Gowen Field Airport
Aircraft Accident/Incident Report

Boise, Idaho 83705
Tuesady, May 27, 1997 11:10 MST

NTSB Narrative Summary Released at Completion of Accident

The pilot was executing an autorotation maneuver for a FAR Part 135 flight check. This autorotation maneuver was to be a 180-degree reversal autorotation to a predetermined spot landing with a power termination. The pilot executed the maneuver, but during the level-off received a low RPM warning horn, and attempted to recover using power. During the attempt to increase power the helicopter's throttle interfered with a nut which had been installed for an external torque meter approximately one week before the accident. The nut on the torque meter installation interfered with the throttle controls in certain positions only. A discrepancy with the helicopter's throttle was noticed by the pilot-in-command, and reported to the FAA examiner before the beginning of the flight check.

NTSB Probable Cause Narrative

the improper torque meter installation by maintenance personnel, attempting flight with known discrepancies by the pilot-in-command and the check airman, and an improper autorotation by the pilot-in-command with improper oversight of the autorotation maneuver by the check airman.

Event Information

Type of Event Accident
Event Date 5/27/1997
Event Day of the Week Tuesday
Time of Event 1110
Event Time Zone Mountain Standard Time
Event City BOISE
Event State IDAHO
Event Country --
Zipcode of the event site 83705
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 GOWEN FIELD
Event Location Nearest Airport ID BOI
Indicates whether the acc/inc occurred off or on an airport On Airport
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation 2848
Weather Briefing Completeness Unknown
Investigator's weather source Witness
Time of the weather observation 0
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID
Elevation of weather observation facility 0
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation
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) 40
Air Temperature at event time (in degrees celsius) 21
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 0
Variable Wind Indicator Unknown
Wind Speed (knots) 0
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None 3
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 190
NTSB Notification Source --
NTSB Notification Date May 28 1997 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 8 2000 12:16PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N35CH
NTSB Number CHI97FA149
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Bell
Aircraft Model 206L3
Aircraft Series Identifier 206L3
Aircraft Serial Number 51335
Certified Max Gross Weight 4150
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 7
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Feb 2 1997 12:00AM
Airframe hours since last inspection --
Airframe Hours 3202
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name JEFLYN AVIATION INC.
Aircraft Owner Street Address 4444 AERONCA
Aircraft Owner City BOISE
Aircraft Owner State ID
Aircraft Owner Country
Aircraft Owner Zipcode 83705
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 JL9A
Owner has at least one certificate Yes - certificate holder
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation External Load
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) Unknown
Second Pilot on Board Yes
Departure Point Same as Event Yes
Departure Airport Code BOI
Departure City
Departure State ID
Departure Country
Departure Time 1000
Departure Time Zone MST
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code BOI
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 10:30AM
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 --