DEFINITION 1. noun form of conspicuous con·spic·u·ous
1. standing out so as to be clearly visible:

I’ve written six articles on ADS-B, my first article in February 2015. A certain amount of research went into those articles; after all, if my articles aren’t accurate, they’re not worth reading. My first article appeared in these magazines in fall 2013. Our publisher liked them … so I just kept going! During that time, we discussed ADS-B more than any other topic that I have addressed. In all those articles and the research around them, I never came across the term “elec­tronic conspicuity” or even the word conspicuity, until recently.

My last article on the subject was called “ADS-B on the Cheap” (April 2018). In the article, I stated: “Naturally, some owners won’t be happy until someone introduces a portable GPS with ADS-B In and Out for $995! I followed that up by saying that won’t happen. Well, I received an email from a gentleman a few weeks ago who had just read the article and pointed out that I was wrong. There is, in fact, a unit being used in the U.K. (as well as Australia and New Zealand) that does all that and is even less than $995, and he’s mad about it. He wants to know why this is not an option here in the U.S. I think his question is valid. We’ll talk about this unit, which comes from a company that we all know very well. But let’s first talk about electronic conspicuity.

Electronic Conspicuity

The concept of “See and Avoid” is basic to flying. We have since added “See and Be Seen” to the discussion. The “be seen” part is not about painting your airplane fluorescent orange. It’s about using technology to enhance your virtual visibility! Pilots in IFR condi­tions get a lot of help from Air Traffic Control (ATC). Active traffic avoidance is best if you can afford it. ADS-B has put traffic avoid­ance and weather (WX) in the cockpits of Light IFR pilots, even VFR pilots where the technology was previously out of financial reach for pilots flying legacy aircraft on a budget.

If you look at accident statistics on mid-air collisions, you may be surprised. I came across these facts in my research:

I’m sure that with time, and ADS-B traffic here in the U.S., these numbers may improve.

Simply stated, the term used to augment the See and be Seen concept in the U.K., Australia, and New Zealand electronically is called electronic conspicuity.

ADS-B Out in the U.S. is done with Mode S transponders on 1090 MHz or UATs on 978 MHz. We have Traffic (via TIS-B) and WX (via FIS-B) here in the U.S. today thanks to the FAA and ADS-B In. The U.K. has ADS-B Out on 1090 MHz like the U.S. but no UAT or 978 MHz, though they have plans to add TIS-B Traffic and FIS-B WX in the next five to eight years. In the meantime, many pilots in the U.K. and New Zealand depend on another technology designed to help them see and be seen electronically that is known as FLARM. First, let’s talk about Class G Airspace.

Class G Airspace

You can’t be a pilot without a clear understanding of airspace. All this talk about ADS-B has certainly highlighted the topic. We talk about Class A, B, C, D, and E airspace as it relates to ADS-B, but we hardly ever talk about Class G which, simply stated, is all the airspace that is not A through E. In the U.K., Class G Airspace goes up to 3,500 feet AGL. In the U.S., Class G Airspace maxes at 1,200 feet AGL, where Class E takes over. In G airspace, you’re entirely on your own, even IFR, although flight following may be available. There is no ATC control in Class G airspace. ADS-B Out or a transponder is not required. Class G airspace is the Wild West of airspace, and while you may be thinking that it’s full of Piper Cubs and gliders and basic aircraft, any aircraft can fly in Class G airspace. In the U.S., if you want to have the benefits of ADS-B Traffic, you need a Mode S ES Tran­sponder with ADS-B Out and an ADS-B receiver. That’s a $5,000 investment. This is the concern from the guy who sent me the email. He’s in the business of supporting experimental builders and restorers of Rutan aircraft and is concerned that many of his followers simply can’t afford the $5,000 to “see and be seen.”

I’m sure some pilots in G Airspace will use an ADS-B receiv­er like the Stratus to attempt to get help with traffic and WX, but we know now that it doesn’t work that way. In order to see the full traffic picture with ADS-B, you must be transmitting an ADS-B Out signal, or another aircraft in your vicinity must be doing that in order to trigger TIS-B and FIS-B information transmitted from a line-of-sight ground station. Pilots flying in Class G airspace in the U.K. and New Zealand have an afford­able equipment alternative to TIS-B.

FLARM is a portmanteau of “flight” and “alarm.” Essentially, it combines the two words. FLARM was invented in 2004 by three Swiss glider pilots/engineers, following many fatal mid-air collisions between gliders. Urs Rothacher, Andrea Schlapbach, and Urban Mäder set off to design a system that would alert the pilots of an imminent collision and tell them the location of the intruder so they could take immediate action. After many sleepless nights, the first proof of concept was finished, and it was a success! FLARM is one of the first examples of using crowdfunding to support an emerging technology, and enough pilots were then found to start production. If that’s not amazing in itself, FLARM Technology openly shares its technology with other manufacturers, provided they stick to the design specs. About 50% of the FLARM products on the market are made by other manufacturers.

How Does FLARM Work?

