Robinson R44 accident near Uvalde, Texas, January 8, 2019
On January 8, 2019 at about 4:00 pm local time, a 2006 Robinson R44 (helicopter), registered N484AB, was substantially damaged in an accident during initial climb near Uvalde, Texas (Garner Field). It was an instructional flight under general aviation rules (Part 91). 1 person had minor injuries; 1 other was unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The slipping of the sprag clutch due to galling of the sprags and corresponding sprag contact surfaces within the clutch assembly, which rendered the helicopter uncontrollable.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- January 8, 2019 · about 4:00 pm local time
- Place
- Uvalde, Texas · Garner Field · map
- Type
- Accident
- Injuries
- 1 person had minor injuries; 1 other was unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Robinson R44 II, built 2006 · all R44s on the register
- Registration
- N484AB · registry record · serial 11390
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The student pilot and flight instructor were conducting a local, instructional flight. The instructor reported that, as the student was transitioning the helicopter through effective translational lift about 40 knots airspeed, he raised the collective to increase the available power to the takeoff power setting. Shortly thereafter, he heard a loud "pop/bang sound," which was followed by an uncommanded right yaw and severe vibrations. Due to the low altitude and airspeed, the instructor immediately took the flight controls and initiated an autorotation. Upon touchdown, the helicopter tilted forward, and the instructor applied aft cyclic to correct; however, the main rotor blades contacted the tailboom, which resulted in the tailboom partially separating from the helicopter. During postaccident examination of the helicopter, the clutch assembly lubricant was drained, and metallic debris was found in the strainer. Disassembly of the clutch assembly revealed galling of the sprags and the corresponding sprag contact surfaces on the clutch shaft and hub. It is likely that the excessive galling resulted in the sprag clutch slipping, which produced the uncommanded right yaw and led to the student's and instructor's inability to maintain helicopter control.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Flight control sys malf/fail during initial climb
- Loss of control in flight during initial climb defining event
- Autorotation Off-field or emergency landing
- Autorotation Collision with terrain or object (not controlled flight into terrain)
The NTSB's findings
- cause Aircraft › Aircraft propeller/rotor › Tail rotor drive system › (general) › Malfunction
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › (general) › Attain/maintain not possible
Flight instructor
- Certificate: flight instructor, commercial pilot
- Ratings: instructor: helicopter; instructor: instrument helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 2,650 hours in all; 1,200 in this make and model; 250 in the last 90 days; 150 in the last 30 days; 2,600 as pilot in command; 1,200 on instruments
- Last flight review: August 15, 2018
- Medical certificate: Class 1 (with waivers/limitations)
- Seat: left
- Injury: minor injuries
Dual student
- Certificate: private
- Ratings: single-engine land
- Flight time: 400 hours in all; 20 in this make and model; 25 in the last 90 days; 10 in the last 30 days; 320 as pilot in command
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 1,680.9 hours
- Last inspection: annual inspection, November 7, 2018; 245 hours since
- Maximum gross weight: 2,500 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming IO-540-AE1A5 (piston); 1,681 hours total
The flight
- Departed from: UVA Uvalde TX at 4:00 pm
- Destination: UVA Uvalde TX
- Flight plan: none
- A second pilot was aboard
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 77°F (25°C), dew point 59°F (15°C)
- Altimeter: 29.95 inHg
- Observation at 3:30 pm
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
7 documents, released by the NTSB on February 21, 2019. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | Maintenance Logbook Entry | PDF, 1 page | View Download |
| 3 | Rhc Clutch Assembly Examination Summary | PDF, 7 pages | View Download |
| 4 | Rhc Maintenance Manual - Inspection Schedule | PDF, 1 page | View Download |
| 5 | Rhc Maintenance Manual - Clutch Assembly | PDF, 2 pages | View Download |
| 6 | Rhc Illustrated Parts Catalog - Clutch Assembly | PDF, 2 pages | View Download |
| 7 | Rhc R44 Service Bulletin SB-79 | PDF, 3 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.