Boulder Municipal Airport
Aircraft Accident/Incident Report

Boulder, Colorado 80301
Saturday, May 18, 1991 10:50 MDT

NTSB Narrative Summary Released at Completion of Accident

THE REAR SEAT PASSENGER SAID THE INSTRUCTOR LET THE FRONT SEAT PASSENGER MAKE THE TAKEOFF AND 'TALKED' HIM THROUGH THE PROCEDURE. SHORTLY AFTER LIFT OFF, BOTH PASSENGERS HEARD A 'WARNING BUZZER' SOUND THAT CONTINUED UNTIL GROUND IMPACT. THE INSTRUCTOR WAS SERIOUSLY INJURED AND COULD NOT RECALL ANY DETAILS OF THE ACCIDENT.

NTSB Probable Cause Narrative

INADVERTENT STALL/MUSH DUE TO THE PASSENGERS'S DELAY IN RELINQUISHING AIRCRAFT CONTROL, AND INADEQUATE SUPERVISION OF THE FLIGHT BY THE PILOT IN COMMAND. FACTORS WERE: MIXTURE NOT LEANED, AND A HIGH DENSITY ALTITUDE TAKEOFF WITH A SLIGHT QUARTERING TAILWIND.

Event Information

Type of Event Accident
Event Date 5/18/1991
Event Day of the Week Saturday
Time of Event 1050
Event Time Zone Mountain Daylight Time
Event City BOULDER
Event State COLORADO
Event Country --
Zipcode of the event site 80301
Event Date Year 1991
Event Date Month 5
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport BOULDER MUNICIPAL
Event Location Nearest Airport ID IV5
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles 3
Degrees magnetic from airport 290
Airport Elevation 5288
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 1200
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling Broken
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 25
Air Temperature at event time (in degrees celsius) 17
Dew Point at event time (in degress fahrenheit) 7
Wind Direction (degrees magnetic) 130
Variable Wind Indicator Unknown
Wind Speed (knots) 7
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) 6980
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 1
Injury Total None --
Injury Total Serious 2
Injury Total All 3
Investigating Agency NTSB
NTSB Docket Number (internal use) 1701
NTSB Notification Source --
NTSB Notification Date --
NTSB Notification Time 0
Fiche Number and/or location -used to find docket information 45578
Date of most recent change to record Dec 12 2000 9:59AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N6AL
NTSB Number DEN91FA072
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 BEECH
Aircraft Model C23
Aircraft Series Identifier C23
Aircraft Serial Number M-1421
Certified Max Gross Weight 2450
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 Annual
Date of Last Inspection Mar 7 1991 12:00AM
Airframe hours since last inspection 68
Airframe Hours 2756
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name DAKOTA RIDGE AVIATION, INC.
Aircraft Owner Street Address 3300 AIRPORT RD., BOX S
Aircraft Owner City BOULDER
Aircraft Owner State CO
Aircraft Owner Country
Aircraft Owner Zipcode 80301
Operator is an individual? --
Operator Name DAKOTA RIDGE AVIATION, INC.
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address
Operator City
Operator State
Operator Country
Operator Zip code
Operator Code DROV
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) Business
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code
Departure City
Departure State
Departure Country
Departure Time 1050
Departure Time Zone MDT
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 Landing
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 26
Runway Length 4100
Runway Width 75
Sight Seeing flight No
Air Medical Flight No
Medical Flight --