Amateur-built III accident near Scottsdale, Arizona, October 27, 1991
On October 27, 1991 at about 4:09 pm local time, a amateur-built III, registered N121ST, was destroyed in an accident near Scottsdale, Arizona. It was a personal flight under general aviation rules (Part 91). 2 people were killed. The weather was instrument conditions (cloud, fog or low visibility).
The NTSB's probable cause their words, unchanged
THE CERTIFIED FLIGHT INSTRUCTORS DECISION TO FLY INTO KNOWN FORECAST WEATHER CONDITIONS SPECIFICALLY PROHIBITED BY THE AIRPLANE'S OWNER'S MANUAL AND DECISION TO ALLOW AN UNQUALIFIED PILOT WITH LIMITED INSTRUMENT FLIGHT EXPERIENCE TO OCCUPY THE LEFT SEAT BEHIND THE FLIGHT INSTRUMENTS WHICH SUBSEQUENTLY RESULTED IN A INFLIGHT LOSS OF CONTROL. CONTRIBUTING TO THE ACCIDENT WAS THE CERTIFIED FLIGHT INSTRUCTOR'S INADEQUATE SUPERVISION OF THE UNQUALIFIED PILOT.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 27, 1991 · about 4:09 pm local time
- Place
- Scottsdale, Arizona · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- instrument conditions (cloud, fog or low visibility)
- Aircraft
- Amateur-built III
- Registration
- N121ST · registry record · serial 3157
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
A GLASAIR III COLLIDED WITH MOUNTAINOUS TERRAIN AFTER AN INFLIGHT ENCOUNTER WITH KNOWN FORECAST ADVERSE WX CONDITIONS. THE AIRPLANE WAS BEING OPERATED UNDER IFR. THE CFI/PIC STATED TO THE CONTROLLER THAT SHE WAS ENCOUNTERING AIRPLANE CONTROL PROBLEMS. THE CONTROLLER HEARD A COMMENT EMANATING FROM THE AIRPALNE ON THE TRACON FREQUENCY STATING 'LOSING CONTROL OF THE AIRCRAFT' BEFORE RADAR AND RADIO CONTACT WAS LOST. RAIN SHOWERS AND LIGHTNING WERE FORECASTED BY THE WX SERVICE BEFORE THE ACCIDENT. A WITNESS AT THE ACCIDENT SITE REPORTED, HIGH WINDS, RAIN SHOWERS AND LIGHTNING AT TIME OF ACCIDENT. THE AIRPLANE WAS NOT CERTIFIED FOR IFR FLIGHT. THE AIRPLANE'S OWNER'S MANUAL PROHIBITED FLIGHT IN CONDITIONS THAT WOULD EXPOSE THE AIRPLANE TO THE POSSIBILITY OF A LIGHTNING STRIKE. THE NONINSTRUMENT RATED SECOND PILOT WAS SEATED IN THE LEFT SEAT IN FRONT OF THE FLIGHT INSTRUMENTS. THE SECOND PILOT HAD NEVER FLOWN ACTUAL INSTRUMENTS AND HAD ONLY FLOWN 4 HOURS OF SIMULATED INSTRUMENT FLIGHT.
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: multi-engine land; single-engine land; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 1,500 hours in all; 1,250 as pilot in command; 1,000 on instruments
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: rgt
The aircraft
- Last inspection: inspection type not recorded, January 2, 2000
- Maximum gross weight: 2,500 lb
- Seats: 2
- Landing gear: retractable
- Engine: Lycoming IO-540-P1A5 (piston); 0 hours total
- Fire on the ground
The flight
- Departed from: FFZ Mesa AZ at 3:52 pm
- Destination: ABQ Alburquerque NM
- Flight plan: VFR then IFR
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 360° at 4 knots
- Visibility: 6 statute miles
- Sky: overcast at 6,000 ft; not recorded
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
- Altimeter: 29.00 inHg
- Observation at 3:46 pm from FFZ, 10 miles away
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.
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.