Hughes OH-6A accident near Laredo, Texas, December 27, 1998
On December 27, 1998 at about 5:58 pm local time, a Hughes OH-6A (helicopter), registered N6638R, was substantially damaged in an accident near Laredo, Texas. 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
The loss of engine power as result of the failure of the power turbine governor. A factor was the lack of suitable terrain available to the pilot for the forced landing.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- December 27, 1998 · about 5:58 pm local time
- Place
- Laredo, Texas · 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
- N6638R · no longer on the register · serial 67-16198
- Damage
- Substantial damage
- Flight
- Public-use flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The engine decelerated and the pilot heard the sound of the engine out audio and observed the red engine out warning light illuminated. When the pilot lowered the collective to enter an autorotation, the engine and rotor RPM increased. The pilot then rolled the throttle off to regain control of the engine RPM. During touchdown, the helicopter landed hard, and the main rotor blades contacted the tailboom. A test run of the engine in a test cell revealed that the engine RPM was not controllable above flight idle, and the engine had a tendency to overspeed and overtemp when the power was advanced. The engine power turbine governor was removed and replaced with an operational unit. The engine operated within normal operational parameters after the governor was replaced. Examination concluded that the failure of the governor's drive shaft bearings resulted in excessive radial and axial play of the drive shaft, which led to a reduced fuel flow to the engine.
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: commercial pilot
- Ratings: single-engine land; instrument: airplane; rotorcraft: helicopter
- Flight time: 2,741 hours in all; 285 in this make and model; 186 in the last 90 days; 35 in the last 30 days; 2,720 as pilot in command
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 6,377 hours
- Last inspection: approved inspection programme, December 26, 1998; 2 hours since
- Maximum gross weight: 2,550 lb
- Seats: 4
- Landing gear: fixed
- Engine: Allison T63-A-720 (turboshaft); 0 hours total
The flight
- Departed from: LRD at 4:30 pm
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
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.