Honeywell International Inc. 9PGTPL-100A Manuale Utente

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1 Mar 2006
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MAINTENANCE MANUAL
TPL-100A Processor / Part No. 940-0530-001
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Hybrid surveillance modifications permit the MILACAS-FR system to do its 
surveillance mission without causing an increase in the signal environment. 
MILACAS-FR uses hybrid surveillance with the 1090-MHz extended squitter to 
minimize the impact on the TCAS signal environment. Currently hybrid surveillance is 
not supplied in the MILACAS-FR system for TCAS 1030-MHz surveillance.
(3) Interoperability with ATC Ground Radar and Other TCAS II Systems
In coordination with the Federal Aviation Administration (FAA), the air traffic control 
(ATC) ON/OFF function was developed to stop ground controllers from receiving 
proximity alarms between formation members within US airspace. When ATC OFF is 
selected, MILACAS-FR aircraft do not respond to ground based Mode 3/A, Mode C, or 
Mode S (UF4 and UF11) interrogations. The system continues to respond to 
airborne-based Mode S interrogations. This gives full TCAS traffic avoidance 
functionality. 
When ATC ON is selected, Mode 3/A and Mode C are de-selected independently of 
the ATC ON/OFF function. All of these features and functions can be selected by the 
aircrew. The functions used are selected at the discretion of the ground controller. 
Normally, in formation, all aircraft (except lead), fly with ATC OFF selected. In large 
formations (four or more), the trail aircraft can fly with ATC ON selected. This allows 
ATC to find the location of the lead and trailing formation aircraft to make sure other 
aircraft do not fly through the formation.  
A MILACAS-FR Processor-equipped aircraft’s answer to ATC ground radar and other 
TCAS II systems is a function of the operational mode of the Identification Friend or 
Foe (IFF) transponder. 
The IFF transponder can stop its replies to ground interrogators while it maintains its 
data-link with airborne equipment (ATC OFF mode). Modes 1, 2, 3/A, C, and 4 are 
individually disabled. Table 1 shows a summary of the answers by the IFF transponder 
to each interrogation format.
Table 1.   MILACAS-FR ATC Interoperability
Interrogation
Reply
IFF Transponder Mode
Mode / UF
ATC On
ATC Off
1
Replies with Mode 1 identity
Replies with Mode 1 identity
2
Replies with Mode 2 identity
Replies with Mode 2 identity
3/A
Replies with Mode 3/A identity
No Reply
C
Replies with Mode C altitude
No Reply
4
Replies with Mode 4 IFF
Replies with Mode 4 IFF
UF0
Replies with DF0/DF16
Replies with DF0/DF16