This is a topic of interest which pops up from time to time, taking a certified plane and going experimental with it, and how that works out with the feds. So I thought I had better mention the Skunkworks project I saw in the weekend.

Basically, it's a C172 fuselage which is being retrofitted as a taildragger - but no gearboxes here - they are putting in undercarriage from what looked like a Piper Pacer, with oleo struts and two hinged point each side. Hardpoints were being installed and steel fittings will be bolted onto them to connect the gear legs. It looked fairly straightforward. And for the wings? They are coming off a Cub is what I was told, I don't know if they're being upsized or anything, but these guys are mad-keen bushpilots so they're probably not joking!

So anyway, I asked the obvious question: how do you go about combining different certified parts into an experimental plane and still get a certificate of airworthiness without going amataur built? Here's what I was told. They called the authorities and they said 'go for it', apparently there was no drama at all... I think "fill your boots" were their exact words... I guess this means it will be straight experimental.

Anyway I'd better not reveal too much about this project because it's not mine, but needless to say I'll be following it with great interest.

My guess is that it would be issued an Experimental Exhibition airworthiness certificate if the FSDO would go along with it. Experimentals have to fit in to one of the following buckets:


Research and development
Showing compliance with regulations
Crew training
Exhibition
Air racing
Market surveys
Operating amateur-built aircraft
Operating kit-built aircraft
Operating light-sport aircraft
Unmanned Aircraft Systems (UAS)

One thing is for sure, unless it squarely fits within the regs, it can't be flown. There was a time before the FAA started strictly enforcing the 51% rule that certificated airplane with a bunch of mods could be "converted" to experimental, but those days are long since gone. If it were possible, I'd have done it years ago, since many of the ordinary stuff that has been done to my airplane has required FSDO approval, just because few after-marketeers have the model (P172D) on their AMLs.

Cary

Sounds like you've visited project CRAZER Battson. Those guys know what they're doing so I'm sure it will fly with the Feds too (eventually).

NZMaule wrote:Sounds like you've visited project CRAZER Battson. Those guys know what they're doing so I'm sure it will fly with the Feds too (eventually).

Haha - yeah I wondered whether you'd have seen it!
I have no doubt it'll tick all the boxes, it's interesting because you hear a lot of people say this kind of thing "can't be done". Grouse to see them getting stuck in and doing it!

US feds vs NZ feds I expect. Nobody could do it worse than here. M Huerta and the rest of his co-conspirators refused to attend the AOPA annual bash this year. And so it goes.

EB

This thread is a bit old and a lot of the experimental operating limitations have changed a lot since then. Saw this on converting a C172 to a V8 engine.

https://airfactsjournal.com/2020/11/the ... xperiment/

Their website has good info on the conversion process from certified to experimental. Flying a 4 seater for less than $20/hr seems a good trade off for swapping to experimental for guys like me that don’t rent their aircraft out and used for recreational purposes. I wonder when an electric engine option will become available.

This thread is a bit old and a lot of the experimental operating limitations have changed a lot since then. Saw this on converting a C172 to a V8 engine.

https://airfactsjournal.com/2020/11/the ... xperiment/

Their website has good info on the conversion process from certified to experimental. Flying a 4 seater for less than $20/hr seems a good trade off for swapping to experimental for guys like me that don’t rent their aircraft out and used for recreational purposes. I wonder when an electric engine option will become available.

IslandFlyerCarib wrote:This thread is a bit old and a lot of the experimental operating limitations have changed a lot since then. Saw this on converting a C172 to a V8 engine.

https://airfactsjournal.com/2020/11/the ... xperiment/

Their website has good info on the conversion process from certified to experimental. Flying a 4 seater for less than $20/hr seems a good trade off for swapping to experimental for guys like me that don’t rent their aircraft out and used for recreational purposes. I wonder when an electric engine option will become available.

I've noted this before, but the thing I'd worry about in the Experimental Airshow and Exhibition category is that there are restrictions and requirements of that certification which at present aren't heavily enforced. That could easily change, and probably will if a bunch of aircraft owners convert certificated aircraft to that category. The FAA currently doesn't pay much attention to the requirements, but that could change, and then you might have a turkey, and one that might be impossible to impractical to convert back to certificated.

Maybe. But, if you convert one, based on "easily complied with" provisions of the certificate......understand that just because those provisions aren't enforced now doesn't mean they won't ever be.

MTV

mtv wrote:

IslandFlyerCarib wrote:This thread is a bit old and a lot of the experimental operating limitations have changed a lot since then. Saw this on converting a C172 to a V8 engine.

https://airfactsjournal.com/2020/11/the ... xperiment/

Their website has good info on the conversion process from certified to experimental. Flying a 4 seater for less than $20/hr seems a good trade off for swapping to experimental for guys like me that don’t rent their aircraft out and used for recreational purposes. I wonder when an electric engine option will become available.

I've noted this before, but the thing I'd worry about in the Experimental Airshow and Exhibition category is that there are restrictions and requirements of that certification which at present aren't heavily enforced. That could easily change, and probably will if a bunch of aircraft owners convert certificated aircraft to that category. The FAA currently doesn't pay much attention to the requirements, but that could change, and then you might have a turkey, and one that might be impossible to impractical to convert back to certificated.

Maybe. But, if you convert one, based on "easily complied with" provisions of the certificate......understand that just because those provisions aren't enforced now doesn't mean they won't ever be.

MTV

And I suspect that the "compliance" requirements may be looser in some FSDOs than in others... Seems like our local guys are "by the book" – and they read the book a lot differently than most any rational human would... "We're not happy until you're not happy..."

Actually, the experimental limitations went through an overhaul about 5-6 years ago, and are now national standard policy and contained in written form, so you will know what you will get. However, local FSDOs can add additional items if they feel are uniquely needed. I read on the Corsair site that the exhibition airworthiness does not have to be reissued every year now, same as standard category