Has anyone experienced ATC losing the SR20Â’s transponder signal. On a recent trip from Duluth to Houston, ATC lost the transponder signal on three separate occasions, during three separate legs of the trip. After recycling the transponder ATC picked the signal up again. After one incident ATC claimed that is was in there equipment. The entire experience seemed very unusual compared to previous cross country trips that I have made in other aircraft. I was a rare experience that when flying on main north/south feeder routes, ATC would loose the signal. Was not sure if this was a problem with the transponder, SR20Â’s groundplane or some other issue. Any help would be appreciated.
Has anyone experienced ATC losing the SR20Â’s transponder signal.
YES.
I have this problem from time to time; much more so than in other airplanes. Not quite often enough to call it “frequent”. I discussed this with Brian Janzig at Cirrus, who told me that they are in fact looking into possible antenna ground plane issues. This was an improvement over other advice I had received when I raised this topic - to make sure that the transponder antenna was clean, and didn’t have a thin film of oil on it… that made very little sense to me.
On a recent trip from Duluth to Houston, ATC lost the transponder signal on three separate occasions, during three separate legs of the trip. After recycling the transponder ATC picked the signal up again.
Very similar to what I experience.
After one incident ATC claimed that is was in their equipment.
I heard the same thing; I was squawking 0351, and they (NY Center) couldn’t see me. They asked me to change to 0357, and they saw me just fine. The strange thing is that this happened twice (on two consecutive days) - I’m not sure if the 0351 assignment twice in a row like that was a fluke, or if they were trying it out for some reason. Anyway, they said that the problem was theirs.
- Mike.
Has anyone experienced ATC losing the SR20Â’s transponder signal. On a recent trip from Duluth to Houston, ATC lost the transponder signal on three separate occasions, during three separate legs of the trip. After recycling the transponder ATC picked the signal up again. After one incident ATC claimed that is was in there equipment. The entire experience seemed very unusual compared to previous cross country trips that I have made in other aircraft. I was a rare experience that when flying on main north/south feeder routes, ATC would loose the signal. Was not sure if this was a problem with the transponder, SR20Â’s groundplane or some other issue. Any help would be appreciated.
I have had this happen on two or three occasions. My SR-20 has about 90 hours, and there does not seem to be a pattern. Just an occasional request from ATC to “reset transponder”. Usually, this is all it takes.
Yes. Madison, Wisconsin approach could not get the transponder in 5841 in February on a trip to Duluth. Also, last month Tampa approach could not get me but said that Jacksonville was picking it up so they switched me to Jacksonville. Tampa said the same thing to me that ATC said to you-“The problem is probably in our equipment.” About four other times in the last month ATC has said they were not picking up the transponder but did so after recycling. It happens enough that I keep wondering if something is wrong with the transponder but after a few hours of no problems I then think it must be alright.
Has anyone experienced ATC losing the SR20Â’s transponder signal. On a recent trip from Duluth to Houston, ATC lost the transponder signal on three separate occasions, during three separate legs of the trip. After recycling the transponder ATC picked the signal up again. After one incident ATC claimed that is was in there equipment. The entire experience seemed very unusual compared to previous cross country trips that I have made in other aircraft. I was a rare experience that when flying on main north/south feeder routes, ATC would loose the signal. Was not sure if this was a problem with the transponder, SR20Â’s groundplane or some other issue. Any help would be appreciated.
Has anyone experienced ATC losing the SR20Â’s transponder signal.
Yes I took plane into local shop we had unit checked everything was fine. Thought it might be getting to hot but do not thinkl that is the problem. Glad to hear cirrus looking into it more.
YES.
I have this problem from time to time; much more so than in other airplanes. Not quite often enough to call it “frequent”. I discussed this with Brian Janzig at Cirrus, who told me that they are in fact looking into possible antenna ground plane issues. This was an improvement over other advice I had received when I raised this topic - to make sure that the transponder antenna was clean, and didn’t have a thin film of oil on it… that made very little sense to me.
On a recent trip from Duluth to Houston, ATC lost the transponder signal on three separate occasions, during three separate legs of the trip. After recycling the transponder ATC picked the signal up again.
Very similar to what I experience.
After one incident ATC claimed that is was in their equipment.
I heard the same thing; I was squawking 0351, and they (NY Center) couldn’t see me. They asked me to change to 0357, and they saw me just fine. The strange thing is that this happened twice (on two consecutive days) - I’m not sure if the 0351 assignment twice in a row like that was a fluke, or if they were trying it out for some reason. Anyway, they said that the problem was theirs.
- Mike.
From the fact that ATC frequently says that the problem is in their equipment maybe they know something about deficiences in their equipment that is not generally known. I was surprised that they took the blame so quickly without suggesting that I check my transponder. (I actually did wipe off the antenna even though it didn’t make much sense to me either).
Has anyone experienced ATC losing the SR20Â’s transponder signal.
YES.
I have this problem from time to time; much more so than in other airplanes. Not quite often enough to call it “frequent”. I discussed this with Brian Janzig at Cirrus, who told me that they are in fact looking into possible antenna ground plane issues. This was an improvement over other advice I had received when I raised this topic - to make sure that the transponder antenna was clean, and didn’t have a thin film of oil on it… that made very little sense to me.
On a recent trip from Duluth to Houston, ATC lost the transponder signal on three separate occasions, during three separate legs of the trip. After recycling the transponder ATC picked the signal up again.
Very similar to what I experience.
