Catto Vs Borer floatplane
- Thread starter Revr
- Start date
other then being much smoother and lighter the nickel leading edge on the catto stands up better when it comes to water erosion, as for performance it also spools up quicker and IMO pulls a little harder, i went from the borer 40 pitch to the catto 37 cruise stayed about the same.
mvivion
SPONSOR
Bozeman,MT
Eddie Foy
MEMBER
South Florida
The 24 dollar question!
BC12D-4-85
SPONSOR
Fairbanks, AK.
Had a quick winter safety visit from the FAA last week. Very cordial and informative. Discussed controlled flight into terrain and carbon monoxide. No other problems.
I mentioned that at one time I had considered installing a wood/composite Catto or similar via a coordinated Field Approval, but had discarded the idea as I wasn't sure the work and expense were worth the potential results. Another local FSDO rep was supportive and offered help with the paperwork but in the end I put the project on hold.
The ramp folks noted the Catto wasn't approved on certified planes like my Taylorcraft. I agreed and then mentioned they were seen from time to time and if the aircraft they were on were experimental? There wasn't much else to say about that from them or me.
So unless experimental some form of approval is required. That's not headline news. And citing CAR 4 certified aircraft as eligible for wood props w/o approval only applies to what that reg calls "light aircraft"....those under 1000# GW.
GAP
I mentioned that at one time I had considered installing a wood/composite Catto or similar via a coordinated Field Approval, but had discarded the idea as I wasn't sure the work and expense were worth the potential results. Another local FSDO rep was supportive and offered help with the paperwork but in the end I put the project on hold.
The ramp folks noted the Catto wasn't approved on certified planes like my Taylorcraft. I agreed and then mentioned they were seen from time to time and if the aircraft they were on were experimental? There wasn't much else to say about that from them or me.
So unless experimental some form of approval is required. That's not headline news. And citing CAR 4 certified aircraft as eligible for wood props w/o approval only applies to what that reg calls "light aircraft"....those under 1000# GW.
GAP
alaskadrifter
Registered User
Alaska
Except that it's written right into many TCDS' in many of these older aircraft. I say as little to a fed as I possibly can.
BC12D-4-85
SPONSOR
Fairbanks, AK.
We're drifting and that's not my intent...the OP asked about Catto and it's not approved unless the aircraft is experimental. And the FAA is aware.
Nor are any unapproved wooden propellers for my Taylorcraft covered by TCDS A-696, which in Item 1 specifies "Approved wood (fixed or adjustable pitch)."
TCDS A-691 for the J-3/PA-11 does list Item 101 "Propeller - Wood (fixed or adjustable pitch)." However I have it in writing that the Catto is currently considered a combination wood/composite propeller and as such is not eligible to be installed as a "wood" propeller.
The quote from my contact at the FSDO:
"Unfortunately, as the Cato propeller is not a wooden propeller of "conventional type" given the fiberglass wrap, I and the gentleman I spoke to within our Technical Standards Branch feel it would not qualify as a minor change. Given that this would be considered a major change to type design, I would like to encourage you to submit for a field approval so that an engineering evaluation may be made by the Administrator."
GAP
skywagon8a
MEMBER
SE Mass MA6
Thanks GAP, That is encouraging, I take that response as "let's run it through the system, it is worth a try". From my previous experience with the Alaska FAA, I take that as an almost YES.
If you could get a section of a blade to show how much is wood and how much is the "fabric" cover along with a conventional wood prop with it's fabric tip cover??????? It's a place to start. Assuming you are silver tonged and can carry on an intellectual friendly discussion with Mr. FAA, progress can be made. It's amazing how well this approach works.
Experimental
BC12D-4-85
SPONSOR
Fairbanks, AK.
Yes I do feel it's something worth doing at some point. I've done it before and it takes some careful research and coordination with a knowledgeable A&P I/A and an FAA inspector that's willing to assist and advise. My verbal and written discussions were positive and I was left with the same feeling as you about their response so far. It takes properly filling out the 337 and ICW forms plus supporting documentation from the manufacturer.
A subsequent before and after balance analysis on the airframe with a prop balancing unit locally available might be valuable along with specified periodic airworthiness inspections on all gear configurations. Prop tip clearance can be adjusted via gear and tire combinations.
Previous success included getting the first Scout set gear installed on my 7GCBC in the early '80s. I got close but no cigar with getting EDO 2000's approved on my PA-11, but didn't have the resources for adequate flight testing.
It may still happen and others may wish to pursue a Catto approval as suggested.
