Hi everyone,

We find ourselves upgrading propellers, a nice position to be in! We are considering moving to composite instead of the ol' Black Mac.
We're sticking with a long two bladed prop, probably an MT or Hartzell Trailblazer.

A question about composite props - how easy are they to repair when minor stone chips appear in the aft face of the blades?

We had quite a bit of gravel rash on our old McCauley, on the aft face of the blades.
I wondered how the MT or Trailblazer will hold up to this kind of wear and tear?

All opinions and thoughts are encouraged! I want to hear those bad experiences as well as the good.

Battson

If you gave me $50,000 to install a free MT, I'd tell you to kiss my ass. Zero data on the Trailblazer...I am convinced all the MT cheerleaders on this site are getting kickbacks, don't drink the Kook-aid!!!

My advice, stick with the Black Mac!

Skalywag wrote:If you gave me $50,000 to install a free MT, I'd tell you to kiss my ass. Zero data on the Trailblazer...I am convinced all the MT cheerleaders on this site are getting kickbacks, don't drink the Kook-aid!!!

My advice, stick with the Black Mac!

I'm going to my mailbox first thing in the morning to pick up my check

That's an awesome post Skaly!

AKT

Well....! We're off to a flying start already!

Anyone else have any views on the suitability / repairability of composite props in the backcountry?

By the way, I am doing a lot of gravel riverbed operations.

Skalywag wrote:If you gave me $50,000 to install a free MT, I'd tell you to kiss my ass. Zero data on the Trailblazer...I am convinced all the MT cheerleaders on this site are getting kickbacks, don't drink the Kook-aid!!!

My advice, stick with the Black Mac!

How about adding a little more color to your post? Anything that would substantiate your bold, and obviously strong opinion on the subject would be helpful...

I mean $50k to turn down a $15k prop has to be rooted in some first hand personal dissatisfaction.

Skalywag wrote:If you gave me $50,000 to install a free MT, I'd tell you to kiss my ass. Zero data on the Trailblazer...I am convinced all the MT cheerleaders on this site are getting kickbacks, don't drink the Kook-aid!!!

My advice, stick with the Black Mac!

Probably one of the most ignorant post's on this site in a long time. As a long time MT prop user I have never received any sort of kick back. I have found the MT prop to be much more durable than metal props. Floats, wheels and skis. I highly recommend MT props.

Opinions and assholes,we all have them! I like my Mt

Battson,

To (hopefully) return this thread to your specific question, before I purchased a composite prop, I did some research on that flavor of props.

One gent I spoke to was the Director of Maintenance of an air carrier that was operating Beech 1900 aircraft off gravel runways regularly. These aircraft were all equipped with composite props. And those props were driven by fairly powerful turbines. He said before they figured out that turning off the nose wheel power steering would reduce rock damage to the props, they experienced frequent rock chips to the face of the blades.

The "fix" they used was "application of Marine Tex or other high quality epoxy coating" to repair those dings. He said turning off the power steering reduced the frequency of rock dings, but they still got many. He said they'd been using this procedure for some time with no issues, and it was approved by yhe manufacturer (this was a 121 operator).

The idea was to reseal the chip so that moisture couldn't seep into the wood core of the prop. Sorry, but I can't recall the manufacturer of the prop....but it wasn't MT.

I've used epoxy material to reseal rock chips on composite props, and seems to work fine.

One of the significant advantages of composite props is that if you're operating on gravel or worse, sand, there is virtually no erosion or damage to leading edges, unlike aluminum props, where you're constantly filing off $$$$ worth of leading edge,till you have a toothpick left. The same goes for props used on seaplanes and ski planes, where leading edge erosion can be substantial. The composite props have a hard steel leading edge which absorbs those rock dings with minimal damage.

I have run several composite props in both recreational flying and commercial ops, and I love them, fwiw. Of course, I got them all for free, otherwise, I'd have hated them.......

MTV

Things are rarely binary. Composite props have been "the standard" in other types of flying for years now. No reason they have to be "good" or "bad" in our application......everything has trade offs. I've seen the repairs on MT props (no experience with trail blazers) and they don't seem to be an issue. Very conventional materials and long history in other industries fixing minor blemishes in epoxy. My mechanic maintains several and he has no fears or qualms about them.

