Why "See and Avoid" Isn't Enough Anymore
An aircraft can be directly ahead while you are looking through the windscreen, and still take several seconds to notice. Against a bright cloud or a patchwork of fields, the first sign may be a small shape that barely seems to move. By the time it becomes unmistakably an aeroplane, much of the available thinking time may already have gone.
Electronic conspicuity gives pilots another way to discover nearby traffic. It can direct your attention towards an aircraft you have missed and help other equipped pilots detect you. Its usefulness depends on what each aircraft transmits, what the other can receive, and how well the pilot uses the information. Understanding those limitations is part of using the equipment properly.
For a pilot, the aim is to combine effective lookout with compatible technology. Looking outside remains essential. The opportunity is to make that search better informed.
Contents
Why another aircraft can be difficult to see
An aircraft approaching on a collision course can remain at almost the same position in your field of view. It offers little sideways movement to attract attention. Its apparent size may increase only slowly at first, then grow rapidly as the distance closes. A shape that seems stationary deserves particular attention.
Contrast makes a difference too. A pale wing against cloud can be difficult to distinguish; the same aircraft seen against darker ground might stand out. Windscreen posts and the aircraft's nose create hidden areas. A clean windscreen improves the view, but even an unobstructed view does not guarantee that your eyes will identify everything within it.
Your eyes also need to refocus when you move from a nearby display to distant traffic. Looking up from a tablet is only the start of the search. On a hazy day with few distinct features, you may be looking into the distance without focusing effectively there. These are human limitations that affect experienced pilots as well as students.
Consider two aircraft approaching head-on, each with a groundspeed of 100 kt. Their closing speed is 200 kt, so a separation of two nautical miles disappears in 36 seconds if both continue unchanged. That example assumes constant speeds and tracks. Within that interval, the pilots still need to detect the conflict and respond. Several seconds spent finding a menu can consume a substantial part of it.
What electronic conspicuity actually adds
Electronic conspicuity means making an aircraft detectable electronically. A suitable device transmits information that a compatible receiver can interpret. For traffic awareness, this can provide a useful indication of where another aircraft is relative to your own.
There are two separate questions to ask about any installation: can other aircraft detect you, and can you receive information about them? A receiver connected to your tablet may improve your own awareness while making no transmission of your position. A transmitter may help other equipped users detect you without providing a traffic display in your cockpit. Some devices do both.
This distinction is easy to overlook in a club aircraft. A moving map full of traffic symbols tells you something about the receiving system. It says very little, by itself, about what the aircraft is transmitting. Ask the school or operator to show you the actual equipment configuration and the relevant status indications.
Think of an alert as a prompt to give a particular part of the sky urgent attention. A bearing and relative height can make a difficult visual search much more focused. The information also helps you relate a radio call to traffic nearby, provided you confirm that the displayed target and the reported aircraft really correspond.
ADS-B, FLARM and ADS-L in practical terms
ADS-B stands for Automatic Dependent Surveillance–Broadcast. An ADS-B Out system broadcasts information including the aircraft's position and identity. ADS-B In describes reception of those broadcasts. In European aviation, 1090 MHz extended squitter is the relevant ADS-B link to understand when discussing an installation with an avionics specialist.
A Mode S transponder does not automatically mean that ADS-B Out is operating. The installation needs the appropriate capability, a position source and correct configuration. A transponder-only aircraft may be detectable by some traffic equipment without supplying the position information needed to place it accurately on a moving map. Treat a non-directional warning according to the device's instructions; it cannot tell you which window to look through.
FLARM is widely associated with gliding. Compatible FLARM units exchange information used to assess potential conflicts. Some equipment, including particular PowerFLARM configurations, can also receive ADS-B traffic. The exact capabilities depend on the model and installation. A label on the panel is insufficient evidence that every nearby aircraft can be detected.
ADS-L means Automatic Dependent Surveillance–Light. It was developed to support electronic visibility using lower-cost, lower-power equipment, particularly for aircraft without certified ADS-B installations. It is a distinct protocol. Having ADS-B reception does not, on its own, establish ADS-L reception, and an ADS-L transmission does not make you visible to every airline traffic system.
The practical question is which signals your equipment sends and receives in its current configuration. If a supplier promises compatibility through a software update, establish whether that update is available and installed. If a service depends on ground retransmission, establish what coverage and supported traffic it actually provides where you fly.
Why the traffic picture will have gaps
Some aircraft carry no compatible transmitting equipment. Others may have a device that is switched off, incorrectly configured or temporarily unable to supply valid position information. Your own receiving equipment can have limitations too. Consequently, an empty traffic display cannot establish that the surrounding airspace is clear.
Compatibility can also work in only one direction. You might receive another aircraft's transmission while its equipment cannot receive yours. The other pilot may remain unaware of your presence. Even when both aircraft carry capable systems, equipment performance and the pilots' use of it still affect the outcome.
Direct air-to-air reception and information delivered through a ground network have different dependencies. A ground service may extend the information available, but it relies on the relevant infrastructure and links. Avoid carrying an assumption about coverage from one flying area into another, particularly when operating across borders.
Position information also has an age and a quality. Learn how your display indicates old reports, loss of connection or unreliable data. A symbol can look reassuringly precise even when the information behind it is incomplete. If the display conflicts with what you can see, treat the display as potentially incorrect and use the available visual and radio information to assess the situation.
