---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 12/30/18: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:51 PM - Transponder question (Rick Beebe) 2. 08:21 PM - Re: Transponder question (Charlie England) 3. 08:51 PM - Transponder question (Paul Millner) 4. 09:07 PM - Re: Transponder question (Kelly McMullen) 5. 10:31 PM - Re: Transponder question (Rick Beebe) ________________________________ Message 1 _____________________________________ Time: 07:51:00 PM PST US From: Rick Beebe Subject: AeroElectric-List: Transponder question What is it about a transponder that makes the FAA require it only be installed by a certified shop? Even if it's just been pulled from the rack? I hadn't thought much about it until a couple weeks ago when I had the plane at the shop for the biennial transponder check. I forgot the log book and he said that if he had to pull the transponder to look at the serial number that it would cost more because they'd have to recertify it. So what can happen to a transponder when it's pulled from the rack? --Rick ________________________________ Message 2 _____________________________________ Time: 08:21:44 PM PST US Subject: Re: AeroElectric-List: Transponder question From: Charlie England On 12/30/2018 9:48 PM, Rick Beebe wrote: > > What is it about a transponder that makes the FAA require it only be > installed by a certified shop? Even if it's just been pulled from the > rack? I hadn't thought much about it until a couple weeks ago when I > had the plane at the shop for the biennial transponder check. I forgot > the log book and he said that if he had to pull the transponder to > look at the serial number that it would cost more because they'd have > to recertify it. So what can happen to a transponder when it's pulled > from the rack? > > --Rick > Only thing I've heard about re-cert is if the static system is opened. My neighbor does xpndr certs; I'll ask him if I see him in the next few days. Charlie --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 3 _____________________________________ Time: 08:51:13 PM PST US Subject: AeroElectric-List: Transponder question From: Paul Millner Technically, I don't think that's strictly true... the rule as I recall it is that high power transmitters (like our transponders and DME equipment, that can output hundreds or even 1,000 watts) must be reinstalled by an A&P or repair station. The concern is that if the antenna connection isn't properly made, it could prove to be a source of ignition, and fires in airplanes are bad things. >> I hadn't thought much about it until a couple weeks ago when I had the plane at the shop for the biennial transponder check. I forgot the log book, and he said that if he had to pull the transponder to look at the serial number, that it would cost more because they'd have to recertify it. I don't believe that's a general requirement; perhaps it's part of his repair stations procedures... I don't think an A&P doing an R&R on a transponder, say, to replace another component has to do a recertification, whatever your guy meant by that term. They just have to determine proper function. Readers have a reference? >> So what can happen to a transponder when it's pulled from the rack? If you improperly reinstall it, you can turn a lot of power into heat. Paul ________________________________ Message 4 _____________________________________ Time: 09:07:48 PM PST US Subject: Re: AeroElectric-List: Transponder question From: Kelly McMullen In theory, if the connection has slightly different resistance after the pull and re-install, the propagation pattern for a transmitter in the 1030-1090Mhz frequency at 150-250 watts could be slightly different. So, in theory a quick look at the ramp checker should be done. As a practical matter, I've never seen it change anything. Any A&P can install the transponder, but a repair station must certify it. Unless you are the builder (manufacturer) of the aircraft and have a proper test set to be able to certify it yourself as the aircraft manufacturer in the case of a homebuilt. Then there is the matter of the shop being jerks. He could wait a day or two for you to bring in the logs. He could do the ramp check...if it isn't turned on until he gets there it takes 5 min for the transponder to warm up (for the old cavity tube variety) or less for solid state. He can make the choice. If he had inquired before starting the test, he could have pulled the unit, got the serial number and reinstalled before doing the test. He is just forgetting that he is in the customer service business, and you can go elsewhere. For those that don't know the full reg on static system checks...it only has to be certified once every 2 years, regardless of how many times you open the system. Now if you change altimeter or encoder, that is different story. If you just open a connection and put it back together, any A&P can do a leak check on the system (holds 1000 ft AGL for 1 minute with no more than 100 ft loss). The certification says the system meets that leak test, and altitude requirements for the altimeter. On 12/30/2018 8:48 PM, Rick Beebe wrote: > What is it about a transponder that makes the FAA require it only be > installed by a certified shop? Even if it's just been pulled from the > rack? I hadn't thought much about it until a couple weeks ago when I had > the plane at the shop for the biennial transponder check. I forgot the > log book and he said that if he had to pull the transponder to look at > the serial number that it would cost more because they'd have to > recertify it. So what can happen to a transponder when it's pulled from > the rack? > > --Rick > ________________________________ Message 5 _____________________________________ Time: 10:31:07 PM PST US Subject: Re: AeroElectric-List: Transponder question From: Rick Beebe In all fairness he let me fly home and email him the serial number. Then he mailed me the sticker for the log book and the bill. It just made me curious, that's all. --Rick On 12/30/2018 11:59 PM, Kelly McMullen wrote: > Then there is the matter of the shop being jerks. He could wait a day > or two for you to bring in the logs. He could do the ramp check...if > it isn't turned on until he gets there it takes 5 min for the > transponder to warm up (for the old cavity tube variety) or less for > solid state. He can make the choice. If he had inquired before > starting the test, he could have pulled the unit, got the serial > number and reinstalled before doing the test. He is just forgetting > that he is in the customer service business, and you can go elsewhere. > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.