Honeywell MKXXII Category 8 Radio Altitude Input Select, Example Digital Radio Altitude Interface

Honeywell

MK XXII EGPWS Installation Manual

3.3.8 Category 8 – Radio Altitude Input Select

Category 8 defines the Radio Altitude and Decision Height interface.

3.3.8.1 Instructions

1.Using Appendix E Tables E 3, under Step/category 8 select Radio Altitude Type. Using table E 3.1.8 and E 3.1.8-x select ID number for your Radio Altimeter and record that number on Table E 3 under Ident No. for step 8. This number will be used during programming of the configuration module.

2.Appendix E Tables E 3.1.8-x, where x is the Radio Altimeter Type number, define the electrical interfaces required to support each Radio Altimeter. Using Table E 3.1.8-x determine the wiring interconnects and record it on Appendix A Fig A1-1.

3.The Decision Height discrete (J1-33, Category 8) indicates to the MK XXII EGPWC whether the aircraft is above or below the selected Decision Height. This discrete is typically connected to the Decision Height output on the Radio Altimeter indicator. If the ‘Minimums- Minimums’ callout is not wanted the Decision Height discrete should be left open. Using Table E 3.1.8-x determine the wiring interconnects for Decision Height and record it on Appendix A Fig A1-1.

3.3.8.2Example

3.3.8.3Digital Radio Altitude Interface

EGPWS MK XXII		J2
ARINC 429	A	21
Radio Altitude	B	4
		J1
DH Discrete (Gnd)		33

Radio Altimeter R/T

A

BARINC 429

Radio Altimeter Indicator

DH

Vendor Model

R/T	Indicator
Collins RAC-870	ALI-55
Honeywell ALA-52A
Honeywell KRA 405B	KNI-415/416

SCALE

ARINC 429

ARINC 429

ARINC 429

Indicator

DH

P1-V

M

A

P1-2

MP-B2

B

R/T

B

P1-3

MP-B3

C

CAGE CODE: 97896 SCALE: NONE SIZE: A DWG NO: 060-4314-225 REV: C SHEET 84