Identification and Avoidance Systems Flashcards
What bus powers the IFF when the switch is at NORM?
The 28V DC ESB
State the locations of the upper and lower IFF antennae.
Upper: On top of the nose cone.
Lower: Below the jet pipe.
State the operation and function of the Crypto switch.
When held in the zero position for more than 2 seconds, the following are erased:
Modes 1, 3A and 4 codes.
Crypto material.
Explain the difference between the Single and Twin options of the rear cockpit IFF codes switch (inc. what happens during ejection as a result).
Single: Emergency mode set, CPI activates and IFF codes and crypto erased if front cockpit ejection seat operates.
Twin: These things only happen if both ejection seats operate.
How many digits does IFF mode 1 have?
2
What is the purpose of IFF mode C, and how does it work?
Uses data from the PDMC to provide an encoded pressure altitude (based off of 1013.25hPa).
Which of the following codes can you change in flight?
Mode 1
Mode 2
Mode 3(A)
Mode 1: Yes
Mode 2: No (set by engineers on ground)
Mode 3(A): Yes.
State how to squawk ident using the DEP and HUD scratchpad only (i.e. not using the CNI/ IFF formats).
Press IFF on the DEP.
With a flashing cursor on Opticator 2 (i.e. next to the 4 digit code), press mode.
State the maximum horizontal and vertical closure rates that TCAS is designed to protect against.
Horizontal: 1200kts
Vertical: 10,000fpm.
Within what time range must both the vertical and horizontal tau values fall in order for TCAS II to generate an RA?
15-35 seconds depending on the sensitivity level (altitude dependant).
State the order of priority of TCAS classifications (ascending), and how they are displayed on the TCAS display.
Other - Blue/ cyan open (unfilled) diamond.
Proximate - Blue/ cyan filled diamond.
Intruder - Yellow circle.
Threat - Red square.
What are the criteria required to activate a Threat on TCAS?
Range and vertical Taus both less than 15-35 seconds (depending on sensitivity level).
What are the criteria required to activate an Intruder on TCAS?
Range and vertical Taus both less than 20-48 seconds (depending on sensitivity level).
What are the criteria required to activate a Proximate on TCAS?
Contact within 6nm and 1200ft, but does not meet threat or intruder criteria.
What are the criteria required to activate an Other on TCAS?
Contact outside 6nm or 1200ft and does not meet the threat or intruder criteria.
How far above and below the aircraft does TCAS look for contacts?
+-12,700ft.
What horizontal range does TCAS interrogate other transponders out to?
Nominally 30nm.
Within what horizontal range will TCAS II start tracking contacts for possible RA actions?
14nm.
Will RAs be generated for contacts not transmitting height information?
No.
What speeds do the TCAS VSI markers represent?
500fpm 1000fpm 2000fpm 4000fpm 6000fpm
How are TCAS contacts without azimuth information displayed?
As text.
For a first time RA, what reaction time is factored into the RA?
How much G will it expect you to use to satisfy RA?
What about in response to a subsequent RA that is activated before you are clear of the initial contact?
5 seconds.
- 75g or 1.25g
- 5 seconds and 1+-1/3rd G.
What TCAS modes will be turned on if the 3A/C text is boxed on the IFF format?
3A
C
S
What is the vertical collision space (i.e. ALIM) range that TCAS II intends to protect?
+-300-700ft, depending on SL.
What should you transmit to ATC if you have to respond to a TCAS RA?
“[Callsign], TCAS RA”
What should you transmit to ATC once clear of a TCAS RA contact?
“[Callsign], Clear of Conflict, returning to FL…”
Below what height are TCAS RAs not available?
1000ft (RadAlt)
