St. Louis Downtown Parks Airport
Aircraft Accident/Incident Report

Cahokia, Illinois 62206
Saturday, September 19, 1998 13:30 CDT

NTSB Narrative Summary Released at Completion of Accident

A witness watched the helicopter as it climbed out after takeoff. The witness said that the helicopter was higher than the telephone lines which ran northeast of the airport. 'He was level and climbing, going away from me when all of a sudden, the sound (engine sound) went quiet, followed by a pop. It was not a loud pop.' The helicopter began a shallow descent. At about 30 to 40 feet above the field, the helicopter 'leveled out,' but 'kept coming down.' The witness said he saw the helicopter 'hit' and then 'cartwheel.' Examination of the helicopter's engine revealed scoring marks on the power-takeoff cylinder (front cylinder) piston, and impact marks in the head. Small metallic particles were embedded in the piston head. The power-takeoff cylinder wall showed scuff marks, and the cylinder head showed impact marks. The two power-takeoff spark plugs' showed no gap at the electrodes, and impact marks. No other anomalies were revealed.

NTSB Probable Cause Narrative

A loss of engine power due to cold seizure of the power-takeoff cylinder. A factor contributing to the accident was the power lines.

Event Information

Type of Event Accident
Event Date 9/19/1998
Event Day of the Week Saturday
Time of Event 1330
Event Time Zone Central Daylight Time
Event City CAHOKIA
Event State ILLINOIS
Event Country --
Zipcode of the event site 62206
Event Date Year 1998
Event Date Month 9
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport ST. LOUIS DOWNTOWN PARKS
Event Location Nearest Airport ID CPS
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles 1
Degrees magnetic from airport 345
Airport Elevation 413
Weather Briefing Completeness Not pertinent
Investigator's weather source Weather Observation Facility
Time of the weather observation 1253 Central Daylight Time
Direction of event from weather observation facility (degrees) 304
Weather Observation Facility ID STL
Elevation of weather observation facility 605
Distance of event from weather observation facility (units?) 15
Time Zone of the weather observation CDT
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) 28
Dew Point at event time (in degress fahrenheit) 17
Wind Direction (degrees magnetic) 190
Variable Wind Indicator Unknown
Wind Speed (knots) 4
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 29
Density Altitude (feet) 2556
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 1
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 1709
NTSB Notification Source --
NTSB Notification Date Sep 21 1998 12:00AM
NTSB Notification Time 900
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 11 2000 11:45AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N611AB
NTSB Number CHI98FA353
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 Barklage
Aircraft Model REVOLUTION MINI 500
Aircraft Series Identifier REVOLUTION
Aircraft Serial Number 0294
Certified Max Gross Weight 840
Aircraft Category Helicopter
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? Yes
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 1
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Jun 30 1998 12:00AM
Airframe hours since last inspection 21
Airframe Hours 96
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name ALLEN G. BARKLAGE
Aircraft Owner Street Address 1146 CROOKED CREEK DRIVE
Aircraft Owner City ST. CHARLES
Aircraft Owner State MO
Aircraft Owner Country
Aircraft Owner Zipcode 63304
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 CPS
Departure City
Departure State
Departure Country
Departure Time 1323
Departure Time Zone CDT
Destination Same as Local Flt --
Destination Airport Code 3SQ
Destination City ST. CHARLES
Destination State MO
Destination Country
Specific Phase of Flight Climb
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:34AM
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 --