Should I buy a used Thorp T18?

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DMD3.

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An already flying Vans RV 6 thru 9 has always been my dream aircraft, as they have the same engine/fuel burn as a spam-can Skyhawk or Cherokee but can rival a Bonanza in cruise speed and do so with fixed-gear, even if they only have 2 seats. But a Thorp can be bought for considerably less than the average RV. And they seem to have similar cruise speeds albeit maybe a bit slower (depending on the engine). My question is, are parts still available from the manufacturer? They have a website (http://thorpcentral.com/the-s-18), so it seems you can still order kits, though they’re calling it the “S18”. Another thing is I don’t have any mechanical skills, so I’d have to find someone to do my condition-inspections as well as routine maintenance/repairs. Would this be a dealbreaker?

On the VAF forum, there are a number of RV owners that don’t perform their own maintenance. And while it’s not as cost-effective, they agree that maintenance won’t be any more expensive than maintaining a certified spam-can. But would I have trouble finding an A&P willing/able to perform maintenance, and also someone who knows about Thorps to do the CI’s (and the pre-buy)? And you may ask why I even want an experimental at all if I’m not going to perform my own maintenance, and I say again, it’s the performance.
 
The Thorp (for the most part) was built from plans and sheet aluminum straight from your local metal supply. Most parts would have to be fabricated. But, assuming you don't wreck the sumnabitch you are not likely to need much in the way of airframe parts. The main gear would be the one "gotta buy" part. The rest could be fabricated by your A&P. Would be a big help to him/her if you got the original plans with the airframe.

Watch the weight - John Thorp designed the airframe to take aerobatic level G loads, but most of them have been built significantly heavier than the original design weight which eats into the load margin.

Ask around at your local EAA chapter, there is likely someone in the area with a T-18 that could lend some expertise.

The S-18 is a modified / improved in some areas version of the original design.

Overall, you get a much better bang for the buck if you don't need a designer label.
 
Oh, and it is a short coupled, hot, taildragger and all that goes with that configuration.
 
Capt. Geoffrey Thorpe said:
The Thorp (for the most part) was built from plans and sheet aluminum straight from your local metal supply. Most parts would have to be fabricated. But, assuming you don't wreck the sumnabitch you are not likely to need much in the way of airframe parts. The main gear would be the one "gotta buy" part. The rest could be fabricated by your A&P. Would be a big help to him/her if you got the original plans with the airframe.

Watch the weight - John Thorp designed the airframe to take aerobatic level G loads, but most of them have been built significantly heavier than the original design weight which eats into the load margin.

Ask around at your local EAA chapter, there is likely someone in the area with a T-18 that could lend some expertise.

The S-18 is a modified / improved in some areas version of the original design.

Overall, you get a much better bang for the buck if you don't need a designer label.
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I’m not much of an aerobatic pilot so that shouldn’t be an issue.
 
DMD3. said:
Yes on buying the aircraft, or yes on my lack of mechanical aptitude being a dealbreaker?
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Some A&Ps won't touch anything E-AB. Consider finding an A&P first (you are going to need one even if you buy an RV) and determining what they are comfortable with.

Note: You don't need an A&P to do maintenance - just the condition inspection. You could hire the local high school shop teacher to work on it for you - he/she probably could use the extra cash... :-)
 
Capt. Geoffrey Thorpe said:
Some A&Ps won't touch anything E-AB. Consider finding an A&P first (you are going to need one even if you buy an RV) and determining what they are comfortable with.

Note: You don't need an A&P to do maintenance - just the condition inspection. You could hire the local high school shop teacher to work on it for you - he/she probably could use the extra cash... :-)
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Well if I have an aircraft that won’t start or is leaking fuel, etc. and I can’t fix it myself, I’d say I do need an A&P. I don’t know any nonA&P’s who could help lol.
 
DMD3. said:
Yes on buying the aircraft, or yes on my lack of mechanical aptitude being a dealbreaker?
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Buy it. Talk to local eaa chapter and local a&p's about experience with it. And if theyre willing to work on it. Some won't touch eab. My a&p however likes to work on something different. Except the hypibipe he has to work on. Says that thing is a pain in the ass.
 
DMD3. said:
Another thing is I don’t have any mechanical skills, so I’d have to find someone to do my condition-inspections as well as routine maintenance/repairs. Would this be a dealbreaker?
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If you have a willing A&P, not a dealbreaker. But think of this as an opportunity to learn new skills.
 
