CPC Navigation Systems & Radar Operations 2 — Questions and Answers
Question 1: Which transponder code must a pilot squawk when experiencing radio communication failure in VMC?
- 7500
- 7600 (Correct answer)
- 7700
- 7000
Correct answer: 7600
Code 7600 is the internationally designated squawk for radio communication failure (NORDO).
Question 2: What is the primary purpose of Secondary Surveillance Radar (SSR) Mode C?
- Aircraft identification
- Pressure altitude encoding (Correct answer)
- Ground speed readout
- Heading information
Correct answer: Pressure altitude encoding
Mode C encodes the aircraft's pressure altitude from the encoding altimeter and transmits it to ATC radar.
Question 3: A controller loses radar identification on an aircraft. What is the FIRST action the controller should take?
- Issue a clearance to climb to a higher altitude
- Advise the pilot and request a squawk ident (Correct answer)
- Immediately issue traffic advisories to all nearby aircraft
- Transfer the aircraft to another sector immediately
Correct 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.
Question 4: In radar operations, what does 'painting' an aircraft target refer to?
- Applying a color code to the data block
- The radar antenna beam illuminating the aircraft to produce a return (Correct answer)
- Updating the flight plan with current position
- Annotating the radar display with weather data
Correct 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.
Question 5: What is the maximum distance from an NDB at which a controller can expect reliable ADF reception for en-route operations?
- 25 NM
- 75 NM (Correct answer)
- 200 NM
- 400 NM
Correct answer: 75 NM
En-route NDBs are typically reliable up to approximately 75 NM during daytime hours under normal conditions.
Question 6: A pilot reports a VOR indication of 270 radial. From which direction relative to the VOR station is the aircraft located?
- Due north of the VOR
- Due east of the VOR
- Due south of the VOR
- Due west of the VOR (Correct answer)
Correct 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.
Question 7: Which radar mode is used exclusively for military IFF (Identification Friend or Foe) and is not used in civil ATC?
- Mode A
- Mode C
- Mode S
- Mode 4 (Correct answer)
Correct answer: Mode 4
Mode 4 is a classified encrypted IFF mode used exclusively by military aircraft and is not part of civil SSR operations.
CPC Navigation Systems & Radar Operations 2
Which transponder code must a pilot squawk when experiencing radio communication failure in VMC?