Glider near miss with Airliner (emergency climb) near Chicago yesterday?

On Wednesday, September 27, 2017 at 6:49:18 PM UTC-7, wrote:
Exactly and the only practical approach to take. What inside s transponder makes it so expensive? Most of the time in gliding it's that the market is so small, free market principals have no effect.

Dennis
DC

Transponders have a fairly impressive amount of electronics, firmware and RF engineering in them. It used to be (1970s-1990s) seen to be obscenely expensive to deliver Mode S capabilities (much more expensive than Mode C). That maybe helped push decisions to develop dual-link ADS-B in the USA which ultimately complicated things... and I suspect slowed overall ADS-B Out adoption and helped increased costs.

One significant thing that happened with transponders in the 1990s is modern FPGAs allowed vendors to shrink lots of hardware complexity and reduce costs. A Mode S transponder is a complex piece of kit, its emulating old Mode A and C transponders, delivers impressive 25' altitude resolution, is able to transmit aircraft data, able to receive legacy TIS-A traffic data, and do ADS-B Out data as well. That you can buy one for as little a $2k is pretty amazing.

FPGA helped greatly reduce costs but so much of the costs are regulatory and compliance related. Look at the long list of RTCA and TSO specs that a transponder like a TT-22 meets. It's interesting to ask manufacturers what it would cost to ship an empty box--it's a serious fraction of the price of one of these transponders.

There is no way that a transponder could ever be built just for the gliding community. The development costs would never be recovered. Luckily Trig and other manufactures happen to make a general purpose transponder in a small form factor and low power consumption that is useful for us.

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And for folks that don't know me or why I'm so interested (or pig headed) about transponders, ADS-B, FLARM etc. I've got a background in microwave engineering and research and technology. And was already interested in this stuff, and got much more interested in it after one day flying out of Minden in a Duo Discus on our way back to the airport when the Hawker 800 and ASG29 mid-air occurred. We knew after a short while that Hawker was down OK but they had not yet located the glider pilot. We assumed the worse and thought he was dead, and remember tieing down the Duo next to his crew who were waiting for news. Since that time I have also lost a friend in a glider-towplane mid-air collision. This stuff gets real very quick.

Some of the responses to events like the Hawker mid-air was am increasing focus on the possibility of mythical cheap UAT technology that seemed to me very unlikely to eventuate, and did not, and even if it had would have been totally incompatible with TCAS so should have been a nonstarter. Unfortunately for some years the discussion of mythical UAT products helped encourage some pilots to wait for future ware, and discouraged some adoption of transponders where they were really needed. That UAT fixation also worked in ways to not encourage FLARM availability in the USA. I spent a fair amount of time trying to correct ideas about how this UAT futureware will fix problems and magically cost so little, etc.

Close encounters with airliners and fast jets and gliders happen much more than people think. Monday is another. A few years after the Hawker midair we had a close encounter between an airliner and a (transponder less) glider in the same frigging Carson Valley area. Maybe just to show their seriousness about that issue the FAA turned up to interview the pilot with FBI special agents in tow. There have been multiple close encounters with fast jets including the jet of the owner of the Examiner publishing company, that got the glider community bad press in his publications for a few years. There have been other non-airline or fast jet mid-air collisions with gliders over the last decade or two, a glider on tow in Colorado with a Cirrus, a towplane and glider in California, and multiple glider on glider mid-air collisions in contests. Hopefully PowerFLARM is the right tool for those later cases and PowerFLARM adoption seems to have helped.

Ultimately the development of TABS was a nice direction, fully compatible with TCAS, some of that was inspired by the early low cost UAT ideas, some encouraged by FLARM, some by other low-power Mode S initiatives, it combines Mode S and 1090ES out with lower cost GPS technology. But the FAA frustratingly left it dangling with no adoption path for certified gliders. And a sword dangling over our heads that if any (experimental gliders) adopts TABS and then gliders lose the ADS-B out exemption affected pilots may have to throw out say the TN72 GPS and replace it with a TN70. A really crazy idea, if this is ever going to be usable and affordable the FAA has to help kick start TABS adoption and help the way for pilots willing to pay to install it now and start to get costs down for everybody. For disclosure I provided some small help to vendors providing input on the development of the TSO-C199/TABS standard. But again TABS and ADS-B Out is getting far ahead here, the real issue in the context of this thread is transponder adoption in busy traffic areas.

And some of my personal close encounters....

Thermalling a few miles from the Panoche VOR, with transponder. As I come around a C152 comes right through my thermal circle at my altitude, came head on out of nowhere, and blended well into the cloudy background. Flying inbound to the VOR. Student may have had a hood on. That convinced me to buy a Xaon PCAS. Which over the years helped provide several useful warning like...

Thermalling in the Mendocino mountains, transponder and PCAS. Several gliders hanging around for a friendly contest start. I get a PCAS alert at close altitude, looking like crazy and see him, coming over a hundred feet or so above me is a DC-7 fire bomber. I assume he did not see me at all and just let him go over.

And then there is are times where it all just works, like with Travis approach, transitioning their very busy airspace on flight following, controllers being fantastic and routing traffic and asking me if I have all the C5s on final visual. Uh yes I do (and they all have TCAS II). Or talking to Reno approach (now NOCAL) and being transponder equipped in the Carson valley and hearing and seeing B737 routed safely around you. That is a great feeling.