Definition of safety by ICAO: Do what you can to keep risks of flying to an acceptable level.
How can we apply this when it comes to how you talk on the radios while you fly a plane?

When a pilot talks to air traffic control (ATC), yes they need to be very clear. Even more than that - you need to make sure you are understood.
For example, if a controller says, “Go to 250” that means the pilot should go to 250 knots? Flight level 250? Or let's say you hear a plane repeat a clearance and ends it with: (clearance) for 255. Is the "for" the number four? For whom? This confusion leads to trouble.
Then how do we solve this one? Two words: standard phraseology.
These words and sentences help everyone understand the same thing, even if they come from different countries or speak different languages.
For a more accurate definition of safety by ICAO check the official link.
When pilots and controllers talk often and clearly, they can share what is happening. This is called situational awareness. It means knowing where you are, what you’re doing, and what other planes are doing too.
For example, if a plane is waiting to take off and another plane is landing, the controller must talk to both pilots so they don’t use the runway at the same time.
The pilots also listen to other planes on the radio. That way, they know what is happening around them and can stay safe.
Good communication keeps everyone on the same page and helps stop mistakes before they happen.
Check out this video on how an accident almost happened because of poor communication
Most problems in aviation happen because of human error, which means someone made a mistake. Sometimes pilots are tired, nervous, or stressed. Sometimes English is not their first language. All of these things can make it hard to speak or listen carefully.
That’s why ICAO tells pilots and controllers to use simple, clear words. They also practice saying and hearing the same words the same way every time. For example, instead of saying “okay,” they say “roger” or “affirmative.” Instead of saying “yes” or “no,” they say “affirm” or “negative.”
This helps make sure that even if someone is tired or stressed, they can still understand what is being said. When people follow the same speaking rules, fewer mistakes happen.
Sooner or later you'll deal with emergencies happen in the air.
Maybe an engine has trouble, or the weather gets really bad. In these moments, you'll have to tell air traffic control right away.
The controller then gives the pilot help, such as a safe place to land or an emergency landing route.
If you're having a hard time clearly explaining the situation, the controller might not understand what’s wrong or how serious it is.
That can delay help.
Clear communication can save lives (in this case it would include yours) when things go wrong.
ICAO wants all aviation organizations to use something called a Safety Management System, or SMS. This is a plan to find problems and fix them before accidents happen. That's also why you're required to take the ICAO English test level 4 every 4 years.
If you're looking for some coaching before your English test contact me below and we'll make sure you're at the exact level you need to pass your exam (and communicate safely, of course.)
Good communication is a big part of SMS. Workers must be able to report things they see that are dangerous, like broken equipment or risky behavior. These reports must be easy to understand so that the safety team can act fast.
Also, the safety team must share important safety information with pilots, engineers, and ground crew. If they don’t explain things clearly, someone might not understand and make a mistake. So, communication helps everyone work together to keep flying safe.
Better communication is one of the best ways to make flying safer. That’s why ICAO teaches pilots and air traffic controllers to use clear words, listen carefully, and follow the same speaking rules all over the world.
When people in aviation talk clearly, they stop confusion, help each other know what’s going on, reduce mistakes, respond better in emergencies, and keep everyone in the safety system informed.
Next time you fly on an airplane, you can feel safe knowing that many people are talking clearly and working together to make sure your flight is smooth and safe from takeoff to landing.
For more on how to pass the ICAO level 4 exam - click here.