# Accident 19980604012339A: Cessna 150M, Livermore, CA, June 4, 1998

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: June 4, 1998, 15:00 local time
- Place: Livermore, CA
- Damage: Substantial damage
- Phase of flight: Fcd/Prec Ldg From Cruise
- Operating rules: General operating rules (Part 91)
- Location: 37.6810° N, 121.7506° W: From the FAA, an estimate near the named town, within about 3 miles
- Nearby events: https://openairdocs.org/map.md?lat=37.6810&lon=-121.7506&mi=10
- Aircraft: N704ZA, a cancelled registration (https://openairdocs.org/deregistered/N704ZA-1998-09-21) (OpenAirDocs)
- Registry model: Cessna 150M (registry code 2071830, https://openairdocs.org/model/cessna-150m) (OpenAirDocs)
- Reported make and model: CESSNA 150M
- Reported engine: CONT O200A
- Fatal injuries: 0
- Pilot flight hours: 1,700 total, 600 in this make and model, 150 in the last 90 days
- NTSB investigation: [NTSB LAX98LA182](https://openairdocs.org/ntsb/LAX98LA182) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19980604012339A

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

LOST RPMS. TRIED FOR HWD BUT LANDED OFF AIRPORT. NOSED OVER. POST IMPACT ENGINE FIRE. THROTTLE DISCONNECTED. (FROM .4) AFTER PERFORMING AIR WORK, THE INSTRUCTOR AND STUDENT WERE RETURNING TO BASE.  THE INSTRUCTOR NOTED A LOSS OF RPM'S FROM 2,300 TO 1,100.  HE TOOK OVER THE ACFT CONTROLS FROM THE STUDENT AND ATTEMPTED TO CORRECT THE PROBLEM.  THE INSTRUCTOR NOTED THAT THE RPM'S REMAINED CONSTANT AT 1,100.  HE CONDUCTED THE EMERGENCY CHECKLIST AND INFORMED THE TOWER OF THE SITUATION.  THE INSTRUCTOR THEN LANDED THE ACFT IN AN OPEN FIELD AND THE ACFT CAME TO REST INVERTED AFTER THE NOSE WHEEL STRUCK A HOLE.  THE ACFT WAS EXAMINED ON-SCENE AND IT WAS NOTED THAT THE BOLT WAS IN PLACE, BUT THAT THE NUT AND COTTER PIN WERE MISSING FROM THE CARBURETOR THROTTLE ATTACHMENT ASSEMBLY.  IT WAS ALSO NOTED THAT THE ACFT HAD FLOWN APPROX. 15 HOURS SINCE THE LAST ANNUAL INSPECTION AND MAINTENANCE HAD BEEN PERFORMED.                                                              (-23) THE PILOT STATED THAT HE AND HIS STUDENT WERE IN CRUISE FLIGHT WHEN THE ENGINE LOST POWER. DESPITE REPEATED ATTEMPTS THE MAXIMUM POWER HE COULD OBTAIN WAS 1100 RPM. AT THIS POWER SETTING HE COULD NOT MAINTAIN ALTITUDE A ND STARTED A DESCENT TO AN EMERGENCY LANDING IN A GRASS FIELD NEAR DUBLIN, CA. FROM THE PILOTS STATEMENT IT APPEARS THAT NORMAL EMERGENCY LANDING PROCEDURES WERE FOLLOWED. (.19) ON JUNE 24, 1998, AT 1500 HOURS PACIFIC DAYLIGHT TIME, A CESSNA 150M, N704ZA, EXPERIENCED A LOSS OF ENGINE POWER AND MADE AN EMERGENCY LANDING IN AN OPEN FIELD 3 MILES WEST OF THE LIVERMORE, CALIFORNIA, AIRPORT. THE AIRCRAFT, OPERATED BY FLYING VIKINGS UNDER 14 CFR PART 91, SUSTAINED SUBSTANTIAL DAMAGE. THE COMMERCIAL RATED FLIGHT INSTRUCTOR PILOT AND STUDENT PILOT, THE SOLE OCCUPANTS, RECEIVED MINOR INJURIES. VISUAL METEOROLOGICAL CONDITIONS EXISTED FOR THE INSTRUCTIONAL FLIGHT AND NO FLIGHT PLAN WAS FILED. IN AN INTERVIEW WITH FEDERAL AVIATION ADMINISTRATION (FAA) INSPECTOR FROM THE OAKLAND, CALIFORNIA, FLIGHT STANDARDS DISTRICT OFFICE, THE PILOT REPORTED THAT THEY WERE IN CRUISE AT 2,500 FEET ABOVE GROUND LEVEL (AGL) WHEN THE ENGINE RPM DROPPED. THEY ATTEMPTED TO LAND AT THE LIVERMORE AIRPORT, BUT MADE AN EMERGENCY LANDING IN AN OPEN FIELD. THE AIRCRAFT CAME TO REST INVERTED. THE ARMY NATIONAL GUARD WAS CONDUCTING MANEUVERS AT THE TIME OF THE ACCIDENT                                                      AND RESCUED THE FLIGHT INSTRUCTOR AND STUDENT PILOT. THEY ALSO EXTINGUISHED A POSTIMPACT ENGINE FIRE.

## The NTSB's investigation of this event (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB LAX98LA182](https://openairdocs.org/ntsb/LAX98LA182), Jun 4, 1998: Cessna 150M (N704ZA), Livermore, CA, substantial damage. Probable cause: The missing nut/cotter pin on the throttle attachment assembly which resulted in the pilot's inability to control engine power, and the hidden obstruction (hole) in the landing area. A factor was the…

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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