Ross4289 wrote:Agree these aren’t that great to fly with a fwd CG and one or two people with a heavy prop, but I typically hit aft CG limits well before I get to gross weight.

A lighter prop would make this even worse.

This is exactly why my 206 wears a 3 blade Mac. My CG is further back then any 180/185 I’ve seen, and when I load it it only gets worse. It also helps that I have 1800lb useful load, so I’m not super concerned about making it lighter. But the prop would be one of the last things I would change on mine simply for the CG calculations. And if I did I’d be putting a 3 blade on, as Rob states, gotta take advantage of the power somehow.

Wow 1800 UL! Is it 3800 gross? My 185 is like 1700 UL with the flint 3600 gross stc

Lots of discussion referencing weight, but few actual numbers.
who can post actual weights for:
86" Mac 2 blade (C58/66/203)
86" or so Mac 3 blade (C401)
83" MT 2 blade
83" MT 3 blade
I'm esp curious of the weight difference between my own 88" C203 & an 83" 2 blade MT.
Thanks.

Ross4289 wrote:Wow 1800 UL! Is it 3800 gross? My 185 is like 1700 UL with the flint 3600 gross stc

No its an older P model so no STC for 3800lbs on it. Empty weight on scales is 1846lbs with all six seats in, thats swinging a big 3 blade mac and 8.50x6 tires. so that gives me 1754 UL. If I take 2 seats out I'm down to pretty much 1800lbs, and take 2 more out, well you can do the math... But it needs the weight on the nose. The only LW thing I have up there is an Odyssey battery. Alt, Starter, prop, all heavy. Need it for W&B.

My recollections from a few years back was my Mac C58 w/o the spinner weighed 56 lbs and change. The MT 3 blade that replaced it weighed less than 1 lb more, also w/o the spinner.

From the type certificate, the Mc 401 is 67.5 lbs.

MT 2 blade- 45.6 lbs
MT 3 blade- 56 lbs

—

Ross4289 wrote:From the type certificate, the Mc 401 is 67.5 lbs.

MT 2 blade- 45.6 lbs
MT 3 blade- 56 lbs

If I recall... that 401 weight is sans spinner and backplate. I think the MT one sheet is pretty close to the last one I pulled off.

A1Skinner wrote:

Ross4289 wrote:Wow 1800 UL! Is it 3800 gross? My 185 is like 1700 UL with the flint 3600 gross stc

No its an older P model so no STC for 3800lbs on it. Empty weight on scales is 1846lbs with all six seats in, thats swinging a big 3 blade mac and 8.50x6 tires. so that gives me 1754 UL. If I take 2 seats out I'm down to pretty much 1800lbs, and take 2 more out, well you can do the math... But it needs the weight on the nose. The only LW thing I have up there is an Odyssey battery. Alt, Starter, prop, all heavy. Need it for W&B.

This is why the RSTOL shines even more on these than the 18x series. You have much more going on behind the cg, and RSTOL unlike cuffs, is helping from the trailing edge.

Take care, Rob

I find this thread very interesting. I fly a lot of props on my my plane for test purposes. If all goes well I hope to meet you and see you at OSH at the Hartzell booth near the tower with a new and worthy product.

We are really near a quality solution for all.

MW

Prop & C180 TCDS indicates my 88" C201 is about 53# with spinner,
not as much heavier than the 2 blade MT as I would have thought.
I did the math for my airplane, losing 7# at <40"> only moves the CG aft about .35"--
not a significant difference.,

My 88" C203 black mac is 59# prop and spinner.

MT 2-blade prop and kevlar spinner is 45.6#.

So that's 14.4lbs at what station is the prop? That's -35 if I recall correctly. It's definitely not 40.

That's 500 in-lbs of moment shifted aft - where most of us really need it. Yes, by itself that only moves the Cg a quarter of an inch aft. But, it helps you take a lot more weight out of the back and overall offset other weight reductions.

