Aircraft Accident/Incident Report

Jefferson, Maryland 21755
Tuesady, September 25, 1990 10:35 EDT

NTSB Narrative Summary Released at Completion of Accident

ACCORDING TO WITNESSES THE ACFT CAME APART IN THE AIR. RADAR DATA SHOWS THE ACFT AT 2600 FT WHEN IT TURNED ABOUT 35 DEGREES RIGHT IN ABOUT 4 SECONDS. THE ACFT SUSTAINED GENERAL DISINTEGATION. EXAMINATION REVEALED THAT THE SPLINES OF THE TAIL ROTOR SPLINED DRIVE SLEEVE WERE EXCESSIVELY WORN, RENDERING LOSS OF TRANSMISSION OF TORQUE TO THE TAIL ROTOR. TWO OTHER HU-269 ACFT HAD SIMILIAR WEAR OF THE SPLINED SLEEVE. 300-HR INSPECTION REQUIRES THAT THE UPPER PULLEY ASSEMBLY BE REMOVED AND INSPECTED, AND BEARINGS LUBRICATED. SCHWEIZER ACFT CORP HAD ISSUED SERVICE BULLETIN N-219 A MONTH BEFORE THE ACCIDENT WHICH REQUIRED RETORQUING OF THE SPLINE RETAINING NUT. HOWEVER, THE ACFT WAS WITHIN THE REQUIRED COMPLIANCE TIME, AND THE BULLETIN WAS NOT DONE.

NTSB Probable Cause Narrative

THE FAILURE OF THE TAIL ROTOR DRIVE TRANSMISSION SYSTEM DUE TO A WORN TAIL ROTOR SPLINED DRIVE SLEEVE, AND INADEQUATE MAINTENANCE AND/OR INSPECTION BY THE OPERATOR. CONTRIBUTING TO THE LOSS OF CONTROL WAS THE STUDENT PILOT'S FAILURE TO MAINTAIN ADEQUATE ROTOR RPM DUE TO INEXPERIENCE.

Event Information

Type of Event Accident
Event Date 9/25/1990
Event Day of the Week Tuesday
Time of Event 1035
Event Time Zone Eastern Daylight Time
Event City JEFFERSON
Event State MARYLAND
Event Country --
Zipcode of the event site 21755
Event Date Year 1990
Event Date Month 9
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 0
Degrees magnetic from airport 0
Airport Elevation 0
Weather Briefing Completeness Not pertinent
Investigator's weather source Weather Observation Facility
Time of the weather observation 95 Eastern Daylight Time
Direction of event from weather observation facility (degrees) 195
Weather Observation Facility ID IAD
Elevation of weather observation facility 313
Distance of event from weather observation facility (units?) 27
Time Zone of the weather observation EDT
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 12000
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) 15
Air Temperature at event time (in degrees celsius) 19
Dew Point at event time (in degress fahrenheit) 11
Wind Direction (degrees magnetic) 190
Variable Wind Indicator Unknown
Wind Speed (knots) 10
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 29.8
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) 2311
NTSB Notification Source --
NTSB Notification Date Sep 25 1990 12:00AM
NTSB Notification Time 1035
Fiche Number and/or location -used to find docket information 45535
Date of most recent change to record Dec 18 2002 11:38AM
User who most recently changed record NTSB\GIUV
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N1094D
NTSB Number BFO90FA079
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 Ground
Aircraft Manufacturer's Full Name HUGHES
Aircraft Model 269C
Aircraft Series Identifier 269C
Aircraft Serial Number 600935
Certified Max Gross Weight 2050
Aircraft Category Helicopter
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 2
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection --
Airframe hours since last inspection 0
Airframe Hours --
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name WHITE OX ENTERPRISE INC.
Aircraft Owner Street Address ROUTE 1 BOX 248
Aircraft Owner City STRASBURG
Aircraft Owner State VA
Aircraft Owner Country
Aircraft Owner Zipcode 22657
Operator is an individual? --
Operator Name NEW HORIZON AVIATION, INC.
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address P.O. BOX 466
Operator City ROUND HILL
Operator State VA
Operator Country
Operator Zip code 22141
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) Instructional
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code W16
Departure City WINCHESTER
Departure State VA
Departure Country
Departure Time 1000
Departure Time Zone EDT
Destination Same as Local Flt --
Destination Airport Code FDK
Destination City FREDERICK
Destination State MD
Destination Country
Specific Phase of Flight Cruise
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:35AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 0
Runway Length 0
Runway Width 0
Sight Seeing flight No
Air Medical Flight No
Medical Flight --