My apologies to the OP for the thread drift. I should have started my own subject at some point.
GAP
BC12D-4-85
SPONSOR
Fairbanks, AK.
As a suggestion (maybe it's already been done) somebody including Catto should go experimental with a Cub or whatever and do some serious testing of approved metal vs Catto propellers. Data flys and BS walks.
I'm sure Catto has done stress analysis of the props if their webpage info is correct. The engine/prop combination can be tested in some form...other prop manufacturers do that routinely. Engine operating parameters can be monitored and a test sequence set up to note any short term durability issues. See exactly what performance benefits and detriments come with the package versus proven metal propellers in various gear configurations.
This would initially be for an FAA Engineering Assisted Field Approval and not a blanket STC. The former is something finite and perhaps achievable, the latter lengthy, expensive, and would require risk protection going forward.
The bottom line question is are the Catto props that much better and equally as airworthy as existing approved propellers on our typical low and slow aircraft? If so then someone should prove that to the FAA.
Edit: My quest for a Catto vs current Field Approved Sen M76AK-2-** on my Taylorcraft (essentially now a C-90 with STC'd and manufacturer approved changes) would likely provide limited parallel benefit for Cub owners with different engine and airframe combinations. That's why I suggest some testing on that aircraft as a start in proving the utility and airworthiness of the package.
GAP
I'm sure Catto has done stress analysis of the props if their webpage info is correct. The engine/prop combination can be tested in some form...other prop manufacturers do that routinely. Engine operating parameters can be monitored and a test sequence set up to note any short term durability issues. See exactly what performance benefits and detriments come with the package versus proven metal propellers in various gear configurations.
This would initially be for an FAA Engineering Assisted Field Approval and not a blanket STC. The former is something finite and perhaps achievable, the latter lengthy, expensive, and would require risk protection going forward.
The bottom line question is are the Catto props that much better and equally as airworthy as existing approved propellers on our typical low and slow aircraft? If so then someone should prove that to the FAA.
Edit: My quest for a Catto vs current Field Approved Sen M76AK-2-** on my Taylorcraft (essentially now a C-90 with STC'd and manufacturer approved changes) would likely provide limited parallel benefit for Cub owners with different engine and airframe combinations. That's why I suggest some testing on that aircraft as a start in proving the utility and airworthiness of the package.
GAP
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mike gittens
Registered User
Hey cub12, Im looking for a catto 84x37, Im in NS Canada and wondering if you know of a canadian dealer
40m
SPONSOR
Shoreham, VT
Worked with Mark Friesen 807-seven37-1367, not sure what his relationship is with Catto but extremely helpful and knowledgeable.
As far as i know i was the only one dealing in Canada, Lately i have just been sending people directly to Catto. but feel free to give me a call if there is something you have questions about, 40m posted my# above. They are a great prop, stand up very well,are extremely smooth and are nice and light.
Marc
Marc
C-FIJK
Registered User
Lewisporte N.L.
cubdriver2
FRIEND
upstate NY
mike gittens
Registered User
Yeah it looks like the used ones are rare, like impossible to find. I sent Catto a quote request, that exchange rate is going to hurt!!!
NunavutPA-12
FRIEND
67.8N,115.1W CYCO Canada
How much lighter than the Borer? I could stand to loose some weight ......on the nose I mean.
NunavutPA-12
FRIEND
67.8N,115.1W CYCO Canada
It would be great to save 20-pounds up front. I wouldn't want to do so at the expense of performance, though.
What could I get on the used market for my 82/44 Borer in decent shape?
What could I get on the used market for my 82/44 Borer in decent shape?
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RaisedByWolves
FRIEND
Tx
82/40 catto will give you the same cruise speed as 82/44 borer, maybe a little more, and much better takeoff performance and quicker throttle response.
C-FIJK
Registered User
Lewisporte N.L.
Carey Gray
Registered User
Thun Field, Washington
I normally run a Borer 82/45 on my 160 Cub. With a Catto 84/37 on it, I get less RPM taking off/climbing out, less RPM wide open and it goes slower.
I haven't done a measured take off/climb comparison, but it feels similar.
If you buy a used Catto without trying it, it might work and it might not. If it doesn't, you're out a prop for a while and some money while Catto figures it out.
The problem is that it's so damn light and such a work of art that it's hard to remove.
I haven't done a measured take off/climb comparison, but it feels similar.
If you buy a used Catto without trying it, it might work and it might not. If it doesn't, you're out a prop for a while and some money while Catto figures it out.
The problem is that it's so damn light and such a work of art that it's hard to remove.
