Warrenton-Fauquier Airport
Aircraft Accident/Incident Report

Midland, Virginia 22728
Sunday, November 29, 1998 15:15 EST

NTSB Narrative Summary Released at Completion of Accident

The pilot/owner was flying his amateur-built helicopter and crashed in a wooded area. Examination of the helicopter revealed that the non-certificated 2-cycle engine had experienced a power loss due to a 'cold seizure.' About 18 Hobbs meter hours prior to the accident the pilot had replaced pistons, rings, wrist pins, rod bearings, thermostat and head O-rings. Metallurgical examination of the PTO cylinder walls revealed deposits from the side (piston skirt) of the accident PTO piston and a previous PTO piston, indicative of a prior cold seizure event. Although the kit helicopter was built according to plans, the engine manufacturer did not recommend several of the engine modifications found on the accident helicopter. Additionally, the engine manufacturer did not recommend the installation of this model engine in the helicopter and published the following warning with the engine manual: 'This engine, by its design is subject to sudden stoppage. Engine stoppage can result in crash landings, forced landings or no power landings. Such crash landings can lead to serious bodily injury or death.'

NTSB Probable Cause Narrative

the improper repair of the engine following a previous engine seizure which resulted in the loss of engine power over unsuitable terrain.

Event Information

Type of Event Accident
Event Date 11/29/1998
Event Day of the Week Sunday
Time of Event 1515
Event Time Zone Eastern Standard Time
Event City MIDLAND
Event State VIRGINIA
Event Country --
Zipcode of the event site 22728
Event Date Year 1998
Event Date Month 11
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport WARRENTON-FAUQUIER
Event Location Nearest Airport ID W66
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles 1
Degrees magnetic from airport 10
Airport Elevation 325
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1500 Eastern Standard Time
Direction of event from weather observation facility (degrees) 28
Weather Observation Facility ID IAD
Elevation of weather observation facility 313
Distance of event from weather observation facility (units?) 42
Time Zone of the weather observation EST
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 22
Dew Point at event time (in degress fahrenheit) 2
Wind Direction (degrees magnetic) 190
Variable Wind Indicator Unknown
Wind Speed (knots) 5
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) 725
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Fatal
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal 1
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 11219
NTSB Notification Source --
NTSB Notification Date Dec 3 1998 12:00AM
NTSB Notification Time 1530
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 18 2001 1:05PM
User who most recently changed record NTSB\MONR
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N500GH
NTSB Number IAD99FA023
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Destroyed
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Armbruster
Aircraft Model MINI-500
Aircraft Series Identifier MINI-500
Aircraft Serial Number 0076
Certified Max Gross Weight 840
Aircraft Category Helicopter
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? Yes
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 Nov 11 1997 12:00AM
Airframe hours since last inspection 75
Airframe Hours 218
ELT Installed Unknown
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name GILBERT B. ARMBRUSTER
Aircraft Owner Street Address 1101 S. ARLINGTON RIDGE ROAD
Aircraft Owner City ARLINGTON
Aircraft Owner State VA
Aircraft Owner Country
Aircraft Owner Zipcode 22202
Operator is an individual? --
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 None
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Unknown
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) Personal
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code HEF
Departure City MANASSAS
Departure State VA
Departure Country
Departure Time 0
Departure Time Zone
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code
Destination City
Destination State
Destination Country
Specific Phase of Flight Cruise
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:34AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 14
Runway Length 4100
Runway Width 60
Sight Seeing flight No
Air Medical Flight No
Medical Flight --