On Friday, April 27, 2012 3:55:23 AM UTC-7, Scott wrote:
On 4-26-2012 18:08, Tony wrote:
On Thursday, April 26, 2012 12:37:54 PM UTC-5, wrote:
On Wednesday, April 25, 2012 7:29:19 PM UTC-7, wrote:
I have a question for the group, will a glider pass a annual if the glider is equipped with a Transponder that is past it’s 24 month certification?

Appendix D to Part 43

(c) Each person performing an annual or 100-hour inspection shall inspect (where applicable) the following components of the cabin and cockpit group:

(4) Instruments—for poor condition, mounting, marking, and (where practicable) improper operation.

Sec. 91.213 — Inoperative instruments and equipment.

(3) The inoperative instruments and equipment are—

(i) Removed from the aircraft, the cockpit control placarded, and the maintenance recorded in accordance with §43.9 of this chapter; or

(ii) Deactivated and placarded “Inoperative.” If deactivation of the inoperative instrument or equipment involves maintenance, it must be accomplished and recorded in accordance with part 43 of this chapter; and

OK I have energy today and did my homework, Thanks.

if the transponder is out of calibration it is not inoperative and does not have to be placarded or removed. in fact it is just required to be left off until it has been calibrated.

I believe the "calibration" is for the Mode-C altitude reporting. You
should still be able to run simple Mode-A (transponder in "On" position
squawking 1200 or whatever you use for "glider" as appropriate, not
"Alt" position) ???

No and no. This has been discussed here multiple times before. You need to read 14 CFR 43 appendix E and F. The biannual transponder test is described in appendix F and is radio frequency proprieties of the transponder only, and has nothing to do with pressure altimetery/encoding. That's covered in Appendix E and only required to be done on install or any time the static system is opened/modified. The biannual checking of RF properties made more sense in the days of traveling wave tube (valve) based transponders, with modern solid state transponders it is hard to justify.

And either way running a transponder in Mode A does not really help a lot. ATC will see a Mode A reply and they may (or may not) route traffic around it or warn other traffic if possible. If you are anywhere a Mode C transponder is required) or even where gliders have operating agreements with ATC) expect to have some ****ed off ATC folks. If you suspect your altimeter/encoder is faulty by all means go to Mode A only or standby, but especially if near ATC be in contact with them about this. A Mode A transponder is totally invisible to TCAS (and I assume most TCAD systems), which only interrogates in Mode C--and this is a significant saftey issue and reason not to want to ever do this near busy airspace (e.g Reno like areas). It also won't help PCAS systems that rely/assume they see Mode C and A relies.

The practical answer to the original question will depend on you A&P. Some may well not want to sign off on a annual if the transponder has not received a check -- I'd argue with them on this, but like many questions what actually happens is up to your A&P. And the practical hassle at worst is what an inspector performing a ramp check is going to believe and that might be all over the map. Hopefully the FAA and their staff would err on the side of doing whatever they can to encourage installation and use of transponders in gliders.

Darryl