Making the argument about rocks and abrasion is one thing (surely debatable)...but saying or making the argument as some have made in other threads/forums that "they won't work" on our planes is just wrong. Go to an aerobatic competition on a weekend; they are hanging on the front end of 540's spinning at 2800 RPM exposed to radical gyroscopic forces every day. If it was a major problem they'd be grounded or their would at least be an AD. Composite props dominate that market.

59SC

Battson wrote:Hi everyone,

We find ourselves upgrading propellers, a nice position to be in! We are considering moving to composite instead of the ol' Black Mac.
We're sticking with a long two bladed prop, probably an MT or Hartzell Trailblazer.

A question about composite props - how easy are they to repair when minor stone chips appear in the aft face of the blades?

We had quite a bit of gravel rash on our old McCauley, on the aft face of the blades.
I wondered how the MT or Trailblazer will hold up to this kind of wear and tear?

All opinions and thoughts are encouraged! I want to hear those bad experiences as well as the good.

Battson

When I was on the verge of buying an MT, a local shop had one removed < 50 hrs having to go back to MT for a rock ding in the face. That was enough for me to stay with the Mac. A couple days not operating during my busy season would be a killer. There have been several other smoked MT's around here (theres a thread with pictures on the sky wagon Facebook....well there WAS anyway).

A local operation that runs one on their float plane seem to love it. If I were primarily on floats I'd do it or if the off-road stuff was a little tamer.
Weight/thrust/etc is honestly secondary to reliability for me....and most guys don't have huge repercussions by being grounded for a day or 2.

All this stuff is just tools. One tire/prop/rear seat/etc etc etc isn't "the best" for all operations IMO. Use whats best for you, but if you are getting mid cord dings, ya might look closely at the repair criteria. Could have changed. It doesn't help that when someone does bring up negatives of an MT they kinda get dogpiled. Makes it a polarizing issue (as u see above) and that doesn't help anyone.

Cheers,
KA

I have had a lot of the same questions.

i currently have a Hartzell, with a hub AD that requires an annual eddy-current inspection. At last rebuild, Hartzell offered a new non-AD 'd hub for 6,000 dollars, though it was 6 months backordered and i had no interest in waiting that long. My other concern was paying the money, then having Hartzell issue another AD. I have to admit, i hate paying 2-3 hundred every annual for a 10 minute test and making arrangements to get it done can be a pain.

So, i have looked long and hard at making the switch to MT, but i keep running into this love/hate relationship, though i have yet to see much in the way of actual examples of delamination (or other issues) that seems to be causing all the hate. I guess some first hand experiences would be welcome as it is an expensive choice.

Chris

" It doesn't help that when someone does bring up negatives of an MT they kinda get dogpiled. Makes it a polarizing issue (as u see above) and that doesn't help anyone."

Cheers,
KA[/quote]

My response to the "as u see above" comment that was probably directed toward me.


Actually I think when someone comes on here and implies MT prop users are getting kickbacks and don't drink the coolaid they are deserving of getting called on it since that is no where near the truth, at least in my case.

Jon,

I have a Whrilwind on the SQ2. You've seen my videos so know what I flown on and off. When I was in Texas I could only fly off fine grain beach type sand with just a couple of times on the type of shale like what's at Skalywag's place. The prop was in pristine condition when I fly up here to Alaska. Nearly 300 hours last year in the aforementioned places you've seen in the videos. By seasons end there were hundreds of chips on the back side of the blades. Two on the front one of which was to the weave. I epoxied those two. I sent the blades back to Whirlwind for complete reconditioning/repainting at the cost of just over a grand (I was more concerned about some spider cracks in the "gel coat" near the root of the blades that ended up being just cosmetic).

I have no idea how a metal blade would have held up. I figure this is just the cost of doing the flying I do. BTW the prop has a nickel leading edge, I'm told far superior to a steel leading edge.


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The performance is great on the couple I'm around but that's it imo.

Minor face damage is extremely easy to repair. I simple dab of over the counter 5 min epoxy is all that is recommended. It can then be sanded smooth and painted. Deeper damage can be repaired as well and is fairly simple.

1. The whole prop has a coating of bondo that will develop cracks over time and look ugly. Manufacturer says it's airworthy but it's ugly.

2. Minor blade strikes that could be filed out and flown home on a metal prop destroy the mt. When a composite structure fails it fails catastrophically.
3. Minor dents in the leading edge all tho small in size and airworthy in size can delaminate the erosion sheath to an unairworthy amount.
4. I have had a rock completely penetrate the face of the prop to the other side.
5. They can be locally overhauled but the blades typically have to be shipped to Germany for repair. Exchange sets are available but not cheap.



