Engine swap: dotting the 'i's and crossing the 't's.

[Rene]

In the distant past a Piper PA-15 had a Continental A-65-8 swapped into it. PA-15's and 17's have different type certificates, that power plant isn't listed on A-800, and the data plate is embossed "Model PA-15 . . . T.C. 800". Wouldn't there have to have been a STC or maybe a 337 covering the conversion?

 

[Bell206]

Wouldn't there have to have been a STC or maybe a 337 covering the conversion?

Yes. But if you think it was altered prior to 1960, then it would have been only a 337. Regardless, swapping A- 65s to the early Pipers was a very common practice.

 

[Magman]

IIRC A -15 could be changed to a -17 ( or possibly the equivalent of) by

Landing Gear and other component swaps.

 

[Rene]

IIRC A -15 could be changed to a -17 ( or possibly the equivalent of) by

Landing Gear and other component swaps.

I am looking into that. From what I can discern, you gained 50 pounds of gross weight (and netted 34) by adding shock struts and the Continental. 17s came with two doors and dual controls (another 12 pounds, dropping the GW increase to 22) but lots of 15's that were converted to 17's didn't have that done, while others had the throttle moved to the center and things like. Not to mention 337s for seats, belts, baggage compartments, etcetera.

There are apparently "legal" PA-17s with 15-xxx serial numbers, this may be one of them.

 

[Bell206]

IIRC A -15 could be changed to a -17

There are apparently "legal" PA-17s with 15-xxx serial numbers, this may be one of them.

Maybe. What aircraft model is listed on the AWC and registration? Back in the day, the CAA would "recertify" aircraft with similar TCs like the Vagabond and the C/F/L Cubs. This followed a different route than a simple engine swap as originally inquired on.

But only the CAA could do that and it was usually recorded in the logbook and a new AWC was issued with recertified model number listed. However, if your AWC still shows PA-15 then you're stuck in a gray area of what model it is and what documentation you need to verify its configuration. The J-3 C/F/L Cubs had similar issues as well.

Perhaps post on the Short Wing Piper Club site for model specific info?

 

[Rene]

Just a neat picture I found while doing some due-diligence. (This plane is for sale, but isn't the plane I was referring to in this thread.)

 

[Rene]

Maybe. What aircraft model is listed on the AWC and registration? Back in the day, the CAA would "recertify" aircraft with similar TCs like the Vagabond and the C/F/L Cubs. This followed a different route than a simple engine swap as originally inquired on.

But only the CAA could do that and it was usually recorded in the logbook and a new AWC was issued with recertified model number listed. However, if your AWC still shows PA-15 then you're stuck in a gray area of what model it is and what documentation you need to verify its configuration. The J-3 C/F/L Cubs had similar issues as well.

Perhaps post on the Short Wing Piper Club site for model specific info?

Thank you. I have seen an Aeronca that had "CONV" physically stamped on its data plate when converted from one model to another. Partly, I am concerned because of my lack of familiarity with the issue. Partly, I am confused because of conflicting information (and part of that is inconsistent paperwork). Yes, the SWP website has been quite helpful.

 

[Bell206]

Partly, I am confused because of conflicting information (and part of that is inconsistent paperwork).

Perhaps direct your questions to the mechanic who signed the last annual inspection or will sign the next one. In order for them to do that they must determine the aircraft conforms to its proper type design or properly altered configuration.

That signature also technically renews the AWC for another year. So they should be able to answer your question and reduce your confusion to a manageable level.

 

[Rene]

Perhaps direct your questions to the mechanic who signed the last annual inspection or will sign the next one. In order for them to do that they must determine the aircraft conforms to its proper type design or properly altered configuration.

That signature also technically renews the AWC for another year. So they should be able to answer your question and reduce your confusion to a manageable level.

Thanks.

I spent much of the evening yesterday reading old logbook entries - many of them written in scribble. But, it was more enjoyable than episode 32 of: "Who's worse, the Bears, Lions, Packers, or Vikings?" I found a few pertinent 337s, along with some drawings and letters from Piper, so I guess that answers my questions as to the A-65-8, shock struts and 1150 lbs. gross weight.

So the papers that say PA-15 are likely correct and those that say -17 likely in error. Plus, the moment on the computed W&B has been 52-1/2 low for most of the airplane's life. That's 0.05" at gross!!!

PS: I love the cryptic quality of some of the old paperwork. It was obviously written by people who knew what they were doing and didn't feel a need to go into too much boring detail.

PPS: Someone on the SWP blog sent me a pic of his data plate. The "15" and last "0" of 800 had been "X"d over with "17" and "5" being new-ish-ly stamped. But his s/n was still 15-something.

 

[Magman]

Did you get the FAA Records from Oklahoma?

There may be 337’s there that are not in your file.

Or the other way around.

