# NTSB GAA20CA062: Bell 47G, N6746D, Groveland, FL, November 7, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: November 7, 2019, 11:05 local (16:05 UTC) - Place: Groveland, FL - Coordinates: 28.405834, -81.837776 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=28.4058&lon=-81.8378&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Hard landing](https://openairdocs.org/ntsb-events/092) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 16, 2020 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 100543 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA20CA062 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/100543/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=100543 - Page: https://openairdocs.org/ntsb/GAA20CA062 ## Probable cause The student pilot's improper cyclic input after a reported hydraulic failure, the reason for which could not be determined, and his failure to follow the emergency procedures, which resulted in a hard landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Student/instructed pilot (probable cause); cases with it: [Bell 47G-2, 1 case](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=1181008), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) - [Use of equip/info: use of policy/procedure](https://openairdocs.org/ntsb-findings/02063032): Personnel issues › Task performance · Student/instructed pilot (probable cause); cases with it: [Bell 47G-2, 1 case](https://openairdocs.org/ntsb-findings/02063032/cases.md?model=1181008), [All aircraft, 191 cases](https://openairdocs.org/ntsb-findings/02063032/cases.md) - [Flight control system](https://openairdocs.org/ntsb-findings/01022700): Aircraft › Aircraft systems · Incorrect use/operation (probable cause); cases with it: [Bell 47G-2, 1 case](https://openairdocs.org/ntsb-findings/01022700/cases.md?model=1181008), [All aircraft, 65 cases](https://openairdocs.org/ntsb-findings/01022700/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Bell 47G-2, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=1181008), [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. - [Landing: Hard landing](https://openairdocs.org/ntsb-events/092) (defining event); cases with it: [Bell 47G-2, 3 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=1181008), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis The student pilot reported that, during landing, the helicopter experienced a hydraulic failure. He added that he "overreacted" by making multiple commands to the cyclic, which resulted in a tail strike, followed by a hard landing and roll-over. The helicopter caught fire, and the student egressed through the left door. The helicopter sustained substantial damage to the fuselage and tailboom. According to Federal Aviation Administration inspectors who interviewed the pilot immediately following the accident, the pilot stated that he overreacted and that he did not accomplish the helicopter manufacturer's Hydraulic Failure emergency procedure because he "didn't want to let go of the cyclic or the collective to turn off the hydraulic pressure switch." The hydraulic pump and the hydraulic lines were damaged during the postaccident fire; therefore, the reason for the reported hydraulic failure could not be determined. ## Factual narrative The student helicopter pilot reported that during landing, the helicopter had a hydraulic failure, to which he "overreacted, causing a loss of control and subsequent roll over." The helicopter caught fire, and the pilot egressed through the left door. During a conversation with the student, he reported that he did not accomplish the helicopter manufactures Hydraulic Failure emergency procedure, because, he "didn't want to let go of the cyclic or the collective to turn off the hydraulic pressure switch." The tail struck the ground and a subsequent hard landing ensued. The helicopter sustained substantial damage to the fuselage and tailboom. According to FAA Aviation Safety Inspectors that interviewed the pilot directly following the accident, the pilot stated that, he overreacted by making multiple commands to the cyclic and a tail strike ensued, followed by hard landing and rollover. The hydraulic pump and the hydraulic lines were damaged during the post-accident fire. ## Aircraft - Registration: [N6746D](https://openairdocs.org/deregistered/N6746D-2023-02-04), registration cancelled 2023-02-04, S/N 2250, built 1958 (OpenAirDocs) - Reported make and model: Bell 47G (2) - Registry model: [Bell 47G-2](https://openairdocs.org/model/bell-47g-2) (registry code 1181008) (OpenAirDocs) - Registry engine: [Lycoming VO-435 series](https://openairdocs.org/engine/lycoming-vo-435-series) (registry code 41525, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 2250 - Year built: 1958 - Engines: Lycoming VO435 194 horsepower reciprocating - Damage: Substantial damage - Fire: On-Ground - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 1, 2019 - Departed: 6FL0, Groveland, FL - Destination: 6FL0, Groveland, FL - Airport: 6FL0, Seminole Lake, runway 18, 3,000 × 200 ft - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 72; injuries: none; commercial; airplane ratings: single-engine sea, multi-engine sea, single-engine land, multi-engine land; instrument ratings: airplane; medical: basicmed, with waivers/limitations; last flight review October 10, 2019; seat: left; flight hours: 19,000 total, 20 in this make and model, 18,925 as pilot in command, 25 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 40° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 82 °F, dew point 73 °F - Altimeter: 30.17 inHg - Observed at: KZPH, 20 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 20191107020869A](https://openairdocs.org/incident/20191107020869A), Nov 7, 2019: Bell 47G-2, Groveland, FL, Substantial damage. Ref SO15 ptrs 202002081: the pilot stated that he was practicing hovering procedures and experienced a hydraulic issue with the controls. He stated that he… ## Other investigations on N6746D (3) 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 MIA02LA101](https://openairdocs.org/ntsb/MIA02LA101), May 28, 2002: Bell 47G-2 (N6746D), Bunnell, FL, substantial damage. Probable cause: The failure of the student pilot to secure the rotorcraft floorboard mounted ballast, resulting in shifting of the ballast on liftoff, and the subsequent dynamic rollover. - [NTSB FTW92LA159](https://openairdocs.org/ntsb/FTW92LA159), Jun 14, 1992: Bell 47G-2 (N6746D), Danbury, TX, substantial damage. Probable cause: THE FAILURE OF THE LANDING GEAR SKID DUE TO INTERNAL CORROSION. A FACTOR WAS THE SOFT GROUND. - [NTSB MIA67A0084](https://openairdocs.org/ntsb/MIA67A0084), Feb 14, 1967: Bell 47G-2 (N6746D), Donelson, TN, substantial damage ## Docket (3 files) The files NTSB released with the investigation on February 5, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=100543. 3.7 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40480508&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Memorandum for Record (item 2, .PDF, 80 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40480509&FileExtension=.PDF&FileName=Memorandum%20for%20Record-Master.PDF - Photo (item 3, .PDF, 274 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40480510&FileExtension=.PDF&FileName=Photo-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.