NTSB Identification: LAX93LA203.
The docket is stored on NTSB microfiche number 51138.
Accident occurred Wednesday, May 05, 1993 in DAVIS, CA
Probable Cause Approval Date: 02/18/1994
Aircraft: ROBINSON R-22, registration: N80156
Injuries: 2 Uninjured.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

THE PILOT DEPARTED FROM THE CONFINED AREA LANDING ZONE DOWNWIND. DURING THE INITIAL CLIMB THE HELICOPTER LOST TRANSLATIONAL LIFT. THE PILOT ADDED MORE COLLECTIVE AND INCREASED THE THROTTLE TO MAXIMUM RPM, BUT WITHOUT SUCCESS, AND THE ROTOR RPM BEGAN TO DECAY. THE HELICOPTER'S LEFT SKID CONTACTED THE TOMATO BED WHILE MOVING FORWARD AND IN A RIGHT YAWING TURN, AND THE HELICPTER ROLLED OVER. THE R-22 PILOT'S OPERATING HANBOOK STATES 'NEVER MAKE TAKE-OFFS OR LANDINGS DOWNWIND...THE RESULTING LOSS OF TRANSLATIONAL LIFT CAN CAUSE THE AIRCRAFT TO SETTLE INTO GROUND OBSTACLES.' IN ADDITION, THE MANUFACTURER ISSUED SAFETY NOTICE RSN-4 WHICH STATES, IN PART, 'POWER IS DIRECTLY PROPORTIONAL TO RPM. IF YOU RAISE THE COLLECTIVE TO STOP THE SHIP FROM SETTLING, YOU WILL PULL THE RPM DOWN EVEN LOWER AND SETTLE EVEN FASTER.'

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

THE PILOT'S FAILURE TO FOLLOW A SAFETY TIP IN THE PILOT'S OPERATING HANDBOOK TO NEVER MAKE A DOWNWIND TAKEOFF, HIS FAILURE TO MAINTAIN ROTOR RPM, AND HIS IMPROPER USE OF THE HELICOPTER FLIGHT CONTROLS. A FACTOR WHICH CONTRIBUTED TO THE ACCIDENT WAS THE TAILWIND.

Index for May1993 | Index of months