NAV/COMM
You are flying through clouds at night.
You cannot see the ground. You cannot see the airport. Another aircraft may be flying only a few thousand feet above or below you.
Yet the pilots know exactly where they are, where they are going, and how to safely reach their destination.
Two things make this possible: navigation and communication.
Modern aviation depends on both. Navigation allows pilots to determine their position and follow the correct route, while communication keeps aircraft connected with air traffic control and other important operational resources.
When these systems work together, they help pilots maintain situational awareness and operate safely in some of the world's busiest airspace.
What is Navigation?
Navigation is the process of determining the aircraft's position and guiding it from one location to another.
In the early days of aviation, pilots depended heavily on visual references such as cities, roads, rivers, and coastlines.
Today, navigation is much more sophisticated.
Modern aircraft can use information from several sources, including:
GPS and other satellite navigation systems
VOR
DME
Inertial navigation systems
The Flight Management System (FMS)
Ground-based navigation aids
These systems allow aircraft to navigate accurately even when pilots cannot see the ground.
GPS and Satellite Navigation
Satellite navigation has transformed the way aircraft operate.
GPS provides highly accurate position information that can be used throughout different phases of flight.
It supports modern procedures such as RNAV and RNP, allowing aircraft to follow precise routes that do not necessarily depend on flying directly from one ground-based navigation aid to another.
This gives airspace designers more flexibility and can make routes more efficient. However, pilots should never assume that GPS is perfect.
Signals can be affected by interference, jamming, spoofing, equipment problems, or other limitations.
This is why pilots need to understand the systems they are using and know what alternatives are available if navigation information becomes unreliable.
The Flight Management System
On modern commercial aircraft, much of the navigation information is managed through the Flight Management System.
Before departure, pilots enter or verify information related to the planned flight, including the route, departure, arrival, performance data, and other operational information.
During the flight, the FMS helps the crew manage the aircraft's lateral and vertical flight path.
But automation does not eliminate the need for monitoring. Pilots continuously check whether the aircraft is following the expected route and whether the information displayed by the system makes sense.
If the aircraft is doing something unexpected, the crew needs to recognize it.
What is Aviation Communication?
Navigation tells pilots where to go.
Communication helps them coordinate how to get there safely.
Throughout a normal flight, pilots communicate with several ATC units.
They may talk to:
Clearance Delivery
Ground Control
Tower
Departure
Area or Center Control
Approach
Each controller is responsible for a different part of the operation.
During these communications, pilots may receive instructions related to altitude, heading, speed, route, runway, traffic, and other operational information.
Clear communication is especially important because a small misunderstanding can have serious consequences.
Why Standard Phraseology Matters
Aviation connects pilots and controllers from different countries and linguistic backgrounds.
Standard phraseology helps reduce ambiguity.
Instead of creating a new sentence for every situation, pilots and controllers use internationally recognized words and structures for routine communication.
For example:
“Climb flight level three five zero.”
“Turn right heading two seven zero.”
“Cleared ILS approach runway two seven.”
These messages are short, specific, and predictable.
That makes communication faster and reduces the possibility of misunderstanding.
Readback Is Part of the Safety System
Some ATC instructions are particularly important and need to be read back correctly.
If a controller instructs an aircraft to:
“Descend to 4,000 feet.”
the pilot reads the instruction back.
This gives the controller an opportunity to identify an incorrect altitude before the aircraft acts on it.
The same principle applies to important information such as runway instructions, headings, clearances, and other safety-critical elements.
Readback is not simply repeating information.
It is a way of detecting communication errors.
When Standard Phraseology Is Not Enough
Not every situation fits into standard phraseology. An engine problem, medical emergency, technical malfunction, weather deviation, or unusual event may require pilots to explain something that cannot be communicated using a few standard expressions.
This is where plain English becomes essential.
Imagine a crew experiencing an electrical problem.
The pilots may need to explain:
“We have lost our main electrical generators. We are operating on backup power and would like to return to the airport.”
There may not be one standard phrase that communicates everything ATC needs to know.
Pilots therefore need enough English to describe the problem, explain their intentions, understand questions, and respond appropriately.
This is one reason English proficiency is so important in international aviation.
Navigation and Communication Work Together
Navigation and communication are separate systems, but pilots constantly use them together.
Imagine ATC says:
“Turn right heading 180, intercept the localizer runway 16.”
The crew needs to understand the instruction, read it back correctly, select or fly the appropriate heading, monitor the aircraft's position, and verify that the localizer is captured correctly.
Communication provides the instruction.
Navigation helps the pilots execute it.
The same relationship exists throughout the flight.
What Happens During a Communication Failure?
Radio communication can fail.
The problem may involve the aircraft's radio, frequency selection, headset, microphone, electrical system, or ground equipment.
The first step is usually to determine whether communication can be restored.
Depending on the situation, pilots may try another radio, another frequency, the previous frequency, or other available communication methods.
If normal communication cannot be established, pilots follow the applicable communication failure procedures.
ATC can also use other methods to communicate with an aircraft in certain situations.
The important point is that a radio failure does not mean the flight suddenly becomes uncontrolled.
Procedures exist specifically for this possibility.
What Happens During a Navigation Failure?
Navigation problems can also occur. A GPS signal may become unreliable. A navigation system may fail. The aircraft may lose access to a particular navigation source.
The crew must identify what has been lost and determine what remains available.
Modern commercial aircraft normally have considerable redundancy, so the failure of one navigation source does not necessarily mean the aircraft can no longer navigate safely.
However, some procedures may no longer be available.
A navigation failure can therefore affect the route, approach capability, or even the airport the crew chooses for landing.
Again, the solution depends on understanding the aircraft's capabilities rather than simply depending on automation.
The Role of Technology
Aviation communication is also changing.
Traditional VHF radio remains extremely important, but aircraft can increasingly exchange information digitally.
Systems such as CPDLC allow pilots and controllers to send certain messages through data link instead of voice.
This can be particularly useful in busy airspace or areas where traditional radio communication has limitations.
Navigation technology continues to evolve as well. More precise satellite navigation, improved avionics, better displays, and increasingly connected aircraft give pilots access to more information than previous generations ever had.
But more technology also creates a new responsibility.
Pilots must understand what the systems are doing.
Navigation answers one fundamental question:
Where are we, and where are we going?
Communication answers another:
How are we going to coordinate with everyone else to get there safely?
Modern technology has made both more accurate and efficient, but technology alone is not enough.
Pilots still need to monitor their position, understand their instruments, communicate clearly, verify instructions, recognize errors, and know what to do when a system does not work as expected.
Because knowing where you are is important.
But understanding what is happening around you is what turns navigation into situational awareness.