Procedure for getting STCs through in the UK

[QDMQDMQDM]

I'm going to add a couple of minor STCs to my cub which I know are already present on other UK aircraft (landing gear safety cables and rear cross brace bracket for front shoulder harness, both F. Atlee Dodge STCs). What procedure do I have to go through for this? Do I actually have to find and contact the owners of the G-reg aircraft which have been so modified? Obviously the work will have to be done by an LAE etc.

Anyway, I guess this is one for Genghis or A+C...?

Thanks,

QDM

[A and C]

It is quite likely that these STC items have been aproved as a minor mod , if the person who raised the minor mod ticked the box on the form to aprove it for all Cubs then if you can get hold of all the drawings and the mod number from one of the other owners in the UK then a licenced engineer can fit the STC under that mod number.

[QDMQDMQDM]

It is quite likely that these STC items have been aproved as a minor mod , if the person who raised the minor mod ticked the box on the form to aprove it for all Cubs then if you can get hold of all the drawings and the mod number from one of the other owners in the UK then a licenced engineer can fit the STC under that mod number.

Thanks. I thought as much. The problem is always trying to find which aircraft has the mod!

It would be sensible for someone to hold a database of STCs approved as minor / major mods in the UK wouldn't it? Actually, it would be most sensible for the CAA to do that.

QDM

[Genghis the Engineer]

The term STC (Supplementary Type Certificate) may possibly not be valid in a UK CAA context for what you are talking about.

An STC is generally awarded to a piece of series kit that is supplied to be fitted straight to an aircraft. The STC if it exists will be held by the equipment supplier and they'll supply you with all the paperwork and guidance you need for a LAME to install and sign it off.

More likely these items have been installed as minor mods. As A&C says, if this is approved for all identical aircraft then the same applies. If it wasn't you need to make a direct application to your CAA regional office. The process is moderately painless, likely to cost you an admin fee of around £70 or so, but it would help enormously if you can get hold of the original application from whoever made it and copy that.

If you want chapter and verse, thing to do is phone the CAA on 01293-576161, ask for "Aircraft Certification", then when you get through to them ask to speak to the "Design Liaison Surveyor" for Piper aircraft. They should have the list of what's approved for all identical.

If CAA make life difficult for you give me a shout, they're usually happy to accept my signature on such things and I'd happily swap whatever time and effort was needed for a bit of Cub time.

G

[QDMQDMQDM]

If you want chapter and verse, thing to do is phone the CAA on 01293-576161, ask for "Aircraft Certification", then when you get through to them ask to speak to the "Design Liaison Surveyor" for Piper aircraft. They should have the list of what's approved for all identical.

I shall do this tomorrow. Excellent -- thank-you.

If CAA make life difficult for you give me a shout, they're usually happy to accept my signature on such things and I'd happily swap whatever time and effort was needed for a bit of Cub time.

Kind offer -- I may well get back to you on it.

The STC if it exists will be held by the equipment supplier and they'll supply you with all the paperwork and guidance you need for a LAME to install and sign it off.

Why couldn't I just do this, then? Why does it have to be a minor mod? I didn't realise this was possible.

Both the things I want to do have F. Atlee Dodge STCs, which are very reputable. He's sort of Mr. Super Cub.

QDM

[Genghis the Engineer]

I gave you the wrong phone number. Try 01293-567171.

I don't know the chap, but if they are cleared on a Super Cub in the UK you shouldn't have a problem. I'm assuming however from the use of the term STC that they're probably cleared in the US which doesn't give automatic cross-approval to the UK.

May all seem a bit silly, but me and my profession are a bit like Keef's. We've a fair bit of flexibility in the interpretation of the word, but not actually allowed to re-write it - that comes from a higher authority. I do however sincerely hope that Keef's higher authority is better informed than mine :p

G

[QDMQDMQDM]

Well, they're certainly helpful people. However, the landing gear safety cables look set to cost me at least a £309 major mod fee, plus all the other costs such a thing would entail. Since they consist of a couple of cables attached to the undercarriage bolts and the whole caboodle, including STC, costs $120 in total, this looks like a non-starter.

Shame, because this is a very good, very simple safety feature. I can see how importing a US aircraft with a few STCs on it must be an absolute nightmare.

The people it would be really useful to have commonality with would be the FAA, not the Europeans.

QDM

[Genghis the Engineer]

Knowing the CAA's definition of major .v. minor I'd have thought if you write up the cables on a "no worse than before" basis you should be able to get it through the regional office as a minor.

Incidentally the current CAA charges (AN25 issue 30 page 8) are £71 for a minor mod, £324 for a major mod.

G

[QDMQDMQDM]

Knowing the CAA's definition of major .v. minor I'd have thought if you write up the cables on a "no worse than before" basis

The fellow said that all STCs must be major mods.

QDM

[Davidt]

I've done a few mods to mine each time producing to the CAA a copy of the FAA STC, the CAA then accepted the mod as a minor mod without much difficulty.

The FAA web site has a STC search section.Very useful for gleaning info about substitutes where an original part is no longer made.

The Americans also have a "field approval" and something called a Form 337 or 137?, I dont know how those equate with our system.

Your engineer should know what the CAA are likley to want.

[QDMQDMQDM]

Interesting. Two people at the CAA said definitively that STCs were major mods by definition and couldn't be minor mods, even if they involved very little.

Just goes to show. How annoying.

QDM

[Genghis the Engineer]

STC is equivalent to a UK major mod approval (known as an AAN - Airworthiness Approval Note). But the UK-CAA and US-FAA systems differ quite markedly.

If you aim for direct read-across from an STC, then CAA will classify it major by default. If on the other hand you simply apply for a minor mod, to do what is in a reasonably trivial STC, then you may well get away with it.

G

[QDMQDMQDM]

If on the other hand you simply apply for a minor mod, to do what is in a reasonably trivial STC, then you may well get away with it

Ah! I don't know what I'd do without this website!

(More work, probably.)

QDM

[Davidt]

Note whats said above, but thats not my experience I replaced a 2 blade prop with a three blade, approved by FAA under an STC went into CAA who approved it as a minor mod.
Paperwork only took a couple of weeks CAA issued a performance correction for my poh. No fuss.

Replaced obsolete starter with light weight high speed version + copper cable kit + all cly engine monitor added all under STC's all treated as minor mods by CAA.

Have fun!

[Genghis the Engineer]

I did make a concerted effort to persuade one of the more senior certification managers at CAA that all this sort of stuff aught to be written down in a CAP so you don't need to pay an expert (ha, who am I kidding!) like me lots of money to explain how the system works.

I thought I was just about winning the argument when he left to work for JAA.

Oh well, at least in the next couple of months we're getting the new CAP 733 explaining all the rules for permit to fly aeroplanes, which will be a major boon.

G