ADS-B Out with Uncertified GPSThere has long been a lack of clarity on the regulatory status of ADS-B Out via a Mode S transponder sourcing its position data from an uncertified GPS. FASVIG has been working closely with the LAA and the CAA to seek to bring clarity to this situation.

The LAA has now announced that for non-certified ‘permit to fly’ aircraft within its remit, it will (for those with a pre-existing MOD 7 transponder approval) grant approval of correctly configured Mode S Extended Squitter ADS-B Out transponders using an uncertified GPS position source, supported by sign-off of the installation by an LAA Inspector and a properly completed new MOD 14 Form. The LAA will process the MOD 14 approval form free of charge. A test flight within the NATS ADS-B ground receiver coverage area (currently southern England) is still required together with a confirmation email from NATS that the ADS-B Out transmission was successful. See MOD 14 Form on LAA website for details. The existing approvals, initially created for those that volunteered to take part in the NATS Southern England ADS-B Trial, now enables the use of ADS-B Out equipment on a general and permanent basis.

The text below will be published in the next issue of the LAA’s Light Aviation magazine. The new MOD 14 Form should be used when retrofitting ADS-B Out to an aircraft with an existing MOD 7 approved Mode S ES transponder installation. For new avionics/transponder installations that require approval via the MOD 7 Form, the ADS-B Out avionics details will simply be supplied on the same MOD 7 Form. Technical Leaflet TL3.03 explains further.

FASVIG hopes to encourage other flying associations with delegated airworthiness oversight to extend this capability to their fleets as well.

Free ADS-B mods
Without doubt the most popular attraction in the homebuilders tent at this year’s Rally was the PilotAware stand. Their low cost traffic detection device gave a great practical demonstration of the benefits of enabling ADS-B. The device displays other traffic through the tablet-based software that most pilots use to navigate these days. If you have a Mode S transponder and a handheld GPS, you more than likely already have everything you need to activate ADS-B transmissions from your aircraft. LAA Engineering has updated the LAA Mod 14 forms to cover the connection of an uncertified GPS to a Mode S transponder and these can be downloaded from the LAA website. The best news is that the modification is free and can be signed off by your inspector. Even if you don’t yet have a way to display other traffic in your cockpit, broadcasting your position to others that do will improve everybody’s safety.