# NTSB ERA24LA263: Rotorway Exec, N99TE, Alva, FL, June 14, 2024

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 3 · Limited · Final report
- Date: June 14, 2024, 18:27 local (22:27 UTC)
- Place: Alva, FL · uneven terrain/canal ditch
- Coordinates: 26.733286, -81.574951
- Nearby events: https://openairdocs.org/map.md?lat=26.7333&lon=-81.5750&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Defining event: [Approach-VFR pattern final: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 3
- NTSB office: Eastern Region Aviation
- Parties: FAA/FSDO
- NTSB case key (mKey): 194479
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA24LA263
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/194479/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=194479
- Page: https://openairdocs.org/ntsb/ERA24LA263

## Probable cause

A loss of tail rotor control as a result of unsecured tail rotor drive belt tensioner bolts.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Tail rotor drive system: tail rotor drive shaft](https://openairdocs.org/ntsb-findings/01046510): Aircraft › Aircraft propeller/rotor · Damaged/degraded (probable cause); cases with it: [Eberhart Terry A ROTORWAY EXEC 162F, 1 case](https://openairdocs.org/ntsb-findings/01046510/cases.md?model=056063T), [All aircraft, 25 cases](https://openairdocs.org/ntsb-findings/01046510/cases.md)
- [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Eberhart Terry A ROTORWAY EXEC 162F, 1 case](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=056063T), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Approach-VFR pattern final: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) (defining event); cases with it: [Eberhart Terry A ROTORWAY EXEC 162F, 1 case](https://openairdocs.org/ntsb-events/333/sequence.md?model=056063T), [All aircraft, 410 cases](https://openairdocs.org/ntsb-events/333/sequence.md)
- [Approach-VFR pattern final: Loss of control in flight](https://openairdocs.org/ntsb-events/240); cases with it: [Eberhart Terry A ROTORWAY EXEC 162F, 1 case](https://openairdocs.org/ntsb-events/240/sequence.md?model=056063T), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md)
- [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Eberhart Terry A ROTORWAY EXEC 162F, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=056063T), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)

## Analysis

The pilot of the experimental amateur-built helicopter stated that, as a part of the preflight inspection, he checked the tail rotor drive belt tension with a spring scale and it was within limits. Shortly after departing on the accident flight, while flying at an altitude between 200 and 300 ft mean sea level (msl), the pilot-rated passenger took over the controls. As they approached an airstrip for landing, at an altitude about 150 ft above ground level (agl) with an airspeed of 20-30 mph, which was just below effective translational lift (ETL), the helicopter made an uncommanded yaw to the left. The passenger was unable to maintain directional control with the application of right anti-torque pedal input. The pilot took over the controls from the passenger and applied forward cyclic in combination with full input of the right anti-torque pedal to correct the yaw. However, the helicopter descended in a sweeping left turn and the pilot was unable to regain full directional yaw control before the helicopter contacted the edge of an irrigation ditch. The helicopter rolled over to the right and came to rest, resulting in substantial damage to the airframe and rotor blades. Postaccident examination of the helicopter revealed that the tail rotor tensioner assembly was not secured. The right side of the tail rotor drive belt jam nut and the self-locking nylon nut were loose. The nuts, when properly secured, placed tension on the tail rotor drive belt. Even though the preflight tail rotor tension test was accomplished and within limits, there was no access to physically view these nuts during preflight inspection. Based on the available information, it is likely that the nuts loosened in flight, which would have allowed slack in the drive belt that prevented full tail rotor drive control

## Factual narrative

On June 14, 2024, at 1827 eastern daylight time, an experimental amateur-built Rotorway Exec 162F helicopter, N99TE, was substantially damaged when it was involved in an accident near Alva, Florida. The airline transport pilot and pilot-rated passenger were not injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot stated that they performed a preflight inspection and as a part of the preflight, he checked the tail rotor drive belt tension with a spring scale and it was within limits at 10 lbs. Shortly after departing from his residence, while flying at an altitude between 200 and 300 ft msl, he handed off the controls to the passenger. Upon reaching a small grass airstrip the passenger flew a high “recon” flight in an easterly direction. During the approach, at an altitude of about 150 ft agl with an airspeed of 20-30 mph, the passenger made a cyclic correction to stay over the runway centerline. He reported that after the correction he noticed the rotor rpm was below 100% so he increased the throttle. He reported that as the helicopter passed through effective translational lift (ETL) it began to yaw to the left with full right pedal applied. The pilot took control of the helicopter and applied forward cyclic in combination with right anti-torque pedal input to correct the yaw. However, the helicopter descended in a sweeping left turn with full right anti-torque pedal applied and he was unable to regain directional control before the helicopter contacted the edge of an irrigation ditch during the landing attempt. The helicopter rolled over and came to rest on its right side, which resulted in substantial damage to the rotor blades and a large crease in the tail boom. The pilot reported that the engine operated as expected for the duration of the flight and no abnormal vibrations or sounds were noted. Additionally, all flight controls were operating as expected until the unanticipated yaw began. An FAA inspector examined the helicopter after the accident and found that the tail rotor bolt tensioner assembly was not secured. The right side of the tail rotor drive belt jam nut and the self-locking nylon nut were loose (see figure 1). The nuts, when properly secured, placed tension on the tail rotor drive belt. There was no access to physically view these critical nuts during a preflight inspection. Figure 1. Examination of tail rotor assembly; tail rotor drive belt nuts out of position.

