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Additional Cockpit Power Supply

I should like to add a power supply to use (preferably a double) for such bits of kit as running a second GPS or charging a mobile phone or IPAD etc. Does anyone have any suggestions please as to most suitable. I dislike the "cigar" lighter things.

Many thanks

UK, United Kingdom

The answer is greatly affected by what aircraft type is involved. If you would like to maintain the C of A of a certified aircraft, there will be more to it than other circumstances. With a bit more info, a few of us can point you the right direction...

Home runway, in central Ontario, Canada

Yes would like to maintain C of A and the a/c is a C172

UK, United Kingdom

What reg? G or N?

In general, one can get a "signed off" installation of a power connector.

It needs to have a circuit breaker dedicated to it.

The connector is, ahem, supposed to come with, wait for it, a Certificate of Conformity, but in reality of you pick a decent quality connector, most freelance installers will do it.

A popular type is this sort of thing

made by Cannon or Amphenol, and available from e.g. RS and this one is the sort of connector I would look at. I had one of those installed when the plane was new, even before the CAA CofA issue so the CAA inspector was OK with it.

Some people install an XLR connector, which is OK too, cheaper, and has no locking so it can unplug


but you won't get those with a CofC, generally.

Shoreham EGKA, United Kingdom

Thank you both. I have seen the 2 pin before but not the 3 pin one. I think I shall speak with my maintenance org. and see what they will fit and then purchase accordingly. Many thanks

UK, United Kingdom

I don't think there is a 2-pin XLR. At least it would be most unusual. The XLR connector is widely used in professional audio apps and it is 3-pin and 5-pin.

There are other connectors, even nicer, from e.g. LEMO, but they are smaller and the connections to them needs to be done by people with some decent soldering skills. The wiring of the plug likewise needs more skills, because you don't want shorts. But the result is very neat.

Shoreham EGKA, United Kingdom

For a C of A installation, try to have your mechanic sign it off as a minor modification. If you have to go the major modification (approval) route, there is more to this than meets the eye. It's not actually relevant to safe flight, but bureaucratic silliness. Avoid if possible.

That said, go easy on your mechanic, and only ask for the current you need. 10 amps is a stretch, 5 amps is fair, but if you can breaker it for 2 amps no one should be troubled.

Also be aware that there is guidance on the operation of "PED's" which I think is FAA technospeak for personal electronic devices. I have been told by Transport Canada that the answer to each is "no" unless shown to be "yes" as an element of an approval process (which is what I'm doing in Germany this week). The less said about what you're going to do with your newly found electrical source, the better.

If you want to do an actual EMI test on the PED in the plane - do I have a test plan for you!

Home runway, in central Ontario, Canada

There is an argument that there is no legal way to install a power connector in a certified aircraft, unless the equipment connected to it is suitably defined and certified.

This also means that the only thing that may be plugged into a cigar lighter socket is the approved supplied cigar lighter.

Needless to say everybody ignores this, but this is why the less said the better

It's the same argument with e.g. installing a connector which brings out the NMEA data coming out of a panel mounted GPS. If the STC (or the FAA approved installation manual, etc) for that GPS does not support that connector (which it won't, without defining what plugs into it) then it cannot be installed.

Needless to say everybody ignores such an anally retarded interpretation, too.

You get this with modern cars too, in Europe. No way to fit a towbar to a VW Scirocco for example, because it was never certified to have one, and it will supposedly fail the MOT if they see one fitted, or even the mounting points added.

That said, interference with avionics is a real problem. Not (IME) with NAV kit, but certainly with VHF comms. I have seen this with various car-market power adaptors, most of which contain crude switch-mode power supply circuits.

Shoreham EGKA, United Kingdom

Life with so many regulations is very awkward at times and what appears to be a very simple change seems time consuming and costly. Thank you for the guidance and the very sound advice to say little if anything.

UK, United Kingdom

Basically you need to clear it with the firm doing the servicing.

If they are happy with it, nobody else is likely to complain.

Shoreham EGKA, United Kingdom
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