Hughes OH-6A accident near Green Valley, Arizona, April 20, 2000
On April 20, 2000 at about 2:15 pm local time, a Hughes OH-6A (helicopter), registered N61869, was substantially damaged in an accident near Green Valley, Arizona. It was a public-use flight under general aviation rules (Part 91). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
Company maintenance personnel's failure to secure an attachment nut to a control link. While maneuvering, the parts separated and resulted in the total cyclic control system failure and impact into rough terrain.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 20, 2000 · about 2:15 pm local time
- Place
- Green Valley, Arizona · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Hughes OH-6A · all OH-6As on the register
- Registration
- N61869 · no longer on the register · serial 69-16002
- Damage
- Substantial damage
- Flight
- Public-use flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
While maneuvering about 20 feet above obstacles looking for the footprints of a group of suspected illegal entrants, the U.S. Border Patrol pilot suddenly experienced an unusual vibration in the cyclic control. After the vibration started, the helicopter almost immediately started turning right and descended. The pilot attempted to stop the turn and descent, but to no avail, and he crashed in the rough terrain. The previous day a 300-hour inspection had been completed by Border Patrol mechanics, and it involved a rebuild of the swashplate assembly. During this maintenance, the cyclic control's longitudinal link (part number 369A7608) was removed and replaced at the stationary swashplate. Upon completion of the maintenance, a cotter pin is required to be installed in the link's attachment nut to secure it. The cotter pin, and the respective nut, were observed missing at the accident site. During the recent maintenance, a mechanic had failed to reinstall the cotter pin into the nut, and it backed off during flight. This maintenance oversight-related failure resulted in the pilot's complete loss of cyclic 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
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 19,560 hours in all; 3,326 in this make and model; 287 in the last 90 days; 93 in the last 30 days; 19,201 as pilot in command; 454 on instruments
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 7,603 hours
- Last inspection: approved inspection programme, April 19, 2000; 2 hours since
- Maximum gross weight: 2,550 lb
- Seats: 4
- Landing gear: fixed
- Engine: Allison 250-C20B (turboshaft); 0 hours total
The flight
- Departed from: TUS Tucson AZ at 1:00 pm
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 130° at 10 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 131°F (55°C), dew point 77°F (25°C)
- Altimeter: 30.00 inHg
- Observation at 1:55 pm from TUS, 23 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
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.