Aircraft Accident/Incident Report

Chandler, Arizona 85249
Tuesady, February 9, 1993 14:55 MST

NTSB Narrative Summary Released at Completion of Accident

THE HELICOPTER'S ENGINE FAILED WHILE ON THE CROSSWIND LEG. THE SURROUNDING TERRAIN WAS CONGESTED FORCING THE PILOT TO LAND IN AN AREA WHICH WAS DOWNWIND. THE HELICOPTER NOSED DOWN ON LANDING IN THE SOFT TERRAIN. EXAMINATION OF THE ENGINE DISCLOSED THAT AN INTAKE VALVE FAILED AND LODGED IN THE PISTON. METALLURGICAL EXAMINATION REVEALED THAT THE VALVE STEM FAILED IN FATIGUE. THE FATIGUE WAS PRECIPITATED BY THE MANUFACTURER'S IMPROPER QUALITY CONTROL WHICH FAILED TO ASSURE THAT THE VALVE WAS GROUND BEFORE IT WAS PLATED.

NTSB Probable Cause Narrative

THE MANUFACTURER'S INADEQUATE QUALITY CONTROL WHICH RESULTED IN THE FATIGUE OF THE VALVE STEM. THE SOFT TERRAIN CONTRIBUTED TO THIS ACCIDENT.

Event Information

Type of Event Accident
Event Date 2/9/1993
Event Day of the Week Tuesday
Time of Event 1455
Event Time Zone Mountain Standard Time
Event City CHANDLER
Event State ARIZONA
Event Country --
Zipcode of the event site 85249
Event Date Year 1993
Event Date Month 2
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 0
Degrees magnetic from airport 0
Airport Elevation --
Weather Briefing Completeness Unknown
Investigator's weather source Pilot
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 0
Lowest Non-Ceiling Height 1500
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) 35
Air Temperature at event time (in degrees celsius) 16
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 270
Variable Wind Indicator Unknown
Wind Speed (knots) 12
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None 1
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 271
NTSB Notification Source --
NTSB Notification Date Feb 9 1993 12:00AM
NTSB Notification Time 1610
Fiche Number and/or location -used to find docket information 52072
Date of most recent change to record Dec 11 2000 1:09PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N89678
NTSB Number LAX93LA111
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 COBB INTL
Aircraft Model EXEC 90
Aircraft Series Identifier EXEC 90
Aircraft Serial Number R.I. 5026
Certified Max Gross Weight 1425
Aircraft Category Helicopter
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? Unknown
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 Jan 11 1993 12:00AM
Airframe hours since last inspection 20
Airframe Hours 541
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name COBB INTERNATIONAL, INC.
Aircraft Owner Street Address 300 S. 25TH AVENUE
Aircraft Owner City PHOENIX
Aircraft Owner State AZ
Aircraft Owner Country
Aircraft Owner Zipcode 85009
Operator is an individual? --
Operator Name COBB INTERNATIONAL, INC.
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address 300 S. 25TH AVENUE
Operator City PHOENIX
Operator State AZ
Operator Country
Operator Zip code 85009
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) Other Work Use
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code
Departure City
Departure State
Departure Country
Departure Time 1450
Departure Time Zone MST
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 Approach
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 --