Aircraft Accident/Incident Report

Granby, New York 13069
Thursday, May 29, 1997 9:20 EDT

NTSB Narrative Summary Released at Completion of Accident

The pilot/owner had completed an uneventful aerial application flight, and he began to reposition the helicopter to another site. En route, at 500 feet AGL, the helicopter's engine began to overspeed. The pilot entered autorotation, and the helicopter struck trees and landed hard. Examination revealed the elastomeric torsional coupling inside the transmission, and the secondary steel drive flanges were sheared. The manufacturer's service data for the coupling stated that mandatory replacement of the coupling should occur at 5,000 hours or 5 years from the date embossed on the rubber, or in accordance with maintenance requirements for the coupling, which ever occurred first. The raised numbers on the coupling indicated a date of May 1988, 9 years before the accident.

NTSB Probable Cause Narrative

failure of the pilot/owner to replace the torsional clutch as specified by the manufacturer, and subsequent failure of the helicopter's clutch, which resulted in a forced landing (autorotation). A related factor was: the encounter with trees in the emergency landing area.

Event Information

Type of Event Accident
Event Date 5/29/1997
Event Day of the Week Thursday
Time of Event 920
Event Time Zone Eastern Daylight Time
Event City GRANBY
Event State NEW YORK
Event Country --
Zipcode of the event site 13069
Event Date Year 1997
Event Date Month 5
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 Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 950 Eastern Daylight Time
Direction of event from weather observation facility (degrees) 320
Weather Observation Facility ID SYR
Elevation of weather observation facility 421
Distance of event from weather observation facility (units?) 19
Time Zone of the weather observation EDT
Lighting Conditions Day
Lowest Ceiling Height 25000
Lowest Non-Ceiling Height 18000
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling Broken
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) 20
Dew Point at event time (in degress fahrenheit) 10
Wind Direction (degrees magnetic) 0
Variable Wind Indicator Variable
Wind Speed (knots) 0
Wind Velocity Indicator Light and Variable
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Serious
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None --
Injury Total Serious 1
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 1467
NTSB Notification Source --
NTSB Notification Date May 29 1997 12:00AM
NTSB Notification Time 1100
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 8 2000 12:17PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N4029S
NTSB Number NYC97LA101
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 137: Agricultural
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Hiller
Aircraft Model UH-12E
Aircraft Series Identifier UH-12E
Aircraft Serial Number 5129
Certified Max Gross Weight 3100
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 1
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection May 13 1997 12:00AM
Airframe hours since last inspection 2
Airframe Hours 6440
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name HELICAIR AG INC.
Aircraft Owner Street Address PO BOX 3139
Aircraft Owner City SALINAS
Aircraft Owner State CA
Aircraft Owner Country
Aircraft Owner Zipcode 93912
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 Yes - certificate holder
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Agriculture
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Unknown
Indicates Domestic or International Flight Unknown
Operator carrying Pax/Cargo/Mail Unknown
Type of Flying (Per_Bus / Primary) Positioning
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code NONE
Departure City FULTON
Departure State NY
Departure Country
Departure Time 815
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 Emergency landing
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 --