After many years of sending copies to the GADO-FSDO and now to the

Registry I do realize that I never receive any type of confirmation on their

status. Nor does the owner get any!

 

[Rene]

Did you get the FAA Records from Oklahoma?

There may be 337’s there that are not in your file.

Or the other way around.

After many years of sending copies to the GADO-FSDO and now to the

Registry I do realize that I never receive any type of confirmation on their

status. Nor does the owner get any!

Yes. The (early) 337 concerning the engine swap that I was looking for was in the OKC record but not the paper file. The paperwork would make Akira Kurosawa (author of 'Rashomon') proud. There is the CAA / FAA version, the sequence of owners' version, and the whats on and in the airplane version. Quite obviously, from a practical point-of-view, the further back in time I went the less concerned all parties involved were in documentation. And there really aren't many real-world differences between a PA-15 and PA-17 anyway . . . even fewer once the 15 gets a Continental, baggage compartment, and bungees.

 

[Magman]

To me; the most significant thing is what your Insurance Company thinks

it is and if it complies with the Type Certificate.

In the absence of any other paperwork you may opt to have your Tech

write up a 337 with 15/17 changes that were accomplished by the

“Unknown Agency”. IIRC the mods are listed in the Aircraft Spec so

that should be “Approved Data”. It might be a good time to update

the Weight and Balance and Equipment List so all is in agreement.

 

[3393RP]

Thanks.

I spent much of the evening yesterday reading old logbook entries - many of them written in scribble. But, it was more enjoyable than episode 32 of: "Who's worse, the Bears, Lions, Packers, or Vikings?" I found a few pertinent 337s, along with some drawings and letters from Piper, so I guess that answers my questions as to the A-65-8, shock struts and 1150 lbs. gross weight.

So the papers that say PA-15 are likely correct and those that say -17 likely in error. Plus, the moment on the computed W&B has been 52-1/2 low for most of the airplane's life. That's 0.05" at gross!!!

PS: I love the cryptic quality of some of the old paperwork. It was obviously written by people who knew what they were doing and didn't feel a need to go into too much boring detail.

PPS: Someone on the SWP blog sent me a pic of his data plate. The "15" and last "0" of 800 had been "X"d over with "17" and "5" being new-ish-ly stamped. But his s/n was still 15-something.

Going over the historical record of an aircraft is always enjoyable. It sounds like this one lived an interesting life.

 

[Rene]

To me; the most significant thing is what your Insurance Company thinks

it is and if it complies with the Type Certificate.

In the absence of any other paperwork you may opt to have your Tech

write up a 337 with 15/17 changes that were accomplished by the

“Unknown Agency”. IIRC the mods are listed in the Aircraft Spec so

that should be “Approved Data”. It might be a good time to update

the Weight and Balance and Equipment List so all is in agreement.

Thanks. It's a big chunk of change for me, and it's not that I don't trust the others involved. I wouldn't be dealing with them if I did not. I just don't like unpleasant surprises.

The Data Plate and AWC say PA-15. There is a 337 for the A-65-8 . . . which seems to have somehow transubstantiated into a C-65-8 and back again . . . just as on some paperwork over the years the airplane morphed into a PA-17 and back again. But, I have 337's for a baggage compartment, and one that increases the gross weight to 1150 pounds after modifications to "PA-17" landing gear. (I just need to find the one for the black stripe . . . maybe it's part of the Stits STC.)

The limitation sheet says PA-17 . . ..

But, had the plane been re-christened as a PA-17 . . . those four items are in A-805, no 337 was required.

There are still some things I haven't figured out. Bungee shocks are items 211 and 212 in A-800. So was the purpose of the 337 concerning the landing gear obtaining a 50 pound increase in gross weight?

SWP says the PA-15 as built lacked a baggage compartment. But A-800 says you can carry 40 pounds in it. Did early s/n's lack a baggage compartment, but later ones have 'em? Of course, it's the 11th revision of A-800. Did earlier type certificates omit baggage? (One of the Cub T.C.'s says "when installed".) And why not authorize increasing the gross weight 50 lbs. when the gear was modified as was done with the J-3?

 

[Rene]

Going over the historical record of an aircraft is always enjoyable. It sounds like this one lived an interesting life.

There is a G-XXX s/n 1942 Cub around here that has Warbird status. But not as a L-4 . . . As a TG-8.

It was converted with a 337, a couple pages of hand drawn diagrams, a letter from Piper, and a list of equipment purchased for the conversion. (Them were the days.)

 

[Bell206]

It was converted with a 337, a couple pages of hand drawn diagrams, a letter from Piper, and a list of equipment purchased for the conversion. (Them were the days.)

You'll find "them days" were still here up to about 2000, when things changed. And the main reason was a small group of people who preferred fraud and money over anything else.

As to the Cub glider, you'll find there are a number of those same glider airframes flying around with engines on the nose. Regardless, with the right knowledge and people you can still work some of that same old magic today.