Aircraft Accident/Incident Report

Custer, South Dakota 57730
Tuesady, August 10, 1999 17:30 MDT

NTSB Narrative Summary Released at Completion of Accident

The helicopter impacted trees and terrain while maneuvering during a sightseeing flight over a national park. The helicopter was in a descending left turn and a high angle of bank with decreasing main rotor rpm. A low rpm warning horn was heard several seconds prior to impact with the trees. An acoustical analysis of a video tape taken by a passenger shows a decrease in the engine gear box and planetary speeds along with a steady state engine speed several seconds prior to the end of the video tape. The end of the video tape recorded the initial impact with the trees. Examination of the engine and airframe revealed no anomalies.

NTSB Probable Cause Narrative

The pilot's failure to maintain adequate altitude/clearance from the trees. Contributing to the accident was the pilot's inadvertent settling with power.

Event Information

Type of Event Accident
Event Date 8/10/1999
Event Day of the Week Tuesday
Time of Event 1730
Event Time Zone Mountain Daylight Time
Event City CUSTER
Event State SOUTH DAKOTA
Event Country --
Zipcode of the event site 57730
Event Date Year 1999
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 Unknown
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 1655 Mountain Standard Time
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID RAP
Elevation of weather observation facility 3162
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation MST
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) 32
Dew Point at event time (in degress fahrenheit) 14
Wind Direction (degrees magnetic) 190
Variable Wind Indicator Unknown
Wind Speed (knots) 15
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
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 2
Injury Total Minor 1
Injury Total None --
Injury Total Serious 2
Injury Total All 5
Investigating Agency NTSB
NTSB Docket Number (internal use) 1628
NTSB Notification Source --
NTSB Notification Date Aug 10 1999 12:00AM
NTSB Notification Time 2256
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Jan 25 2001 8:30AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N67JJ
NTSB Number CHI99FA285
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 Bell
Aircraft Model 206B
Aircraft Series Identifier 206B
Aircraft Serial Number 4062
Certified Max Gross Weight 3200
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 5
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Jul 31 1999 12:00AM
Airframe hours since last inspection 45
Airframe Hours 2721
ELT Installed Unknown
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name INTERSTATE HELICOPTERS
Aircraft Owner Street Address 941 SW 22ND
Aircraft Owner City OKLAHOMA CITY
Aircraft Owner State OK
Aircraft Owner Country
Aircraft Owner Zipcode 73109
Operator is an individual? --
Operator Name RAPID HELICOPTERS INCORPORATED
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 620 W BOULEVARD
Operator City RAPID CITY
Operator State SD
Operator Country
Operator Zip code 57701
Operator Code HFXA
Owner has at least one certificate Yes - certificate holder
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) Unknown
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code
Departure City
Departure State SD
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 Maneuvering
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 25 2001 8:38AM
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 Yes
Air Medical Flight No
Medical Flight --