ADS-L: what helicopter pilots need to know

FLARM’s 24 October newsletter puts ADS-L back on the pre-flight reading list. What does it mean for the box already fitted to your helicopter? ADS-L is worth understanding, especially if you fly in Europe, but the useful starting point is simple: check what your equipment transmits and what it receives separately. An upgrade that makes you visible to more receivers may leave the traffic picture in your own cockpit unchanged.

What is ADS-L?

ADS-L stands for Automatic Dependent Surveillance – Light. It is a protocol for sharing aircraft position and other data using relatively inexpensive, low-power equipment. The published radio specification, ADS-L 4 SRD860, uses the licence-free spectrum around 868 MHz. EASA also envisages mobile-network links. Its ADS-L guide explains the different links and intended uses.

The aim is a common language across more of light aviation. For helicopter pilots sharing airspace with gliders, light aircraft and other users, that is a useful direction. The practical benefit still depends on the equipment fitted, its installation and who can receive its transmissions.

What changes if you already have FLARM?

In its ADS-L and FASST-CH briefing, FLARM says ADS-L complements its existing system. Its upgrade licence enables ADS-L Out: transmission of your position. Reception needs a separate check; FLARM says channel switching can limit ADS-L reception and that it will prioritise FLARM performance.

FLARM lists PowerFLARM Core, Portable and Fusion as upgradeable; PowerFLARM Flex includes ADS-L without a separate licence, but the 24 October newsletter describes activation as an upcoming software update. Confirm activation on your unit before relying on it. Classic FLARM is excluded under the current specification. For equipment built by another manufacturer, confirm support and licensing with that manufacturer; FLARM identifies the AIR Avionics AT-1 as an exception whose licence is sold through its own shop.

Ask your installer three precise questions: will this installation transmit ADS-L, will it receive ADS-L, and will received traffic reach the display and alerts I actually use? “ADS-L compatible” alone does not answer all three.

Does it replace ADS-B or a transponder?

ADS-L and ADS-B are different protocols. EASA says certified ADS-B and Mode S transponders are not expected to gain ADS-L through upgrades in the near future. A receiver may support several protocols, but its supported inputs and cockpit connections determine what you see.

Treat any airspace equipment requirement separately. ADS-L is recognised as one means of electronic conspicuity for manned aircraft in U-space under SERA.6005(c); that does not confer general airspace access or remove another applicable equipment requirement. Check the current rules for the route and aircraft.

What is coming next?

FLARM’s announced ADS-L transceiver module is intended to receive FLARM and ADS-L simultaneously across six channels. The manufacturer currently expects availability in mid-2027. This is a component for future avionics products and integrations; it is not a capability to assume in today’s installed equipment.

What is happening in Switzerland?

Switzerland is a reason to follow the subject closely. The Federal Office of Civil Aviation’s FASST-CH programme targets an interoperable conspicuity ecosystem by 2028. Its current notice says it plans to incorporate an electronic conspicuity mandate into regulation during 2027, followed by a one-year transition.

That is a developing national programme, rather than an enacted Europe-wide ADS-L deadline. Visiting pilots should check the final Swiss requirements, applicability and accepted equipment before a trip. Owners considering Swiss financial support should also note FOCA’s stated application deadline of 30 November 2026 and check eligibility directly.

A useful check before your next flight

Identify the exact installation. Record the device model, firmware, enabled licences, antennas and connected display. Have your maintenance provider confirm the appropriate update and installation instructions before changing anything.

Check performance as well as settings. FOCA’s conspicuity FAQ stresses antenna placement, obscuration and following the manufacturer’s instructions. A feature enabled in a menu is only part of the installation.

Keep the lookout. Electronic traffic information helps direct attention; an empty display does not establish clear airspace. See-and-avoid obligations continue. Brief passengers to call out traffic and keep heads-out time central to the cockpit routine.

Put the relevant equipment checks into your aircraft-specific routine using the Helipaddy Checklist Generator. For terrain and lookout considerations, our mountain flying guide is a useful companion. When planning the landing itself, use your Helipaddy account to review the destination information and contact the site for permission.

Technical and regulatory sources checked 24 October 2026. Confirm current manufacturer instructions and applicable airspace requirements before flight.