Welcome to Flightinfo.com

  • Register now and join the discussion
  • Friendliest aviation Ccmmunity on the web
  • Modern site for PC's, Phones, Tablets - no 3rd party apps required
  • Ask questions, help others, promote aviation
  • Share the passion for aviation
  • Invite everyone to Flightinfo.com and let's have fun

Transponder on while taxiing

Welcome to Flightinfo.com

  • Register now and join the discussion
  • Modern secure site, no 3rd party apps required
  • Invite your friends
  • Share the passion of aviation
  • Friendliest aviation community on the web

Correcting

Well-known member
Joined
Apr 17, 2003
Posts
104
I'm a fractional guy, so more often than not, I'm at an airport where I don't have to operate with the transponder on while taxiing. So when I get to a place that does have that requirement (like IAD), I sometimes forget to leave/turn it on. It's never been a big deal (yet) but I still hate when I forget.

My question for you controllers, is...

What if I just left my transponder turned on while taxiing at every controlled airport I go to so that I get in the habit of always having it on for taxi? Would it cause problems for controllers at those airports that don't have the ground radar in operation?
 
I don't know about a problem with controllers, but from a pilots perspective there's nothing like going into an uncontrolled airport and getting an RA on short final.
 
I don't know about a problem with controllers, but from a pilots perspective there's nothing like going into an uncontrolled airport and getting an RA on short final.


If your TCAS is working properly, that shouldn't happen.
 
I could be mistaken, but I believe one major carrier's SOP is to have it on from push to parking, regardless.
 
Since I work at ATL (where you have to have it on) I say leave it on....but I am biased. There are days when I feel like I am the transponder-police. This is for your safety. The AMASS (safety feature on the ground radar) can only work truly properly if its on.
 
At ORD we want it on because of ASDE-X but you would be suprised at how many planes forget to turn it on. Now in low visibility we may get a bit edgy about it if one of our planes comes up missing on the ASDE-X however in okay visibility we can look at the window and see you. The main reason we want it on is becuase the built in saftey logic which doesn't work all that great but with it on if you go across a protected area it will imediatly alert us to a potential conflict I.E. landing or departing traffic that may hit you if you continue to cross an active runway while lost. I'm not a big fan of using ASDE-X other then its saftey logic. If you forget to turn it on, so what....more then likely the controller knows where you are. As for uncontrolled fields etc.... Well, my first airport was a class D. We had a few issues with aircraft on final asking if someone was on short final when in fact someone in the runup had there transponder on. I know it shouldn't be an issue but it sometimes is where a plane goes around due to an RA but its a small issue. Leaving the transponder on wont really hurt anyone but can cause some issues sometimes with some TCAS systems. I wouldn't worry about it. I would do what ever your company does. If your at ATL or ORD or wherever that they want you to turn it on and you forget, we will remind you but its not like "hey idiot turn on your transponder." We know most airports dont have the requirment and we know that most pilots turn it off when the clear the runway. Our ATIS has a "ASDEX operations are in affect, pilots shall have transponder with mode c on while operating on the airport." Our ATIS is like 5 minutes long. I personally don't expect every pilot to remember the little snipit of info. Do what you want, but remember, I don't know any controller that is going to get upset, they will just remind you. I remind 5-10 planes an hour and I never unkey and say idiot. Im a pilot myself. I was trained to turn it off when I land. After a while it will be come so routine with the changes in equipment that its going to be the norm to leave it on. You are in a grace period. Don't worry about it, who cares.
 
What about the likelyhood of two airplanes with the same code? Say, an airplane comes in with a certain code and sits for an hour or so, in the mean time another airplane comes in, or is ready to depart, and is issued the same code.
 
Or like in PVG where they dont even give you time to clear the rwy before they are crying about turning of the transponder
 
Well, if a plane landed with the same code and he is at the gate the transponder should be off. Also we he arrived, the system should remove his strip from the ARTS and the NAS and any other plane with the same transponder will then show up. The problem with ASDEX in our case is it doesn't respond with any primary targets so even if you were to taxi with a 1200 code then at least we can see a target in low visibility and the saftey logic would in turn work. Planes taxi with the wrong codes all the time, we don't get their data blocks but at least we can see a target which is better then nothing.
 

Latest resources

Back
Top