Mode A & C Flashcards
The military developed an identification system known as?
IFF or Identification Friend or Foe
How is this identification process accomplished?
The use of airborne transponders and ground based interrogation systems
What happens during this identification process?
The transponder is interrogated by the ground station and the transponder replies with the code
When an aircraft can be located and identified, it can then be?
Separated from other aircraft in the ATC environment
What does RADAR stand for?
Radio Detection and Ranging
What determines the distance to the target?
The amount of time to the target and back
What does PSR stand for and which radar does it operate on?
Primary Surveillance Radar
Operates on the normal radar
What does SSR stand for and what does it operate on?
Secondary Surveillance Radar
Operates on a coded reply from the airborne transponder
The SSR interrogates the transponder in one or two modes:
Mode A for identification
Mode C for altitude reporting
What gives ATC the location (horizontal and vertical) and identification of aircraft under their control?
ATCRBS
Who are the reply codes set by?
The pilot
What is it called when aircraft’s are communicating?
Sqwak calls
What modes does a transponder use to respond?
Mode A and C
How is altitude information supplied to the transponder?
By an altitude digitizer
If the ground controller has requested the pilot to send the special IDENT function with the replies, the aircraft will be displayed as:
A double arc and a bloom
The peak power transmitted from the transponder is ______ and extends the useful distance of the SSR to approximately _______.
300 Watts
200 Miles
How is the altitude information sent to the transponder?
Through a wiring harness interface
The altitude information is provided by the altimeter itself and not what?
Not a special altitude transducer
The codes the encoder uses to relay the binary digitized altitude information are called what?
Grey Codes
The type of interrogation is determined by what?
The spacing between two pulses (P1&P3) transmitted by the SSR on a carrier of 1030 MHz +_ 0.2
What is the spacing for Mode A P1 and P3?
8 microS +_ 0.2
What is the spacing for Mode C P1 & P3?
21 microS +_ 0.2
Also contains third pulse (P2)
What pulse does P2 transmit?
2 microS +_ 0.15
What is the purpose of the P2 pulse?
Allows the airborne transponder to determine whether the interrogation came from the main beam or a side lobe of the SSR
What happens if the transponder has been interrogated by side lobe?
No reply is generated
If P1 is larger than P2 the interrogation is:
A valid main beam interrogation
If P2 is equal to or larger than P1 the interrogation is:
From a side lobe of the SSR
The transponder replies to both the Mode A and C interrogations with:
A coded pulse group a carrier of 1090 MHz +_ 3
The transponder is required certification every:
24 Calendar Months
What text provides the testing standards, certification, and equipment to perform the test?
FAR part 43 appendix F
Testing of Mode A will:
Test the validity of the entered aircraft code
Testing of Mode C will:
Validate the correct altitude reporting
Testing of the pitot-static system is required under:
FAR part 91.411
Appendix E
The binary system used for this octal notation and this identification number consists of:
four digits (O through 7), which gives the transponder the capability of 4096 different identification numbers
How many pulses can the coding of a Mode A reply consist of?
fifteen
12 of the 15 pulses for the coding of a Mode A reply carry what?
The identification number
The two other pulses from the fifteen are called?
Framing pulses
One placed at the beginning of the 12 and one at the end of the 12
What is the last pulse of the 15?
A special pulse identification to aid the radar operator
Mode C uses how many data bits to encode the aircraft altitude?
10
What is pressure altitude transmitted at?
29.92 Hg and is corrected at the ground station
What does the Cavity Oscillator do?
Employs a triode vacuum tube to generate the necessary RF Power
What does the Altitude Alert System do?
Signals an alert when the altitude displayed to the flight crew deviates from the selected altitude
What text should you consult about Altimetry System Error Containment?
FAA Appendix G Part 91
What version of TCAS II must all aircraft have after March 2002?
Version 7.0 or later
Authority for an operator to conduct flight airspace where RVSM is,
is issued in:
Operations specifications, a letter of authorization, or management specifications
Some things that can affect transponder performance:
Corrosion
Bad coax
Actual poor performance from the transponder
