Identification SSR

Question 1

Methods of Identification - Mode A

Answer 1

• Observing the pilot’s compliance with the instruction to select a discrete 4 digit code
• Recognising a validated 4 digit code previously assigned to an AC callsign
• Observing an IDENT feature when it has been requested

Question 2

Actions when Mode A is incorrect

Answer 2

• Pilot instructed to reset assigned code
• If discrepancy persists; A0000
• If continues; switch off transponder
  + Corrupt code may be retained provided Mode C verified

Question 3

SSR Mode S - Elementary

Answer 3

• Selective interrogation

- AC ident

Question 4

SSR Mode S - Enhanced

Answer 4

• Selective interrogation
• AC ident
• Selected altitude
• IAS
• GS
• Magnetic heading
• ROC/ROD

Question 5

Methods of Identification - Mode S

Answer 5

• Direct recognition of AC ident provided either
  + AC ident feature matches FPL and displayed in FPS
  + Correlation of AC ident feature with AC callsign used in RTF

Question 6

Action on Loss of Identity and Exception

Answer 6

• A pilot shall be informed whenever ident is lost
• Except when using SSR and overlapping/garbling provided that the controller anticipates ident will be re-established immediately after