AFS-BH430-IBF-ICA
Aerospace
Filtration Systems, Inc.
Revision: B
Proprietary Information
Use or disclosure of this material is subject
2
AFS Bell 230 and 430 IBF
to the restrictions on the title page
Instructions for Continued Airworthiness
Cockpit switch/indicator
A push button switch, labeled “IBF 1”or “IBF 2”, is used to OPEN
or CLOSE the respective bypass door. This switch is normally
CLOSED and is pressed to the OPEN position only when the cockpit
indicator, an amber caution “FILTER” light in the switch,
illuminates.
The “FILTER” portion of the switch illuminates any time the
differential pressure reaches or exceeds a preset value.
The “BYPASS” portion of the switch illuminates when the bypass
door is completely open.
Differential pressure
Drop in pressure across the filter assembly, which is measured by the
differential pressure switch and the filter maintenance aid.
Delta P switch
Differential pressure switch.
Filter
Barrier type filter media made of multi-layers of cotton gauze
saturated with specially formulated oil that forms a tack barrier that
increases the capture efficiency of the filter.
Filter assembly
Filter media supported by pleated stainless steel screen on both sides
and the filter assembly frame components around the perimeter of
the filter media.
Filter assembly frame
Structure that frames, retains, and seals the outside edges of the filter
media.
Filter downstream side
Clean side of the filter media (i.e. the side of the filter facing engine
inlet).
Filter media
A wet media consisting of multi-layered cotton gauze saturated with
specially formulated oil.
Filter pleats
Stainless steel screen is used to form the pleats and hold the filter
media in place.
Filter upstream side
Dirty side of the filter media (i.e. the side facing into the air stream
on which the dirt collects).
Inches of water
Unit of measure used for the differential pressure measured across
the filter, as measured with a water manometer or similar apparatus.
Oiling
Process used to apply a uniform amount of oil on filter media.
On-condition
Indicates that servicing of the filter is based on a Filter Maintenance
Aid (FMA) indication in the area marked in “RED”, Power
Assurance Check (PAC) results (where a failed PAC is the result of
Summary of Contents for AFS-BH430-IBF-ICA
Page 3: ......