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Transponder Certification Requirements

richpezz

Member
I've just completed the build on my RV12is and awaiting my FAA Registration / DAR Airworthiness Inspection.

Question: Do I need to have my TRANSPONDER certified by an avionics shop or am I OK to fly for two years until my first test / certification?

Any input would be appreciated.

Txs

Rich P.
 
You need to get it certified

A transponder certification is a system test, it is not just testing a single box.
The antenna, encoder and wiring are all part of the system.
 
It really matters on the airspace you will be flying in. If a transponder is not required, then you can make your first flight where you are located. However, do NOT operate the transponder in flight until it has been certified by an appropriate technician.

I sometimes run across this as a DAR. IF the transponder signoff is not in the book and the aircraft is located in airspace that requires it, then I do remind them that it needs to be certified prior to the flight. It is not technically an airworthiness item for an airworthiness inspection, but it is an operational requirement, which is the responsibility of the pilot.

Vic
 
I sometimes run across this as a DAR. IF the transponder signoff is not in the book and the aircraft is located in airspace that requires it, then I do remind them that it needs to be certified prior to the flight. It is not technically an airworthiness item for an airworthiness inspection, but it is an operational requirement, which is the responsibility of the pilot.

Vic

I believe the above is correct. My DAR believed the above to be correct. But, just to be sure, he said, I’ll double check with the FSDO. You guessed it, the morons there said it was required before A/W could be issued. It was easier to just get it done (fortunately there’s a shop on-airport) than argue with the government. This was the first, but unfortunately not the last, time the FSDO didn’t understand their own rules.
 
Just do it

The certification takes about ten minutes plus another ten for paperwork. The shop charged me $100. Just do it.
 
I know it's rare these days, but if the altitude data is not supplied by the EFIS (ie: separate altimeter/encoder) then an altitude data correspondence test must also be accomplished on new installations. Technically it has to be done with a glass panel as well but I think everyone knows (even the feds) if the altimeter is also the encoder it's not really necessary but I will still list the SN of the air data unit on the test sheet and sign it off as xpdr test with data correspondence, I do verify correct displayed/xmitted altitude as well to keep it 'legal'. And I do charge more than $100 :eek:

For more FAQ's on this topic I have some common questions listed on my website.
 
Vic is correct and your FAA guy is wrong. The transponder certification is an operational issue. It has nothing to do with airworthiness certification.

Again, like Vic, if the aircraft is located where transponder is required, I remind the builder that the check IS required before flight.
 
Again, like Vic, if the aircraft is located where transponder is required, I remind the builder that the check IS required before flight.

Or if you're so inclined, you can get a ferry permit to your local avionics shop to have it done.
 
Per FAR 91:

(c) Transponder-on operation. While in the airspace as specified in paragraph (b) of this section or in all controlled airspace, each person operating an aircraft equipped with an operable ATC transponder maintained in accordance with §91.413 of this part shall operate the transponder, including Mode C equipment if installed, and shall reply on the appropriate code or as assigned by ATC, unless otherwise directed by ATC when transmitting would jeopardize the safe execution of air traffic control functions.

I guess the above hinges somewhat on the FAA's definition of "...operable ATC transponder maintained ...".
 
Curious: What possible definition could there be, other than the obvious one?
‘If it works, and has been inspected and tested, you have to turn it on.’
 
Curious: What possible definition could there be, other than the obvious one?
‘If it works, and has been inspected and tested, you have to turn it on.’

And it has to be inspected and tested to fly in controlled airspace unless you get a ferry permit to fly with it inoperative.
 
You should be able to fly without it certified if you stay out of controlled airspace and placard it DO NOT USE. What would the DAR do if you took it out of the airplane? Will it crash?
 
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Vic is correct and your FAA guy is wrong. The transponder certification is an operational issue. It has nothing to do with airworthiness certification.

Again, like Vic, if the aircraft is located where transponder is required, I remind the builder that the check IS required before flight.

Yep, I concur with Vic and Mel. The transponder isn't an airworthiness item.
 
FAR 91.215 (d)

Situation: At an airport within the 30 mile Class C boundary, but below the Class C altitude. No transponder installed (ever). As I read the FAR 91.215 (d) (3) I can request a deviation from the Transponder requirement:

(d) ATC authorized deviations. Requests for ATC authorized deviations must be made to the ATC facility having jurisdiction over the concerned airspace within the time periods specified as follows:

(1) For operation of an aircraft with an operating transponder but without operating automatic pressure altitude reporting equipment having a Mode C capability, the request may be made at any time.

(2) For operation of an aircraft with an inoperative transponder to the airport of ultimate destination, including any intermediate stops, or to proceed to a place where suitable repairs can be made or both, the request may be made at any time.

(3) For operation of an aircraft that is not equipped with a transponder, the request must be made at least one hour before the proposed operation.


Seems straight forward. Am I reading it wrong (THAT'S happened before!)?
 
