Key Topic 72: Aircraft Antenna Systems and Frequencies

Question 1

3-72K1: What type of antenna pattern is radiated from a ground station phased-array directional antenna when transmitting the PPM pulses in a Mode S interrogation signal of an aircraft’s Traffic alert and Collision Avoidance System (TCAS) installation?

A. 1090 MHz directional pattern.
B. 1030 MHz omnidirectional pattern.
C. 1090 MHz omnidirectional pattern.
D. 1030 MHz directional pattern.

Answer 1

D. 1030 MHz directional pattern.

Question 2

3-72K2: What type of antenna is used in an aircraft’s Instrument Landing System (ILS) marker beacon installation?

A. An electronically steerable phased-array antenna that radiates a directional antenna pattern.
B. A folded dipole reception antenna.
C. A balanced loop reception antenna.
D. A horizontally polarized antenna that radiates an omnidirectional antenna pattern.

Answer 2

C. A balanced loop reception antenna.

Question 3

3-72K3: What is the frequency range of an aircraft’s Very High Frequency (VHF) communications?

A. 118.000 MHz to 136.975 MHz (worldwide up to 151.975 MHz).
B. 108.00 MHz to 117.95 MHz.
C. 329.15 MHz to 335.00 MHz.
D. 2.000 MHz to 29.999 MHz.

Answer 3

A. 118.000 MHz to 136.975 MHz (worldwide up to 151.975 MHz).

Question 4

3-72K4: Aircraft Emergency Locator Transmitters (ELT) operate on what frequencies?

A. 121.5 MHz.
B. 243 MHz.
C. 121.5 and 243 MHz.
D. 121.5, 243, and 406 MHz.

Answer 4

D. 121.5, 243, and 406 MHz.

Question 5

3-72K5: What is the frequency range of an aircraft’s radio altimeter?

A. 962 MHz to 1213 MHz.
B. 329.15 MHz to 335.00 MHz.
C. 4250 MHz to 4350 MHz.
D. 108.00 MHz to 117.95 MHz.

Answer 5

C. 4250 MHz to 4350 MHz.

Question 6

3-72K6: What type of antenna is attached to an aircraft’s Mode C transponder installation and used to receive 1030 MHz interrogation signals from the Air Traffic Control RADAR Beacon System (ATCRBS)?

A. An electronically steerable phased-array directional antenna.
B. An L-band monopole blade-type omnidirectional antenna.
C. A folded dipole reception antenna.
D. An internally mounted, mechanically rotatable loop antenna.

Answer 6

B. An L-band monopole blade-type omnidirectional antenna.