Electrical Comms Test 3 | Questions with 100% Correct Answers

Electrical Comms Test 3 | Questions with 100% Correct Answers What are 3 warnings for HF systems? 1. DO NOT OPERATE THE HF SYSTEM WHILE THEAIRPLANE IS REFUELED OR DEFUELED 2. MAKE SURE THAT PERSONNEL STAY A MINIMUM OF 6 FEET AWAY FROM THE VERTICAL STABILIZER WHEN THE HFSYSTEM TRANSMITS 3. Make sure the airplane is not in or near any large metal structures What are the components of HF? - HF control panel - Transceiver - HF coupler - Antenna - Lightning Arrester*some installations (727) Where is the HF antenna located? Integrated into the leading edge of the vertical stab How is the coupler charged? 7 psi Nitrogen Why is the coupler charged with nitrogen? - Prevents Arcing - Corrosion - Provide a uniform cooling medium What frequency is HF? 2 MHz - 30 MHz How many HF channels are there? 28,000 What are the lengths of HF waves? 2 MHz = Wavelength of about 150 meters 30 MHz = Wavelength of about 10 meters What are HF test frequencies? 2.5, 5, 10, 15, and 20 MHz How do you know HF is tuning? If you hear the tune tone for more than 7 seconds, then it is an indication of a tuning failure. Most coupler/transceiver combinations indicate failure in less time than that. Typical Tune tone last for about 2 seconds. Why is HF used? - Extended Range - Twin Engine - Operational - Performance - Standards ETOPS HF waves bounce off the ___________ Ionosphere Propagation characteristics of the HF band are most suitable for long distance communications. Propagation is best at night. Long distance comm consists of? HF or SATCOM SELCAL Selective calling What is the purpose of selcal? Alleviate pilot workload How is the flight crew notified of a selcal? Chime and light How many tones does selcal send? 4 distinct audio tones (in pairs of 2) Selcal code rules - Four letters, written or transmitted as an ordered two sets of two letters each - A through S, excluding I, N and O - The letters within a given pair are written or transmitted in alphabetical order How many possible selcal audio tones are there? 16 Each selcal letter designates a specific __________ frequency audio tone What systems does selcal work with? VHF, HF, SATCOM Why is the service interphone unique? To activate the system, you must first power the system through a dedicated switch in the flight deck (usually overhead) What must be done if you sell an aircraft? Change the code trough use of dip switch Which interphone always turn on when aircraft power is on? Flight interphone What is always considered a hot mic when in use? Oxygen mask always a hot mic when in use How does the ground crew get the flight crews attention? Flight crew call button How does the flight crew call the ground crew? Really loud horn in nose wheel well (ground crew call) What happens to the PA volume when engine starts? Volume of PA changes 6 db, PA amplifier Who developed ACARS? ARINC ARINC Communications Addressing and Reporting System Which systems does ACARS work with? VHF 3 (primary), HF, SATCOM What are the 5 types of ACARS messages? 1. OOOI 2. FMS 3. Ping Messages 4. Manually Sent 5. Health Monitoring OOOI - Aircraft automatically reports phase of flight - Out of Gate - Off the Ground - On the Ground - Into Gate FMS ACARS interfaces with the Flight Management System to communicate flight plans and weather information