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MT Composite Prop certified but Catto not certified

slowjunk

Registered User
I am surprised that MT has been able to get a fixed pitch composite prop certified but Catto has not been able to do the same. I called MT and they said they didn't have an STC for a PA-18 but they did say they are always working on getting more applications certified. I wonder if MT is claiming that the fiberglass covering is non-structural. It is nice that they have a bonded on nickel leading edge just like the Catto.

https://www.mt-propeller.com/en/entw/pro_fixed.htm

Certified application:
http://www.mt-propellerusa.com/pdf/stcflyer/FL035US.pdf
 
Professional pilots (Brian Sutton) has an stc for an MT on a cub. Are the MT's solid nickel LE now? The ones I've been around are a thin stainless steel "wrap" on the LE, and very susceptible to damage...
 
I think the difference is MT is spending the time and money to work through the certification process and catto isnt.

I am building a pa-22/20 with an o-320 and would love to run a catto. Catto has had a survey on his site asking what certified aircraft the public would be interested in pursuing. It's been up for a couple of years. I have submitted to the survey a couple of times and even sent him an email with no response.

It's frustrating because I have seen that you can get Catto for lsa cubs running O-320's. So the engineering is worked, they are flying and safe, and you can order the prop now. Just no faa stc.

Neither Catto or the faa seem interested in changing any time soon. I think he is content being a small custom shop working with Valdez, IAC, and a small volume of LSA aircraft on unique projects. I guess you can't blame him. I think he is living the parable of the fisherman. Good for him. Too bad for us.




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Maybe the solution is for you to use the experimental category and enjoy the freedom it allows. The only thing restricting you is you.
 
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Certifying a propeller requires a lot of work and expense. I certainly can't blame Mr. Catto if he's reluctant to go down that road. And, bear in mind that there are actually two approvals required.....first of all, the prop itself has to be certified as an airplane part. Then, an STC has to be issued for each and every make and model of airplane that the prop would be used on.

In the case of MT props, MT itself has got the props approved by the FAA, but it's often users/dealers who have gotten the STCs for installation of the props.

In any case, approving a propeller on a certified airplane is a big deal, and I suspect Mr. Catto's business with the experimental crowd may be paying the bills. It'd be pretty hard for me to visualize how long it'd take to recover the cost of certification.

But, I'll bet if someone on this forum is willing to undertake that certification, Catto might be happy to let you spend your time and money.

MTV

MTV
 
Is it legal to install a Catto prop on a certified airplane that's parked? When does it potentially become a problem...upon installation, engine start, or when moving under it's own power (like 14 C.F.R. § 1.1.)? The reason I ask is there's more than one Catto prop installed locally, but unless the FSDO folks detect some critical phase of operation they may be limited in their ability to enforce the FAR's.

Gary
 
I am surprised that MT has been able to get a fixed pitch composite prop certified but Catto has not been able to do the same. I called MT and they said they didn't have an STC for a PA-18 but they did say they are always working on getting more applications certified. I wonder if MT is claiming that the fiberglass covering is non-structural. It is nice that they have a bonded on nickel leading edge just like the Catto.

https://www.mt-propeller.com/en/entw/pro_fixed.htm

Certified application:
http://www.mt-propellerusa.com/pdf/stcflyer/FL035US.pdf
the fibreglass on an MT is only a thin layer to protect the wood
 
Who knows maybe someone could pull together a GoFundMe campaign and fund the process.

Or, AOPA will have a breakthrough with the faa on simplifying the certification process.

There is clearly an interested market. Sooner or later Catto or someone else will break into the certified market. Until then we have to wait.


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Catto has all they can do as it is so why spend several $100K to certify on particular prop on one particular airplane. I have met Craig Catto an I think he would be bored with that. However I did ask him if someone else put up the money and ran it with some sort of compensation for him would he do it. He said he would.

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The 1A2 type certificate allows 'any other wood propeller that meets following...." to be installed on O235's and 0290's. So I don't think it's too much of a stretch to use the MT prop that gas been certified with the O240. Flange bolts and pitch?

But the TC gets more specific with the O320.

Aerodon
 
Ya that was the subject of a previous discussion and it headed into a conversation of whether a prop made from wood laminate was composite and whether a catto prop with a composite outside is really a wood prop. Some folks seem
To be running a catto on their 290s and ha


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. . . Had Concluded that catto is a wood prop with a cover. Interesting interpretation but like you said that language wasn't carried forward in the 320s, which is what I have. So the philosophical debate is academic for me.


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Is it legal to install a Catto prop on a certified airplane that's parked? When does it potentially become a problem...upon installation, engine start, or when moving under it's own power (like 14 C.F.R. § 1.1.)? The reason I ask is there's more than one Catto prop installed locally, but unless the FSDO folks detect some critical phase of operation they may be limited in their ability to enforce the FAR's.

Gary

IN other places the key words are something like: with intent of flight.
 
I've had a couple of MT props on aerobatic planes with mixed results. Both CS. The two blade eventually eroded behind the SS leading edge and had to go back to MT for replacement, on me. The three blade didn't have that problem but the finish eroded in a few spots. We were always told to avoid flying them in any but the lightest of rain.

Jim
 
Interesting comment to remind me that composite has drawbacks too. It reminds me of sailing where Carbon fiber/Kevlar sails are technically better than canvas, but the extra performance results much higher cost, less service life and uv degradation. There are no free lunches.


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I thought the rain damage issue was addressed by adding the Nickle leading edge.


