Scudrunners

I see there is a Pitts S1 on the COPA site. O320 with 500 hrs. Price is “Make an offer”. I’m not sure what a reasonable offer would be on this aircraft. Thoughts from the membership?

Cash is king right now.

Don't know anything about the airplane but I have three thoughts:

Damage: ground loops? Spar damage? Bent main gear? Prop swaps?

Airframe: Fabric is the biggie. Actually, the paint. Is it cracking?
Look along the wing ribs inside the prop blast.

Engine: Internal corrosion. Cam lobes/lifter spalling. Corrosion
on cylinder walls. Metal in pressure screen? Bearing material is
something else to look for.

Check the log book/s to see how often it flew.

Sitting and not being run is really bad for an airplane.

I'm assuming its experimental.

So the upper end for a really nice experimental S1S with a 360 constant speed that flies regularly with almost new fabric and a great engine and no damage history etc. would likely be in the 40-60K USD range. Subtract 10 or so for a 320 fixed pitch. See Barnstormers for examples.

Fabric will last about 20 years give or take and costs about 30K to redo. So if you'll only get 5 years on the fabric take say 25K off the 40K.
Engine will last about 1000hrs .. perhaps more, perhaps less when flown hard and will cost about 25KUSD to overhaul, so if its at 500hrs so you could say take 12K USD off if it was flown regularly, if it sat for more than 6 months or a year ... the lifters will be toast within a year (see Andy's pic).

So you can immediately see the problem. The cost of redoing fabric and engine is more than the plane is worth! So the only way to get a good deal is if the engine and fabric are pretty new (seller is taking a bath). If you have to do the fabric and engine its cheaper to just buy a plane with newer fabric and engine. If you are handy and can do fabric and paint then of course you can save a ton of money because the cost of materials (fabric and paint) is only a few thousand.

Anyway find out about the fabric, when the engine was last overhauled and number of hours per year flown, damage history etc. Those will dictate if its something you want to own and will be able to fly for 5-10 years without trouble, or if you'll have to throw 30-40k at it within a few years.

Hope that helps

I know the guy who built it, if you're serious I could put you in contact with him.

Not sure how its been treated since it left him, but I wouldn't hesitate to put my family in a plane he built.

You can tell a lot by looking at the weld quality. If the welds look professional, non lumpy etc. then odds are the fuselage structure is sound. Its very difficult to break a Pitts fuse unless you ground loop it. Sometimes they will crack at the gear attach points especially with solid gear.
You can tell a lot about how the wings are doing by strumming on the drag and anti drag wires (i.e. open the wing access holes and twang them). Also look at the lower wing tips for repairs .. that's indicative of ground loops.
Walk away if the welds look lumpy, walk away if the drag anti drag wires make rattling noises and are not musical note-ish tight and walk away if the wing tips have had anything more than superficial repairs.

Like any aircraft - but especially homebuilt! - you first ask the question:

What was it, when it was new? Which model was constructed? S-1C is
different from S-1S. Sparcraft wings? Which engine and prop? Inverted
systems? The builder of this aircraft has a good reputation here, which
is a good sign.

What has happened to it since then? Damage from groundloop? Damage
from inactivity? Damage from time?

For me, it's binary evaluation. Either it's a project, which in case it's pretty
well worthless (see Peter's arithmetic) or it's flying. Best is an aircraft that
flew at least 50 hours on the tach last year. Pull the oil screen pressure
housing and check for metal.

Hopefully it doesn't have an oil filter. If it does have one, take it off and
cut it open. If the filter is brand new, be very suspicious that someone knows
the engine is making metal and they removed the evidence before you got
there. A new oil filter is cause for internal corrosion inspection.

If it has just a pressure screen, pull the housing. Hopefully the gasket is
old and burned which is a sign that it hasn't been pulled for many years
which is quite common but completely illegal. If the screen hasn't come
out in years, you can actually tell if the engine is making metal.



That's the pressure screen from a Lycoming in a Pitts (not mine) that sat
and corroded internally. The cam lobes are making metal. Don't buy that
engine. Ask Peter about Lycomings in Pitts that make metal.

When you look at a used Pitts, consider:

0) Damage from accidents?
1) Lycoming internal corrosion?
2) rib / spar / wire internal wing condition (see Peter above)
3) paint cracking

A Pitts is really just a tube & fabric aircraft with a Lycoming. Yes, it has
inverted fuel and oil but that's not hard to deal with. Manuals are readily
available. Oddly corrosion of the tube frame is not typically a problem,
but it certainly is on other types!

Note the above indexing starting at zero. We're C/asm programmers here,
not Pascal or Modula-2 or Ada.

Note that cam lobe wear is the Achilles Heel of Lycomings. Any problem
with the valves or rings or pistons or cylinders, you can order BRAND NEW
cylinder kits from Lycoming for us$1.5k each which include

- new assembled cylinder with valves & springs & retainers installed
- new piston with new rings and wrist pin and plugs

So if the cam lobes and lifters are good, and the bearings aren't making
metal, for 4 x 1.5k = us$6k you can put a new top on a Lycoming four cyl
and fly the snot out of it. I might suggest you change the mags and starter
at the same time. Also, one item that never gets attention is the fuel
divider on the top of the engine. They work until they don't. More of a
problem in the south in the heat, actually.

Thanks! I appreciate the wisdom you guys are sharing!

You've probably already read it, but

http://www.steenaero.com/PittsS1/history.cfm

That's a quick reference to the many different models of Pitts!

PS. It's not hard to tell if a Lycoming is done inside. Just pull one rocker cover:



If it looks like that, the engine is done. Note that this picture was taken of a
very expensive Lycoming IO-540 which was very low time. Looked great on
paper. It had already been completely rebuilt once before because of internal
corrosion, and not very long before that photo was taken. Needless to say,
this Lycoming needed to be taken apart and required a new cam, lifters and
cylinders. Again.

I took a look at the Ad and spoke to my dad who's flown that one (years ago)

Engine: O320
Radios: Basic handheld Com
Doesn't have aileron on top wing
Fabric and Paint look original (1995)

20K-30K CAD