Avionics News December 2012 - 22

ADS-B CIRCA 2013

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box that costs $3,000 installed or added several hundred dollars to the cost of an electronic flight bag or portable GPS navigator. Conversely, with ADS-B In receivers costing anywhere from a few hundred dollars (to play on portable and installed devices), the aircraft owner FIS-B and TIS-B would help raise their equipment levels to match the stand-alone traffic and weather systems – all for only the cost of installing a 978 MHz UAT or, alternatively, a stand-alone receiver and a minimal cockpit display. The stand-alone 978 MHz receiver option brings the UAT capabilities to aircraft equipped with the other ADS-B Out solution – the 1090 Mode S transponder with extended squitter, or 1090ES.
PROGRESS ON THE SECOND FRONT

With more WAAS GPS navigators available – Avidyne, Garmin and Honeywell are all pursuing new all-in-one GPS/ nav/comm solutions with integral multifunction displays – the choices for pilots who want In continue to grow and go down in price.
ADS-B Out aircraft are in range of a ground station, a nearby aircraft with ADS-B In only may not see any traffic, since ground stations work on-demand – such as when an ADS-B-participating aircraft is in range to wake up the station.
ISSUE TWO: CONFUSION ABOUT THE OPTIONS

With 1090ES – the solution required for access above flight level 180 – the thought was some operators will need the high-altitude alternative, won’t necessarily have collision-avoidance and in-cockpit weather, but still want it. An acquaintance with a turbocharged piston single fits into this group. “I don’t want to lose the ability to use the airplane all the way to its ceiling, but I also don’t want to keep paying a monthly fee for something I can get for free,” he explained at EAA AirVenture in Oshkosh, Wis., in July. “As it’s been, I could never seem to scrape together the $6,000 or $7,000 cost of installing one of the better CAS systems. But, I can afford a 1090ES solution and a stand-alone 978 receiver to work with the display in my all-in-one box.” As for the cost of the second box? Well, he’s getting a nice trade-in value from his old datalink receiver that’s largely offsetting the cost of the 1090ES transponder and installation and connecting it to his WAAS GPS for position source. “The 978 receiver is inexpensive enough that it will be covered by about 18 months of savings from the subscription service I’m cancelling.” He could be a poster pilot for the FAA’s entire philosophy of a two-tiered ADS-B solution. With tomorrow’s transponders becoming available today, ADS-B gaining traction – both Out and In – let’s look at the developments in the technology. There are shortcomings, though. For example, if no
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Then, there’s deciding what form of ADS-B Out solution to pick. Some solutions have the vulnerability of being brought down with a critical single-failurepoint. Owners must understand that ADS-B Out works through three components under the 1090ES option: a TSO-145-approved position source – WAAS GPS is the most popular – a TSO-C166b-approved Mode S transponder using the 1090 MHz frequency spectrum of transponders and with extended squitter and a TSOC10b-approved altitude source, either a stand-alone encoder or one integral to the transponder, as we’re seeing more of today. Now, let the encoder fail. Such a failure could leave an aircraft grounded and its people stranded because the aircraft is unable to enter controlled airspace – ADS-B won’t be getting an altitude squawk. Similarly, let the position source or the 1090ES transponder fail and you’re out; or the mere loss of the extended squitter due to antenna or cabling problems lock you out of airspace where ADS-B Out is required.

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Avionics News December 2012

Table of Contents for the Digital Edition of Avionics News December 2012