Case Study Near Mid Air Glider and C421 - Benefits of PowerFlarm and Transponders

With all the discussion about FLARM, ADS-B and the Pros/Cons, I thought the time is right to bring some facts into the discussion. Last September I had a near mid air with a C421. Since I had recently equipped over the previous winter with a Mode S transponder (Trig T22), I was curious whether: 1) It was working... 2)Did the FAA use my target to call traffic.

Turned out the answer was yes! to both questions. I filed a near mid report to the FAA which resulted in two interviews and this radar ARTCC video with ATC controller audio. I think you'll find it quite interesting.

https://dl.dropbox.com/s/k8ph9wogyif...1 TT.wmv?dl=0

The FAA statement incorrectly identified the twin as a King Air with only (my visual esimate)
horizontal separation estimate of 500ft.

https://dl.dropbox.com/s/e6gvhn6dybx...FAA.pdf?dl =0

According to the radar we passed by at 10,000msl zero vertical and 1300ft horizontal. By pure luck and good scanning technique, I sighted the C421 15 seconds before crossing. PowerFlarm PCAS went off 2-3 seconds later. PowerFlarm would have got my attention if my visual scanning had failed me. No evasive action occurred on my part.

When you listen to the audio/video you will see a red "CA" meaning Conflict Alert going off for the controller. This went off at 33 seconds. If FAA modified their ADS-B ERAM software, they could send out ADS-B packets for aircraft on a collision course. PowerFlarm would then have given plenty of warning without cluttering the bandwidth of ADS-B with unnecessary information.. This recommendation was made to the FSDO FAA representative who interviewed me.

I am complete agreement with Darryl Ramm's analysis of this whole transponder (Mode S) PowerFlarm recommendation. They complement each other quite well... and this is the best solution for the time being. As he has said, the whole ADS-B thing with TABS looming in the near future is in a state of flux. I wouldn't be surprised to see combined Mode-S/ADS-B transponders coming onto the market in abundance within 3 or 4 years.

In case you are wondering ... I did NOT recommend in my response to the FAA NPRM immediately equipage of gliders with transponders. Instead, utilize good airspace practices, training and a short "wait and see" for more affordable equipment to become available. However, if you have the money... by all means equip with a transponder and PowerFlarm.

Walter Rogers "WX" Discus 2A