InHot,
I'm unfamiliar with the "30 mile class C boundary." Are you confusing this with the "mode C veil?"; 30 miles around class B airports?
 
You're right, I meant to say Class B aircspace that requires mode C.

FAR 91.215 refers to that airspace as:

(2) All aircraft. In all airspace within 30 nautical miles of an airport listed in appendix D, section 1 of this part from the surface upward to 10,000 feet MSL

which is, mode "c" veil I beleive..

Sorry for the confusion.
 
My home field (KLVK) is about 3 nm inside the mode C veil around SFO. They routinely approve non-transponder aircraft to arrive/depart LVK, as long as they come or go the shortest route to/from the boundary (e.g., east of the airport). I do not know if they will waiver non-ADSB aircraft.
 
do it

It's odd how such a simple issue can get you the wrong answer from an official person. The DAR who did my airworthiness cert 4 years ago told me that E-LSA is built as an exact copy of an FAA approved prototype, and therefore my xponder inherited that approval and did not need to be checked until 2 years passed. That seemed logical so I didn't question it. When I did get it checked 2 years later, the avionics shop that checked it emphatically informed me that the DAR was not correct. Another 2 years has passed and it is time to do it again. Fortunately it is fairly quick and not terribly expensive. In my area a mobile shop will come to my hangar to do it.
 
Our local avionics shop requires an ADS-B check at the same time as the transponder check and so charges more for an ADS-B equipped aircraft. They way I understand it there is not such requirement for ADS-B out check with ramp test equipment, initial or recurring. It so happens some of the newer ramp testers also have a function to check ADS-B out. That function is merely used to confirm an installation is working correctly as a convenience. It saves an initial compliance flight check. I think the shop is adding the ADS-B check to every transponder check to help pay for their new fancy ramp tester without cause.

Effectively ADS-B transmitters automatically get checked multiple times a minute during operation and if they ever act up or go down an optional panel light might go on or an EFIS might flag it. Or you won't know immediately. The FAA's ADS-B system monitors your unit at all times it is operating. If the failure is egregious be sure the FAA will send a letter of non-compliance. So every flight provides an official test of your ADS-B.

Am I wrong or is the local radio shop wrong?
 
Wrong shop

The avionics shop is wrong. The two year recertification was discussed during rulemaking, and the fact that your ADS-B out is monitored for performance by the FAA system was seen as an adequate substitute for a periodic recertification.
The transponder rule didn't change though, so we still need to make that trip to the avionics shop for the transponder SYSTEM check. So, if you disturb your transponder system in any way, i.e. change coax, change antenna, then a new transponder cert is required.....

And, if your transponder isn't certified on airworthiness day, it is an operational issue, not airworthiness, so, it would not need a ferry permit, but it would need an operational deviation approval from ATC, if needed to fly to the avionic shop.
 
It's odd how such a simple issue can get you the wrong answer from an official person. The DAR who did my airworthiness cert 4 years ago told me that E-LSA is built as an exact copy of an FAA approved prototype, and therefore my xponder inherited that approval and did not need to be checked until 2 years passed. That seemed logical so I didn't question it. When I did get it checked 2 years later, the avionics shop that checked it emphatically informed me that the DAR was not correct. Another 2 years has passed and it is time to do it again. Fortunately it is fairly quick and not terribly expensive. In my area a mobile shop will come to my hangar to do it.

Very similar to my experience. When I went into the avionics shop after having flown for 2 years, the tech was not pleased that the equipment had not ever been tested. Clearly confusion that affected many of us.

BTW the first avionics inspection ran the equipment all the way up to the high altitudes (forget exactly but the routine ran towards 20K feet) testing my static system. Needed to access the AHARS in the tail for the test equipment which is a PITA. Thought that was overkill to run it all the way to nosebleed altitudes for an RV-12, but that is what they do and charged at least a couple of hundred dollars for it. For my subsequent 2 yr inspections its a quick on the ramp procedure and ~$100.
 
Every VFR XPDR check I ever had did not involve a static system check that needed an external connection. They just verified it was broadcasting field Pressure altitude.
 
Also keep in mind. If you have a digital transponder, Mode C, S or ES they can usually display pressure altitude on the screen. I always change Garmin GTX units from flight level (FL) to feet (FT). They all seem to default to flight level out of the box. The point being you can set your ship's altimeter to 29.92 and cross-check the transponder's pressure altitude reading. They should match. Do this on the ground or while in cruise if you get bored. You will know your system is functional or bad before needing a ramp tester. Even if you have an older analog tube type transponder you can request your pressure altitude reading from ATC over the radio.
 
Jim,

The problem with what you suggest (at least in my D180 setup) is that the encoder signal is coming from the same source as the altimeter. If we had standalone altimeters and encoders I would agree with the cross check.

Rich
 
Very similar to my experience. When I went into the avionics shop after having flown for 2 years, the tech was not pleased that the equipment had not ever been tested. Clearly confusion that affected many of us.

