# NTSB CEN17LA365: Gaddis Michael Exec 162 F, N123XZ, Plymouth, IN, September 16, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 16, 2017, 17:15 local (21:15 UTC) - Place: Plymouth, IN - Coordinates: 41.345832, -86.291946 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.3458&lon=-86.2919&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report November 6, 2019 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA - NTSB case key (mKey): 96081 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN17LA365 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/96081/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=96081 - Page: https://openairdocs.org/ntsb/CEN17LA365 ## Probable cause A failure of the drive belt for reasons that could not be determined based on the available information. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Main rotor drive](https://openairdocs.org/ntsb-findings/01046300): Aircraft › Aircraft propeller/rotor · Failure (probable cause); cases with it: [Gaddis Michael EXEC 162-F, 1 case](https://openairdocs.org/ntsb-findings/01046300/cases.md?model=05610U3), [All aircraft, 15 cases](https://openairdocs.org/ntsb-findings/01046300/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Gaddis Michael EXEC 162-F, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=05610U3), [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. - [Approach: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Gaddis Michael EXEC 162-F, 1 case](https://openairdocs.org/ntsb-events/330/sequence.md?model=05610U3), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Landing-flare/touchdown: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Gaddis Michael EXEC 162-F, 1 case](https://openairdocs.org/ntsb-events/092/sequence.md?model=05610U3), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis As the helicopter approached the airport, the pilot reported that the helicopter's engine rpm increased, and the rotor rpm decayed. He conducted an autorotation to the field. An examination of the helicopter revealed that the helicopter's main rotor drive belt/cog belt lost teeth resulting in a failure of the belt to drive the main rotor blades. The drive belt had recently been installed, about 3.5 hours prior to the accident. The circumstances of the accident are consistent with improper tension of the cog belt resulting in a failure of the belt. ## Factual narrative On September 16, 2017, about 1715 eastern daylight time, an amateur-built Exec 162-F helicopter, N123XZ, performed a forced landing to a field near Plymouth, Indiana. The pilot and passenger were not injured, and the helicopter was substantially damaged. The helicopter was registered to North Indiana Rotor LLC and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The local flight departed from Plymouth Municipal Airport (C65), Plymouth, Indiana.The pilot reported that while approaching the airport, the helicopter's engine rpm increased, and the rotor rpm decayed. Unable to maintain altitude, the pilot conducted an autorotation to a field. The helicopter landed hard, the skids bent, and the tail boom buckled, resulting in substantial damage. An examination of the helicopter by the responding Federal Aviation Administration inspector revealed that the helicopter had a Pro Drive system driving the main rotor blades. The main rotor drive belt/cog belt began losing teeth resulting in a failure of the belt to drive the main rotor blades. The Goodyear Falcon PD belt had recently been installed, about 3.5 hours prior to the accident. ## Aircraft - Registration: [N123XZ](https://openairdocs.org/deregistered/N123XZ-2018-09-25), registration cancelled 2018-09-25, S/N 6377, built 1998 (OpenAirDocs) - Reported make and model: GADDIS MICHAEL EXEC 162 F (NO SERIES) - Registry model: [Gaddis Michael EXEC 162-F](https://openairdocs.org/model/gaddis-michael-exec-162-f) (registry code 05610U3) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Helicopter, amateur-built - Serial number: 6377 - Year built: 1998 - Engines: Rotorway 162-F 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, August 29, 2017, 277 hours before - Departed: C65, PLYMOUTH, IN - Destination: C65, PLYMOUTH, IN - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 49; injuries: none; commercial, flight instructor; medical: class 2, without waivers/limitations; last flight review June 16, 2017; seat: left; restraint: 3-point; flight hours: 393 total, 250 in this make and model, 346 as pilot in command, 26 in the last 90 days, 11 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 82 °F, dew point 59 °F - Altimeter: 30.05 inHg - Observed at: KOXI, 17 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 20170916019469A](https://openairdocs.org/incident/20170916019469A), Sep 16, 2017: Gaddis Michael EXEC 162-F, Plymouth, IN, Substantial damage. PIC and passenger departed C65 and approximately 1645 EST. While airborne approximately 15 minutes, PIC and passenger heard strange noise. PIC attempted to… ## Other investigations on N123XZ (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 CEN15CA155](https://openairdocs.org/ntsb/CEN15CA155), Feb 26, 2015: Gaddis Michael Exec 162 F (N123XZ), Plymouth, IN, substantial damage. Probable cause: The failure of the helicopter's main drive belt resulting in the pilot performing a forced landing, during which the helicopter's fuselage was substantially damage. ## Docket (2 files) The files NTSB released with the investigation on March 15, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=96081. 2.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40460849&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Record of Conversation - FAA Hudson (item 2, .PDF, 52 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40460850&FileExtension=.PDF&FileName=Record%20of%20Conversation%20-%20FAA%20Hudson-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.