DADE Aircraft Communication Systems 2 — Questions and Answers
Question 1: Which SELCAL code format is used to alert a specific aircraft on HF or VHF radio?
- A two-letter prefix followed by a four-digit number
- A four-letter code using characters A through S (excluding I, N, O) (Correct answer)
- A six-character alphanumeric string assigned by ICAO
- A three-digit octal code broadcast on 121.5 MHz
Correct answer: A four-letter code using characters A through S (excluding I, N, O)
SELCAL codes consist of four letters chosen from A through S, excluding I, N, and O, to uniquely identify an aircraft.
Question 2: When an aircraft loses all radio communication in VFR conditions, the pilot should squawk transponder code:
- 7500
- 7600 (Correct answer)
- 7700
- 7000
Correct answer: 7600
Squawk 7600 indicates loss of communications (NORDO); 7500 is hijacking and 7700 is emergency.
Question 3: A dispatcher notices ATIS information 'Kilo' is current. What does this indicate?
- The airport is operating under IFR minimums
- The ATIS broadcast has been updated 11 times since midnight
- The current ATIS identifier is the 11th sequential letter of the alphabet (Correct answer)
- Wind shear advisories are in effect
Correct answer: The current ATIS identifier is the 11th sequential letter of the alphabet
ATIS identifiers cycle through the phonetic alphabet; 'Kilo' is the 11th letter, indicating the 11th update.
Question 4: What is the primary purpose of ACARS (Aircraft Communications Addressing and Reporting System)?
- To provide ATC with real-time radar coverage of oceanic tracks
- To relay digital data messages between aircraft and ground stations (Correct answer)
- To broadcast weather observations from aircraft to NWS automatically
- To encrypt voice communications between cockpit and dispatch
Correct answer: To relay digital data messages between aircraft and ground stations
ACARS is a digital datalink system used to exchange pre-formatted and free-text messages between aircraft and ground operations or ATC.
Question 5: Under FAR Part 121, the dispatcher must be able to communicate with the aircraft at all times during flight. What system is required for extended overwater operations beyond VHF range?
- TCAS II with Mode S transponder
- HF radio or an approved satellite communication system (Correct answer)
- ELT operating on 406 MHz
- DME/VOR with RNAV capability
Correct answer: HF radio or an approved satellite communication system
FAR 121.99 requires HF radio or satellite communication for flights beyond the range of VHF ground stations.
Question 6: Which frequency is designated as the international aeronautical emergency frequency?
- 121.5 MHz (Correct answer)
- 123.45 MHz
- 156.8 MHz
- 406.0 MHz
Correct answer: 121.5 MHz
121.5 MHz is the international VHF emergency and guard frequency monitored by ATC and military facilities.
Question 7: A flight crew reports they are unable to contact dispatch via ACARS. As dispatcher, what is your FIRST action?
- Declare an emergency with ATC on behalf of the flight
- Attempt contact via an alternate means such as HF radio, SATCOM, or relay through ATC (Correct answer)
- File a NASA ASRS report immediately
- Notify the FAA FSDO of the communication failure
Correct answer: Attempt contact via an alternate means such as HF radio, SATCOM, or relay through ATC
The dispatcher should attempt contact through any available alternate communication path before escalating to emergency procedures.
DADE Aircraft Communication Systems 2
Which SELCAL code format is used to alert a specific aircraft on HF or VHF radio?