A transponder is important and Mode S is going to become even more important as ADS-B traffic becomes more prevelent. ?Mode-C is great for if the other traffic has PCAS or ADS-B in (TIS-B) to pick up your 978 mhz ADS-B out. ?But that only works if you are within range of an ADS-B tower. ?Mode-S with Extended Squitter will work whether you are within range of an ADS-B transmitter or not. ?Often times, especially in the mountains, I am out of range of the ADS-B towers.
I bought a PCAS several years ago after a very close call while cruising at 10,500' in the middle of nowhere when I met a Piper Arrow at the same altitude flying a course 90 degrees to mine. ?We were both at the right altitude. ?I don't think he ever saw me. ?I started to roll right, then realized that I couldn't miss him, so rolled hard left and a hard pitch down and passed about 10 feet below and 20 feet behind him. ?I manueverd hard enough to break the power cord on my GPS before it bounced off the inside of the canopy. ? Now the PCAS companies are folding up and going away as the TIS-B traffic information has become available. ?However, it is important to understand that under the same circumstances as my near miss above with today's ADS-B service, if I had TIS-B and he had a Mode-S transponder, he would show up as traffic on my GPS even though we were in an area where no TIS-B service is available. ?If he had a Mode-C and 978 mhz ADS-B out, he still wouldn't show up as traffic on the ADS-B receiver as that requires one to be within range of an ADS-B tower. -Jeff Scott Los Alamos, NM > ----- Original Message ----- > From: brian.kraut at eamanufacturing.com > Sent: 01/29/14 02:09 PM > To: KRnet > Subject: Re: KR> Cowling, altitudes, stall spin > > When flying at high altitudes (as I almost always do) it becomes even > more important to have a Mode c transponder. Once you have the > transponder your size is not that important. Up at those altitudes and > speeds the big planes you worry about all have TCAS and are talking to > controllers and I suspect that they really don't do a lot of looking for > traffic out the window anyway so does not really matter how big a plane > you are flying.
