Aircraft Accident/Incident Report

Parkman, Wyoming 82838
Tuesady, June 1, 1999 11:00 MDT

NTSB Narrative Summary Released at Completion of Accident

An hour after landing in an open field (6,200 feet msl) near Parkman, Wyoming, in the Bighorn National Forest, the pilot performed a practice takeoff without his passenger to test the aircraft's performance. The helicopter hovered normally after effective translational lift was achieved, and he climbed out at 40 knots. Shortly after clearing a 75-foot ridge 100 to 150 yards from the takeoff field just after coming out of ground effect, the aircraft experienced a downdraft and subsequently began to lose altitude. The power required for the helicopter to climb was greater than the power available. The aircraft impacted the ground through 60 to 80 feet of trees, and came to rest in an inverted position. According to the pilot, there were no mechanical problems and the engine was running on impact. Density altitude at the time of the accident was calculated to be 7,578 feet. According to calculated weight and performance data, the gross weight of the aircraft at the time of departure was approximately 1,232 lbs. At an indicated airspeed of 35 knots, the maximum obstacle clearance height was calculated to be 75 feet, with a maximum distance of 800 feet.

NTSB Probable Cause Narrative

The pilot's inadequate in-flight planning by exceeding the helicopter's performance climb capability. Factors were the downdraft encountered during initial climb following takeoff, and the high density altitude.

Event Information

Type of Event Accident
Event Date 6/1/1999
Event Day of the Week Tuesday
Time of Event 1100
Event Time Zone Mountain Daylight Time
Event City PARKMAN
Event State WYOMING
Event Country --
Zipcode of the event site 82838
Event Date Year 1999
Event Date Month 6
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 6200
Weather Briefing Completeness Unknown
Investigator's weather source Pilot
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 5000
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) 13
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 45
Variable Wind Indicator Unknown
Wind Speed (knots) 5
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 15
Altimeter Setting at event time (in. Hg) 29
Density Altitude (feet) 7578
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Minor
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor 1
Injury Total None --
Injury Total Serious --
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 182
NTSB Notification Source --
NTSB Notification Date Jun 2 1999 12:00AM
NTSB Notification Time 1500
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 12 2000 11:38AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N7052L
NTSB Number DEN99LA092
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 Hughes
Aircraft Model 269A
Aircraft Series Identifier 269A
Aircraft Serial Number 980962
Certified Max Gross Weight 1670
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 --
Airframe Hours --
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name KENT W. POTTER
Aircraft Owner Street Address 801 2ND AVE.
Aircraft Owner City LAUREL
Aircraft Owner State MT
Aircraft Owner Country
Aircraft Owner Zipcode 59044
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 Yes
Departure Airport Code NONE
Departure City
Departure State
Departure Country
Departure Time 1055
Departure Time Zone MDT
Destination Same as Local Flt --
Destination Airport Code 6S8
Destination City LAUREL
Destination State MT
Destination Country
Specific Phase of Flight Takeoff
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 --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --