transponder not working

A few days ago I was getting ready to do a cross country with one of
my students. This was going to be his first cross country, so the
focus was going to be on pilotage, dead reckoning, planning, cockpit
management, and stuff like that. I was going to save the flight
following, flight plan, class C stuff for a later lesson.

He planned to a class D airport about 25 miles northeast of SFO, away
from the Bravo, but still under the mode C ring. He seemed to have his
stuff together, so after a few checkpoints I decided to go ahead and
call up Norcal to get following. I thought "might as well".

So I show my student how to get the frequency out of the AF/D. Then I
give them a call, tell our location, altitude, type, etc. The
controller gives us a squwak code and wait for him to tell us he has
us on radar. A few seconds later he calls us back and tells us to
recycle our transponder, as he isn't seeing anything on the scope. I
recycle it a few times, check the circuit breaker, and anything else I
can think to do. He comes back saying he doesn't have us, and I just
respond, "thanks anyway".

We ended up diverting somewhere else, did a few short/soft fields,
then called it a day. If we hadn't called flight following, we would
had never known about the transponder not working, and would have
violated some airspace. Scary stuff. It makes me nervous, as I did
another student's first cross country to class E airport underlying a
class C a few days prior (in a different plane). We made sure the mode
C was on and I even monitored their approach frequency, but I didn't
call them. It really makes you wonder... I just think it's distracting
having to constantly listen for your call sign while you're trying to
explain important stuff to your student.

Anyways, I was wondering, would it be a dumb idea to just call up a
radar facility to just ask if they can see your transponder?

--"Norcal center, this is cessna XXXX 10 miles south of blah blah,
6000 feet VFR, I don't want advisories, but can you tell me if you can
see my transponder"
--"cessna XXXX, sqwak 4545 and ident"
--"cessna XXX yes I see you"
--"ok thanks have a good day"

Does anybody do this? Has a problem like this ever been encountered by
anyone else? Is there any other way to check that your transponder is
working before you enter airspace?

buttman wrote:


Does anybody do this? Has a problem like this ever been encountered by
anyone else? Is there any other way to check that your transponder is
working before you enter airspace?

It's common. Many towers have displays remoted from radar facilities
many miles away. If you are behind hills, etc., they will never see you,
and a lot of aircraft owners unnecessarily freak out about
"non-functional" transponders because of this. Danbury, CT (DXR), is an
excellent example, remoted from HPN with a severe hill between.

Rip

buttman wrote in news:1180576884.287284.107090
@g37g2000prf.googlegroups.com:

A few days ago I was getting ready to do a cross country with one of
my students. This was going to be his first cross country, so the
focus was going to be on pilotage, dead reckoning, planning, cockpit
management, and stuff like that. I was going to save the flight
following, flight plan, class C stuff for a later lesson.

He planned to a class D airport about 25 miles northeast of SFO, away
from the Bravo, but still under the mode C ring. He seemed to have his
stuff together, so after a few checkpoints I decided to go ahead and
call up Norcal to get following. I thought "might as well".

So I show my student how to get the frequency out of the AF/D. Then I
give them a call, tell our location, altitude, type, etc. The
controller gives us a squwak code and wait for him to tell us he has
us on radar. A few seconds later he calls us back and tells us to
recycle our transponder, as he isn't seeing anything on the scope. I
recycle it a few times, check the circuit breaker, and anything else I
can think to do. He comes back saying he doesn't have us, and I just
respond, "thanks anyway".

We ended up diverting somewhere else, did a few short/soft fields,
then called it a day. If we hadn't called flight following, we would
had never known about the transponder not working, and would have
violated some airspace. Scary stuff. It makes me nervous, as I did
another student's first cross country to class E airport underlying a
class C a few days prior (in a different plane). We made sure the mode
C was on and I even monitored their approach frequency, but I didn't
call them. It really makes you wonder... I just think it's distracting
having to constantly listen for your call sign while you're trying to
explain important stuff to your student.

Anyways, I was wondering, would it be a dumb idea to just call up a
radar facility to just ask if they can see your transponder?

Are oyu sure you're an instructor?


Bertie

"buttman" wrote in message
oups.com...

A few days ago I was getting ready to do a cross country with one of
my students. This was going to be his first cross country, so the
focus was going to be on pilotage, dead reckoning, planning, cockpit
management, and stuff like that. I was going to save the flight
following, flight plan, class C stuff for a later lesson.

He planned to a class D airport about 25 miles northeast of SFO, away
from the Bravo, but still under the mode C ring. He seemed to have his
stuff together, so after a few checkpoints I decided to go ahead and
call up Norcal to get following. I thought "might as well".

So I show my student how to get the frequency out of the AF/D. Then I
give them a call, tell our location, altitude, type, etc. The
controller gives us a squwak code and wait for him to tell us he has
us on radar. A few seconds later he calls us back and tells us to
recycle our transponder, as he isn't seeing anything on the scope. I
recycle it a few times, check the circuit breaker, and anything else I
can think to do. He comes back saying he doesn't have us, and I just
respond, "thanks anyway".

