Ayres S-2R accident near Williams, California, May 6, 1987
On May 6, 1987 at about 2:15 am local time, a Ayres S-2R, registered N4216X, was substantially damaged in an accident near Williams, California. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this accident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 6, 1987 · about 2:15 am local time
- Place
- Williams, California · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Ayres S-2R
- Registration
- N4216X · no longer on the register · serial 1973R
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
THE PLT REPORTED HE HEARD SOMETHING BREAK. THE SOUND WAS FOLLOWED BY A VIBRATION. THE PLT THEN TURNED TO LAND ON A ROAD. HE WAS UNABLE TO MAINTAIN ALT AND AIRSPEED. THE ROCKWELL S2R LANDED IN A CULTIVATED FIELD AND NOSED OVER AFTER A COLLISION WITH A DIRT BANK. POST ACCIDENT EXAM OF THE PROP HUB ASSEMBLY REVEALED THAT THE COUNTERWEIGHT BEARING SHAFT WAS FRACTURED ON ONE OF THE PROP BLADES. THIS WOULD ALLOW ONE PROP BLADE TO ROTATE AT A DIFFERENT PITCH ANGLE. THE ROCKWELL S2R HAD A TWO BLADED HAMILTON STANDARD 12D40-305 PROP INSTALLED. IT HAD BEEN MODIFIED IN ACCORDANCE WITH STC #SP1408NW WHICH REPLACES THE HAMILTON STANDARD COUNTERWEIGHT BEARINGS WITH MIDWEST AVIATION ROLLERS.
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
- Flight time: 5,165 hours in all; 5,029 in this make and model; 174 in the last 90 days; 55 in the last 30 days; 5,809 as pilot in command
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 6,616 hours
- Last inspection: annual inspection, April 26, 1987; 79 hours since
- Maximum gross weight: 6,000 lb
- Seats: 1
- Landing gear: fixed
- Engine: P&W R-1340-AN-1 (piston); 0 hours total
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 15 statute miles
- Sky: scat at 20,000 ft
- Temperature: 91°F (33°C), dew point 54°F (12°C)
- Altimeter: 29.00 inHg
- Observation at 1:46 am from MVY, 30 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.