The communication chain below is a useful way to discuss a club installation. Each stage needs to work before a traffic indication can help the pilot.
Understanding this subject brings Human Performance and Air Law together: how your eyes detect traffic, who gives way and what responsibility remains with the pilot. Easy EASA's theory training helps you connect those principles to the decisions you will discuss with your instructor during flight training.
What has changed in Europe
In April 2025, EASA launched the voluntary ¡Conspicuity Declaration and the ADS-L Coalition. The declaration encourages greater electronic visibility across general aviation. The coalition brings technology providers and other participants together to develop and support interoperable equipment.
Development continued after that announcement. ADS-L 4 SRD860 Issue 2 was published in December 2025, including provisions for ground-to-air retransmission and improvements supporting interoperability. In May 2026, EASA and EUROCONTROL published use cases for direct air-to-air traffic awareness and for electronic conspicuity in U-space without an air traffic control service. These describe how systems could support pilots and drone operations and contribute to assessment and validation work.
A published standard creates a basis for implementation. It does not establish that every existing device has been upgraded or that a supporting ground service is available throughout Europe. For an aircraft owner, the useful next step is a specific conversation about the installed equipment and the routes flown.
There is no blanket requirement arising from those initiatives for every private aircraft to carry ADS-L. A separate rule already applies in designated U-space: manned aircraft that are not receiving an air traffic control service must continuously make themselves electronically conspicuous to the U-space service providers. Suitable ADS-L equipment is one route to meeting the relevant requirements; it is not the only route.
Check the published requirements for the airspace you intend to use. Carrying a portable conspicuity device does not automatically satisfy a transponder mandatory zone's requirements. Equipment that improves your traffic awareness and equipment that fulfils a particular airspace-entry requirement must each be assessed for that purpose.
Set up the equipment before taxiing
A useful familiarisation session takes place with the aircraft parked. Ask someone who knows the installation to demonstrate its normal indications and alerts. Work through the tasks you would otherwise be tempted to investigate in the air, including restoring the normal display after an accidental screen change.
For each flight, confirm the following points using the equipment instructions and the operator's procedures:
The transmitting and receiving functions you intend to use are operating, with the correct aircraft identity where required.
The device has a valid position source and adequate power for the intended flight.
The display is connected to the intended receiver, with a suitable traffic scale and understood filtering.
Alerts can be heard through the intended audio arrangement and their meaning is understood.
Portable equipment and cables are secure, clear of controls and positioned without obstructing the outside view.
Antenna position deserves attention. The airframe or a person's body can shield signals, so a convenient mounting point may perform poorly. Follow the approved installation or manufacturer's positioning guidance. Avoid changing settings or relocating a device during a busy departure because the traffic picture looks quieter than expected.
In a rental aircraft, include equipment differences in the briefing. Two aeroplanes with similar tablets can have very different traffic capabilities. A short explanation before starting is more useful than trying to work out those differences while approaching an unfamiliar circuit.
Use alerts to improve the outside search
When traffic information appears, keep control of the aircraft and use the available direction, distance and relative height to guide your lookout. Listen for relevant radio information. Where an air traffic service is available, ask for clarification if needed. An advisory or caution from a traffic-awareness device does not provide a commanded avoiding manoeuvre.
For example, traffic reported to your right and slightly below deserves a directed search through the relevant part of the canopy. Move your head to inspect areas hidden by a post. Continue to assess whether the aircraft's position or movement presents a conflict, while keeping awareness of the rest of the airspace. A second aircraft can be present outside the area highlighted by the first alert.
If you cannot see the reported traffic, continue assessing the available information and take the action necessary to avert collision. Keep searching while responding to the developing risk. SERA retains the pilot-in-command's responsibility for preventing collisions. The appropriate response depends on the developing situation, the aircraft's equipment and the applicable procedures.
After the immediate concern has passed, resume a systematic scan. Avoid following one symbol around the screen while the rest of the flight continues unattended. A traffic display should help you direct your attention outside; repeated checking of the same target can quietly achieve the opposite.
Make it part of your normal flying
Effective scanning involves moving your eyes through manageable sections of the view and pausing to focus. Include areas above and below the horizon, and move your head around obstructions. Before turning, check the airspace into which you intend to fly. Your instructor can help you develop a scan suited to the aircraft's visibility and the phase of flight.
Prepare cockpit tasks early enough to preserve that lookout time. Set up the expected radio frequencies and understand the arrival before entering a busy area. If you are flying with another qualified pilot, agree who is flying and how other tasks will be shared. Two people looking down at the same screen provide no additional outside observation.
During a training debrief, discuss a specific traffic encounter: what first drew your attention, how quickly you found the aircraft and whether operating the equipment distracted you. That gives you something concrete to improve on the next flight. Equipment familiarity and a disciplined scan develop through deliberate practice.
Electronic conspicuity can give you a valuable earlier indication of a developing conflict. Make yourself electronically visible where possible, understand the traffic your installation can detect, and use its information to support an active outside search. The useful result is time to recognise what is happening and make a safe decision.
For a student pilot, traffic awareness links the limitations of human vision with practical rules of the air. The video below introduces Easy EASA's online theory course and shows how our training supports the understanding you bring to those cockpit lessons.
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