Aircraft Accident/Incident Report

Nezperce, Idaho 83543
Monday, April 5, 2004 8:00 PDT

NTSB Narrative Summary Released at Completion of Accident

While en route to apply dry fertilizer to a field, the aircraft's engine popped and then experienced a significant loss of power. Because there was not sufficient power to keep the aircraft airborne, the pilot elected to execute a forced landing in a nearby field. He therefore started dumping his load of fertilizer, and attempted to set the aircraft down on the soft terrain. Although the touchdown was successful, soon thereafter the main gear sank into the soft terrain, and the right main gear leg folded aft. As the gear leg collapsed, the nose and right wing of the aircraft impacted the terrain. A post-accident inspection of the engine revealed that the head of the number seven cylinder had fractured circumferentially just above the location where the head screws into the cylinder barrel. Although the head had not separated from the barrel, the fracture was far enough around the barrel that it created a misalignment of the cylinder geometry to an extent that the intake valve would not close. There was no indication of detonation or any other anomaly that would have been expected to apply greater than normal loads to the cylinder structure.

NTSB Probable Cause Narrative

The circumferential fracture of the number seven cylinder head while en route to an aerial fertilizer application, leading to a forced landing on soft terrain, resulting in the collapse of the right main gear leg. Factors include soft terrain at the location where the pilot found it necessary to attempt the forced landing.

Event Information

Type of Event Accident
Event Date 4/5/2004
Event Day of the Week Monday
Time of Event 800
Event Time Zone Pacific Daylight Time
Event City Nezperce
Event State IDAHO
Event Country --
Zipcode of the event site 83543
Event Date Year 2004
Event Date Month 4
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 461422N
Event Location Longitude 1161426W
Event Location Airport --
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 Pilot
Time of the weather observation
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID --
Elevation of weather observation facility --
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation --
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) 10
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) --
Variable Wind Indicator Variable
Wind Speed (knots) --
Wind Velocity Indicator Light and Variable
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) --
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) 15803
NTSB Notification Source FAA Operations Center
NTSB Notification Date Apr 5 2004 12:00AM
NTSB Notification Time 915
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Jun 30 2004 12:15PM
User who most recently changed record NTSB\MONR
Basic weather conditions Visual Meteorological Cond
FAA District Office Spokane FSDO

Aircraft Involved

Aircraft #1

Aircraft Registration Number N48564
NTSB Number SEA04LA065
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 137: Agricultural
Type of Flight Plan filed None
Flight plan Was Activated? No
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Grumman
Aircraft Model G-164
Aircraft Series Identifier --
Aircraft Serial Number 1675
Certified Max Gross Weight 4500
Aircraft Category Airplane
Aircraft Registration Class U.S. Registered/U.S. Soil
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 Mar 30 2004 12:00AM
Airframe hours since last inspection 33
Airframe Hours 7525
ELT Installed No
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name Kenneth J. Kuther
Aircraft Owner Street Address --
Aircraft Owner City Nezperce
Aircraft Owner State ID
Aircraft Owner Country USA
Aircraft Owner Zipcode 83543
Operator is an individual? No
Operator Name --
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City --
Operator State --
Operator Country --
Operator Zip code --
Operator Code --
Owner has at least one certificate --
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation Agriculture
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 No
Departure Airport Code 0S5
Departure City Nezperce
Departure State ID
Departure Country USA
Departure Time 810
Departure Time Zone PDT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code 0S5
Destination City --
Destination State --
Destination Country --
Specific Phase of Flight Maneuvering - aerial application
Report sent to ICAO? No
Evacuation occurred No
Date of most recent change to record May 5 2004 11:41AM
User who most recently changed record STAM
Since inspection or accident Time of Accident
Event Location Runway Number and Location --
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --