Section Ill. TECHNICAL PRINCIPLES OF OPERATION
Hydraulic fluid, taken from the test stand reservoir or the aircraft reservoir, is forced under pressure by
the test stand high pressure pump (directly driven by the gasoline engine), first through a relief valve,
check valve, high pressure filter and a two way selector valve to the supply port on the test stand and
then to the aircraft being tested through one of the external hoses provided.
The fluid is then returned to the test stand. Complete instrumentation is provided on the control panel
to indicate test stand engine rpm, oil pressure and alternator output, plumbing system pressure, return
flow gpm, hydraulic fluid temperature, hydraulic fluid reservoir level and fuel level.
Hose assemblies are furnished with the test stand to connect the stand to the aircraft. The hoses are stored on
two hooks, located on the front of the test stand.