Aircraft Accident/Incident Report

Sheridan, Wyoming 82801
Wednesday, September 6, 2000 14:40 MDT

NTSB Narrative Summary Released at Completion of Accident

The pre-departure weather briefing received by the pilot called for occasional moderate turbulence below Flight Level 180. The captain stated that while descending at Flight Level 260, the airplane encountered unforecasted turbulence. One passenger was thrown "about the cabin" and sustained a broken ankle while returning to his seat after securing the galley at the pilot's request.

NTSB Probable Cause Narrative

the pilot's inadvertent flight into unforecasted turbulent weather conditions. A contributing factor was the turbulence.

Event Information

Type of Event Accident
Event Date 9/6/2000
Event Day of the Week Wednesday
Time of Event 1440
Event Time Zone Mountain Daylight Time
Event City SHERIDAN
Event State WYOMING
Event Country --
Zipcode of the event site 82801
Event Date Year 2000
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 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 1456 Mountain Daylight Time
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID SHR
Elevation of weather observation facility 4024
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation MDT
Lighting Conditions Day
Lowest Ceiling Height 6000
Lowest Non-Ceiling Height 1900
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling Overcast
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) 54
Dew Point at event time (in degress fahrenheit) 46
Wind Direction (degrees magnetic) 290
Variable Wind Indicator Unknown
Wind Speed (knots) 15
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) 4411
Intensity of Precipitation Light
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 11
Injury Total Serious 1
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 10492
NTSB Notification Source OPERATOR
NTSB Notification Date Sep 8 2000 12:00AM
NTSB Notification Time 1031
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Sep 19 2001 10:36AM
User who most recently changed record NTSB\MONR
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N1625
NTSB Number DEN00LA165
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed IFR
Flight plan Was Activated? --
Damage None
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Gulfstream
Aircraft Model G-IV
Aircraft Series Identifier G-IV
Aircraft Serial Number 1358
Certified Max Gross Weight 75000
Aircraft Category Airplane
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 14
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Sep 1 2000 12:00AM
Airframe hours since last inspection 36
Airframe Hours 390
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name TEXACO INC.
Aircraft Owner Street Address 176A AIRPORT RD
Aircraft Owner City WHITE PLAINS
Aircraft Owner State NY
Aircraft Owner Country
Aircraft Owner Zipcode 10604
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 Yes
Departure Point Same as Event No
Departure Airport Code HPN
Departure City WHITE PLAINS
Departure State NY
Departure Country
Departure Time 1300
Departure Time Zone EDT
Destination Same as Local Flt crash at destination city
Destination Airport Code SHR
Destination City
Destination State
Destination Country
Specific Phase of Flight Descent
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Aug 24 2001 4:00AM
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 --