INLET BARRIER FILTER SYSTEM - Donaldson Company, Inc.

Aerospace Filtration Systems, Inc.
AFS-BH206B-IBF-KIT-ICA, Revision Initial Release Proprietary Information
a. Gain access to the top side of the Bypass Floor Assembly (Refer to paragraph 4-3.1).
b. Connect a Barfield (or equivalent) altimeter test set vacuum system to the plenum tube assembly
(Appendix A, Figure A-9, Item 3), by slipping a piece of 3/16 inch ID vinyl tubing over the end of
the tube assembly. Ensure that the fit between the tubing and tube assembly is tight, i.e., no
leakage.
c. Ensuring that aircraft electrical power is ON, operate the test set to an indicated altitude above the
field elevation and gradually increase altitude. The differential pressure switch should actuate and
send a signal to the Cockpit Indicator illuminating the “IBF FILTER” light within the following
range:
d. If the Cockpit Indicator does not illuminate, pull IBF circuit breaker. Run the altimeter test set up
to top of the range, check for continuity across the terminals of the Differential Pressure Switch. If
continuity is present, the Differential Pressure Switch function is acceptable and the rest of the
circuit is suspect. Upon completion of testing, ensure that aircraft electrical power is OFF. Refer to
Table 8-2.
e. This will functionally check both the differential pressure switch and the “IBF FILTER” Cockpit
Indicator.
8-5.3.6. INSTALLATION
Test Station Elevation (ft)
Test Method 0 1000 2000 3000 4000 5000
Altimeter Test Set
(ft above test station elevation)
410 ±40 ft 420 ±40 ft 440 ±40 ft 450 ±40 ft 460 ±40 ft 480 ±50 ft
Test Station Elevation (ft)
Test Method 6000 7000 8000 9000 10000
Altimeter Test Set
(ft above test station elevation)
490 ±50 ft 510 ±50 ft 520 ±50 ft 540 ±50 ft 560 ±60 ft
a. Gain access to the area below the Bypass Floor Assembly (Refer to paragraph 4-3.2)
b. Properly orient the Differential Pressure Switch (Refer to Appendix A, Figures A-5, Item 27) in
the Clamp (Refer to Appendix A, Figures A-5, Item 27) below the Floor.
c. Attach hoses, fittings, and attaching hardware (Refer to Appendix A, Figures A-5).
d. Connect and secure connector (See Appendix A, Figures A-12, Item 6).
e. Perform Function Check of Differential Pressure Switch (Refer to paragraph 8-5.3.5).
Use or disclosure of this material is subject 8-27 AFS Bell 206B IBF Instructions for Continued Airworthiness
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