Systems For Communication

Question 1

What other means of communication are available to ATCOs? (5)

Answer 1

• Direct Controller to Controller Communication (Talking)
• Normal Telephone Communication
• Interphone (via Controllers Headset)
• Intercom system.
• Mobile telephones.

Question 2

What is ATOTN?

Answer 2

Air Traffic Operational Telephone Network

This is a telephone network

Question 3

What is AFS?

Answer 3

Aeronautical Fixed Service
A telecommunication service between specified fixed points (Unit to Unit) provided primarily for the safety of ANS.

Question 4

What is the disadvantage of ATOTN?

Answer 4

An airport may only have one line, so only one
ATCO can use it at any time, or have one line per
position (I.e. TWR, RAD)

Question 5

What is SELCAL?

Answer 5

Selective Calling

SELCAL is a signalling method (Audio Tones) which can alert an individual aircraft that a ground station wishes to communicate with it.

Question 6

What frequency is SELCAL transmitted over?

Answer 6

HF
VHF

Question 7

How do we know the code for SELCAL contact?

Answer 7

FPL - Other Info

Question 8

What should pilots do before flight with SELCAL?

Answer 8

Pre flight SELCAL check

Question 9

What are ATC sequence of actions if SELCAL calls are unanswered?

Answer 9

After two calls on the primary frequency and two calls on the secondary frequency, the ATCO should revert to voice calling.

Question 10

If SELCAL is unserviceable what should the pilots do?

Answer 10

The aircraft should maintain a continuous listening watch on its subsequent flight until SELCAL again becomes available.