# NTSB GAA19CA250: Bell 47G, N5990, Denton, TX, May 6, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: May 6, 2019, 10:20 local (15:20 UTC) - Place: Denton, TX - Coordinates: 33.20222, -97.198059 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.2022&lon=-97.1981&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-hover: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report March 3, 2020 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 99392 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA19CA250 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/99392/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=99392 - Page: https://openairdocs.org/ntsb/GAA19CA250 ## Probable cause The flight instructor's improper decision to instruct the student pilot to establish a hover and reposition the helicopter with a tailwind, which resulted in the student pilot's loss of pitch control. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Instructor/check pilot (probable cause); cases with it: [Bell 47G-2, 3 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=1181008), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Student/instructed pilot (probable cause); cases with it: [Bell 47G-2, 7 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=1181008), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: pitch control](https://openairdocs.org/ntsb-findings/01062022): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Bell 47G-2, 1 case](https://openairdocs.org/ntsb-findings/01062022/cases.md?model=1181008), [All aircraft, 526 cases](https://openairdocs.org/ntsb-findings/01062022/cases.md) - [Wind: tailwind](https://openairdocs.org/ntsb-findings/03034015): Environmental issues › Conditions/weather/phenomena · Decision related to condition (probable cause); cases with it: [Bell 47G-2, 1 case](https://openairdocs.org/ntsb-findings/03034015/cases.md?model=1181008), [All aircraft, 594 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md) - [Wind: tailwind](https://openairdocs.org/ntsb-findings/03034015): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [Bell 47G-2, 1 case](https://openairdocs.org/ntsb-findings/03034015/cases.md?model=1181008), [All aircraft, 594 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-hover: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Bell 47G-2, 1 case](https://openairdocs.org/ntsb-events/400/sequence.md?model=1181008), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md) - [Maneuvering-hover: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Bell 47G-2, 5 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=1181008), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Bell 47G-2, 6 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=1181008), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) - [Landing: Part(s) separation from AC](https://openairdocs.org/ntsb-events/338); cases with it: [Bell 47G-2, 2 cases](https://openairdocs.org/ntsb-events/338/sequence.md?model=1181008), [All aircraft, 563 cases](https://openairdocs.org/ntsb-events/338/sequence.md) ## Analysis The student pilot reported that he hovered the helicopter to the parking pad and landed with the helicopter's nose facing north. The skid placement on the parking pad was incorrect, and the flight instructor directed the student to reposition the helicopter about 3 ft to the left. The student brought the helicopter to a hover and repositioned it 3 ft to the left. However, before the student established a descent and landed, the helicopter encountered a tailwind gust. The nose pitched down, the rotor rpm decreased, and the helicopter traveled about 75 ft forward. The skids contacted the ground hard, and the helicopter came to an abrupt stop, upright and facing downslope. The main rotor blades struck the tail rotor drive shaft and the tailboom. The tail rotor gear box and the tail rotor separated from the helicopter. The helicopter sustained substantial damage to the tail rotor drive system, the tailboom, and the main rotor blades. The pilot reported that there were no mechanical malfunctions or failures with the helicopter that would have precluded normal operation. The airport's METAR reported that, about the time of the accident, the wind was from 180° at 15 knots and that the cloud layer was broken at 800 ft. ## Factual narrative The student helicopter pilot reported that he hovered to the parking pad and landed with the nose of the helicopter facing north. The skid placement on the parking pad was incorrect, and the instructor directed the student to reposition the helicopter about 3ft to the left. The student brought the helicopter to a hover and repositioned the helicopter 3ft to the left. However, before the student established a descent and landed, the helicopter encountered a tailwind gust. The nose pitched down, the rotor rpm decreased, and the helicopter traveled about 75ft forward. The skids contacted the ground hard, and the helicopter came to an abrupt stop, upright and facing downslope. The main rotor blades struck the tail rotor drive shaft and the tailboom. The tail rotor gear box and the tail rotor separated from the helicopter. The helicopter sustained substantial damage to the tail rotor drive system, the tailboom, and the main rotor blades. The airport's Meteorological Aerodrome Report, about the time of the accident, reported that the wind was from 180° at 15 knots, and the cloud layer was broken at 800ft. The predominant wind about 30 minutes prior to the accident was from 170° at 13 knots. One-hour prior, the wind was from 160 at 09 knots. The pilot reported that there were no mechanical malfunctions or failures with the helicopter that would have precluded normal operation. ## Aircraft - Registration: [N5990](https://openairdocs.org/aircraft/N5990), registered now, S/N 2396 (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: 2396 - Year built: 1992 - Airframe hours: 3360.1 - Engines: Lycoming VO-435-A1 270 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 7, 2018 - Departed: DTO, DENTON, TX - Destination: DTO, DENTON, TX - Airport: DTO, Denton Enterprise - Equipment: ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 54; injuries: none; student; medical: class 3, without waivers/limitations; seat: left; restraint: 3-point; flight hours: 24 total, 15 in this make and model, 24 as pilot in command, 15 in the last 90 days, 5 in the last 30 days, 1 in the last 24 hours - Flight instructor; age 61; injuries: none; flight engineer, airline transport, flight instructor; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: helicopter, airplane; medical: class 1, with waivers/limitations; last flight review February 7, 2019; seat: right; restraint: lap only; flight hours: 30,000 total, 200 in this make and model, 25,000 as pilot in command, 100 in the last 90 days, 50 in the last 30 days, 10 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 15 knots - Visibility: 10 statute miles - Lowest ceiling: 8,000 ft broken - Temperature: 77 °F, dew point 63 °F - Altimeter: 29.95 inHg - Observed at: KDTO ## 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 20190506004139A](https://openairdocs.org/incident/20190506004139A), May 6, 2019: Bell 47G-2, Denton, TX, Substantial damage. While landing main rotor struck tail boom of aircraft ## Docket (2 files) The files NTSB released with the investigation on September 4, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=99392. 3.7 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40475446&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Photo (item 2, .PDF, 1 photo, 224 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40475447&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.