Status:	Final
Date:	09 MAY 1985
Time:	08:44
Type:	Consolidated PBY-5A Catalina
Operator:	Drilling Muds
Registration:	N84857
C/n / msn:	1522
First flight:
Total airframe hrs:	1481
Engines:	2 Pratt & Whitney R-1830-94
Crew:	Fatalities: 1 / Occupants: 2
Passengers:	Fatalities: 0 / Occupants: 1
Total:	Fatalities: 1 / Occupants: 3
Airplane damage:	Substantial
Airplane fate:	Written off (damaged beyond repair)
Location:	Lewistown Municipal Airport, MT (LWT) (United States of America)
Phase:	Standing (STD)
Nature:	Survey/research
Departure airport:	Lewistown Municipal Airport, MT (LWT/KLWT), United States of America
Destination airport:	Reno/Tahoe International Airport, NV (RNO/KRNO), United States of America

Narrative:
During taxi to takeoff the brakes failed. The pilot attempted to groundloop the aircraft, which rolled down hill and collided with a gully. During preflight the co-pilot inadvertently added hydraulic fluid in the alcohol tank. The hydraulic pump cavitated.

PROBABLE CAUSE:
aircraft preflight..inadequate..pilot in command
hydraulic system..pressure too low
brakes(emergency)..not used..pilot in command
aircraft service..improper..copilot/second pilot
safety system(other)..not engaged
emergency procedure..not followed..pilot in command
supervision..poor..pilot in command
CONTRIBUTING FACTORS:
fluid,hydraulic..inadequate
acft/equip inadequate,visual restriction..copilot/second pilot
hydraulic system,reservoir..low level
window,inspection/observation..blocked(partial)
crew/group coordination..poor..pilot in command
anti-ice/deice system,propeller..unmarked

Events:

Sources:
» NTSB