Aircraft Accident/Incident Report

Huntsville, Utah 84319
Saturday, August 8, 1998 16:30 MDT

NTSB Narrative Summary Released at Completion of Accident

The flight instructor and his student were from Fort Worth, Texas, and they were crossing a mountain ridge eastbound at 9,500 feet msl when the flight instructor reported that they 'encountered a serious downdraft.' He immediately began a 180 degree turn and then reversed direction again back eastbound. The flight instructor stated that the 'airplane was descending about 2,500 feet per minute with full power.' The student stated that 'just as we hit some trees, I remember hearing the stall horn.' The forecast wind aloft was approximately 10 knots at 9,000 feet msl. The density altitude for 10,000 feet was calculated to have been 13,061 feet. Using the airplane's manufacturer Climb Performance charts, N54TM had approximately 210 feet per minute climb capability. The degree of bank that the flight instructor utilized for his turns was not documented, but, the book 'Flight Theory For Pilots' states that as the turning bank angle increases, the energy demands to maintain level flight asymptotically increases. The flight instructor reported that he acquired most of his flight training in Colorado Springs, Colorado, before moving to Fort Worth, Texas.

NTSB Probable Cause Narrative

The flight instructor's failure to ensure adequate altitude/clearance with terrain, resulting in an encounter with a downdraft, loss of airspeed, onset of a stall/mush, and collision with high terrain.. Contributing factors were high density altitude, downdrafts, mountainous terrain, and trees.

Event Information

Type of Event Accident
Event Date 8/8/1998
Event Day of the Week Saturday
Time of Event 1630
Event Time Zone Mountain Daylight Time
Event City HUNTSVILLE
Event State UTAH
Event Country --
Zipcode of the event site 84319
Event Date Year 1998
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 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 1653 Mountain Daylight Time
Direction of event from weather observation facility (degrees) 250
Weather Observation Facility ID OGD
Elevation of weather observation facility 4470
Distance of event from weather observation facility (units?) 24
Time Zone of the weather observation MDT
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 15000
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) 33
Dew Point at event time (in degress fahrenheit) 8
Wind Direction (degrees magnetic) 0
Variable Wind Indicator Variable
Wind Speed (knots) 3
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) 11649
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 2
Injury Total All 2
Investigating Agency NTSB
NTSB Docket Number (internal use) 1326
NTSB Notification Source --
NTSB Notification Date Aug 9 1998 12:00AM
NTSB Notification Time 1249
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 11 2000 11:42AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N54TM
NTSB Number FTW98LA352
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 Piper
Aircraft Model PA-28-161
Aircraft Series Identifier PA-28-161
Aircraft Serial Number 28-7816150
Certified Max Gross Weight 2325
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 4
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Unknown
Date of Last Inspection --
Airframe hours since last inspection --
Airframe Hours --
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site Yes
ELT Type --
Aircraft Owner Name JAMES R. GRAY
Aircraft Owner Street Address 9001 S. NORMANDALE ST., A1080
Aircraft Owner City FT. WORTH
Aircraft Owner State TX
Aircraft Owner Country
Aircraft Owner Zipcode 76116
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) Instructional
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code U27
Departure City TREMONTON
Departure State UT
Departure Country
Departure Time 1545
Departure Time Zone MDT
Destination Same as Local Flt --
Destination Airport Code EGE
Destination City EAGLE
Destination State CO
Destination Country
Specific Phase of Flight Cruise
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 --