It is called guard because everybody is supposed to listen/guard the frequency just in case someone has a problem. Guard definitions: a state of caution, vigilance, or preparedness against adverse circumstances. watch over in order to protect or control.
Why is aircraft emergency called guard?
What is the frequency supposed to be used for? 121.5 MHz is a guarded frequency, hence the “Guard” comment you constantly hear. 121.5 MHz, and UHF 243.0 MHz for military operations, are monitored by ATC and others, including maritime agencies.
What does guard mean in aviation?
The aircraft emergency frequency (also known as GUARD) is a frequency used on the aircraft band reserved for emergency communications for aircraft in distress.
What does radio Guard mean?
A ship, aircraft, or radio station designated to listen for and record transmissions and to handle traffic on a designated frequency for a certain unit or units. Dictionary of Military and Associated Terms.
What is the 121.5 frequency?
International Distress/Emergency Frequencies
121.5 MHz: International Aeronautical Emergency Frequency. 156.8 MHz: International Maritime Distress, Calling and Safety Frequency. 243.0 MHz: NATO Combined Distress and Emergency Frequency.
What do pilots say in an emergency?
Pilots believing themselves to be facing an emergency situation should declare an emergency as soon as possible and cancel it later if the situation allows. The correct method of communicating this information to ATC is by using the prefix “MAYDAY, MAYDAY, MAYDAY” or “PAN PAN, PAN PAN, PAN PAN” as appropriate.
Is 121.5 still monitored?
DOES ANYONE STILL MONITOR 121.5 MHZ ELTS? Even though satellites no longer monitor 121.5 MHz signals, the search and rescue community will still respond when notified through other means. ELTs were originally intended to use 121.5 MHz to inform air traffic control and pilots monitoring the frequency of an emergency.
What does to be on guard mean?
Definition of on guard against
: alert and ready to respond to possible danger, threats, problems, etc. We need to be on guard against attack.
What happens if you squawk 7500?
The transponder sends the four-digit squawk code and aircraft altitude to air traffic control. The code should always be 1200, unless another code is assigned by ATC. However, if there is an emergency squawk 7500 for hijack, 7600 for communication failure, or 7700 for emergency.
What does squawk 7000 mean?
7000. ICAO. VFR standard squawk code when no other code has been assigned. US.
What frequency does an ELT transmit on?
ELTs of various types were developed as a means of locating downed aircraft. These electronic, battery operated transmitters operate on one of three frequencies. These operating frequencies are 121.5 MHz, 243.0 MHz, and the newer 406 MHz. ELTs operating on 121.5 MHz and 243.0 MHz are analog devices.
What are the two frequencies that commonly used for distress urgency and safety?
The frequency band 406-406.1 MHz is used exclusively by satellite EPIRBs (emergency position indicating radio beacons) in the Earth-to-space direction. The frequencies 161.975 MHz (VHF-CH AIS 1) and 162.025 MHz (VHF-CH AIS 2) are used for AIS search and rescue transmitters (AIS-SART) in search and rescue operations.
Who controls communications when you are in distress?
6.6 Control of Distress Traffic
The control of distress traffic is the responsibility of the aircraft in distress or of the station which relays the distress message.
What do squawk codes mean?
SQUAWK codes are four digits and they are used to easily identify a specific aircraft when detected on a radar, or to determine what an aircraft needs in the case of an emergency or situation in which a flight plan needs to be changed.
What frequency would you use in the event of an emergency?
Although the frequency in use or other frequencies assigned by ATC are preferable, the following emergency frequencies can be used for distress or urgency communications, if necessary or desirable: 121.5 MHz and 243.0 MHz. Both have a range generally limited to line of sight.
Does ATC monitor guard?
Most ATC Facilities monitor 121.5MHz and can provide help for you on guard. You can use guard if you loose contact with ATC and ask for a new frequency or you might actually even hear the controlled looking for you on guard.