Ground Testing Transponders

[smithgd]

Hi

Can someone help me to understand transponder testing?

1) I understand there is kit out there that can test transponders on the ground, i can only find one by aeroflex are there any others?

2) Can you simulate the aircraft being in the air to test mode C replies? If so any procedures to do this so passing aircraft don't have a heart attack as you pop up in front of them?

3) Any formal training/quals needed to do this?


Cheers
smithgd

[Filler Dent]

1. TIC TR-220 springs to mind by these people. Tel Instrument Electronic Corp. - Home (http://www.telinst.com/)

2. You have to put the aircraft in the air mode, ATC Xpdrs work only in the air. Your barometric altitude should be set to QFE so other aircrafts TCAS should ignore you. You can also gag the antennas and make use of a closed hangar, which helps - but is more important if your testing TCAS at height. ie. your simulating flight.

3. A JAR 66 B2 licence is preferred.

[Wodrick]

Should that not be a B2 is required (test equipment)

[ampclamp]

yes you can simulate airmode, depends on your aircraft type of course as to how that can be done.

An ATC 601 or 600 for example will do the job for testing.
Depending on where you are and what system you op under, radio licence , B2 or equivalent needed to sign off.

Testing an ATC would normally require a setting a test squawk code.

Some sets have antenna cuffs that fit over the antennae others just use a small vertical antenna on a mount/ground plane.

[aveng]

In oz we use a test code, pretty sure its "2100" though haven't done test for a while. The newer sets with the antenna "boots" (should) stop the signal being picked up by atc. Just dont forget to pull breakers for pitot heaters etc before putting A/C in air mode.:ok:

[matkat]

EASA AD 2006-0265 mandates a check of both mode "S" and "C" on a 2 yearly cycle we do it with a field test kit, sorry do not have the model number handy.

[BAe146s make me cry]

http://www.aeroexpress.com/products/pdfs/atc601.pdf

I've just realised 'IFR' is now 'Aeroflex' - Sorry! :O

The IFR ATC 601 is by far the most common ATC Xponder test kit
in UK Part 145 MROs at present.

As for who is qualified to perform the work? A skilled
& suitably trained technician strictly following the applicable AMM
ATA Chapter 34.

A type rated B2/Avionics licenced aircraft engineer with a company approval will be required to certify the work completed.

BAe 146??? :{:{:{

[happybiker]

As the previous responses indicate you need to exercise care when carrying out ground tests on ATC Transponders, particularly Mode C as there has been a number of false warnings with TCAS equipped aircraft in the vicinity when testing is underway.

CAA has published guidance on ground testing of ATC Transponders in CAAIP (CAP562). It is well hidden but you will find it in Part 11, Leaflet 11-22 "Experience from Incidents" Appendix 34-3 The link below should take you to the CAP


CAP 562: Civil Aircraft Airworthiness Information and Procedures (CAAIP) | Publications | CAA (http://www.caa.co.uk/application.aspx?catid=33&pagetype=65&appid=11&mode=detail&id=92)

[smithgd]

Thanks for the info chaps, very useful.

Next silly question... I assume there is a fancy piece of kit that will test the encoder, by providing a pressure?

cheers
smithgd

[BAe146s make me cry]

Let me introduce you to the GE/Druck ADTS 505. I've used this bit of
equipment since 2003 (in various countries) AND it's my favourite
Pitot/Static test set. Beats any old manual thing I have ever used
before such as Barfield, Penny & Giles etc.

Air Data Test Set, Aviation Test Equipment, Pressure Controller, Pressure Sensor, Calibration Instruments, Civil Flightline ADTS 505 - GE Druck (http://www.gesensing.com/products/adts505.htm)

However, I will still use a Bryans leak tester for basic Pitot/Static
leak checks because the ADTS 505 is just TOOO sensitive!

BAe146??? :{:{:{

[ampclamp]

geez mate those 146's made me cry a few times too, what a pig of an aircraft.

smithgd, yes using a pitot static tester will give you the req'd altitude inputs for mode c .
I think the airbuses (at least) you can dial an altitude into the cfds or cmc test to alleviate the need for pump up of the P/S system

aveng I believe is correct test code to be entered into the atc controller is 2100 [ NB!! in Australia that is.]

[BAe146s make me cry]

A related pig was/is getting an ADTS 505 set up correctly for an EGPWS
function check IAW AMM on a Bae146...

The static plate adaptor for S1,S2,S3 isn't the easiest thing to set up.
Then you have S4 for the BARC input BUT also (dependant on effectivity) there is the fwd outflow valve control S4 input - blanked during the check? - Memory getting hazy around about NOW!

As mentioned before, I despised the BAe146 once, not now though :eek:
Although sometimes, it does bite back & tears roll once more!

BAe146??? :{:{:{

[smithgd]

Thanks guys.