Avionics installation

[Harold Holiman]

George,

I am having trouble posting on this new site. This is the third try so here goes again. I get several different answers around here as to what is required for avionics installation. My understanding is (1) for a simple slide in change for a newupgrade model using the same mounting tray it can be done by a log book entry by a A&P. (2) To remove radio and install complete new radio model including new mounting a 337 is necessary. (3) For vfr use the installation does not have to be done only by a licensed avionics shop. Any A&P can legally install a radio. Are my beliefs correct or what is correct regarding avionics installations.
Thanks,
Harold

[GAHorn]

Good questions, Harold!
This very series was asked by me of my Avionics Inspector at the SAT FSDO. Here's what he said.
Opinions vary on this, but the FAA position is that radio installations, if included as original installations from the mfr., do not require Form 337's (Major Alterations and Repairs Form) for replacement radios unless a major alteration or repair is necessary for the installation. While it's never wrong to have a Certified Repair Station (CRS) perform the work, it's also not necessary unless the TSO of the avionics mfr. requires it, or unless an installation process is required that is a part of that TSO.
In other words, if you're replacing a nav/com with another nav/com, then your A&P can legally do this, and make a logbook entry, and equipment list change (and wt/bal change, if any). If you're replacing a Loran with a "slide-in" replacement GPS, that requires only an antenna removal/installation,....then that is also an A&P function. But, if that GPS is going to be an IFR certified unit, or if it is going to interface to a flight control system such as an autopilot, ... then you've now gotten into the region of installations of new equipment (annunciator panels, interface boxes) and you're also attempting to certify the system as a whole, to perform and influence the flight and aircraft in ways that a stand-alone radio never did. You are now making a major alteration to the aircraft, and you'll need a Form 337 and an avionics shop (CRS).
In a related question, ....non-TSO'd radios may be installed in VFR aircraft. There is no requirement that radios be TSO'd to be installed into our 170's. But if you do install a radio that is TSO'd, you'll have to compy with the installation stipulations of that TSO, if any. IF there are any such requirements, then it's likely you'll be getting involved with 337's and CRS's again.
Consider this: Virtually all avionics of current vintage have installation manuals/instructions approved by their mfr., and the governing authority (if req'd.). Those manuals will usually contain sufficient information to indicate the level of expertise and tools necessary for a correct installation. That information contained in that manual/procedure, is your best guide as to whether or not a CRS, a Form 337, an A&P, or even if simply doing it yourself under the watchful eye of an A&P is all that is required.
If it's still not clear, then contact your local FSDO and talk to your avionics inspector. (Mine rolls his eyes every time he gets another Form 337 just because someone replaced their Com 120 with a Com 810. It should be a simple logbook entry.)

[Bill Venohr]

OK George, your answer now begs the question what about TSO? What is it, is it required, etc.? Also, what if I replace a NAV/COM with an entirely new one that requires installation of a nav head and new antenna? THanks.
Bill

[GAHorn]

OK George, your answer now begs the question what about TSO? What is it, is it required, etc.? Also, what if I replace a NAV/COM with an entirely new one that requires installation of a nav head and new antenna? THanks.
Bill

The term "TSO" stands for Technical Standard Order. All other questions were already addressed in my response.

[echild]

I bought the King GPS/COM a year or so ago from an avionics shop here in the Atlanta area. The fellow installed in but didn't hook up the altitude portion of it. I believe it would be a simple hook up to add this feature. Should just be a connection to the encoder.

I called King to get a copy of the installation manual and schematic for my files and was told that it would be impossible to get a copy. They only send them to the avionics shop.

Does anyone know how I could get these two items? It works beautifully and takes up little panes space. Mine is installed on the lower left side of the panel.

Everett Childers

[GAHorn]

A good relationship with a local avionics shop is a valuable resource. Most shops will loan you a manual or allow you to read/copy theirs.

[N2255D]

I have a copy of the manual somewhere in my books. Do you need just the wiring diagram? Let me know what you need and I can fax or mail you copies. I'll lok for the manual tomorrow. Walt

[n3833v]

Since radios were discussed, how about one unit replacement of gyros, attitude indicators and other instruments. I read in the manual that a pilot owner can do maintence replacement of certain instruments. I am replacing a horizon gyro and want to know if I as pilot/ owner can sign or if an IA&P must sign.
John -n3833v

[GAHorn]

Since radios were discussed, how about one unit replacement of gyros, attitude indicators and other instruments. I read in the manual that a pilot owner can do maintence replacement of certain instruments. I am replacing a horizon gyro and want to know if I as pilot/ owner can sign or if an IA&P must sign.
John -n3833v

I don't know what manual you were reading, but that is incorrect info. FAR 43, Appendix A, Para. (c) describes the Preventive Maintenance a pilot may perform. Instrument replacement is not one of them.

[N1478D]

There's at least one 170 now with a Garmin 430 installed in the panel

[GAHorn]

There's at least one 170 now with a Garmin 430 installed in the panel

The Garmin 430 has a feature in which it will start the flight timer either on power-up or upon reaching a certain speed. To ensure accuracy in your airplane Joe, you'd better program it to start the timer on power-up.

[N1478D]

Wish it was my 170 that has the 430 installed George, you have to be happy that cooler weather is around the corner. You might be able to climb up over Lake Travis pretty soon.