Cessna 172RG accident near Hayward, California, January 15, 1991
On January 15, 1991 at about 4:56 pm local time, a Cessna 172RG, registered N9721B, was destroyed in an accident near Hayward, California. It was a business flight under general aviation rules (Part 91). 1 person was killed. The weather was instrument conditions (cloud, fog or low visibility).
The NTSB's probable cause their words, unchanged
THE PILOT'S FAILURE TO MAINTAIN ALTITUDE. CONTRIBUTING FACTORS RELATED TO THE PILOT'S IMPROPER VFR PROCEDURES AND HIS MISJUDGED EVALUATION OF THE WEATHER IN DAYLIGHT CONDITIONS. ADDITIONAL FACTORS RELATED TO THE PRESENCE OF LOW CLOUDS AND TO THE RESTRICTED VISIBILITY.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- January 15, 1991 · about 4:56 pm local time
- Place
- Hayward, California · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- instrument conditions (cloud, fog or low visibility)
- Aircraft
- Cessna 172RG · all 172RGs on the register
- Registration
- N9721B · no longer on the register · serial 172RG0991
- Damage
- Destroyed
- Flight
- Business flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE 1700 HOUR INSTRUMENT RATED PILOT WAS FAMILIAR WITH THE ROUTE OF FLIGHT BETWEEN HAYWARD (HWD) AND SAN CARLOS (SQL) HAVING REPORTEDLY FLOWN THE ROUTE TO WORK OVER 100 TIMES. THE PILOT'S SQL DESTINATION DID NOT HAVE A PUBLISHED INSTRUMENT APPROACH. SO, THE PILOT PLANNED TO EXECUTE AN IFR APPROACH TO HWD AND THEN INITIALLY FLY UNDER SVFR TOWARD SQL. APPROACHING SQL THE PILOT PLANNED TO REQUEST A SVFR CLEARANCE INTO ITS CONTROL ZONE. WHILE FLYING ENROUTE THE PILOT WOULD BE OVER OPEN WATER IN UNCONTROLLED AIRSPACE WHERE ONLY ONE MILE OF FLIGHT VISIBILITY WOULD BE REQUIRED. AFTER EXECUTING THE INSTRUMENT APPROACH TO HWD THE PILOT RECEIVED, AS PLANNED, THE REQUESTED CLEARANCE OUT OF ITS CONTROL ZONE. AFTER RECEIVING A SVFR CLEARANCE INTO SQL'S CONTROL ZONE THE PILOT FAILED TO MAINTAIN ALTITUDE AND HE DESCENDED INTO THE SAN FRANCISCO BAY. AT THE TIME THE PILOT WAS IN HWD'S AIRSPACE, ITS WEATHER WAS, IN PART: 200 FOOT OVERCAST CEILING AND ONE MILE VISIBILITY IN FOG.
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: private
- Ratings: single-engine land; instrument: airplane
- Flight time: 1,703 hours in all
- Medical certificate: Class 3 (valid medical--w/ waivers/lim.)
- Seat: unk
The aircraft
- Last inspection: inspection type not recorded, January 2, 2000
- Maximum gross weight: 2,650 lb
- Seats: 4
- Landing gear: retractable
- Engine: Lycoming O-360-F1A6 (piston); 0 hours total
The flight
- Departed from: CCR Concord CA at 4:20 pm
- Destination: SQL San Carlos CA
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 1 statute miles
- Sky: overcast at 200 ft; not recorded
- Temperature: 52°F (11°C), dew point 52°F (11°C)
- Altimeter: 30.00 inHg
- Observation at 4:50 pm from HWD, 6 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.