After one incident ATC claimed that is was in their equipment.
I heard the same thing; I was squawking 0351, and they (NY Center) couldn’t see me. They asked me to change to 0357, and they saw me just fine. The strange thing is that this happened twice (on two consecutive days) - I’m not sure if the 0351 assignment twice in a row like that was a fluke, or if they were trying it out for some reason. Anyway, they said that the problem was theirs.
- Mike.
From the fact that ATC frequently says that the problem is in their equipment maybe they know something about deficiences in their equipment that is not generally known. I was surprised that they took the blame so quickly without suggesting that I check my transponder. (I actually did wipe off the antenna even though it didn’t make much sense to me either).
Has anyone experienced ATC losing the SR20Â’s transponder signal.
Jim:
Interesting information. During one of my three separate outages (as explained earlier), after recycling the transponder at the request of ATC, the controller indicated he was picking up the signal again. He then gave me another frequency to tune. Before I had a chance to tune in the new frequency, the original controller radioed me to state that the problem was definitely in their equipment. I should have asked how he was so sure. Something strange is happening.
Stuart
From the fact that ATC frequently says that the problem is in their equipment maybe they know something about deficiences in their equipment that is not generally known. I was surprised that they took the blame so quickly without suggesting that I check my transponder. (I actually did wipe off the antenna even though it didn’t make much sense to me either).
Regarding oil on the transponder antenna – the following paragraph is from the http://www.avionicswest.comAvionics West web site. In an article on antennas, he’s talking about the transponder antenna when he says:
The biggest enemy of the pulse antenna is oil, lead and dirt. Because these antennas are on the bottom of the aircraft, they are subject to getting pretty grimy at times. Picture this if you would. Customer comes into the avionics shop and reports, “My transponder is intermit”. Shop sends customer to lunch. While customer is feeding face, avionics manager cleans sludge and grime off antenna. Transponder now checks good with test box. Customer returns from lunch and gets a bill for $95.00, which he/she gladly pays. Transponder now works so customer is happy. Avionics manager is happier than a rooster in a hen house because the fix was easy and fast. Point of this is; many of the transponder/DME problems we see are related to filthy antennas; clean them occasionally. RF doesnÂ’t transmit through grime very well.
FWIW, I have had ATC tell me on 2 or 3 occasions that they weren’t receiving my transponder (SR20 serial #1116) but I had the same experience as you guys - after recycling it, they can pick me up again. Of the 40 hours I’ve put on the plane so far, at least 20-25 hours have been in class B and/or receiving flight following, so hearing this 2 or 3 times didn’t seem particularly frequent to me…
Steve
The biggest enemy of the pulse antenna is oil, lead and dirt.
Steve,
True, I’m sure, but my first complaints came shortly after departure from Duluth, in a brandy-new, squeaky clean machine; and, when I got the advice to clean the transponder antenna, there was almost nothing on it (barely visible on a clean white paper towel).
I understand how enough grime can create a virtual short for R.F. signals (esp. at transponder frequencies), but if the amount of residue that I found on my transponder antenna was causing the problem, I suspect that 90%+ of the transponders out there would have this problem.
I think that there’s an antenna ground plane issue here (or something like that), and it’s just enough to cause the problem we’re seeing. Or maybe the issue is in the real mystery in all of this - why so many of us are hearing ATC say that they think the problem is theirs.
Is there anyone out there driving enough airplanes regularly (including SR2X) to be able to say definitively that this is more of a problem in the SR2X than in other airplanes? I can say that it certainly is more of a problem for me NOW in the SR2X than it has been in the PAST in other airplanes… but is that difference in ATC or in my airplane?
- Mike.
Of the 40 hours I’ve put on the plane so far…
It just occurred to me – you took delivery just before I did. I’m more of a deliquent than you are, though: I hit 60 hours today!
- Mike.
I’m a CFII and fly different airplanes almost every day (Arrows,T-34s,T-41s,172s,etc.). It is not uncommon to be asked to recyle. However, so far, I have not been asked in 120+ hours flying my SR20.
The biggest enemy of the pulse antenna is oil, lead and dirt.
Steve,
True, I’m sure, but my first complaints came shortly after departure from Duluth, in a brandy-new, squeaky clean machine; and, when I got the advice to clean the transponder antenna, there was almost nothing on it (barely visible on a clean white paper towel).
I understand how enough grime can create a virtual short for R.F. signals (esp. at transponder frequencies), but if the amount of residue that I found on my transponder antenna was causing the problem, I suspect that 90%+ of the transponders out there would have this problem.
I think that there’s an antenna ground plane issue here (or something like that), and it’s just enough to cause the problem we’re seeing. Or maybe the issue is in the real mystery in all of this - why so many of us are hearing ATC say that they think the problem is theirs.
Is there anyone out there driving enough airplanes regularly (including SR2X) to be able to say definitively that this is more of a problem in the SR2X than in other airplanes? I can say that it certainly is more of a problem for me NOW in the SR2X than it has been in the PAST in other airplanes… but is that difference in ATC or in my airplane?
- Mike.
I’m a CFII and fly different airplanes almost every day (Arrows,T-34s,T-41s,172s,etc.). It is not uncommon to be asked to recyle. However, so far, I have not been asked in 120+ hours flying my SR20.
Bill,
Thanks - that’s the sort of feedback I was hoping for. I still feel as though it’s happening to me much more often in my SR20 than in other airplanes in the past. Today I flew from SMQ to ORF, and had to recycle on departure.
- Mike.