# NTSB CHI06CA168: Schweizer 269C, N1675U, Grand Forks, ND, June 17, 2006 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: June 16, 2006, 19:30 local (Jun 17, 2006, 00:30 UTC) - Place: Grand Forks, ND - Coordinates: 47.95, -97.183334 - Nearby events: https://openairdocs.org/map.md?lat=47.9500&lon=-97.1833&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report October 3, 2006 - Report: Approved by Office Director - Parties: FAA-Fargo FSDO - NTSB case key (mKey): 64091 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI06CA168 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/64091/pdf - Page: https://openairdocs.org/ntsb/CHI06CA168 ## Probable cause The dual student's failure to maintain rotor speed during the recovery from the intentional autorotation and the flight instructor's delayed remedial action. Contributing factors were the flight crew's intentional autorotation and dual student's misjudged flare. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with terrain/water, landing - flare/touchdown - autorotation - intentional, flightcrew (contributing factor) - flare - misjudged, dual student (contributing factor) - rotor rpm - not maintained, dual student (cause) - remedial action - delayed, pilot in command(cfi) (cause) - terrain condition - ground ## Analysis The helicopter was substantially damaged when the tail rotor struck the taxiway during recovery from an intentional autorotation. The flight instructor and commercial pilot (dual student) were not injured. The flight instructor stated that the instructional flight included 180-degree autorotations, which were terminated into a hover with the addition of engine power. He reported that on the first autorotation the dual student flared high and during the recovery the rotor speed decayed requiring a landing on the taxiway. He noted that the dual student was subsequently instructed to increase engine power as collective was increased during the recovery in order to maintain rotor speed. On the second autorotation, he stated that the dual student flared lower and a "little more aggressively." He noted that as the dual student increased the collective, the rotor speed again decayed. The flight instructor stated that "as the collective continued upward the engine and rotor [speed] decreased." He "intervened on the controls and continued to increase the collective and throttle and level the aircraft, [when] the tail struck the taxiway." The flight instructor subsequently landed the helicopter after noting an airframe vibration. The flight instructor reported no malfunctions or failures prior to the accident. ## Factual narrative The helicopter was substantially damaged when the tail rotor struck the taxiway during recovery from an intentional autorotation. The flight instructor and commercial pilot (dual student) were not injured. The flight instructor stated that the instructional flight included 180-degree autorotations, which were terminated into a hover with the addition of engine power. He reported that on the first autorotation the dual student flared high and during the recovery the rotor speed decayed requiring a landing on the taxiway. He noted that the dual student was subsequently instructed to increase engine power as collective was increased during the recovery in order to maintain rotor speed. On the second autorotation, he stated that the dual student flared lower and a "little more aggressively." He noted that as the dual student increased the collective, the rotor speed again decayed. The flight instructor stated that "as the collective continued upward the engine and rotor [speed] decreased." He "intervened on the controls and continued to increase the collective and throttle and level the aircraft, [when] the tail struck the taxiway." The flight instructor subsequently landed the helicopter after noting an airframe vibration. The flight instructor reported no malfunctions or failures prior to the accident. ## Aircraft - Registration: [N1675U](https://openairdocs.org/deregistered/N1675U-2020-12-05), registration cancelled 2020-12-05, S/N S1878, built 2005 (OpenAirDocs) - Reported make and model: Schweizer 269C - Registry model: [Schweizer 269C](https://openairdocs.org/model/schweizer-269c) (registry code 8059502) (OpenAirDocs) - Registry engine: [Lycoming HIO-360 series](https://openairdocs.org/engine/lycoming-hio-360-series) (registry code 41524, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: S1878 - Airframe hours: 480 - Engines: Lycoming H10-360-O1A 190 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 1, 2006 - Departed: GFK, Grand Forks, ND - Airport: GFK, Grand Forks Intl ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 40; injuries: none; flight instructor, airline transport; airplane ratings: multi-engine sea, single-engine sea, multi-engine land, single-engine land; instrument ratings: airplane, helicopter; medical: class 1, without waivers/limitations; last flight review September 1, 2005; seat: right; flight hours: 6,831 total, 270 in this make and model, 4,665 as pilot in command, 135 in the last 90 days, 54 in the last 30 days, 3 in the last 24 hours - Co-pilot; age 33; injuries: none; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review March 1, 2006; seat: left; flight hours: 280 total, 47 in this make and model, 44 as pilot in command, 50 in the last 90 days, 18 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 70 °F, dew point 45 °F - Altimeter: 29.90 inHg - Observed at: GFK ## 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 20060616015189A](https://openairdocs.org/incident/20060616015189A), Jun 16, 2006: Hughes 269C, Grand Forks, ND, Substantial damage. (-23) On 6/16/2006 at 1930 CDT, a HU-300-C, N1675U, owned by the university of north dakota and piloted by [privacy data omitted] as flight instructor… ## Other investigations on N1675U (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 CEN14CA513](https://openairdocs.org/ntsb/CEN14CA513), Sep 22, 2014: Schweizer 269C (N1675U), Grand Forks, ND, substantial damage. Probable cause: The flight instructor's inadequate supervision and delayed remedial action during a practice autorotation, which resulted in a tail rotor strike. 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.