Yes, it's a lot of money for 14 lbs.

soyAnarchisto wrote:My 88" C203 black mac is 59#... That's -35 if I recall correctly. It's definitely not 40.

Everyone is always so confident on this this forum. LOL



FWIW... when folks talk about the "Black Mac," they are referring to the 403, 3 blade. Spec sheet says 64.5lbs w/o spinner.

Bigrenna wrote:Everyone is always so confident on this this forum. LOL

FWIW when folks talk about the "Black Mac," they are referring to the 403, 3 blade. Spec sheet says 64.5lbs w/o spinner.

Not picking on you bro, just adding clarity for accuracy

1) Confidence is a prerequisite to being a good pilot. right wrong or indifferent, just do something.

2) The trouble doesn't stop with confidence or even start there, it is when we compare apples to volkwagens....
soy is quoting a modern C203, your screen shotting a relic C50 (I happen to like the relic better) Any semantic juggling
sarcastic exaggeration, or optimistic 'rounding' and the entire exchange goes from data point worthy to pipe dream stuff.

3) Black Mac may indeed be what some 'folks' call the 403 boat anchor, but it is actually an STC'd McCauley line that spans from 2 blade variants clear to 5 blade models (Think BE20). Including soy's C203., and the 3B C435, but not the C403

This is probably a good time to hit the brakes, as Maverick should be along anytime now to wield the latest Www. word for how to get a right answer by posting wrong
As for the cost of the 14? pounds off the nose (if anyone is in agreement on that number?)
In the name of accuracy, I'd offer that it's not just 14#

It's

A) less weight

B) better CG

C) better throttle response as a result of (A)
If you STOL of any flavor other than a glider, you know this is paramount.

D) better dampener (albeit at a cost of poorer flywheel)

IMHO ea of these attributes is as important as the next, and ea brings some worth to the table. And there are a few other smaller pro's, and of course con's, these are just the glaring ones.

Again, they're all a compromise, but I'd say currently the deck is pretty well stacked in favor of these props. And in my opinion, when and if an all composite prop hits the market, if the blade geometry isn't any better, it will still be a better prop, let's just hope we see some advantage in the airfoil as well.

Take care, Rob

Having said all that.... there are two major bummer with the MT of any flavor for me.

1) they can't handle the desert.
FWIW, I am on my umpteenth set of blades on various hubs. The vendors will wave the purely cosmetic rhetoric... whatever... If I paid top dollar for my paint job and it wrinkled like a prune in a year I'd be pissed, and there is no arguing the cosmetics of a paint job. But, we're not talking wrinkle paint style wrinkles here, we're talking prune deep wrinkles measurable in 16th's, not thousandth's, wrinkles that would have you doing something if it was ice, causing the deformation. Evidently since it's wood shrinking under the jacket it's we can call it cosmetic...
I will add that MT Germany has been most gracious in helping, I just think they're hands are tied with what they can do.

2) These props are subject to a TBO, regardless of what 'Part' of the FAR's you and your ship are operating under, with the way the current FAA TC is worded. To be very specific, how the 'for continued airworthiness' under Note 10 is worded. I have no interest in being 'corrected' I am merely confidently (just for Greg ) passing on accurate information. We're all big kids that get to make our own choices, read the TC, and do what you want with it.

We'll probably all stick our heads in the sand and ignore it... and for the average pilot, you probably believe that part 91 is somehow making you excluded. That is unless of course you own a Robinson, Cirrus, or anything else that actually has life limits or components as such. The truth is, it's just worded poorly (for us) and unarguably limits the service life of the prop. Remember, regardless of being part 91, and regardless of the limits being described in an SB, the requirement to adhere to them is in the TC...

Don't shoot me, I didn't write the TC... but the bottom line is, if you own an MT, you probably ought to know you own a life limited prop, at least until that bit is revised

In the name of accuracy below is exactly how that is worded (copy / paste) and referring to the SB, the big bore Conti's seem to all come in at a TBO of 2400 hrs / 72 mo.s, and if your IA is good with you running it forever good for you! Just thought someone should probably be bringing this up.