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I can't find a trike version for sale (hen's tooth), otherwise I would have already made that my choice. The interior is cramped (reminds me of my old C-150, a bit worse on the headroom, though I find the Glasair I the worst of all 3 on the cabin/seating space). But for my use case (solo acro/form/occassional xc flying) it would do the same as the rv-6A I'm currently captured into finding. Thorps tend to be found at a good discount over RVs. I do think they're a good value, hen's tooth dynamic notwithstanding.

So yeah, if you're cool with taildraggers, absolutely I would say go for it. If you find a S-18T, don't buy it, it's a death trap, but do send me the link so I can go and help the owner dispose of it. ;) Good luck!
 
hindsight2020 said:
I can't find a trike version for sale (hen's tooth), otherwise I would have already made that my choice. The interior is cramped (reminds me of my old C-150, a bit worse on the headroom, though I find the Glasair I the worst of all 3 on the cabin/seating space). But for my use case (solo acro/form/occassional xc flying) it would do the same as the rv-6A I'm currently captured into finding. Thorps tend to be found at a good discount over RVs. I do think they're a good value, hen's tooth dynamic notwithstanding.

So yeah, if you're cool with taildraggers, absolutely I would say go for it. If you find a S-18T, don't buy it, it's a death trap, but do send me the link so I can go and help the owner dispose of it. ;) Good luck!
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Is that a turbocharged version? I can’t find any info on an S18T.
 
And near impossible to retrofit (economically). Most of these kits seem to be built from the landing gear out.
 
Mustang 2 probably has a handful more tricycle ones built
 
Just because there's romance involved with tail wheels, that doesn't mean it's always going to end well.
 
I like them!
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Capt. Geoffrey Thorpe said:
Oh, and it is a short coupled, hot, taildragger and all that goes with that configuration.
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I think in the case of a T-18 this should be relevant to the original poster. Watch a T-18 land and I think you’ll see it’s not a mild handling RV in this respect. They approach and land maybe 10 kts faster with therefore about 50% more kinetic energy.

(I learned to fly in a Luscombe, admire the T-18 and have nothing against tail wheel aircraft, but they are not all the same for an unfamiliar pilot)

It would also be important to understand that these are plans built aircraft manufactured by people with widely varying skills under regulation that inspects for minimum acceptable quality, and not more. One T-18 might be a magnificent beauty while another is a horrible mish-mash of poor workmanship. I chatted a while ago with the owner of a transient T-18 being repaired on the ramp on a ferry flight home to Texas. It was very much in the latter category, looked like something from a junkyard. He bought it for very little but had a huge amount of rework ahead of him.

Another issue I’ve understood is that some were built with pulled rivets, and are generally undesirable. Also, the original design and therefore some early examples have converted Lycoming O-290G (Ground Power Unit) engines that were available inexpensively way back when. An O-320 or 0-360 is much better so check for that.

There’s also an issue with tail stall when full flaps are used, something to be aware of, and in addition most of them are 40 or more years old.

I think these are the reasons why T-18s on the open market have relatively low value, even while being a neat design done by a capable aeronautical engineer.
 
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DMD3. said:
An already flying Vans RV 6 thru 9 has always been my dream aircraft, as they have the same engine/fuel burn as a spam-can Skyhawk or Cherokee but can rival a Bonanza in cruise speed and do so with fixed-gear, even if they only have 2 seats. But a Thorp can be bought for considerably less than the average RV. And they seem to have similar cruise speeds albeit maybe a bit slower (depending on the engine). My question is, are parts still available from the manufacturer? They have a website (http://thorpcentral.com/the-s-18), so it seems you can still order kits, though they’re calling it the “S18”. Another thing is I don’t have any mechanical skills, so I’d have to find someone to do my condition-inspections as well as routine maintenance/repairs. Would this be a dealbreaker?

On the VAF forum, there are a number of RV owners that don’t perform their own maintenance. And while it’s not as cost-effective, they agree that maintenance won’t be any more expensive than maintaining a certified spam-can. But would I have trouble finding an A&P willing/able to perform maintenance, and also someone who knows about Thorps to do the CI’s (and the pre-buy)? And you may ask why I even want an experimental at all if I’m not going to perform my own maintenance, and I say again, it’s the performance.
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Thorp Central sold the design and manufacturing rights to the S-18 in 2024. The company is called Thorp Aircraft now. A google search for the name Thorp Aircraft will point you to the corporate website.

The T-18 was 38" at the shoulders and the S-18 is 40" at the shoulders, built with a more forgiving airfoil and folding wing, and is 5" longer than the T-18. Thorp Aircraft is taking the design to full kit status.
 
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