For those of you who have installed the Northpoint XP470 (PPonk), which propeller did you choose and why?

Thanks!

MT two blade. I already had it and liked it because it is light and smooth.

I also went with the MT 2 blade. I intended to overhaul and use my C66 but it didn't make it through inspection. I read a lot of good reviews about the MT and liked the lighter weight on the nose and smoothness. I asked the guy at the prop shop what he thought about the MT's and he really seemed to like them, even though he couldn't sell me since Flight Resources holds the STC.

I am running MT two blade. I really like it. Pulls hard and pretty fast.

If I were on floats, worked the plane at gross weight often, or did not place priority on speed, I would run MT three blade.

These props are of excellent design and supported by a great company.

The benefits of composite construction are ideally suited to propellers in several ways.

1. Complex contouring improves aerodynamic efficiency in all respects.

2. Material can be added instead of only removed.This means that the blades can outlast your engine, your airplane and you.

3. Fatigue life is practically infinite for composites.

4. Does not support harmonic vibration (think swinging a canoe paddle through the air)

5. Composite props are significantly lighter than metal, out front, and spinning, where reduced mass really counts.

I’m not sure I’ll ever consider installing another metal prop.

Here's something to try with a "lightweight" prop; hand starting, for those times when the battery just can't get the job done. I had to go down that road last winter when my battery gave up and it wasn't much fun. There just isn't enough mass weight to make it a simple flip of the prop like it was with my metal prop.

Mapleflt wrote:Here's something to try with a "lightweight" prop, hand starting for those times when the battery just can't get the job done. I had to go down that road last winter when my battery gave up and it was much fun. There just isn't enough mass weight to make it a simple flip of the prop like it was with my metal prop.

Extra rotating mass has some advantages for sure, especially during starting and for smoothness at low idle. I still prefer the composite advantages and take care to make sure my electrical system won’t leave me needing to start my airplane by hand.

I have hand propped my old 180 with MT on the Bushwheels a few times. The engine was O 470K and I made sure the blade was positioned at 10 30 to 11 o'clock----not down low. I am a little over six feet tall but still pulling from way up there so not really getting a lot of momentum. Basically if the impulse mags are set properly, just pulling it through was enough to get it started. I was very careful to get out of the way.

We went Hartzell 8068. The weight savings would have been nice but we wanted to be able to go back on wheels with the 182 and the longer 2 blade had too little ground clearance. Cost was also a consideration.
Unfortunately for us, the new Hartzell Voyager composite was not certified yet.
But you should look closely at both composite propellers. RAF members get a nice discount on the Voyager.

Joewcasey wrote:For those of you who have installed the Northpoint XP470 (PPonk), which propeller did you choose and why?...

I'm curious which props are actually on the STC?
I'm kinda thinking only Hartzell or Mac 3 bladers, at least before Steve Knopp sold the STC.
So the MT (either 2 or 3 blade) would be via a separate STC?

Speaking of the XP470, I wonder if North Point has any plans to add mogas approval to the STC?
7.5 compression is still 87 octane friendly.
Or maybe Petersen or EAA could add it to their approved model list for their mogas STC's.
There's enough of these engines out there to make it worth their while.

If budget constraints are a factor a full meat 86"-88" C66/58 are pretty tough to beat. If not, Scolopax's post sums it all up pretty well.

The one caveat might be the guy who needs to work the plane really hard while potentially subjecting the prop to a lot of hard weed whacking. The MT is just not going to cut the same brush as a metal prop before it starts shedding itself, not that I condone trimming alders or taxiway signs with your prop . just sayin...

I have propped an O-470-50 with an MT 3 blade, do not recommend it. Never tried it when it wore a 2 blade MT, but doubt it'd be any fun, if at all doable, never the less, sometimes we overthink things. If you are sporting an O-470-50, there is no excuse for not carrying something like this ;

https://antigravitybatteries.com/products/micro-starts/xp-1/

edit; I see Marty has successfully propped his 2 blade... it works . I'll still the easy (read; safer) way out and jump it ...

https://antigravitybatteries.com/produc ... arts/xp-1/

I'm definitely getting this or something along the same lines.

Rob wrote:If budget constraints are a factor a full meat 86"-88" C66/58 are pretty tough to beat. ...

Full meat C58/C66 blades are pretty difficult to find. If there is a good source, I didn’t come across it during my exhaustive search last year. There are a lot of blades that wouldn’t be returned to service by a reputable shop floating around the used market.

I think that there is a long two blade MAC that can be purchased new that will work. Maybe a C204? But it’s not a whole lot less expensive than a MT.

The dynamics of a composite prop, which will eliminate all harmonics and remove all rpm limitations from idle to redline inspires tremendous confidence when running an old crankshaft that’s been installed on multiple engines over decades for thousands of hours.

If this was the only advantage to composite, it would be enough to change my mind.

hotrod180 wrote:So the MT (either 2 or 3 blade) would be via a separate STC?

MT holds the STCs for big bore continentals.

have propped an O-470-50 with an MT 3 blade, do not recommend it.

What happened with that combo?

I had my starter adapter fail and had to hand prop a Hartzell 3 blade on a 470-50 with 8.5 cylinders.

It was HARD. We were about to give up until we found an old diagram of how to hand prop a DC3 using a rope with sleeves on it to get multiple turns of the prop. This ended up working, glad I had help from my friends, not something I feel like doing again.

Mantoga wrote:have propped an O-470-50 with an MT 3 blade, do not recommend it.

What happened with that combo?

It started... no surprise, I have owned no electrics airplanes, propped R-985 Ag Cats, and several other flavor of 'dead battery' flat 4's and 6's...
consequently propping another wasn't a 'problem' it just wasn't 'ideal'

What 'happened' is I learned that an MT is

slicker than I realized
it is sharper than I realized,
and it is lighter than I realized.

I had a fresh engine, great mags, spot on timing, and an excellent carb. All the things that have probably been out of mind for sometime, by the time you get to a dead battery.... how an ideal engine starts has little relevance to how one 'that was running a while ago' does.....

Bolted on to a big 6, this was enough to make carrying a light weight back up plan a much more appropriate approach in my mind.

Maybe I'm getting soft in my old age

Take care, Rob

I just spoke to an engine shop that does the Northpoint conversions on 0-470's and they did not recommend the MT 2 blade prop. This is the first time I've heard this. The claim was that it's too light for the conversion. Has anyone had any issues out of the ordinary with the MT 2 blade on a Northpoint Pponk?

My Pponk engine is not a Northpoint, but I assume it's the same. The only problem I had was using a lightweight starter with the MT 2 blade - had a little kickback which broke the starter adaptor spring. After fixing that and putting in a heavy starter (Hartzell Energizer), I've had no problems (nearly 5 years) and love the prop. I've never heard anyone say 2 blade MT props shouldn't be put on a Pponk engine.

MT two blade, already had it and really like it, I will put an MT prop in every airplane I own,(If there is prop for it) really like the lightweight and the performance.

Has anyone had any issues out of the ordinary with the MT 2 blade on a Northpoint Pponk?

I've had mine on for almost 50 hrs now and like it. Just enjoyed that combination again a few hrs ago.