Transponder Off Within Mode C Veil

U

Unregistered

Guest
I flew from my home airport (non-towered) to another non-towered field within the mode C veil of a class Bravo airport. I did several practice take off and landings and flew to the local practice area and worked on some PTS maneuvers. I then returned to my home airport.

Upon landing I realized that I had failed to turn on the mode C transponder in the aircraft.

Should I submit an ASRS report?
 
You aren't the first and won't be the last. I wouldn't bother.
 
Nope, they won't care. There would be no way of proving that you had it off anyway...other than your admission here.
 
Submit it -- ASRS reports never hurt, and someone might learn from your mistake, especially if you can talk about WHY you made that mistake as well as the mistake itself.
 
airguy said:
Cuz people ALWAYS follow their checklist, right? :rolleyes:
Click to expand...

Well if you have a checklist and flow you probably won't - (Lights Camera Action) I check without a list prior to takeoff - it is on the end of the run-up checks as well as lights, timers etc
 
Based on what I know, even with your transponder off, if they found you interesting (buzzed a power plant, over flew an interesting area) they would have followed you to the field. Just because you may only look like a flock of birds occasionally on an approach scope, does not mean you are not clearly a plane on someone else's ;)

ASRS, even when not to protect your butt, is a good idea, and helps with the actual mission of the ASRS system!
 
To ATC, an aircraft with its transponder off looks exactly like an aircraft with a completely non-functioning transponder (i.e. no mode C, no mode A, no nuthin'). As such, they won't come track you down unless something really bad happened and they think you were the culprit.

Nevertheless, there's never harm in completing an ASRS report, particularily if there's something to be gained from it, like a datapoint.

I will say I'm spoiled by my GTX-330, which goes into ALT mode automatically on my takeoff roll.
 
Seems to have little informational value as an ASRS report, other than to reinforce "don't forget it."
 
Does ATC radar even have the ability to track primary targets, or is that left to military radar?
 
Ron Levy said:
Submit it -- ASRS reports never hurt, and someone might learn from your mistake, especially if you can talk about WHY you made that mistake as well as the mistake itself.
Click to expand...

Sac Arrow said:
Seems to have little informational value as an ASRS report, other than to reinforce "don't forget it."
Click to expand...

Submit it- still useful data.
 
Approach: 'I have some traffic in the pattern at smalltown, primary return only'
Plane: 'Roger'



As there is no fee or other downside to filing an ASRS, you can do it if it makes you feel better. If the DOT SWAT team hasn't broken down your door yet, chances are they never will.
 
dans2992 said:
Does ATC radar even have the ability to track primary targets, or is that left to military radar?
Click to expand...

Sure it just shows up as a blip. On the newer equipment, they can even put a tag on it (ID). Label it traffic or birds. Obviously they're not going to get an altitude readout on it.

In this case I'm sure the controller couldn't care less about a primary in the veil. They're not security guards or traffic cops. They care about what affects their traffic in their airspace.
 
At my home airport, which is under the SFO mode C veil, I would bet that pilots take off without remembering to turn on the squawk several times per day. The tower controllers have gotten really good at reminding people to "check transponder."
 
Probably no reason to... Most of the new ones automatically go to "ground" mode.
 
tmyers said:
If that is the case why turn it to standby?
Click to expand...

When i was based at Springfield, Mo, you'd hear from the controllers if you left your xpdr on while taxiing around. I guess it cluttered up their screens.

At a non-towered airport I don't think it matters.
 
tmyers said:
If that is the case why turn it to standby?

Sent from my Nexus 7 using Tapatalk
Click to expand...

I'm based at a Class C, so mine goes to standby on the ramp before I shutdown and doesn't get turned back on until after I have called up CD and dialed in my departure squawk on the next flight.
 
The transponder "on" change came about because of ASDE-X. Unless you're operating out of a class B or one of the few Cs that have it, using the old procedure from the AIM isn't going to be a problem. Can't go wrong if you leave it on though.
 
It has only been recently that I have started turning mine to standby and then back to Alt when getting ready to depart. I don't fly to that many controlled fields but a couple years ago I was making regular trips to KTRI and they never mentioned it. That is a low use airport maybe that is why they never commented on it.
 
Velocity173 said:
The transponder "on" change came about because of ASDE-X. Unless you're operating out of a class B or one of the few Cs that have it, using the old procedure from the AIM isn't going to be a problem. Can't go wrong if you leave it on though.
Click to expand...

An instructor I occasionally fly with points out that it can create false alarms for aircraft on short final if they are using traffic alerting equipment.
 
If you have a newer transponder with "GND" mode, that should not be the case, however.
 
dans2992 said:
If you have a newer transponder with "GND" mode, that should not be the case, however.
Click to expand...

I suspect that "newer transponder" describes a very small percentage of the aircraft based at Palo Alto Airport.
 
