N/A Airport
Aircraft Accident/Incident Report

Yuba City, California 95991
Saturday, July 9, 2011 14:30 PDT

NTSB Narrative Summary Released at Completion of Accident

The pilot reported that, during the initial climb, he heard a “loud pop” and observed fire coming from both exhaust stacks before the engine lost power. He subsequently made an off-airport landing to an adjacent road. During the landing, the airplane slid into a ditch, the landing gear sheared off, and the airplane nosed over. A postaccident engine examination revealed that the blade retaining ring of the 1st-stage compressor blades had fractured into several pieces; about 30 percent of the ring was not recovered. A metallurgical examination of the recovered sections of the retaining ring revealed that all but two of the fractures were due to ductile overload. An examination of the nonoverload fractures revealed fatigue originating from the rivet hole areas, which was indicative of high-cycle fatigue. The power section had been overhauled 747 hours before the accident. According to the overhaul manual current at the time of the overhaul, the blade retaining ring was an on-condition inspection item and not required to be replaced at overhaul. The fatigue fracture of the 1st-stage compressor blade retaining ring likely affected the engine’s ability to produce power.

NTSB Probable Cause Narrative

High-cycle fatigue on the 1st-stage compressor blade retaining ring, which resulted in the ring’s fracture and a subsequent loss of engine power.

Event Information

Type of Event Accident
Event Date 7/9/2011
Event Day of the Week Saturday
Time of Event 1430
Event Time Zone Pacific Daylight Time
Event City Yuba City
Event State CALIFORNIA
Event Country --
Zipcode of the event site 95991
Event Date Year 2011
Event Date Month 7
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 390406N
Event Location Longitude 1214407W
Event Location Airport N/A
Event Location Nearest Airport ID --
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness --
Investigator's weather source Weather Observation Facility
Time of the weather observation 1453 Pacific Daylight Time
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID KMYV
Elevation of weather observation facility --
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation PDT
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 33
Dew Point at event time (in degress fahrenheit) 16
Wind Direction (degrees magnetic) 190
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 16
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 29.75
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor --
Injury Total None 1
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 32890
NTSB Notification Source FAA AWP Operations Center
NTSB Notification Date --
NTSB Notification Time --
Fiche Number and/or location -used to find docket information --
Date of most recent change to record Jul 8 2014 12:02PM
User who most recently changed record plah
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N7503L
NTSB Number WPR11LA320
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 137: Agricultural
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name SCHWEIZER AIRCRAFT CORP
Aircraft Model G-164B
Aircraft Series Identifier --
Aircraft Serial Number 826B
Certified Max Gross Weight 5200
Aircraft Category Airplane
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 1
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Apr 19 2011 12:00AM
Airframe hours since last inspection 373
Airframe Hours 10282
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name ONSTOTT DUSTERS INC
Aircraft Owner Street Address --
Aircraft Owner City YUBA CITY
Aircraft Owner State CA
Aircraft Owner Country USA
Aircraft Owner Zipcode 95991
Operator is an individual? No
Operator Name ONSTOTT DUSTERS INC
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City YUBA CITY
Operator State CA
Operator Country USA
Operator Zip code 95991
Operator Code --
Owner has at least one certificate Yes - certificate holder
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation --
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Aerial Application
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code --
Departure City Yuba City
Departure State CA
Departure Country USA
Departure Time 1430
Departure Time Zone PDT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code --
Destination City Yuba City
Destination State CA
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jun 16 2014 6:20PM
User who most recently changed record plah
Since inspection or accident Last Inspection
Event Location Runway Number and Location N/A
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --