Transponder test after static system opened?

Hi all,
So are you required to get a transponder test any time the static
system has been opened (for VFR flight)?

You are required to get a static/altimeter/xpdr test for IFR flight
any time the static system has been opened (91.411).

91.413 refers to maintenance on the transponder (and presumably
encoder) but has no reference to the static system.

My IA wants me to get a transponder test because he had some of the
static hoses off. I'd prefer to wait until I get some radio work
done in a month or so.

Thanks,
Jack





91.413 ATC transponder tests and inspections.

(a) No persons may use an ATC transponder that is specified in 91.215(a),
121.345(c), or §135.143(c) of this chapter unless, within the preceding 24
calendar months, the ATC transponder has been tested and inspected and
found to comply with appendix F of part 43 of this chapter; and

(b) Following any installation or maintenance on an ATC transponder where
data correspondence error could be introduced, the integrated system has
been tested, inspected, and found to comply with paragraph (c), appendix E,
of part 43 of this chapter.

....

No!

If the static system has been opened, and resealed, it should have no
effect on the operation of your encoder or transponder. There is no
requirement to get either checked.

If you have had your transponder checked in the last 24 months it is
still good until the end of the 24th month.

Paragraph "b" has nothing to do with the static system being opened.
They are talking about a "data correspondence error" which is the way
the encoder talks to the transponder.

Dave
www.craigmileaviation.com



Jack I wrote:
Hi all,
So are you required to get a transponder test any time the static
system has been opened (for VFR flight)?

You are required to get a static/altimeter/xpdr test for IFR flight
any time the static system has been opened (91.411).

91.413 refers to maintenance on the transponder (and presumably
encoder) but has no reference to the static system.

My IA wants me to get a transponder test because he had some of the
static hoses off. I'd prefer to wait until I get some radio work
done in a month or so.

Thanks,
Jack





91.413 ATC transponder tests and inspections.

(a) No persons may use an ATC transponder that is specified in 91.215(a),
121.345(c), or §135.143(c) of this chapter unless, within the preceding 24
calendar months, the ATC transponder has been tested and inspected and
found to comply with appendix F of part 43 of this chapter; and

(b) Following any installation or maintenance on an ATC transponder where
data correspondence error could be introduced, the integrated system has
been tested, inspected, and found to comply with paragraph (c), appendix E,
of part 43 of this chapter.

...

On 9-Mar-2004, dave wrote:

No!

If the static system has been opened, and resealed, it should have no
effect on the operation of your encoder or transponder. There is no
requirement to get either checked.

If you have had your transponder checked in the last 24 months it is
still good until the end of the 24th month.

Paragraph "b" has nothing to do with the static system being opened.
They are talking about a "data correspondence error" which is the way
the encoder talks to the transponder.


I am not qualified to answer the original question, but I believe that there
may be an error in the above statement. The encoder is, in fact, connected
to the static system. That is where it gets its pressure reading for
altitude, just like the panel altimeter. It would thus seem logical that
its operation SHOULD be tested if the static system is "unsealed". The
obvious way to test the encoder would be by observing transponder return
altitude codes in mode C operation while testing the static system.
However, the transponder test involving verification of output power level,
etc. probably does not need to be done.

--
-Elliott Drucker

wrote:
On 9-Mar-2004, dave wrote:


No!

If the static system has been opened, and resealed, it should have no
effect on the operation of your encoder or transponder. There is no
requirement to get either checked.

If you have had your transponder checked in the last 24 months it is
still good until the end of the 24th month.

Paragraph "b" has nothing to do with the static system being opened.
They are talking about a "data correspondence error" which is the way
the encoder talks to the transponder.



I am not qualified to answer the original question, but I believe that there
may be an error in the above statement. The encoder is, in fact, connected
to the static system. That is where it gets its pressure reading for
altitude, just like the panel altimeter. It would thus seem logical that
its operation SHOULD be tested if the static system is "unsealed". The
obvious way to test the encoder would be by observing transponder return
altitude codes in mode C operation while testing the static system.
However, the transponder test involving verification of output power level,
etc. probably does not need to be done.


hi Elliott,

The fact the static system has been opened, resealed and verified there
are no leaks has no effect on the encoder at all. It has the same air
pressure on its pressure transducer as it had before the system had been
opened. The encoder will operate the same whether or not there is a
static system attached to it at all. It senses a pressure and reports it
to the altimeter.


BTW, I operate a repair station doing the 91.411 and 91.413 inspections
and certifications.
I have turned down work because of this.

Cheers
Dave

dave wrote:


It senses a pressure and reports it
to the altimeter.

It doesn't report anything to the altimeter. It reports it to the
transponder which reports it to anybody who is listening.

I guess he does not trust his work and is unsure that he did not leave
out some hose connections possibly to the encoder?
If your biannual altimeter and transponder test is still within the
allowed two year time you only have to do a static system test to test
that the new connections do not leak per part 23.1325 paragraph 2i or
2ii which is a simple and quick one minute leakage test using the
existing airplane's altimeter.
Why pay for a $200 test when a $10 test is what is needed?


On Tue, 09 Mar 2004 20:19:01 -0600, Jack I wrote:

Hi all,
So are you required to get a transponder test any time the static
system has been opened (for VFR flight)?

You are required to get a static/altimeter/xpdr test for IFR flight
any time the static system has been opened (91.411).

91.413 refers to maintenance on the transponder (and presumably
encoder) but has no reference to the static system.

My IA wants me to get a transponder test because he had some of the
static hoses off. I'd prefer to wait until I get some radio work
done in a month or so.

Thanks,
Jack





91.413 ATC transponder tests and inspections.

(a) No persons may use an ATC transponder that is specified in 91.215(a),
121.345(c), or §135.143(c) of this chapter unless, within the preceding 24
calendar months, the ATC transponder has been tested and inspected and
found to comply with appendix F of part 43 of this chapter; and

(b) Following any installation or maintenance on an ATC transponder where
data correspondence error could be introduced, the integrated system has
been tested, inspected, and found to comply with paragraph (c), appendix E,
of part 43 of this chapter.

...

Jack I wrote in message ...
Hi all,
So are you required to get a transponder test any time the static
system has been opened (for VFR flight)?

Hmmm, the last time I checked... the static system is always in a
perpetual state of being "opened", except maybe when the port is
blocked by icing.