# NTSB ERA15LA376: Hughes 269, N9567F, Eustis, FL, September 25, 2015 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: September 25, 2015, 10:40 local (14:40 UTC) - Place: Eustis, FL - Coordinates: 28.834999, -81.581665 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=28.8350&lon=-81.5817&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach: Loss of tail rotor effectiveness](https://openairdocs.org/ntsb-events/242) - Highest injury: Serious injuries - Injuries: 2 serious - Status: Completed, report March 14, 2016 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 92058 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA15LA376 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/92058/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=92058 - Page: https://openairdocs.org/ntsb/ERA15LA376 ## Probable cause The pilot's failure to maintain yaw control as he slowed the helicopter during a landing approach, which resulted in a loss of helicopter control due to a loss of tail rotor effectiveness. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: yaw control](https://openairdocs.org/ntsb-findings/01062024): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Hughes 269B, 1 case](https://openairdocs.org/ntsb-findings/01062024/cases.md?model=4470502), [All aircraft, 149 cases](https://openairdocs.org/ntsb-findings/01062024/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Hughes 269B, 5 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=4470502), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: prop/rotor parameters](https://openairdocs.org/ntsb-findings/01062052): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Hughes 269B, 1 case](https://openairdocs.org/ntsb-findings/01062052/cases.md?model=4470502), [All aircraft, 182 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach: Loss of tail rotor effectiveness](https://openairdocs.org/ntsb-events/242) (defining event); cases with it: [Hughes 269B, 1 case](https://openairdocs.org/ntsb-events/242/sequence.md?model=4470502), [All aircraft, 100 cases](https://openairdocs.org/ntsb-events/242/sequence.md) - [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Hughes 269B, 5 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=4470502), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The commercial pilot was flying the helicopter about 600 ft above ground level and at a speed of 60 to 70 mph and began descending and slowing the helicopter as it approached a friend's home, where he planned to land. The right-seat passenger, who was a student pilot, reported that the helicopter got "low and slow" during the approach and began "violently spinning to the right." The student pilot also reported that the wind was light and variable and that there were no mechanical malfunctions or failures during the flight. Postaccident examination of the wreckage revealed no evidence of a mechanical malfunction or anomaly. A cell phone video provided by a witness confirmed the student's report that the helicopter was at a low altitude and airspeed when it yawed right, then spun right, and descended to ground impact. The engine could be heard running throughout the accident sequence. It is likely that, during the landing approach, the helicopter's airspeed dropped below effective translational lift, and when the pilot added power to compensate, the helicopter yawed right. The pilot was unable to stop the yaw and lost control of the helicopter due to a loss of tail rotor effectiveness. ## Factual narrative On September 25, 2015, about 1040 eastern daylight time, a Hughes 269B, N9567F, collided with terrain following a loss of helicopter control during an approach to a private landing area near Eustis, Florida. The commercial pilot and a passenger, who was also a student pilot, were seriously injured, and the helicopter was substantially damaged. The helicopter was owned and operated by the student pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Day, visual meteorological conditions prevailed, and no flight plan was filed. The local flight originated from Leesburg, Florida (LEE) about 1020. The student pilot reported the following. He was in the right, cockpit seat and the pilot was in the left seat. The pilot was approaching the residence of a friend, at an altitude of 600 feet above the ground and a speed of 60-70 mph. The pilot began descending and slowing down the helicopter as they approached the residence. The helicopter then began "spinning slowly to the left a few times then violently spinning to the right." He then recalled waking up on a medical air ambulance helicopter after the accident. The student pilot later reported that the helicopter was "low and slow" during the approach and that there was no mechanical malfunction or failure during the accident flight. He reported the wind as light and variable. He also stated that the height-velocity curve for the Hughes 269B should have been followed. An inspector with the Federal Aviation Administration (FAA) responded to the accident site and examined the wreckage. The helicopter came to rest on its right side. The main rotor blades received structural damage and remained attached to their hub. The tail rotor drive shaft was