## Aircraft

- Registration: [N99TE](https://openairdocs.org/aircraft/N99TE), registered now, S/N 6306 (OpenAirDocs)
- Reported make and model: ROTORWAY EXEC (162F)
- Registry model: [Eberhart Terry A ROTORWAY EXEC 162F](https://openairdocs.org/model/eberhart-terry-a-rotorway-exec-162f) (registry code 056063T) (OpenAirDocs)
- Registry engine: [Rotorway RW152](https://openairdocs.org/engine/rotorway-rw152) (registry code 55006, reciprocating) (OpenAirDocs)
- Category: Helicopter, amateur-built
- Serial number: 6306
- Year built: 1999
- Airframe hours: 415
- Engines: ROTORWAY RW162F 140 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Condition, January 21, 2024, 10 hours before
- Departed: PVT, Alva, FL
- Airport: 87FL, Alma Airport, runway 9, 2,882 × 75 ft, grass/turf
- Equipment: Unknown

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 66; injuries: none; commercial, flight instructor, airline transport; airplane ratings: single-engine land, multi-engine land, single-engine sea; instrument ratings: airplane, helicopter; medical: basicmed, with waivers/limitations; seat: right; restraint: 4-point; flight hours: 7,000 total, 10 in this make and model, 6,625 as pilot in command, 10 in the last 30 days
- Pilot-rated passenger; injuries: none; commercial, flight instructor; airplane ratings: single-engine sea, single-engine land; instrument ratings: helicopter; medical: class 3; seat: left; restraint: 4-point

## Weather

- Conditions: Visual (VMC), Day
- Wind: 220° at 9 knots
- Visibility: 10 statute miles
- Temperature: 84 °F, dew point 73 °F
- Altimeter: 29.87 inHg
- Observed at: FMY, 18 nm away
- METAR: KFMY 142153Z 22009KT 10SM SCT025 29/23 A2987 RMK AO2 SLP117 T02890228

## 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 20240614018579A](https://openairdocs.org/incident/20240614018579A), Jun 14, 2024: Eberhart Terry A ROTORWAY EXEC 162F, Alva, FL, Substantial damage. On June 14, 2024 an expiermental helicopter flew from , Alva, Florida to 87FL. After one pass of the airport the helicopter entered what was described as an…

## Docket (6 files)

The files NTSB released with the investigation on April 1, 2025, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=194479. 4.6 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 891 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18067809&FileExtension=pdf&FileName=Pilots%206120%20Accident%20Report_N99TE_Redacted-Rel.pdf
- Memo for record_pilot conversation (item 2, PDF, 2 pages, 572 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18083019&FileExtension=pdf&FileName=FINAL%20Record%20of%20Convo%20w%20Robert%20Roper%206%2016%202024%20v02_Redacted-Rel.pdf
- Pilot's statements (item 3, PDF, 2 pages, 62 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18073643&FileExtension=pdf&FileName=Pilot%20Statements_Redacted-Rel.pdf
- Memo for record_FAA conversation (item 4, PDF, 1 page, 98 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18081517&FileExtension=pdf&FileName=Memo%20for%20Record_FAA%20Conversation_Redacted-Rel.pdf
- POH excerpt_preflight checklist (item 5, PDF, 1 page, 206 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18083059&FileExtension=pdf&FileName=POH%20Excerpt_%20Preflight%20Checklist-Rel.pdf
- Photos_accident site and helicopter damage (item 6, PDF, 6 pages, 2.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18075835&FileExtension=pdf&FileName=Accident%20Site%20and%20Damage%20Photographs_N99TE-Rel.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.