Accident Sikorsky H-19/S55 N9894, Monday 18 March 1991

You can contribute by submitting additional or updated information.

Date:	Monday 18 March 1991
Time:	17:30 LT
Type:	Sikorsky H-19/S55
Owner/operator:	Avag, Inc.
Registration:	N9894
MSN:	55998
Engine model:	WRIGHT R-1300
Fatalities:	Fatalities: 0 / Occupants: 1
Other fatalities:	0
Aircraft damage:	Substantial
Category:	Accident
Location:	Richvale, CA - United States of America
Phase:	Manoeuvring (airshow, firefighting, ag.ops.)
Nature:	Agricultural
Departure airport:
Destination airport:
Investigating agency:	NTSB
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
THE PILOT STATED THAT HE WAS DISPENSING HIS 20TH LOAD OF INSECT SPRAY OVER ALMOND TREES. DURING A SWATH RUN THE ENGINE LOST POWER AND THE HELICOPTER IMPACTED THE TREES AND THEN THE GROUND. THE ENGINE'S NUMBER 4 CYLINDER INTAKE VALVE KEEPER FAILED.

Probable Cause: THE FAILURE OF THE ENGINE'S NUMBER 4 CYLINDER INTAKE VALVE KEEPER. TREES UNDER THE HELICOPTER AT THE TIME OF THE LOSS OF ENGINE POWER WERE FACTORS IN THE ACCIDENT.

Accident investigation: