Just calculated my empty W & B information for my C182P with Aerocet 3500L's. Im 2144 lbs empty with a CG of 36.35. Problem is, without any weight / ballast in the cargo area and two 180 pound people in the front seat, I'm having trouble staying in the envelope (too far forward) with any fuel quantity other than almost empty.

Is there an approved weight / counter balance I can install back in the tail to help this? 20 lbs around 175" would help quite a bit. Texas Skyways 0-520 and 3 blade prop isnt helping the cause.

thx.

garth

Garth,

Well, the first thing you need to do is replace that big (heavy) chunk of aluminum on the bow with a new, LIGHT, three bladed prop from MT.....

Second, if you don't already have an extended baggage compartment in the plane, install one. Selkirk makes good ones. This not only expands your stowage space, but also allows you to move some "useful" ballast farther aft.

If you're flying a seaplane, and especially to the north of where your nametag says you live, you REALLY MUST carry some survival gear in that airplane. My survival kit weighs about 30 pounds. Secure that as far aft as possible in your extended baggage compartment and your forward CG problem may well be solved.

I flew a C 185 amphib at one point that had a 25 pound lead weight attached to the tailwheel stinger to keep the plane in CG. The first 100 hour inspection, I had a mechanic remove that useless ballast, with the assurance that I'd always carry survival gear in the aft baggage. Never had a problem with that setup, and yes, I was able to keep it (barely) within CG.

A Beaver amphib I flew had the big battery removed from the tray aft, and a smaller battery installed forward. Again, I simply lashed the survival kit onto the original battery tray, which fixed the CG issue (oh, and I ALWAYS burned gas from the front tank first) AND kept the survival gear out of the cabin but still easily accessable.

I would never install useless weight on an airplane to fix a CG issue if there was any other way to deal with it, especially an amphibious seaplane, all of which already have a VERY limited useful load. It's easy to fix a forward CG problem, but then find yourself a few pounds over gross weight.....because you're going to carry some "stuff" anyway....

MTV

Would it be practical to mount the battery farther back, and use slightly heavier cables to reduce the cable losses?

A 25 lb battery at the rear of an extended baggage area (Sta 160") would add the same moment as a 105-pound passenger up front, or offset the moment of around 220# of fuel. That would seem to be a good start. There is also the A/P servos/controller (9 lbs on mine) and ELT (6 lbs on mine), which might pump that up to nearly 170 pounds of front passenger moment or 355# of fuel moment. Add the tie downs, and perhaps you could be close after all.

Garth, flying virtually the identical plane to yours, I can shed some light on this subject. As you know, mine is a 73 182P, with Aerocet 3500's and the Pponk motor. Mike V. hit the nail on the head with the prop. Unfortunately I think you said in a prior post you had just bought a new 3 blade Hartzell. When I first bought mine it had the 3 blade 401 mac on it, which I would guess weighs about the same as your Hartzell (heavy). I never ran the numbers, but I can tell you with a good load of fuel, two front seaters, and nothing in the back, cg was forward. Frequently would run out of trim when landing. After talking with Larry at Flight Resources, he convinced me the the 2 blade MT would probably be the optimum prop for my motor vs the 3 blade. He said over 300hp go with 3, 300 and under 2. It saved me 41 pounds on the nose of the plane vs the 3 blade Mac. The difference in flight characterstics, particularly landings, was incredible. The MT outperformed the mac in all aspects. That amount of weight saved on the nose of the plane with all that arm forward of the cg makes it a different plane. I assume your battery is already aft of the rear baggage like most 182Ps. Also like MTV said put your survival gear full aft, that's what I do. Plus, when flying 2 passengers of more, I frequently put the big guy in the back. Be careful of putting to much weight to far forward in those large Aerocet float lockers. Gas cans, boat motors, etc should be as far back in the compartment as possible. I also put heavy stuff like beer full aft in rear baggage. You will get used to loading your plane differently than your maule, which I suspect liked weight forward. You have the HP and floats to get off the water with a slightly aft CG. You'll be all smiles the first time you have it on the water. If you haven't already broke the bank I would highly recommend the wing extensions. Make a big difference for float flying when loaded. One other thing you'll find, with the extended baggage and huge float lockers, it is possible and tempting to overload it. With the 88 gallon wings pay close attention to fuel load. Don't be tempted to carry fuel you don't need. Get a good fuel computer and use it. Flying around with 50 gallons instead of 80 really helps when you don't need all that gas. Hopefully we can hook up this summer and you can try my plane. Russ

guys - thanks for the input. Russ - having the same plane / engine / float combo as me really helps in the advice dep't. Your right - i just bought this prop ($10K ) and the only reason was that this is the only prop seaplanes west is working with to approve the 400 lb upgross (along with strut change). I really prefer to be "legal" so im quite interested in getting this upgross - thing that im starting to wonder is, if i get this upgross, will i even ever be able to get into the legal area at all?? I'm going to take a closer look at that.

According to my calculations, I'll need about 80 lbs in the "B" baggage area to make things legal where i don't need to worry too much about things. I'm going to look into the Selkirk baggage extension as Mike sugggests- that should help as well and I'm definately going with the wing extensions - I'm just not sure about this year or next. The wife is getting a little

I'll also look into moving the battery further back than it already is (its just behind the B baggage area)

Yes Russ - I'd look forward to meeting you this summer - maybe at Crane Lake for a hamburger and a flight in each of our planes to compare.

garth

Garth, even with the heavy 3 blade, you'll find that in real world seaplane flying getting enough weight aft really isn't a problem. Unless you like flying by yourself with full fuel and an empty plane, there always seems to be a hundred pounds of loose stuff to throw in the aft baggage. When flying with wife and kids I have wife and one kid in back, and other kid up front. Although the rate my boy is growing he'll outweigh his mom real soon. Once you actually fly it I suspect it won't be bad. You can carry a couple of those collapsible 5 gal water jugs and fill with lake water and throw back there to balance things out if needed. You'll also find that loading slightly aft cg will increase cruise speed. I have factory extended baggage on mine, which goes back about 18inches from the rear of the door. I considered adding selkirk, but decided the plane already has too much room for stuff and that adding more baggage room would just temp me to take more crap I don't need not to mention the weight of that stuff. I've found that no matter what plane I've had, the list of essentials to take along expands to fill all available space. Its a shame Seaplanes West doesn't seem to want to acknowledge the MT prop as a real player. I spoke with Jim about that one time and he just said he didn't want to bother with including it on the STC. Can you imagine the cg issue you would have on the 3400 amphibs? It's hard to imagine any Cessna 18 series on amphibs not using a MT.

My 182 has a small bag of shot in the tail cone and a battery behind the baggage .
GT

So, I've spent about the last 2 hours mucking around with this excel sheet and found an error in it (I didnt develop the original program). You still have to watch loading in the forward area, but it is not near as bad as i first thought. I ran a new CG calculation dropping 40 lbs off the nose for an MT prop and as the guys mentioned, it was amazing at the improvement on the loading characteristics. But, with my prop on there, it definately does not look like I need any balast, or loading past the rear baggage (selkirk extended with 30 lbs would prevent most issues tho). This was a really good exercise. I played around with many loading situations and got to know a lot about how to load different combinations.

garth

Good on you, Garth. I have on occasion found W/B from a mechanic to be in error. Wouldn't have caught it had I not been familiar with a virtually identical airplane/configuration. I'm not very familiar with the 182 on floats, but virtually all amphibious float planes tend toward the front of the C/G envelope. The numbers you noted earlier, however did seem pretty extreme.

Glad you were able to figure it out. As I noted earlier, I would do everything i could to avoid having to install ballast.

MTV

mtv wrote:, but virtually all amphibious float planes tend toward the front of the C/G envelope. The numbers you noted earlier, however did seem pretty extreme. MTV

Hey mike - i'm actually going to be on straight floats so i cant imagine the loading for the amphibs . Been thinking about it - for the cost of a Selkirk Extended Storage area ($400 plus install) i think it would be worth it - storing my survival gear / etc. in the very back only helps. I'll just tell the wife it's a safety thing

Still can't believe the improvement on the W & B with the MT vs. the three blade tho.

Garth, I was just looking at the Selkirk extended again. I guess it would be OK to jam the light stuff back there out of the way, sleeping bags etc. Price isn't all that bad considering its certified airplane stuff. If you can't believe the W&B difference with the MT, you'd probably be even more surprised with the performance difference, much more quiet, and way smoother. They are great props. Lots of people pull all kinds of stuff out of an airplane to gain 40 pounds more useful load. Bolting on the MT was the easiest useful load increase I've ever had.

Wing extensions are a safety thing also. I can honestly say I'm probably not pushing daisies right now because they bailed me out of a bad pilot decision.

Garth, Mike & Russ are bang on with advice! This last week at Cherry Pocket i have been flying a 185 on 3400 Aerocets, 3 blade 80" Hartzell doing lost of commercial land & sea training for a customer in FL. It has the worst vibration i have experienced on a 185 and talk about fall out of the sky on 180 degree emergency power off spot landings! I am going to take him up to Spruce Creek airpark and have Larry Slashinger demo his 185 with a MT. I have flown a 182 with win-X, P-ponk 275hp and 3 blade Hartzell, 3500l's at Surfside and it was not bad at all, but my 1954 230hp 180 did better on same floats. Get the Selkirk baggage and you'll be fine! Case of beer or whisky and a shotgun in back is fine for ballast & survival, go hunting then have a drink???? You will like your new machine, congrats!

Brian

Rhyppa wrote:Garth, I was just looking at the Selkirk extended again. I guess it would be OK to jam the light stuff back there out of the way, sleeping bags etc. Price isn't all that bad considering its certified airplane stuff. If you can't believe the W&B difference with the MT, you'd probably be even more surprised with the performance difference, much more quiet, and way smoother. They are great props. Lots of people pull all kinds of stuff out of an airplane to gain 40 pounds more useful load. Bolting on the MT was the easiest useful load increase I've ever had.

Russ - what is the full model number on your MT and if you don't mind me asking - what is that prop worth?
Garth

I don't have my prop log with me, but I recall MTV-15-D/210-58, which means 210 cm, or about 83 inches. What's it worth or what does it cost? It was worth every penny I spent. I think they cost about $13,000 new at the time. Mine had been run into a dock by a prior owner. I purchased it with brand new bladeS and factory overhaul hub - I think it was about $9000 used and seller had to pay for the STC for my plane. Jeff at Park Rapids had it from a plane he was working on. I think I got about $3500 out of my 401 mac so new difference was under $6K. Do you have any vibration with your new prop and the SW engine mount?

I have been thinking about a MT for my 185 but not sure of the durability and maintainence of paint peeling off the blades for a working plane like mine. I had a 80" wood sensenich before on one of my super cubs and it cracked and took a long time to get it repaired. What are the reports from working 185's with MT's? Time down is $$ for me. I still have a 2 blade Mac and have thought about a 84" 401 Mac as a replacement.

Brian, all I can speak to is durability on a float plane. I've now run it two full seasons, about 140 hours, and the prop looks like it came out of the crate from the factory. There is not so much as a mark on it. I've definitely had it in the spray, worked it in rough water, etc. No way an aluminum prop would be in that good of condition, especially the leading edge. The stainless leading edge on the MT seems to prevent all water erosion. I don't have any paint missing. Two things working in your favor with the MT, first, 40 pound weight savings vs 3 blade alum on the nose keeps the bow of the floats higher in the water, meaning less chance to pick up spray. Second, it is a shorter than most seaplane props, again increasing water clearance. No aluminum prop I've had on prior float planes or this plane have held up as well in water. Also, my plane sits outside year round and no signs of any weather effect on the prop.

Brian,

My experience with the MT props on seaplanes is pretty much the same as Ryppa's. On a Husky with the 210 cm prop, I saw some erosion of the paint near the leading edge, but just the most surficial layer. As Ryppa noted, that stainless leading edge REALLY reduces prop blade erosion on floats.

Naturally talent and perseverance on the part of a pilot can ruin almost anything, but I'd much rather run an MT prop on a floatplane than an aluminum prop. Every time the mechanic files those aluminum prop blades to remove the water damage, you're losing some performance.

MTV

I've never run a metal prop on floats that wasn't bare of paint on the leading edge. I guess they sell a nice touch up paint kit for the MT but I have no need for one. besides the stainless edge, they have some type of hard epoxy coating on them protecting the paint. I just can't see a problem unless you plan on using it for a brush cutter. I questioned all these things before buying, and I didn't get my answers from MT, I spoke with a commercial operater up in Red Lake Ont that has one on his 180. He couldn't say enough good things about it versus the metal props he's run for 40 years. Figure if it held up in his type of application mine shouldn't be any problem.

I like simple solutions- the easiest thing would be to have the passenger ride in the back. When riding as a passenger I like to be up front, but not if it puts the CG out of limits. You could even remove the co-pilot seat to get rid of that weight, and the passenger sitting in the back would have tons of leg room. Of course you'd have to do a W&B calculation to see if that would get the CG in a better spot.

It wouldn't cost anything, and seems a little unorthodox, but if it changed the CG enough it would be very simple.
-Nate