Palmpilot said:
I suspect that "newer transponder" describes a very small percentage of the aircraft based at Palo Alto Airport.
Click to expand...

Any Garmin GTS-327 or 330 transponder has this, I believe. This model transponder alone accounts for a good number of aircraft.

I monitor 1090Mhz from an antenna at my house and a surprising number of planes have Mode S (ie. "newer") transponders, even if they are not broadcasting position.



I can see when one of my partners flips on the avionics master and the transponder starts broadcasting our Mode S hex code, and I'm 8 NM away from the airport!
 
Velocity173 said:
The transponder "on" change came about because of ASDE-X. Unless you're operating out of a class B or one of the few Cs that have it, using the old procedure from the AIM isn't going to be a problem. Can't go wrong if you leave it on though.
Click to expand...


Correct, and since the thing has to be interrogated to reply anyway, most of the time the smaller airports aren't covered on the ground by the primary radar sweep that's needed to trigger a transmission.

It's a lot simpler just to leave it on, but I grew up doing Lights, Camera, Action so sometimes my fingers find it on already, sometimes off. Depends on who flew the airplane last.

The Garmin's with their "auto off and on" thing actually have to be overridden at airports with ASDE-X. Or just to follow the AIM. That isn't taught much by anyone. The Garmin "fixed" a problem that no longer exists. They really should offer a firmware upgrade to dump the feature if desired now.
 
dans2992 said:
Any Garmin GTS-327 or 330 transponder has this, I believe. This model transponder alone accounts for a good number of aircraft.

I monitor 1090Mhz from an antenna at my house and a surprising number of planes have Mode S (ie. "newer") transponders, even if they are not broadcasting position.



I can see when one of my partners flips on the avionics master and the transponder starts broadcasting our Mode S hex code, and I'm 8 NM away from the airport!
Click to expand...

There are a lot of rental planes with old equipment at my home field. And the rental planes do most of the flying.
 
Brad Z said:
To ATC, an aircraft with its transponder off looks exactly like an aircraft with a completely non-functioning transponder (i.e. no mode C, no mode A, no nuthin'). As such, they won't come track you down unless something really bad happened and they think you were the culprit.

Nevertheless, there's never harm in completing an ASRS report, particularily if there's something to be gained from it, like a datapoint.

I will say I'm spoiled by my GTX-330, which goes into ALT mode automatically on my takeoff roll.
Click to expand...
Is this automatic or is there a setup? I have GTX-330 (without ES) and have not noticed this. I'll have to check next time I fly.
 
I never turn my transponder to ALT . . . . it does it automatically at 30 knots. Or was it 50? I think its 30.

Now, I verify it is squawking ALT when I bring up the gear and the flaps . . .
 
I visited the tower at a class bravo airport and learned that they track you as you taxi with ground radar. Their job is a lot easier if your transponder doesn't go to standby, and quit squawking, as Garmins do. With the transponder on, your blip on the ground radar is labeled with your tail number, but without it they have to mentally keep track of you as your unlabeled blip moves about the field.

I also learned that most of the tower controllers, not being pilots, were unaware that some GA planes were equipped with transponders that automatically quit squawking on the ground. They were frequently dealing with the consequences of that, without knowing why it happens.
 
I thought the "ground" mode for the GTX330 incorporated something that still allowed them to ID you on the ground? Is ASDE-X based on Mode C or Mode S?
 
silver-eagle said:
Is this automatic or is there a setup? I have GTX-330 (without ES) and have not noticed this. I'll have to check next time I fly.
Click to expand...

It's in the setup somewhere.

Many aircraft around DC have it disabled so your plane doesn't start squawking the 'mark of the terrorist' during taxi over to the fuel pumps.
 
Reno (KRNO) used to ***** people out if they left their transponder on, on the ground. I guess they had on field radar that got cluttered by a lot of ground transponders.
 
weilke said:
It's in the setup somewhere.

Many aircraft around DC have it disabled so your plane doesn't start squawking the 'mark of the terrorist' during taxi over to the fuel pumps.
Click to expand...


What a crap hole to live in. Seriously.
 
weilke said:
It's in the setup somewhere.

Many aircraft around DC have it disabled so your plane doesn't start squawking the 'mark of the terrorist' during taxi over to the fuel pumps.
Click to expand...

? It would only do that if you had 1200 programmed in as your last code. Since you're already inside the SFRA you should never have this situation arise where turning on the avionics power turns on a transponder in 1200 mode.

What they DO need to disable is the "VFR" button such that an inadvertant button press (say, during turbulence while trying to press a different button) can cause a real mess. Yes, I could be speaking from experience....
 
Old Thread: Hello . There have been no replies in this thread for 365 days.
Content in this thread may no longer be relevant.
Perhaps it would be better to start a new thread instead.
Back
Top