Photo 1 – View of Main Wreckage (Photo Courtesy of FAA) (item 12, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40410817&FileExtension=.PDF&FileName=Photo%201%20%E2%80%93%20View%20of%20Main%20Wreckage%20(Photo%20Courtesy%20of%20FAA)-Master.PDF - Photo 2 – View of Main Wreckage (Photo Courtesy of FAA) (item 13, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40410818&FileExtension=.PDF&FileName=Photo%202%20%E2%80%93%20View%20of%20Main%20Wreckage%20(Photo%20Courtesy%20of%20FAA)-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.