FLARM works by calculating and broadcasting its own future flight path to nearby aircraft. This is air-to-air technology. At the same time, it receives the future flight path data from sur­rounding traffic. A smart motion prediction algorithm calcu­lates a collision risk for each aircraft based on an integrated risk model. When a collision is imminent, the pilots are alerted to the relative position of the intruder, enabling both to avoid a collision. Each FLARM system determines its position and alti­tude with a sensitive Global Navigation Satellite System (GNSS) receiver. Based on speed, acceleration, track, turn radius, wind, and other parameters, a precise projected flight path is calculat­ed. This flight path, together with additional information such as a unique identifier, is encoded before being broadcast over an encrypted radio channel. FLARM is available in many configu­rations, including remote-mounted and portable units, and in many countries essentially fills the void that ADS-B In provides for us here in the U.S. It is approved in the U.K. by the European Union Aviation Safety Agency (EASA) for fixed installations in certified aircraft. It is the recommended “electronic conspi­cuity” device to be used by members of the Soaring Society of America here in the U.S.

FLARM Technology shares its technology with other manufacturers as long as they adhere to its design specs. About half of FLARM products on the market are made by other manufacturers, including this FLARM Eagle Mobile unit from LX Navigation.

So let’s take a look at the portable unit available today that I mocked in my article back in 2015: A portable GPS with ADS-B Out and In (that I said would never happen) and that just hap­pens to also include FLARM. I remember talking to the sales manager of uAvionix shortly after the ADS-B mandate date came and went and asked him, “What’s next?” He indicated that uAvionix was just getting started and the rest of the world was what was next. My focus has been on the U.S., so I admit I missed this. Once I discovered it, I asked the same question. Why is this not an option for pilots in Class G airspace in the U.S.?

uAvionix SkyEcho

SkyEcho is a portable ADS-B In/Out transceiver approved by the U.K. Civil Aviation Authority (CAA) and Australia’s Civil Aviation Safety Authority (CASA) as an electronic conspicuity device (ECD). SkyEcho transmits your aircraft position, altitude, course, and speed on 1090 MHz ADS-B, enhancing your ability to “See, Be Seen, and Avoid” other aircraft. Configurable as a transmitter or receiver only, SkyEcho transmits 1090ES ADS-B where transmitting electronic conspicuity devices are allowed (U.K., New Zealand, and Australia), while receiving 1090ES ADS-B and 978 MHz ADS-B (where available), or FLARM (in Europe). SkyEcho includes a TSO-certified GPS and barometric altimeter, providing accurate and high integrity position data to you, as well as surrounding traffic and ATC. SkyEcho is also able to receive Weather, Flight Information Services (FIS) and Traffic Information Services (TIS) over 978 MHz UAT where available. Here’s the features as stated by uAvionix in its product sheet.

The uAvionix SkyEcho, a portable ADS-B In/Out transceiver approved by the U.K.’s CAA and Australia’s CASA. It has not been approved in the United States. It costs about $775 or $1,095 Australian Dollars (AUD).

  • Reports surrounding aircraft positions in real time to your Electronic Flight Bag (EFB) application.
  • Transmits ADS-B on 1090 MHz and meets MOPS DO-260B Class A0 25W output power.
  • Integrated TSO Certified uAvionix FYX SIL 1 GPS
  • Integrated Barometer for Pressure Altitude.
  • GDL90 traffic reports over Wi-Fi.
  • FLARM compatible in Europe when paired with a compatible EFB application.

The SkyEcho includes a window RAM mount, soft case, and USB-C charging cable.


The SkyEcho is another brilliant (a commonly used British term) piece of technology from uAvionix! If you remember where we were before the skyBeacon came to market, aircraft owners were looking at a $5,000 bill to meet the ADS-B Out mandate. uAvionix offered a simple, functional solution for less than half that.

Currently, pilots with simple non-transponder-equipped aircraft flying exclusively in Class G U.S. airspace must spend a minimum of about $4,500 to equip for ADS-B Out (a new Mode S ES Transponder installed). This allows them to be “Seen.” Now add an ADS-B receiver like (ironically) the uAvio­nix Sentry Mini at $349 so they can also “See.” Consider this statement from FLARM Technology:

“Research and several accident in­vestigations have shown that despite the VFR-principle of “see and avoid,” it’s often impossible to see the other aircraft. This is not only true when the other aircraft comes from such a direction that the view is obstructed by their own aircraft. The human visual system is not capable of reli­ably detecting objects on a collision course, since they are on a fixed point on the windshield. Several other physiological and psychological fac­tors further decrease the chance of seeing the other aircraft in time.”

I understand why the FAA insists on certified, installed equipment in certified aircraft to safely separate IFR and VFR traffic sharing con­trolled airspace. I think light aircraft, gliders, and hot-air balloons flying exclusively in uncontrolled airspace should also have an affordable op­tion. I’ll go one step further. Class E below 10,000 feet does not require a VFR pilot to have a radio, transpon­der, or ADS-B on board. Class G in the U.K. is up to 3,500 feet AGL. It is only up to 1,200 feet AGL in the U.S. Why not also make an affordable option like the SkyEcho available to VFR pilots in Class E available? It’s called “electronic conspicuity” in oth­er countries. Call it what you want, but the uAvionix SkyEcho and FLARM are likely making Class G airspace in the U.K. (and beyond) safer airspace. Congrats uAvionix. You’ve done it again!

Thanks for Reading!

Until next time … SAFE and Happy Flying!