Aircraft Accident/Incident Report

Northampton, Pennsylvania 18013
Tuesady, August 11, 1998 18:32 EDT

NTSB Narrative Summary Released at Completion of Accident

The pilot departed his home in the home-built helicopter on a maintenance test flight. The purpose of the flight was to track the main rotor system after repair and re-assembly of the helicopter. The main transmission, transmission mast, main rotor system, and tailboom and associated components had been replaced following a rollover accident. The pilot changed the blade track by adjustment of the pitch change links during ground runs prior to takeoff. Witnesses to the accident reported unusual sounds from the helicopter before two sharp reports and an uncontrolled descent. One main rotor blade was found 400 feet from the main wreckage. Examination of the wreckage revealed rotor to tailboom contact. Fracture separation of one rotor blade and fracture of the pitch horn on the same side were due to overload. The pitch change link barrel was loose on the fractured horn with no torque applied to the barrel nuts.

NTSB Probable Cause Narrative

the improper maintenance adjustment and the failure to properly torque the pitch-change link barrel by the owner/builder which resulted in main rotor to tailboom contact and main rotor separation.

Event Information

Type of Event Accident
Event Date 8/11/1998
Event Day of the Week Tuesday
Time of Event 1832
Event Time Zone Eastern Daylight Time
Event City NORTHAMPTON
Event State PENNSYLVANIA
Event Country --
Zipcode of the event site 18013
Event Date Year 1998
Event Date Month 8
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
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 Not pertinent
Investigator's weather source Weather Observation Facility
Time of the weather observation 1851 Eastern Daylight Time
Direction of event from weather observation facility (degrees) 210
Weather Observation Facility ID ABE
Elevation of weather observation facility 394
Distance of event from weather observation facility (units?) 15
Time Zone of the weather observation EDT
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 3000
Sky/Lowest/Cloud Conditions Scattered
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) 27
Dew Point at event time (in degress fahrenheit) 17
Wind Direction (degrees magnetic) 270
Variable Wind Indicator Unknown
Wind Speed (knots) 7
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 29
Density Altitude (feet) --
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) 1892
NTSB Notification Source --
NTSB Notification Date Aug 11 1998 12:00AM
NTSB Notification Time 1850
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 11 2000 11:42AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N2XK
NTSB Number IAD98FA092
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 Ground
Aircraft Explosion None
Aircraft Manufacturer's Full Name Austin
Aircraft Model REVOLUTION MINI 500
Aircraft Series Identifier REVOLUTION
Aircraft Serial Number 303
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 Feb 2 1998 12:00AM
Airframe hours since last inspection 35
Airframe Hours 55
ELT Installed Unknown
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name CHARLES J. AUSTIN
Aircraft Owner Street Address 535 INSTITUTE DRIVE
Aircraft Owner City BANGOR
Aircraft Owner State PA
Aircraft Owner Country
Aircraft Owner Zipcode 18013
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 NONE
Departure City BANGOR
Departure State PA
Departure Country
Departure Time 1800
Departure Time Zone EDT
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 Maneuvering
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 0
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --