[quote author=Colonel Sanders link=topic=4492.msg11819#msg11819 date=1476162085]
As Peter points out, internal corrosion of the Lycoming
and fabric/paint condition are tremendously important.
[/quote]
Would you trust 35 year old fabric that still looks like new and is in very good condition?
Most planes I have checked out you can sort of guess/see how old the fabric is, and my guess is usually quite correct, but there is one that looks like it was recovered yesterday yet is 35 years old. I am kind of in doubt how to deal with that...
I usually walk away if it's older than 20 years and it shows.
Differences Pitts s1s - Ultimate 10-180
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Colonel
- Posts: 3450
- Joined: Wed Apr 29, 2015 10:31 am
Somebody has probably sprayed it again, which
makes it heavier.
Synthetic fabric might be ok. The problem is that
there might be corroded/broken stuff underneath,
and the paint dries out and cracks and peels off.
Each aircraft is different. Heck, my Maule has the
original fabric from 1967, and it's fine. But it has
always been hangared in a low-salt environment.
Again, be sure to check for main gear alignment
and any other evidence of a groundloop - like a
prop change, with no other log entries. Someone
might have "forgotten" to enter groundloop damage
and the resulting repairs - of whatever dubious
quality - in the logs.
For some reason, people have a way of forgetting
about these sorts of things:
[img][/img]
makes it heavier.
Synthetic fabric might be ok. The problem is that
there might be corroded/broken stuff underneath,
and the paint dries out and cracks and peels off.
Each aircraft is different. Heck, my Maule has the
original fabric from 1967, and it's fine. But it has
always been hangared in a low-salt environment.
Again, be sure to check for main gear alignment
and any other evidence of a groundloop - like a
prop change, with no other log entries. Someone
might have "forgotten" to enter groundloop damage
and the resulting repairs - of whatever dubious
quality - in the logs.
For some reason, people have a way of forgetting
about these sorts of things:
[img][/img]
-
cgzro
I think Joanne slid her ultimate (the two tone blue one) upside down on the runway during an inverted night ribbon cut.. ballsy. She was ok IIRC.
Concerning old fabric that looks great. Well its probably ok but thats not the problem. Synthetic fabric that looks great is probably still almost as strong as when it was made and thats relatively easy to check for. You cut out a strip from the top wing and clamp both ends and then test how much weight it supports. Its all spelled out in AC43-13 so thats not a hard check to do, although its annoying to have to cut the fabric off. You can also do a punch test but thats not considered reliable.
Anyway the real issue with aerobatic planes is not the fabric, it can be cracked and paint peeling etc and still be in no danger of tearing off the airframe. The issue you need to be concerned about is broken rib lacing. The rib laces are what keep the fabric from ballooning off the surface of the wing and changing the airfoil shape. Not good. Rib lacing starts to break when the wing is flexing forward and aft or things inside are moving. This of course can be disastrous so rib lacing is the canary in the coal mine.
So if the fabric is good, have a really good look at all the rib lacing. You will need to ensure every inspection hole is opened in the bottom of both wings. If they are not already open then that's a bad sign because it means the owner did not care to check. They should be opened from day one and regularly looked inside to check the ribs and lacing. You can also test the drag anti drag wires which will when properly installed give you a satisfying low piano kind of sounding note. A rattly sound when you pluck them is a grounding event.
Anyway when you look at an aerobatic plane discount how nice the paint/fabric/engine paint appears and look inside to make your decisions.
Concerning old fabric that looks great. Well its probably ok but thats not the problem. Synthetic fabric that looks great is probably still almost as strong as when it was made and thats relatively easy to check for. You cut out a strip from the top wing and clamp both ends and then test how much weight it supports. Its all spelled out in AC43-13 so thats not a hard check to do, although its annoying to have to cut the fabric off. You can also do a punch test but thats not considered reliable.
Anyway the real issue with aerobatic planes is not the fabric, it can be cracked and paint peeling etc and still be in no danger of tearing off the airframe. The issue you need to be concerned about is broken rib lacing. The rib laces are what keep the fabric from ballooning off the surface of the wing and changing the airfoil shape. Not good. Rib lacing starts to break when the wing is flexing forward and aft or things inside are moving. This of course can be disastrous so rib lacing is the canary in the coal mine.
So if the fabric is good, have a really good look at all the rib lacing. You will need to ensure every inspection hole is opened in the bottom of both wings. If they are not already open then that's a bad sign because it means the owner did not care to check. They should be opened from day one and regularly looked inside to check the ribs and lacing. You can also test the drag anti drag wires which will when properly installed give you a satisfying low piano kind of sounding note. A rattly sound when you pluck them is a grounding event.
Anyway when you look at an aerobatic plane discount how nice the paint/fabric/engine paint appears and look inside to make your decisions.
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GoBoy
- Posts: 98
- Joined: Wed Jun 24, 2015 1:35 pm
We owned the Prototype Ultimate that Gord Price use to fly around , display etc
When Gord's business closed down , we bought the aircraft at the auction .
Sadly , nobody wanted to buy it from us so we parted most of it out.
Sold the avionics package for what we bought the aircraft for, the engine and prop went to a homebuilder
and the rest of it went to an owner in the states that still has it in storage waiting rebuild.
When Gord's business closed down , we bought the aircraft at the auction .
Sadly , nobody wanted to buy it from us so we parted most of it out.
Sold the avionics package for what we bought the aircraft for, the engine and prop went to a homebuilder
and the rest of it went to an owner in the states that still has it in storage waiting rebuild.
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digits
[quote author=Colonel Sanders link=topic=4492.msg11819#msg11819 date=1476162085]
I cannot emphasize how important weight is!
Do not buy a heavy airplane. Many homebuilts
are real porkers.
[/quote]
what would be a reasonable max empty weight for an s1s?
I cannot emphasize how important weight is!
Do not buy a heavy airplane. Many homebuilts
are real porkers.
[/quote]
what would be a reasonable max empty weight for an s1s?
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cgzro
a 180hp I think < 800lbs would be good. 200hp /constant speed < 900lbs would be ok.
There are some that are in the 750lb range but thats quite rare but I'm sure they are spectacular to fly at that weight and would be great if you can find one.
There are some that are in the 750lb range but thats quite rare but I'm sure they are spectacular to fly at that weight and would be great if you can find one.
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Colonel
- Posts: 3450
- Joined: Wed Apr 29, 2015 10:31 am
I might be wanting to weigh it myself - I don't
trust W+B's.
It should have a tiny, modern battery, and a
lightweight starter, and a lightweight alternator.
Also, on an S1 I would go for a metal fixed-pitch
2-blade prop and wind it up to 3300 RPM. Your
neighbors will love you. I'm kind of old school
when it comes to overspeeding props, though -
I have been told there are some very nice MT
three-blade fixed pitch props out there, too,
but I would not overspeed them without a
phone call to Gerd first.
Peter used to get death threats about his
airplane noise, and he has c/s prop. I think
it was the mayor of La Chute that personally
tried to get rid of Dmitri and his fixed-pitch
prop S1. Anyone remember the guys in St
Catherines that got sued for noise and kicked
off the field? They went to Phoenix, last I
heard, though I think one went Tony Robbins.
Anyways. Instead of spending $$$ on a 210hp
pump-up 4-cyl parallel valve, shave the pounds.
Pull the wooden seat back forward. If you see
a 25lb lead-acid battery there, it's time to shed
some weight. Presolite starter? Pull it and replace
with B&C. For alternator, either B&C or Plane Power.
Boat anchors for avionics? Toss 'em.
trust W+B's.
It should have a tiny, modern battery, and a
lightweight starter, and a lightweight alternator.
Also, on an S1 I would go for a metal fixed-pitch
2-blade prop and wind it up to 3300 RPM. Your
neighbors will love you. I'm kind of old school
when it comes to overspeeding props, though -
I have been told there are some very nice MT
three-blade fixed pitch props out there, too,
but I would not overspeed them without a
phone call to Gerd first.
Peter used to get death threats about his
airplane noise, and he has c/s prop. I think
it was the mayor of La Chute that personally
tried to get rid of Dmitri and his fixed-pitch
prop S1. Anyone remember the guys in St
Catherines that got sued for noise and kicked
off the field? They went to Phoenix, last I
heard, though I think one went Tony Robbins.
Anyways. Instead of spending $$$ on a 210hp
pump-up 4-cyl parallel valve, shave the pounds.
Pull the wooden seat back forward. If you see
a 25lb lead-acid battery there, it's time to shed
some weight. Presolite starter? Pull it and replace
with B&C. For alternator, either B&C or Plane Power.
Boat anchors for avionics? Toss 'em.
-
cgzro
Only one death threat in 17 years :)
I recall somebody in the US had a bullet hole in the turtle deck!
Secret is to pull prop back to 2600 and fly low.
The noise footprint is much larger from 5000ft than at 1000ft.
Also if you can get a Harvard to fly regularly that too will solve your nose complaint problems.
I recall somebody in the US had a bullet hole in the turtle deck!
Secret is to pull prop back to 2600 and fly low.
The noise footprint is much larger from 5000ft than at 1000ft.
Also if you can get a Harvard to fly regularly that too will solve your nose complaint problems.
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