And yet, they are still the compromise I settle for...

Oh, and as a side note, this exists only on the FAA TC, not the EASA

Take care, Rob

(a) Aircraft installations must be approved as part of the aircraft type certificate and demonstrate compliance with the applicable aircraft airworthiness requirements.
(b)***** All MTV-XXX propellers****** are to be operated within the limits of MT-Propeller Operation and Installation Manual No.E-124 for non reversible propellers and No. E-504 for reversible propellers, and adhere to the TBO-limits shown in Service Bulletin No. 1( ).
(c) Propeller maintenance, on overhaul, and airworthiness limitations shall be accomplished in accordance with MT-Propeller Overhaul Manual No. E-220 for non reversible propellers and No. E-519 for reversible propellers, latest revision.

This is a great question you have about props.

But let's hear some more about flying in Guatemala! It's a beautiful country.

Rob wrote:.....soy is quoting a modern C203, your screen shotting a relic C50....

I think Renna was pointing out that the arm for the prop is indeed -40",
as per that W&B sheet (which looks like factory issue) as well as the C180 TCDS.

The C50 prop is a different hub and old design which is no longer available and not what is installed on my plane. According to McCauley application guide, page 51, the prop that is installed on my plane 88" is 59#:

https://mccauley.txtav.com/-/media/mcca ... guide.ashx

Of course that very same document claims the 82" variant is also 59#, so you got me how that works. There are 2 other flavors that report both the 82" and 88" lengths are 52#s. So I believed the 59# which was also reported/quoted by a local prop shop.

Also, see the note at the bottom of page 4 which says that the term BLACKMAC covers all the STC's McCauley props in that doc from 2-blade to 5. I hear plenty of people refer to the seaplane prop as a blackmac - but since it's on the TCDS for the 180 I don't need the STC for it so maybe according to the semantic police I'm not allowed to call it a blackmac. I defer to the greater wisdom and the higher certificate holder.

And the -40 station arm does appear correct according to my ancient WnB which was superseded 15 iterations ago in 1992 when it was installed. I was confused by the fact that in spite of searching and reading it 5 times over, the 5A6 rev 68 TCDS for the skywagon does not list the arm for any of the prop combinations. It's also not listed in the station diagram of the 100 series service manual, either. What prop #11 for my plane, a 1955 180 which refers to station 30 pitch settings, which initially confused me because I was looking for the location of the entire prop:

Aircraft reworked per Cessna Service Kit SK180
-
46:
McCauley constant speed propeller (Threadless) (Floatplane, Amphibian,
Landplane, Skiplane)
(a)
Hub 2A34C203/90DCA
-
2 blades
Diameter: not over 88 in., not under 86.5 in.
Pitch settings at 30 in. sta.:

soyAnarchisto wrote:.........Also, see the note at the bottom of page 4 which says that the term BLACKMAC covers all the STC's McCauley props in that doc from 2-blade to 5. I hear plenty of people refer to the seaplane prop as a blackmac - but since it's on the TCDS for the 180 I don't need the STC for it so maybe according to the semantic police I'm not allowed to call it a blackmac.....

As you point out, "black mac" seems to be almost all-encompassing,
it sure makes it a lot more clear when people refer to their prop by model: "C203" "C66", etc.
I see prop-for-sale ads / posts all the time: "McCauley prop for C180" or similar.
Not very informative.

Patrick,

You may want to give Jimmy a call.

Not MT related but a good story on 2 vs 3 bladed props.
In short, he sold 17 Piper Pawnee Bravos 300 right after the "improved " change for a 3 blade prop. to obtain better performance.
1 or two planes still came with 2 blades in the group bringing them down here.
Turns out the 3 bladed ones did not only stay way behind enroute but to their dismay could not take the load of the 2 bladed ones at work.
He had to change all to 2 bladed ones and loose quite some money.

Called him 2 days ago to pls remind me the details of the story. It was a 1 hr interesting conversation.