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Although my initial post was rude, crude, and tactless; am I really so full of it [emoji848]

Jokes aside for a moment, I owned a composite prop and sold it. The STC holder would NOT do transfers at that time. So had pretty much one option to sell it, which was back to the STC holder. When I sold them the 90 hour like new prop, at a significant loss, was asked not to post the details regarding why I sold it on this website.

I have not, and will not, post the step by step, rabbit hole process, including extensive photographs/documentation/invoices etc. that led to that decision.

Back to jokes, purely fictional satire! I do lousy maintenance, break starter adaptors for fun, and the mechanics I work with are all incompetent. Overhauled a less than 2 year old, 600 hour engine, just to boldly show my ignorance. Happily spent over 30K, and enjoyed 3 months of wagon downtime. The engine shop that tore the 470 down/inspected/overhauled, who couldn't find a smoking gun for the starting issues that put metal into the engine either, needs another 40+ years of experience. Not wanting to risk breaking stuff at startup if the timing is off by one degree, or battery is weak, or cranking rpm isn't just right, or a solenoid is going bad, or have the wrong style adaptor/starter etc etc, makes me an ignorant a-hole [emoji857]


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I like the MT a lot, had mine for 1200hrs so far, 1 small nick, very easy to repair.
Epoxy, sand it and you are good to go.

Mine is on a 182 flying lots of backcountry, its durable in my opinion.

I do think they do give a real advantage for the backcoutry by being light, wide (its like an air brake) you also get quick throttle response .

.........

G44 wrote:" It doesn't help that when someone does bring up negatives of an MT they kinda get dogpiled. Makes it a polarizing issue (as u see above) and that doesn't help anyone."

Cheers,
KA

My response to the "as u see above" comment that was probably directed toward me.


Actually I think when someone comes on here and implies MT prop users are getting kickbacks and don't drink the coolaid they are deserving of getting called on it since that is no where near the truth, at least in my case.[/quote]


No it wasn't directed at you. But since you brought it up....
I was referring to previous threads.
Few products are as polarizing and some owners are pretty defensive....which is silly (odd).

Hi Battson,
I still have not made the Chamois pursuit

Before I venture down a longwinded Rabbit hole, let me just put it out there, there are currently NO composite props that meet the criteria of your first post. No one, is currently making a Long, 2 bladed, constant speed, composite propellor for the big 6's. Craig Catto is making some dandy, long, fixed pitch, 4 cyl choices, but no one is currently making anything that will dethrone a 88"-90" C66 in the missions it shines in. And that propellor doesn’t work for you….

All of the props in your OP will take Superficial, Smooth stone chips just fine. The Aluminum props will just see dings, and lose paint or a touch of metal. The composite props will lose a touch of paint, and probably gain a couple little ugly epoxy patches which can be color matched if you feel so inclined.

Having said that I urge you to not make a purchase based on that single piece of knowledge. After all, buying a $10K-$20K propellor, is a substantial investment, (no matter what your bank account looks like) and more importantly, as Skaly and Slohawk note, a poor choice can leave your $200k bird ground bound, for extended stays.

Things I would urge you to evaluate would be;

1) First and as always, most importantly, Mission, mission, mission.... sounding like a broken record here, but as obvious as it is, if you elect to choose the softest tire on the market, you should have no gripes when it gets cut like soft butter with a hot knife, when it sees shale... choosing the lightest weighing prop can yield similar results. Will the mission need the weight loss more than the robustness? Some spell lightweight W-E-A-K.... in this application, I concur. (But two of my airplanes are still wearing a light weight props )

2) TBO's.... TBO's are like paychecks. Good bad or indifferent, It's how society has elected to judge a component's net worth. Electing to follow a TBO may a purely personal choice (for some), but as a general rule a component with a shorter TBO, has a shorter TBO for a reason, putting your head in the sand will not make that reason go away

3) Repair / service manuals.... A comprehensive, and open minded look in the manuals the most revered props on this website, will shed far more light that anyones opinion. There ways we simply must maintain these propellors. The books will tell you that information, the salesmen will not, the guy who really wants to believe his $20K investment is superior to others probably won't. In fact he probably hasn't gone down that rabbit hole himself

4) Customer service.... and not from the sales department! Selling $20K props has made them good at making you feel good. Poll the people who have had catastrophic failures, and how they were treated afterwards, because that relationship is likely to be far more important to your continued happiness with a product than the one that is forgotten shortly after you hand over your hard earned cash.

