Navigation Systems & Radar Operations Flashcards

Which transponder code must a pilot squawk when experiencing radio communication failure in VMC?

Answer: 7600

Code 7600 is the internationally designated squawk for radio communication failure (NORDO).

What is the primary purpose of Secondary Surveillance Radar (SSR) Mode C?

Answer: Pressure altitude encoding

Mode C encodes the aircraft's pressure altitude from the encoding altimeter and transmits it to ATC radar.

A controller loses radar identification on an aircraft. What is the FIRST action the controller should take?

Answer: Advise the pilot and request a squawk ident

The controller must advise the pilot of the loss of radar identification and request re-identification procedures such as ident or a heading change.

In radar operations, what does 'painting' an aircraft target refer to?

Answer: The radar antenna beam illuminating the aircraft to produce a return

Painting refers to the primary radar antenna beam striking the aircraft and producing a radar return or blip on the display.

What is the maximum distance from an NDB at which a controller can expect reliable ADF reception for en-route operations?

Answer: 75 NM

En-route NDBs are typically reliable up to approximately 75 NM during daytime hours under normal conditions.

A pilot reports a VOR indication of 270 radial. From which direction relative to the VOR station is the aircraft located?

Answer: Due west of the VOR

A radial is measured FROM the station, so the 270 radial extends due west — the aircraft is west of the VOR.

Which radar mode is used exclusively for military IFF (Identification Friend or Foe) and is not used in civil ATC?

Answer: Mode 4

Mode 4 is a classified encrypted IFF mode used exclusively by military aircraft and is not part of civil SSR operations.