Canadair CL600-2A12 incident near Twentynine Plms, California, December 6, 1987
On December 6, 1987 at about 9:23 pm local time, a Canadair CL600-2A12, registered N125PS, was involved in an incident near Twentynine Plms, California. It was a personal flight under general aviation rules (Part 91, subpart F). No one was hurt; 2 people were on board or involved. 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 incident. 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
- December 6, 1987 · about 9:23 pm local time
- Place
- Twentynine Plms, California · map
- Type
- Incident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Canadair CL600-2A12 · all CL600-2A12s on the register
- Registration
- N125PS · no longer on the register · serial 3058
- Damage
- Not recorded
- Flight
- Personal flight · general aviation rules (Part 91, subpart F)
The NTSB's narrative final · quoted from the NTSB record
THE WATER FILTER HOUSING LOWER SEAL WAS MIS-INSTALLED WHICH ALLOWED WATER TO SEEP OUT AND RUN DOWN THE HOUSING CASE. OVER TIME THE WATER DROPPED ONTO A LAVATORY DRAIN LINE, FOLLOWED THE LINE TO A LOW POINT & COLLECTED ON THE STAB AUG COMPUTER BOX. THE FLUID ACCUMULATION RESULTED IN CORROSION ON ONE OF THE CIRCUIT BOARDS WITHIN THE COMPUTER BOX CAUSING A POWER IMBALANCE WITHIN THE YAW DAMPER SYSTEM AND A SUBSEQUENT UNCOMMANDED RUDDER SIGNAL. DRG THE CLIMB TO CRUISE TRANSITION A MACH TRIM FAILURE OCCURRED WHICH WOULD HAVE NECESSITATED THE USE OF THE AUTOPILOT FOR SPEEDS IN EXCESS OF 0.7 MACH. OPERATION OF THE AUTOPILOT, HOWEVER, RESULTED IN OPERATION OF THE YAW DAMPER SYSTEM WHICH HAD BEEN DETERMINED TO HAVE BEEN PRODUCING UNCOMMANDED RUDDER INPUTS. AS THE ACFT WAS LEVELLED AT FL330 AND THE AIRSPD WAS ALLOWED TO EXCEED MACH 0.7 THE COPLT ACTIVATED THE AUTOPLT WHICH POWERED THE MALFUNCTIONING DAMPER SYSTEM AND A DUTCH ROLL MANEUVER ENSUED. PIC DISCONNECTED THE AUTOPLT, EXECUTED A DESCENT AND RECOVERY.
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, flight instructor
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 10,510 hours in all; 325 in this make and model; 150 in the last 90 days; 10,195 as pilot in command
- Medical certificate: Class 1 (valid medical--w/ waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 336 hours
- Last inspection: 100-hour inspection, October 29, 1987; 36 hours since
- Maximum gross weight: 43,100 lb
- Seats: 6
- Landing gear: retractable
- Engine: Ge CF34-1A (turbofan); 0 hours total
The flight
- Departed from: SNA Santa Ana CA at 8:30 pm
- Destination: LAS Las Vegas NV
- Flight plan: IFR
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 260° at 65 knots
- Visibility: 100 statute miles
- Sky: clear
- Temperature: 55°F (13°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 |
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.
Other NTSB records under N125PS the same tail number, which may have belonged to a different aircraft at the time
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.