Aircraft Accident/Incident Report

Thermal, California 92501
Tuesady, May 28, 1996 7:11 PDT

NTSB Narrative Summary Released at Completion of Accident

The flight was part of an engineering test flight series to complete the Part 27 certification for a new rotorcraft. The specific test point was part of a flight strain survey and involved cyclic control reversals. The pilot had set the parameters and executed the cyclic control inputs as planned. Almost simultaneous with the aft movement of the cyclic there was a loud noise and immediate vibrations in the aircraft and the controls. A pilot in the chase aircraft informed the pilot that a main rotor blade had struck and severed the tail boom. A power off autorotation was accomplished without the tail rotor system. The resultant hard landing was onto a pile of dry brush which was ignited by the hot engine exhaust. The brush fire destroyed the aircraft.

NTSB Probable Cause Narrative

inadequate design of the stress limits for cyclic control of the helicopter.

Event Information

Type of Event Accident
Event Date 5/28/1996
Event Day of the Week Tuesday
Time of Event 711
Event Time Zone Pacific Daylight Time
Event City THERMAL
Event State CALIFORNIA
Event Country --
Zipcode of the event site 92501
Event Date Year 1996
Event Date Month 5
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 Not pertinent
Investigator's weather source Weather Observation Facility
Time of the weather observation 652 Pacific Daylight Time
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID TRM
Elevation of weather observation facility 117
Distance of event from weather observation facility (units?) 4
Time Zone of the weather observation PDT
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) 20
Air Temperature at event time (in degrees celsius) 20
Dew Point at event time (in degress fahrenheit) 11
Wind Direction (degrees magnetic) 320
Variable Wind Indicator Unknown
Wind Speed (knots) 7
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 29
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) 303
NTSB Notification Source --
NTSB Notification Date May 28 1996 12:00AM
NTSB Notification Time 815
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 8 2000 10:00AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N600RN
NTSB Number LAX96LA207
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 McDonnell Douglas
Aircraft Model MD-600
Aircraft Series Identifier MD-600
Aircraft Serial Number RN001
Certified Max Gross Weight 4100
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 Annual
Date of Last Inspection Dec 15 1995 12:00AM
Airframe hours since last inspection 39
Airframe Hours 39
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name MCDONNELL DOUGLAS HELICOPTER
Aircraft Owner Street Address 5000 EAST MCDOWELL RD.
Aircraft Owner City MESA
Aircraft Owner State AZ
Aircraft Owner Country
Aircraft Owner Zipcode 85215
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) Unknown
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code TRM
Departure City
Departure State CA
Departure Country
Departure Time 640
Departure Time Zone PDT
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 Maneuvering
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 --