5) The BIG damage repairs. You wouldn't select a bush beater airplane solely on how well the grease wipes off the belly, don't pick a propellor sole on how it sheds superficial stone damage. Ask how it takes a stop sign, because it's the big damage that's going to leave you parked on a mountain side, not missing paint or dings. You are not buying a small disc'd prop meant to go on the nose of a lightweight acro buzzer, nearest I can tell for your mission, you are buying a giant weed wacker / stickball bat.

Anyways.. these are just some thoughts regarding props in general that anyone should consider. As luck would have it, I also have a bit of Mac (dozens) and MT (only 3) experience, some good, some bad (with both flavors). I can share some of that experience on another post, this afternoon. Skaly's initial post and MT experience does not surprise me in the least bit, nor does G44's. I know people that love them, I know people that hate them. All the reasons above and a few more (not another posters opinion) will determine which category you fall in. For my money MT’s in specific are just like any other prop out there, full of compromises... and merits

Take care, Rob

Rob wrote:Hi Battson,
I still have not made the Chamois pursuit

Before I venture down a longwinded Rabbit hole, let me just put it out there, there are currently NO composite props that meet the criteria of your first post. No one, is currently making a Long, 2 bladed, constant speed, composite propellor for the big 6's. Craig Catto is making some dandy, long, fixed pitch, 4 cyl choices, but no one is currently making anything that will dethrone a 88"-90" C66 in the missions it shines in. And that propellor doesn’t work for you….

All of the props in your OP will take Superficial, Smooth stone chips just fine. The Aluminum props will just see dings, and lose paint or a touch of metal. The composite props will lose a touch of paint, and probably gain a couple little ugly epoxy patches which can be color matched if you feel so inclined.

Having said that I urge you to not make a purchase based on that single piece of knowledge. After all, buying a $10K-$20K propellor, is a substantial investment, (no matter what your bank account looks like) and more importantly, as Skaly and Slohawk note, a poor choice can leave your $200k bird ground bound, for extended stays.

Things I would urge you to evaluate would be;

1) First and as always, most importantly, Mission, mission, mission.... sounding like a broken record here, but as obvious as it is, if you elect to choose the softest tire on the market, you should have no gripes when it gets cut like soft butter with a hot knife, when it sees shale... choosing the lightest weighing prop can yield similar results. Will the mission need the weight loss more than the robustness? Some spell lightweight W-E-A-K.... in this application, I concur. (But two of my airplanes are still wearing a light weight props )

2) TBO's.... TBO's are like paychecks. Good bad or indifferent, It's how society has elected to judge a component's net worth. Electing to follow a TBO may a purely personal choice (for some), but as a general rule a component with a shorter TBO, has a shorter TBO for a reason, putting your head in the sand will not make that reason go away

3) Repair / service manuals.... A comprehensive, and open minded look in the manuals the most revered props on this website, will shed far more light that anyones opinion. There ways we simply must maintain these propellors. The books will tell you that information, the salesmen will not, the guy who really wants to believe his $20K investment is superior to others probably won't. In fact he probably hasn't gone down that rabbit hole himself

4) Customer service.... and not from the sales department! Selling $20K props has made them good at making you feel good. Poll the people who have had catastrophic failures, and how they were treated afterwards, because that relationship is likely to be far more important to your continued happiness with a product than the one that is forgotten shortly after you hand over your hard earned cash.

5) The BIG damage repairs. You wouldn't select a bush beater airplane solely on how well the grease wipes off the belly, don't pick a propellor sole on how it sheds superficial stone damage. Ask how it takes a stop sign, because it's the big damage that's going to leave you parked on a mountain side, not missing paint or dings. You are not buying a small disc'd prop meant to go on the nose of a lightweight acro buzzer, nearest I can tell for your mission, you are buying a giant weed wacker / stickball bat.

Anyways.. these are just some thoughts regarding props in general that anyone should consider. As luck would have it, I also have a bit of Mac (dozens) and MT (only 3) experience, some good, some bad (with both flavors). I can share some of that experience on another post, this afternoon. Skaly's initial post and MT experience does not surprise me in the least bit, nor does G44's. I know people that love them, I know people that hate them. All the reasons above and a few more (not another posters opinion) will determine which category you fall in. For my money MT’s in specific are just like any other prop out there, full of compromises...

Take care, Rob

Excellent post Rob.