BTW the first avionics inspection ran the equipment all the way up to the high altitudes (forget exactly but the routine ran towards 20K feet) testing my static system. Needed to access the AHARS in the tail for the test equipment which is a PITA. Thought that was overkill to run it all the way to nosebleed altitudes for an RV-12, but that is what they do and charged at least a couple of hundred dollars for it. For my subsequent 2 yr inspections its a quick on the ramp procedure and ~$100.

For a first time check or anytime the altimeter or encoder is replaced a "Data Correspondence" check is required. That purpose of that check was to confirm that the encoder (separate) and altimeter matched within 125'.

With an AHRS which uses digital output, and acts as both the altimeter and encoder, that test is no longer required (per advisory circular).

So the shop was trying to do the right thing but not quite up to speed in the new world of glass panels.
 
The point being you can set your ship's altimeter to 29.92 and cross-check the transponder's pressure altitude reading. They should match.
Provided your altimeter is also calibrated on an annual basis, that is.
 
The avionics shop is wrong. The two year recertification was discussed during rulemaking, and the fact that your ADS-B out is monitored for performance by the FAA system was seen as an adequate substitute for a periodic recertification. The transponder rule didn't change though, so we still need to make that trip to the avionics shop for the transponder SYSTEM check. So, if you disturb your transponder system in any way, i.e. change coax, change antenna, then a new transponder cert is required.....

And, if your transponder isn't certified on airworthiness day, it is an operational issue, not airworthiness, so, it would not need a ferry permit, but it would need an operational deviation approval from ATC, if needed to fly to the avionic shop.

Is this still valid?

My friend's FAA PAPR has been clean as a hound's tooth for 4+ years now. Nothings been changed or tampered with on the 261 Xponder Dynon provides.
 
For a first time check or anytime the altimeter or encoder is replaced a "Data Correspondence" check is required. That purpose of that check was to confirm that the encoder (separate) and altimeter matched within 125'.

With an ADHRS which uses digital output, and acts as both the altimeter and encoder, that test is no longer required (per advisory circular).

So the shop was trying to do the right thing but not quite up to speed in the new world of glass panels.

Bold portion noted, Thank You.

Do you know the Advisory circular # the FAA provided stating this test is no longer required?
 
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My friend paid $175 to get his transponder Altitude 2 year certification for the soon to be new owner ( a commerical pilot) and now his altitude has no reading on Flight Aware after being certified. His plane now fails the FAA PAPR report 100% for B alt and G alt readings ( red blocks)

In going into the Skyview menu under Setup>serial port 3>Xpnder 261> standard "1200" is used, both gnd and air and is the correct setting. However at the top of the screen in the Transponder box on the top row, the box is lit in Yellow and is locked in "Standby" mode, not Green "1200" with a little red "RE" circle next to it.

Any suggestions on how to take the transponder out of "Standby" mode, since it seems the guy that certified the altitude from the transponder didn't go back and leave the settings the way he found them.

Before certification: https://flightaware.com/live/flight/N836BL/history/20220625/1457Z/KWHP/KWHP/tracklog
After certification: https://flightaware.com/live/flight/N836BL/history/20220702/1450Z/KWHP/KWHP/tracklog
 
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My friend paid $175 to get his transponder Altitude 2 year certification for the soon to be new owner ( a commerical pilot) and now his altitude has no reading on Flight Aware after being certified. His plane now fails the FAA PAPR report 100% for B alt and G alt readings ( red blocks)

In going into the Skyview menu under Setup>serial port 3>Xpnder 261> standard "1200" is used, both gnd and air and is the correct setting. However at the top of the screen in the Transponder box on the top row, the box is lit in Yellow and is locked in "Standby" mode, not Green "1200" with a little red "RE" circle next to it.

Any suggestions on how to take the transponder out of "Standby" mode, since it seems the guy that certified the altitude from the transponder didn't go back and leave the settings the way he found them.

Before certification: https://flightaware.com/live/flight/N836BL/history/20220625/1457Z/KWHP/KWHP/tracklog
After certification: https://flightaware.com/live/flight/N836BL/history/20220702/1450Z/KWHP/KWHP/tracklog

Two comments:

First, be sure that the Transponder set up menu has been set back to "Auto": SETUP MENU > TRANSPONDER SETUP > AUTO ALT/GND > AUTOMATIC (AIR DATA)

See page 11-42, "Performing Transponder Checks", of the SkyView System Installation Guide.

Example:

i-7tkvPzb-M.png


Second, the "Standby" mode (SBY) is active when none of the other modes are active (It does not have its own key to select it). Have him try to select "AUTO" (or "ALT") in the main Transponder menu.

See page 6-2, "Transponder Operation", of the SkyView Classic/Touch Pilot's Guide for details.

Example:

i-wPDFnZb-M.jpg

My guess is that the second suggestion will get the transponder out of "Standby" mode.
 
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Thanks, it was the 2nd step that fixed it. Go to "Xpnder" button then press "ALT" button so that it highlights. "1200 R" is now displayed on top bar of main screen.
 
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