Ashland Municipal Airport - 433 Dead Indian Memorial Road, Ashland, OR 97520 - Office: (541) 488 1964

Pre-owned Avionics Buying Guide

A Buyers Guide To Pre-owned Avionics

If you had a choice of buying a piece of new equipment from your local avionics shop or used on EBay for $5,000 less which would you choose? Buying a used piece of equipment for your aircraft from an unknown source may seem like a good idea and many clients often contemplate the idea, but there are pitfalls to be aware of.

To clarify, we are not talking about the used equipment that we as an avionic shop can supply – we have access to used equipment that comes from reputable sources (such as other shops) with the necessary documentation. Rather, we are talking about that bargain you found on-line, on the FBO’s noticeboard, or something another pilot wants to sell you that “works just fine”.

Get As Much Information As Possible

Firstly, make sure you find out as much as you can about the units past before you make a decision to buy. Questions you should attempt to answer are:

  • Why is this unit being sold?
  • What’s the serial number? – from this you can ascertain the age of the unit and if it has been reported stolen.
  • Get as much additional information as possible e.g. if the unit has been overhauled get a copy of the tear down report, get pictures of the unit etc.
  • Ask about warranties
  • What’s the Mod and software status? Find out what mods and software updates are available and which have been done.
  • What extras come with it? Ask if the manuals, connectors, trays etc are included.

Paperwork? What Paperwork!

Find out what documentation comes with the equipment you are considering and how the used equipment is classified. Is it ‘overhauled’, is it ‘serviceable’ or is it ‘as-removed’.

  • If it is ‘overhauled’, it will have an FAA 8130 form with it. This will specify the latest work done on the unit, including repairs and updates. The unit will have been tested to the manufacturer’s original specification, thereby verifying the units’ serviceability. Testing will have been carried out by an authorized repair facility.
  • As a ‘serviceable’ unit, it should have a maintenance release (sometimes called a ‘yellow tag’). This means the unit was tested either before removal from a panel or on the bench and was found to be working properly.
  • ‘As-removed’ units are exactly as described. There will have been no testing or operational checks performed on the unit, and it is unlikely to come with any warranties.

Don’t Forget To Consider The Dates

Pay attention to your warranty information – warranties often start from date of sale or repair, not the date you install it. Similarly, look at the actual date an overhaul was performed. An overhauled unit that has been on the shelf for 10 years is not the same equipment as an overhauled unit from a month ago. Parts can deteriorate if they remain in an unused state and this is especially true of gyro units.

Can Your Instruments Talk?

Another thing people often forget when they get caught up in the excitement of getting a bargain, is whether the equipment they have bought will actually talk to the existing equipment they already have installed. Don’t forget to make sure that everything can communicate with everything else!

Economics Do Make Sense!

We had a customer who came in with an ARC transponder they had purchased on-line which they assured us was in “perfect working order”. The unit was 40 years old, missing the rack and connectors and upon testing we discovered that the signals were out of tolerance. The unit needed repair and additional parts, and as you can see from the costs below this was not such a bargain when you consider that for $1,750 the customer could have had a piece of modern technology in the form of a brand new transponder with full warranty.

$65040 year old ARC transponder, bought online, missing connectors and rack, and found to be out of tolerances. No warranty

$600Repair costs to correct out of tolerance signals

$350Purchase of rack and connectors (which included 18 very expensive pins)

$1,600 – Total costs for unit to be repaired and in an installable condition

Compared To…

$1,750 – Brand new transponder with full 2 year warranty

Age Does Matter

Here’s another example for you to ponder…

The Narco unit you are considering is over 20 years old; that means it’s got 20 year old technology. On equipment of this age it is often getting harder to find replacement parts as the supplies are not available from the manufacturer, existing stocks are becoming depleted, and as such are getting harder to find, and the likelihood is that pretty soon it will fail just due to it’s age. Even if repairs are possible, no one will warranty the unit for more than a month or so – in another few months you could find yourself in the same position you are right now – looking for another unit. A new Comm unit would have modern technology, comes with a 2 year warranty and is likely to serve you without problems for the next 10 –15 years. So how does this look monetarily?


  • Cost: $1,295
  • Repair Cost: $300+
  • Warranty: < 90 day
  • Life Span: < 5 years
  • Technical Age: 25 years


  • Cost: $1,750
  • Repair Cost: $450
  • Warranty: 2 years
  • Life Span: 15+ years
  • Technical Age: Current

The sad truth is that if it’s too good to be true, it unfortunately probably is! If the price is too low be additionally cautious as the unit could be: missing parts, accessories, racks, connectors or cables etc; inoperable or requiring repair; or worse still – stolen. This is not to say that you can’t find bargains in used equipment and buying used parts through an avionics shop can save you many a headache. If you are going to do it on your own just remember, you can never ask too many questions or get too much information.

For more information on our current list of pre-owned avionics for sale please contact us at our main office number (541) 488-1964.