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I ran MT props on a couple of seaplanes, where they were regularly exposed to spray and water erosion. They tolerated that issue far better than metal props. There was some erosion of the paint near the tips, behind the metal LE, but purely cosmetic. Those same props were used on skis in winter, and again they tolerated snow erosion issues far better than metal props.

MTV
 
I would guess that Hartzell has 1000x more pull with their decades old FAA connections and could get a prop approved made out of spruce pitch faster than Craig Catto could get a proven professionally built one.
Pure old politics again.
As far as when it would become illegal, the only time that would be enforceable (and hold up in court) is if they actually sighted the airplane flying, and waited for you to land, to taxi it up and as you steped out, and tapped you on the shoulder. Imho.

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....As far as when it would become illegal, the only time that would be enforceable (and hold up in court) is if they actually sighted the airplane flying, and waited for you to land, to taxi it up and as you stepped out, and tapped you on the shoulder.

And what, at any other time, if an agent merely asks when you installed the prop, if you flew with it, checks against the airframe lots, etc.? Lying is a felony, even when there is no underlying crime (ask Martha Stewart):

18 USC 1001
Except as otherwise provided in this section, whoever, in any matter within the jurisdiction of the executive, legislative, or judicial branch of the Government of the United States, knowingly and willfully

(1)falsifies, conceals, or covers up by any trick, scheme, or device a material fact;

(2)makes any materially false, fictitious, or fraudulent statement or representation; or

(3)makes or uses any false writing or document knowing the same to contain any materially false, fictitious, or fraudulent statement or entry;

shall be fined under this title, imprisoned not more than 5 years or, if the offense involves international or domestic terrorism (as defined in section 2331), imprisoned not more than 8 years, or both. If the matter relates to an offense under chapter 109A, 109B, 110, or 117, or section 1591, then the term of imprisonment imposed under this section shall be not more than 8 years.

Taking the 5th in what should be an administrative procedure will be awkward.


 
Yep I would like to legally put one on. But, I don't think having your plane mysteriously show up at a fly In and arguing that it's legal as it sitssitting on the field at a fly in and saying that it is legal since it's sitting still will get you too far. And a bigger concern is if you have accident could insurance deny your claim if they find out that you were flying a non certified prop installed by the operator.


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Sorry message was jumbled my fat figures accidentally hit send. But I think I made my point.


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If the feds want to make a issue of a catto prop on a certified aircraft all they have to do is tag the aircraft as non airworthy. Once that is done you can't fly it until you have a IA fix the problem and sign it off. This is not a legal action on your record just a pain in the butt. Some don't know what one looks like, some do. Best to just keep it in a hanger and stay away from large events. From what I have seen up here most insurance companies don't look too close but it would suck having them deny you 90 grand policy.
DENNY
 
Denny,
That sounds right, they used to run around all the time red
Tagging folks with big tires at Hood Strip......
Steve. I hear what your saying, but I think the issue would be WHEN does it become enforceable, bolted on? Resting
Ontop of the cowling? Or laying on the hanger floor. Obviously bolting it on implys you MIGHT fly it, it would certainly draw attention from them, and as Denny says, they could "red tag" it and even make you produce paper
Work to prove it has been returned to service with a legal
prop, but weather simply having sitting on a parked aircraft is somehow commiting a federal crime is a quite a streach. I really think it would likely involve a phone call and they would simply tell you to get it the heck off there or dont get caught flying it........... But maybe I missed something as I always figured you can do ANYTHING to your parked airplane??? I do see your point though. Fly Safe. E
 
And his shop would need a PMA in order to sell the STC'd part. Another hurdle.
Parts Manufacturing Authorization is the approval to manufacture approved parts. For some like me it is a big deal. Not something I can wrap my head around. However with the guidelines provided by the FAA, my wife whipped out the appropriate paperwork in a weeks worth of her spare time. The FAA was happy and I started manufacturing brake parts. The FAA did come visit me on an annual basis to check up that I was following procedure. The combination of the PMA and the STC is approval to manufacture and provide approved parts for installation on someone else's airplane. The exchange of money is not a concern of the FAA.

The STC is the approval of the item for the installation on a specific airplane.
 
If the feds want to make a issue of a catto prop on a certified aircraft all they have to do is tag the aircraft as non airworthy. Once that is done you can't fly it until you have a IA fix the problem and sign it off. This is not a legal action on your record just a pain in the butt. Some don't know what one looks like, some do. Best to just keep it in a hanger and stay away from large events. From what I have seen up here most insurance companies don't look too close but it would suck having them deny you 90 grand policy.
DENNY


Talked to my insurance company and told them I was thinking of running a Cato prop. They said that the policy would be written experimental and the premium would go up 10%, other than that they had no issue as I recall the discussion 6 months ago. My -12 is certified
Doug
 
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Can a field approval be approved by a DER (outside the FAA)?

I inquired about Catto prop approval and the FSDO was receptive and the first question was "Is there a existing field approval for this prop"?

I had been in contact with Craig Catto and he indicated after I sent him some of my correspondence from my FSDO there may be a possibility for a field approval via outside DER. Once a field approval is granted installing a Catto prop should be much easier since precedent seems essential. No inspector will sign off this improvement without previous approval....it's the climate we live in.

It was also the opinion of one of the inspectors that the 'any other wood prop' statement on the type cert was interpreted by them as 'approved wood prop' although the wording is much broader....

What it came down to after all my communications was the phrase my parents used "Because I SAID SO"!

Catto said they weren't persuing STC for the fixed pitch any more.
 
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