Propeller choices for Australia
 

The time has come to replace the propellers...

I was hoping I could hear from someone that has MT propellers installed on their aircraft, and operates them and maintains them.

What I don't want to hear is someone's uninformed opinion of a mate who heard the lame say he heard from a friend that they were s#!t.

Actual experiences with their use, operation and maintenance please, would be very welcome and helpful.

I have an MT. It is currently interstate for repair of one blade which is expected to take 5 weeks or so. My guess is that the cause was gravel damage.

Hi mate,

Thanks for that. Have you been happy with it otherwise? Was it the leading edge that got damaged? Anything else you think I should know?

I don't own an MT (and probably will never) but have maintained quite a few, most I have worked on have been a pain. Larger stone chips (the kind you get from gravel strips) will require replacement of the leading edge (send away).

They are actually a wooden propeller with a Carbon fiber covering nor a true carbon fiber prop and if treated poorly (chips not repaired) can suffer from the inner wood getting damp and rotting.

Factory support used to be pretty poor but better now that there are authorized repair centers in Aus.

In addition to these issues I have always wondered if there will be flow on effects in the engine counterweights from the lack of blade inertia and subsequent high deceleration rate on shut down.

I would probably only consider them for AUS if it was a high wing aircraft operated mostly from sealed strips and there was a major advantage in cost or performance.

High wing - tick, but I don't know why? Tailwheel has the prop further from the ground at times.
Sealed strips - tick. My guess is that the crack in the fibreglass (not carbon on mine) started when the LE got a little ding on gravel some time ago (before I bought it). Hard to see in the black, back face.
Performance advantage - a little tick, slightly lighter.
Cost? When the overhaul is due I will compare the cost with the price of a new metal Hartzell.

I don't think my engine has counterweights.

Happy with it otherwise? Looks pretty. I don't do snap rolls or gyroscopic manoeuvres so the lower inertia is no advantage for me.

Had them on my low wing for a while now, easier to start, more ground clearance, much less noise and vibration, some more speed, and better climb performance.

On a per hour basis cheaper than metal.

Negatives is the initial cost, you are paying a premium for them.

Never had to send them away.

Thanks for the replies.

I will be putting them on a low wing 6 seat twin, so it's a tough choice...

6yr calendar TBO is not ideal for private ops

TBO
 

I think you will find most other props will have a similar calendar time with the exception of those listed in AD/PROP/1, and I understand that is under review with CASA favouring the manufacturers TBO .

My operator has an aircraft with MT propellers. They've been nothing but trouble, developing cracks and chips in normal operation (only ever operated on sealed surfaces) that then take weeks to either be repaired or have a new assembly shipped from Germany.

When working, they are smooth and quiet, and they do look cool, but I definitely wouldn't recommend them. We're replacing that aircraft with one fitted with metal props.

I could have had any of the MT offerings or others for the IO540……I went the Hartzel BA prop. :ok:

Check the part numbers on their offering and then email me bloke :ok:

Thanks skkm, appreciate the feedback.

When you say 'repair chips and cracks' who do you have repair them? Is your LAME familiar with new composites? The reason I started this thread came from talking to LAME's about them, and found their knowledge of new ideas somewhat lacking, and actual experience with them, non-existent. I talked to the manufacturer, and their repair procedure for most stone chips on anything other than the metal leading edge is clean the area, fill with epoxy resin, sand back, done.

No LAME that I spoke to (5 of them) had any idea what the repair procedure was, and I got the impression that they thought they were 'new fangled black magic' that they didn't trust, but didn't have any hard data to back it up. That's why I am asking people that actually use them for their experience.

If it's not to personal, what sort of application are they being used in? You don't have to be specific!

Jaba, I will give you a ring tomorrow, or drop around, hopefully I wouldn't have lost what little remains of my mind in the mean time!

I'm sorry I don't know any details about how repairs have been carried out on our blades, but our MRO is a large outfit that definitely knows how to handle composites. Most of our issues were cracks rather than chips, and so I believe much of the repair work had to be carried out by MT themselves, or at least under their guidance, hence the lengthy delays due to their very small presence in Australia.

The aircraft's a light twin used for IFR training.

Hi RatsoreA,

I found this thread rather interesting as I just read an article on MT Propellers and how they made etc in US AOPA magazine just last month.

They talked about how they are made and advantages etc over metal and old style wood props going back to WW2 when wooden props were favoured over metal in many applications and widely used on German fighters and bombers as well as famous allied aircraft etc.

I wrote some more in this post but deleted it as there is a heap of info on their website which you no doubt have read through re construction, installation, advantages etc..

One of the original applications was a 5 blade prop fitted to the PA42-1000 Cheyenne's. They gave 5kt faster cruise, reduced TKOF distances and faster climb rates.

You may want to contact the owner/ operators of VH-BUR which has them fitted, they may be able to assist with some info, the Cheyenne had very little ground clearance (4inches IIRC) with the huge original 4 bladed, 9 feet diameter props, the MT's improved that by a few inches. They may have some experience with stone chips and repairs etc and may be able to offer some additional advice since they changed from original props to MT. Cheers:ok:.

For stone chips, the manufacturers manual says fill void with an appropriate Epoxy resin (5 min. Epoxy), sand the filled spot with sandpaper, apply lacquer
layer to protect the repaired spot against moisture. Biggest challenge is to get someone to actually read and understand section 6 of the MT operation and installation manual.

During the next repair/overhaul which for me is 2400 hrs and 72 months they will have a look at these areas again. The blades themselves have no life limit.

MTs are very big in north america and canada, maybe in 50 years Australia will stop reinventing aviation, in the US putting some epoxy on a blade, sanding it back, and spraying lacquer is something the owner can do.

The Vans Aircraft forums have data from propeller tests, where they tried different props on the same engine and airframe.

It's good reading, and a summary is:

Hartzell C2YR-1BF/F7496.........208.9 (metal)
Whirlwind 200RV....................206.9
Whirlwind 200c.....................205.6
Hartzell C2YK-1BF/F7666A-4..205.4 (metal)
Aeocomposites...................204.6
Whirlwind Series 150...........201.9 (3 blade)
MT MRV12B/183-59............200.7 (3 blade)

Fastest prop METAL two Bladed F7496 Hartzell
Slowest 3 Bladed MT composite/wood (by 8.2 MPH slower)
Least expensive prop Hartzell C2YK & C2YR
Most expensive Aerocomposite (I think?)

That is not really true, go back to the source, the MT was not tested on the same frame RV-8.com - Prop

That is a fairly small engine, you will MTs being used more on higher HP piston and turbine aircraft. As the article says, the Whirl Wind is specially designed for the airframe.

I have been associated with an aeroplane fitted with mt MTV-12-B-C propellers and they are garbage.

Small chips cause cracks in the leading edge, which requires replacement, even though the aeroplane was only ever operated on sealed strips. Delamination is a problem as well.

mt customer service is piss poor, one notable occasion they took themselves off to Oshkosh so no communication or shipping from their office for two weeks.

They look good, but in the end you will pay.

https://cimg7.ibsrv.net/gimg/pprune....d245ffe8ae.jpg
I wouldn't buy them

Ouch. That looks very annoying and expensive.

I had a screw fall out of my spinner on my MT prop on a Continental and it took out a chunk from the prop 4 inches by 1 inch in size on the trailing edge, close to the root.

It was also incredibly difficult to balance it leading up to that.