Aircraft Accident/Incident Report

Scottsdale, Arizona 85260
Tuesady, December 28, 1993 11:20 MST

NTSB Narrative Summary Released at Completion of Accident

PRIOR TO THE ACCIDENT FLIGHT, THE HELICOPTER WAS EXAMINED BY THE FAA AND ISSUED AN EXPERIMENTAL AIRWORTHINESS CERTIFICATE. THE AIRCRAFT THEN DEPARTED ON A FERRY FLIGHT OF TWO HELICOPTERS TO RETURN TO THE HELICOPTER COMPANY BUILDING. AFTER DEPARTURE, THE SECOND AIRCRAFT OBSERVED AN OBJECT GO THROUGH THE ROTOR SYSTEM OF THE ACCIDENT HELICOPTER. THE PILOT BEGAN A PRECAUTIONARY LANDING AND, SUBSEQUENTLY, EXPERIENCED AN ANTI-TORQUE SYSTEM FAILURE. AFTER TOUCHDOWN, A POSTCRASH FIRE CONSUMED 2/3 OF THE AIRCRAFT. ONE TAIL ROTOR BLADE HAD BEEN STRUCK BY A FIBERGLASS COWLING PANEL THAT WAS LATER LOCATED ALONG THE FLIGHT PATH.

NTSB Probable Cause Narrative

A failure of the pilot-in-command to adequately conduct a preflight inspection and properly secure a fuselage cowling panel that struck a tail rotor blade, resulting in a subsequent failure of the tail rotor drive system. Factors in this accident were an in-flight separation of the cowling panel, and the inability of the pilot to effect directional control of the helicopter.

Event Information

Type of Event Accident
Event Date 12/28/1993
Event Day of the Week Tuesday
Time of Event 1120
Event Time Zone Mountain Standard Time
Event City SCOTTSDALE
Event State ARIZONA
Event Country --
Zipcode of the event site 85260
Event Date Year 1993
Event Date Month 12
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 1130 Mountain Standard Time
Direction of event from weather observation facility (degrees) 270
Weather Observation Facility ID SDL
Elevation of weather observation facility 1508
Distance of event from weather observation facility (units?) 6
Time Zone of the weather observation MST
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) 45
Air Temperature at event time (in degrees celsius) 16
Dew Point at event time (in degress fahrenheit) 2
Wind Direction (degrees magnetic) 190
Variable Wind Indicator Unknown
Wind Speed (knots) 4
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) --
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) 1769
NTSB Notification Source --
NTSB Notification Date Dec 28 1993 12:00AM
NTSB Notification Time 1042
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 11 2000 1:48PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N7456T
NTSB Number LAX94LA083
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 Ground
Aircraft Explosion None
Aircraft Manufacturer's Full Name ROTORWAY
Aircraft Model EXEC-90
Aircraft Series Identifier EXEC-90
Aircraft Serial Number RI5001
Certified Max Gross Weight 1425
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 Continuous Airworthiness
Date of Last Inspection Dec 27 1993 12:00AM
Airframe hours since last inspection 1
Airframe Hours 612
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name COBB INTERNATIONAL
Aircraft Owner Street Address 4141 W. CHANDLER BLVD.
Aircraft Owner City CHANDLER
Aircraft Owner State AZ
Aircraft Owner Country
Aircraft Owner Zipcode 85226
Operator is an individual? --
Operator Name COBB INTERNATIONAL
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 4141 W. CHANDLER BLVD.
Operator City CHANDLER
Operator State AZ
Operator Country
Operator Zip code 85226
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) Ferry
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code
Departure City
Departure State
Departure Country
Departure Time 1115
Departure Time Zone MST
Destination Same as Local Flt --
Destination Airport Code P19
Destination City CHANDLER
Destination State AZ
Destination Country
Specific Phase of Flight Cruise
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 --