Sikorsky S55B accident near Richvale, California, February 4, 1992
On February 4, 1992 at about 5:30 pm local time, a Sikorsky S55B (helicopter), registered N1033, was substantially damaged in an accident near Richvale, California (Richvale airport). It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE FAILURE OF THE LATERAL CONTROL ARM IN THE CYCLIC CONTROL SYSTEM.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 4, 1992 · about 5:30 pm local time
- Place
- Richvale, California · Richvale · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Sikorsky S55B · all S55Bs on the register
- Registration
- N1033 · registry record · serial 1328
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
AS THE HELICOPTER WAS BEING REFUELED IN PREPARATION FOR AN AERIAL APPLICATION FLIGHT, THE PILOT WAS IN THE HELICOPTER AND THE MAIN ROTOR BLADES WERE ROTATING AT 'FLIGHT RPM.' ACCORDING TO THE PILOT, THE HELICOPTER SUDDENLY 'JUMPED ABOUT TWO FEET IN THE AIR AND AT THE SAME TIME ROLLED TO THE RIGHT AND MOVED FORWARD.' THE MAIN ROTOR BLADES STRUCK THE FUEL TRUCK AND THE HELICOPTER ROLLED OVER. AN EXAMINATION OF THE HELICOPTER'S STRUCTURE REVEALED THAT THE LATERAL CONTROL ARM COMPONENT IN THE CYCLIC CONTROL SYSTEM HAD FRACTURED AT A TAPER PIN HOLE. THEREAFTER, THE DISCONNECTED CYCLIC CONTROL SYSTEM PERMITTED THE MAIN ROTOR BLADES TO TILT DOWN, AND THE ROLL OVER WAS UNAVOIDABLE. NO PRE-EXISTING DEFECT WAS REPORTED OBSERVED IN THE LATERAL CONTROL ARM WHEN THE HELICOPTER WAS PREVIOUSLY INSPECTED, ABOUT 14 OPERATIONAL HOURS PRIOR TO THE ACCIDENT.
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: airline transport pilot, commercial pilot
- Ratings: single-engine land; rotorcraft: helicopter
- Flight time: 22,020 hours in all; 6,200 in this make and model; 120 in the last 90 days; 50 in the last 30 days; 20,500 as pilot in command
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 5,616 hours
- Last inspection: annual inspection, October 10, 1991; 89 hours since
- Maximum gross weight: 7,500 lb
- Seats: 2
- Landing gear: fixed
- Engine: Curtis Wright R-1300 (piston); 0 hours total
- Operator: Avag Corporation
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 340° at 10 knots, gusting 10
- Visibility: 50 statute miles
- Sky: clear
- Temperature: 57°F (14°C), dew point 0°F (-18°C)
- Altimeter: 30.00 inHg
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.