sheared in two locations. The tail rotor blades remained attached to their hub. Control continuity was established from the cockpit to the main rotor and tail rotor system except for impact damage. There was sufficient fuel on board and there was oil in the engine. An external examination of the engine revealed no anomalies. His overall assessment of the wreckage did not reveal any evidence of a mechanical malfunction or anomaly. The cellular telephone video provided by a witness confirmed the left hand and right hand yaw and spiral during the final descent. The engine could be heard running throughout the accident sequence. The FAA issued Advisory Circular (AC) 90-95, Unanticipated Right Yaw in Helicopters, in February 1995. The AC stated that the loss of tail rotor effectiveness (LTE) was a critical, low-speed aerodynamic flight characteristic which could result in an uncommanded rapid yaw rate which does not subside of its own accord and, if not corrected, could result in the loss of aircraft control. It also stated, "LTE is not related to a maintenance malfunction and may occur in varying degrees in all single main rotor helicopters at airspeeds less than 30 knots." Paragraph 6 of the AC covered conditions under whichLTE may occur. It stated: "Any maneuver which requires the pilot to operate in a high-power, low-airspeed environment with a left crosswind or tailwind creates an environment where unanticipated right yaw may occur." Paragraph 8 of the AC stated: "OTHER FACTORS...Low Indicated Airspeed. At airspeeds below translational lift, the tail rotor is required to produce nearly 100 percent of the directional control. If the required amount of tail rotor thrust is not available for any reason, the aircraft will yaw to the right." Paragraph 9 of the AC stated: "When maneuvering between hover and 30 knots: (1) Avoid tailwinds. If loss of translational lift occurs, it will result in an increased high power demand and an additional anti-torque requirement. (2) Avoid out of ground effect (OGE) hover and high power demand situations, such as low-speed downwind turns. (3) Be especially aware of wind direction and velocity when hovering in winds of about 8-12 knots (especially OGE). There are no strong indicators to the pilot of a reduction of translation lift... (6) Stay vigilant to power and wind conditions." ## Aircraft - Registration: [N9567F](https://openairdocs.org/deregistered/N9567F-2018-06-26), registration cancelled 2018-06-26, S/N 210459 (OpenAirDocs) - Reported make and model: HUGHES 269 (B) - Registry model: [Hughes 269B](https://openairdocs.org/model/hughes-269b) (registry code 4470502) (OpenAirDocs) - Registry engine: [Lycoming HIO-360 series](https://openairdocs.org/engine/lycoming-hio-360-series) (registry code 41524, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 210459 - Year built: 1972 - Airframe hours: 4763 - Engines: Lycoming HIO-360-A1A 160 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Rentoumis Michael G - Registered owner: Rentoumis Michael G - Airworthiness certificate: Standard, Normal - Last inspection: Annual, November 30, 2014, 6 hours before - Departed: LEE, Leesburg, FL - Destination: Eustis, FL ## Flight crew As NTSB recorded them. NTSB leaves out names. - Student pilot; age 53; injuries: serious; student; medical: class 3, with waivers/limitations; seat: right; restraint: 4-point; flight hours: 31 total, 26 in this make and model - Pilot; age 66; injuries: serious; commercial, flight instructor, airline transport; airplane ratings: single-engine land, single-engine sea, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review August 15, 2015; seat: left; restraint: 4-point; flight hours: 18,000 total, 350 in this make and model, 15,000 as pilot in command, 191 in the last 90 days, 47 in the last 30 days, 9 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 120° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 72 °F - Altimeter: 29.96 inHg - Observed at: LEE, 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 20150925017279A](https://openairdocs.org/incident/20150925017279A), Sep 25, 2015: Hughes 269B, Eustis, FL, Destroyed. On a personal flight to visit friends pilot allowed the aircraft to slow down below efective transational lift at altitude while on approach to a field .… ## Docket (4 files) The files NTSB released with the investigation on January 29, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=92058. 3.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40436244&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Memorandum for Record – Telephone Interview, FAA Inspector Sheppard (item 2, .PDF, 58 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40436245&FileExtension=.PDF&FileName=Memorandum%20for%20Record%20%E2%80%93%20Telephone%20Interview,%20FAA%20Inspector%20Sheppard-Master.PDF - Photo Array (item 3, .PDF, 1.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40436246&FileExtension=.PDF&FileName=Photo%20Array-Master.PDF - Video File - Witness Cell Phone Video (item 4, .PDF, 37 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40436247&FileExtension=.PDF&FileName=Video%20File%20-%20Witness%20Cell%20Phone%20Video-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.