We ended up diverting somewhere else, did a few short/soft fields,
then called it a day. If we hadn't called flight following, we would
had never known about the transponder not working, and would have
violated some airspace. Scary stuff. It makes me nervous, as I did
another student's first cross country to class E airport underlying a
class C a few days prior (in a different plane). We made sure the mode
C was on and I even monitored their approach frequency, but I didn't
call them. It really makes you wonder... I just think it's distracting
having to constantly listen for your call sign while you're trying to
explain important stuff to your student.

Anyways, I was wondering, would it be a dumb idea to just call up a
radar facility to just ask if they can see your transponder?

--"Norcal center, this is cessna XXXX 10 miles south of blah blah,
6000 feet VFR, I don't want advisories, but can you tell me if you can
see my transponder"
--"cessna XXXX, sqwak 4545 and ident"
--"cessna XXX yes I see you"
--"ok thanks have a good day"

Does anybody do this? Has a problem like this ever been encountered by
anyone else? Is there any other way to check that your transponder is
working before you enter airspace?


It's not at all unusual for aircraft to call for a transponder and encoder
check.

In article .com,
buttman wrote:

So I show my student how to get the frequency out of the AF/D. Then I
give them a call, tell our location, altitude, type, etc. The
controller gives us a squwak code and wait for him to tell us he has
us on radar. A few seconds later he calls us back and tells us to
recycle our transponder, as he isn't seeing anything on the scope. I
recycle it a few times, check the circuit breaker, and anything else I
can think to do. He comes back saying he doesn't have us, and I just
respond, "thanks anyway".

Was the ident light blinking? How low where you? There are some
pretty good sized hills around CCR, so you might have been below
radar coverage. I'm not sure if Norcal has a feed from Travis,
but the controller would probably know if you where in an area he
can't see and hand you off to Travis if that was the case.

John
--
John Clear - http://www.clear-prop.org/

Is there any other way to check that your transponder is
working before you enter airspace?

I sometimes ask for a Mode C check.
It checks the encoding altitmeter in addition to general operation.

Tony

--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE

On May 30, 9:05 pm, (John Clear) wrote:
In article .com,

buttman wrote:

So I show my student how to get the frequency out of the AF/D. Then I
give them a call, tell our location, altitude, type, etc. The
controller gives us a squwak code and wait for him to tell us he has
us on radar. A few seconds later he calls us back and tells us to
recycle our transponder, as he isn't seeing anything on the scope. I
recycle it a few times, check the circuit breaker, and anything else I
can think to do. He comes back saying he doesn't have us, and I just
respond, "thanks anyway".

Was the ident light blinking? How low where you? There are some
pretty good sized hills around CCR, so you might have been below
radar coverage. I'm not sure if Norcal has a feed from Travis,
but the controller would probably know if you where in an area he
can't see and hand you off to Travis if that was the case.

John
--
John Clear - http://www.clear-prop.org/

ident light was not blinking, but some of these planes have a real dim
ident light and the sun was behind us.

Also, we were at about 3000 feet and just south of Modesto. I don't
think radar coverage was the issue.

On May 30, 9:18 pm, tony roberts wrote:
Is there any other way to check that your transponder is
working before you enter airspace?

I sometimes ask for a Mode C check.
It checks the encoding altitmeter in addition to general operation.

Tony

--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE

huh

I've never heard someone ask for such a thing. What do you say, just
your tailnumber and location and they come back with "yeah I see you",
or is it more involved than that?

huh

I've never heard someone ask for such a thing. What do you say, just
your tailnumber and location and they come back with "yeah I see you",
or is it more involved than that?

If it's busy I don't say anything.
If I'm out at 2100 hours, and the tower staff are sitting there bored
out of their minds, I'll sometimes call, "Kelowna Tower, Cessna 172 Golf
India Charlie Echo requesting Mode C check - I have 4200 ft" and they
will respond, "India Charlie Echo Altimeter setting is 29.96 - we read
4350ft." Then I know that although I am out, I am still legal.
If of course the call India Charlie Echo we read 4550 feet then I know
to have my modre C encoder checked before I fly through any serious
airspace.

HTH

Tony

--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE

tony roberts wrote:

I sometimes ask for a Mode C check.
It checks the encoding altitmeter in addition to general operation.

Our plane flies in Bravo/Charlie/IFR enough that we know ours works.

However, we went through a spell where we were told by ATC that they
were getting double returns from us. Our favorite avionics guy checked
it twice with nothing found. The double return would happen in a
relatively specific geographical area. We would often get asked if we
had multiple transponders in the aircraft.

The problem disappeared, and we've since met others who had been told of
double returns. We've chalked it up as a since-repaired FAA radar /
computer issue.

I'd simply ask ATC for checks, as Tony mentioned.