Aircraft Accident/Incident Report

Culpeper, Virginia 20110
Friday, March 25, 2011 12:38 EDT

NTSB Narrative Summary Released at Completion of Accident

The aerial application flight had departed and was enroute to apply agricultural product to a nearby field; the engine rpm increased uncommanded and the pilot performed a forced landing in an open field. The pilot reported that after the helicopter came to rest, he exited and put his hand on the transmission, which was hot. He then felt the transmission cooler, which he stated was similar in temperature to the surrounding air temperature. Seven days before the accident, a continued airworthiness inspection was performed on the helicopter; the main transmission gearbox oil was drained, and the main rotor transmission was removed to facilitate engine removal. Particulate matter may have been inadvertently left in or around the main rotor transmission during its removal. During the flight the particulate matter may have become lodged in one of the journals inside the transmission and caused its failure, which then allowed the engine to overspeed and the helicopter to lose lift. However, the investigation was not able to conclusively determine the cause of the failure because the transmission could not be secured for a teardown.

NTSB Probable Cause Narrative

Mechanical failure of the transmission for reasons that could not be determined because the transmission could not be torn down.

Event Information

Type of Event Accident
Event Date 3/25/2011
Event Day of the Week Friday
Time of Event 1238
Event Time Zone Eastern Daylight Time
Event City Culpeper
Event State VIRGINIA
Event Country --
Zipcode of the event site 20110
Event Date Year 2011
Event Date Month 3
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 382826N
Event Location Longitude 0774701W
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 Weather Observation Facility
Time of the weather observation 1220 Eastern Daylight Time
Direction of event from weather observation facility (degrees) 302
Weather Observation Facility ID CJR
Elevation of weather observation facility 316
Distance of event from weather observation facility (units?) 5
Time Zone of the weather observation EDT
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) 8
Dew Point at event time (in degress fahrenheit) -2
Wind Direction (degrees magnetic) 240
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 5
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 30.02
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) 30364
NTSB Notification Source FAA Eastern ROC
NTSB Notification Date --
NTSB Notification Time --
Fiche Number and/or location -used to find docket information --
Date of most recent change to record Jul 17 2012 4:40PM
User who most recently changed record gots
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N4033P
NTSB Number ERA11LA216
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 HILLER
Aircraft Model UH-12E
Aircraft Series Identifier --
Aircraft Serial Number 5178
Certified Max Gross Weight 2800
Aircraft Category Helicopter
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 4
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Mar 18 2011 12:00AM
Airframe hours since last inspection 2
Airframe Hours 3340
ELT Installed No
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name KRITTER CROPDUSTING, INC
Aircraft Owner Street Address --
Aircraft Owner City CULPEPER
Aircraft Owner State VA
Aircraft Owner Country USA
Aircraft Owner Zipcode 22701
Operator is an individual? No
Operator Name KRITTER CROPDUSTING, INC
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City CULPEPER
Operator State VA
Operator Country USA
Operator Zip code 22701
Operator Code UKRG
Owner has at least one certificate Yes - certificate holder
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Agriculture
Operator Certificate Number UKRG465U
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 --
Departure City Culpeper
Departure State VA
Departure Country USA
Departure Time 1215
Departure Time Zone EDT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code --
Destination City Culpeper
Destination State VA
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jul 17 2012 4:39PM
User who most recently changed record gots
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 --