Robinson R22-BETA accident near Phoenix, Arizona, April 20, 1991
On April 20, 1991 at about 11:20 pm local time, a Robinson R22-BETA (helicopter), registered N4066J, was substantially damaged in an accident near Phoenix, Arizona. It was an instructional flight under general aviation rules (Part 91). 1 person was seriously injured and 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE PILOT'S FAILURE TO MAINTAIN MAIN ROTOR RPM. FACTOR CONTRIBUTING TO THE ACCIDENT WAS THE PILOT'S INADEQUATE IN-FLIGHT PLANNING.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 20, 1991 · about 11:20 pm local time
- Place
- Phoenix, Arizona · map
- Type
- Accident
- Injuries
- 1 person was seriously injured and 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Robinson R22-BETA · all R22-BETAs on the register
- Registration
- N4066J · no longer on the register · serial 1506
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE INSTRUCTOR PILOT ENTERED AN AUTOROTATION WHILE IN CRUISE FLIGHT AT AN ALTITUDE OF 500 FEET ABOVE THE GROUND AND AT AN AIRSPEED OF 60 KNOTS. THE MAIN ROTOR TACHOMETER DECREASED BELOW ITS MINIMAL RANGE FOR FLIGHT WHEN THE HELICOPTER ENTERED THE AUTOROTATION. THE INSTRUCTOR PILOT CONTINUED THE AUTOROTATIVE DESCENT UNTIL PASSING 150 FEET ABOVE GROUND LEVEL BEFORE INITIATING A POWER RECOVERY. THE MAIN ROTOR RPM DID NOT INCREASE AND THE AIRCRAFT COLLIDED WITH GROUND.
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: single-engine land; instructor: helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 2,261 hours in all; 1,750 in this make and model; 233 in the last 90 days; 84 in the last 30 days; 2,115 as pilot in command; 1,669 on instruments
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Last inspection: inspection type not recorded, January 2, 2000
- Maximum gross weight: 1,370 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O-320-B2C (piston); 0 hours total
- Operator: Avcon, INC.
The flight
- Flight plan: none
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 260° at 10 knots
- Visibility: 40 statute miles
- Sky: clear
- Temperature: 84°F (29°C), dew point 34°F (1°C)
- Altimeter: 29.00 inHg
- Observation at 9:49 pm from DVT, 4 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | 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.