• If You Are Having Trouble Logging In with Your Old Username and Password, Please use this Forgot Your Password link to get re-established.
  • There is no better time to show your support for SuperCub.Org than during our annual calendar campaign! All the details are HERE

Flying the Super 18

I think amphibs have more drag due to the wheels, etc, but I have never flown the same plane with both types of floats.

sj
 
Amphibs don't have any significant amount of additional drag, BUT they put a lot of weight out front, as in in front of your propeller, in the form of nosewheels and retraction mechanisms.

So, amphibs tend to be very nose heavy, and typically run forward CG. Forward CG means slower speeds, in any airplane.

Steve,

Let's look at the "composite" question on the MT props:

It is made of wood (two flavors of wood, actually) carbon kevlar sheathing, a gel coat, and paint, plus a stainless steel leading edge.

If you look up the word "composite" in a dictionary, you'll find that the MT really is the ultimate in composite construction. :angel:

MTV
 
On the other question regarding props on the Super 18, it will be really interesting if they can get past the new FAR 23 noise standards. They are tough to comply with.

And, as to using Super Cub parts on a newly certificated airplane, on a new TC, as the Super 18 guys are doing, the answer is no. Except for the "stock super cub parts" that are used to manufacture the airplane, and those will have to be stamped iwth a part number for the Super 18.

So, for example, even though Cub Crafters' Top Cub would work just fine on Fluidyne C2200 retractable wheel skis, you can't use them, cause they are not approved on that airplane.

Same will be true of the Super 18. Everything will have to have a separate approval.

I don't think I'd want to put a 2400 pound airplane on the little Baumanns. Now, the next size up....could be great.

I don't know of any float approved on the Super Cub that comes even close to that bouyancy, except the Baumanns. I can tell you that at 2200 they are fine, though.

MTV
 
steve said:
Crash,

The picture would do no good since my ASI is totally whacked. I flight plan 100kts (115mph) with 31" tires, belly pod, extended wings, etc. I have done some GPS tests in many directions and calm winds and that is about all she has. That is running 2400rpm at 24" of MP at low levels. If I push it to 25" mp I can eeek out another few knots - but at the cost of a lot more fuel than the knots are worth.
sj

Our planes are basically the same standard body, 180 hp PA-18's except you have drooped tips and a constant speed MT prop. I run a fixed pitch prop.

Facts:

You cruise at 115 mph with a pod and big tundra tires.

I cruise at 107 with pod and big tundra tires.

On a 100 mile trip you arrive 3.9 minutes before I do.

The constant speed prop with governor, mp gauge, prop control etc. is around 22 lbs heavier.

MT conversion makes the plane more complex to operate.

The MT prop conversion is $13,500.00 vs $3,200.00 for a McCauley fixed pitch.

Not saying one is better then the other but these are the same kinds of facts we need on a stock wing versus the slotted.

How much shorter will it get off, if at all. How much slower will it fly on short final resulting in a shorter landing distance.

Take care! Crash
 
Why wouldn't a slotted wing cub take off shorter than a round wing cub? Has bigger flaps and more wing area? If your at the same weight and same prop of course.
 
Steve,

Have you gone up to the 4-7000 ft range to see what that constant speed will true out at? Any better than 100kts?

I would imagine you would open up the spread between your and Crashes speed even more as you go up.

Lance
 
Hi Guys,
I'm not sure how this thread got hijacked, but I thought I should clear a few things up. The weight difference between a McCauley 1A200/82xx with its normal spinner and mounting bolts is normally less than a pound from the MT MTV-15-B/210-58 with its spinner and mounting bolts. The remaining components which include the governor, governor drive adapter, manifold pressure gauge, cable, hose, firewall extension, and miscellaneous hardware will only add a little more than 6 pounds, which is generally offset by the installation of our exhaust. In other words, if you brought me your 180 H.P. airplane with a McCauley 1A200 propeller and a standard exhaust, I could send it back to you with the MT constant speed propeller, and our exhaust at about the same weight. There is NO 22 pound difference!
As far as the speed goes, you will ALWAYS be comparing apples to oranges if you are comparing two different planes regardless of how similar you think they may be. Power settings alone are difficult to match up since 2450 RPM might be 75% power with one fixed pitch propeller, but 85% power with another. This doesn't even take into consideration altitude, temperature, and humidity. I think Crash has a pretty exceptional airplane since he can fly 107 MPH at 75% power with a fixed pitch McCauley propeller. Mine would only go about 95 on a good day back when I was running the fixed pitch prop, which is why I got into this whole mess of writing STC's to begin with...
Now, back to the Super 18. You can probably expect to see a constant speed propeller option in the near future. I think Mark and the gang have an excellent product and conduct themselves with the utmost honesty and integrity. I wish them well with all their endeavors.

Brian Sutton
Professional Pilots Inc.
www.propilotsinc.com
 
Kase,
It is hard to get the slot at the correct angle on floats. Once you get airborne, you have excess speed and you open the face on the slot so you climb like a scalded ape. On wheels, you can vary your technique a bit, but it is too technique sensitive for me to take advantage of. The excess 100 lbs you have from all the crap is compensated for by the extra wing and flap area. For me, the ground roll or water distance ends up being about equal.

PPI Brian,
Thanks for the great post. Your point about 75% power being different for every prop is something I only recently realized. I have to run between 2550 and 2600 to get 75% power. After that it seems to climb rapidly for every RPM increase. I only tested that twice and both times the atmospheric conditions were similiar. Is it fair to assume that you can dial the thrust down lower on the constant speed to have less thrust upon landing than the fixed?
Crash,
Are those % power #'s similiar to yours?
 
Hi Brian; The 22 lbs difference I came up with was comparing a P235 at 37 lbs or a GM 82/42 at 33 lbs to your 45 lb MT prop with an extra 10+ lbs (my guess, these things usually weigh more then advertised) for all the stuff to make it work. I flew a 45 lb A200 during Bear hunting season and don't have anything good to say about it. Pull the power back and it DID feel nose heavy. It also took a lot longer to spool up then I am used to.

Groundloop; I don't really pay much attention to percentage of power settings. I just run at between 2200 and 2500 rpm. The thing I like about a Super Cub is the simplicity of operation. Shove the throttle forward and go, pull it back and land. I don't see a manifold pressure gauge and prop control as a plus in a Super Cub. Plus the additional $10,500.00 in your pocket will buy a lot of avgas.

This is where I usually cruise at.......

IMG_0596.JPG


Crash
 
Let's get back to the wing for a minute. Is there a standard length/round tip slotted wing? I'm not interested in extended wings. What advantages would I notice going from a stock wing to a stock wing with slots?

SB
 
Crash,

The other factor here, to compare apples to apples, is fuel burn. That may not make any difference to you, if all you do is short trips. It will make a difference in a lot of parts of the world, though.

What kind of fuel burn do you run at that power setting, and have you strobed your prop to verify the accuracy of your tach?

Just curious.

As Brian says--those are pretty exceptional Cub numbers in my experience. I don't have a lot of experience in 180 Cubs, though.

MTV
 
StewartB,
I think the rounded wing with a slot would be dangerous. To me, one of the advantages of the extended wing is having the ailierons way out there . You can feel the extra aileron at slow speeds, especially when heavy.
The large flaps are the best thing since zippers on pants. If I didn't like the way cub flaps land, I would own a husky. The larger flaps make it all the sweeter. I still wish I could have the husky speed :D , but as everyone knows, light aviation is all about trade offs.
 
Loop,

I thought the point of slots was to direct air over the wing, which should coincidentally increase the effectiveness of the ailerons, particularly at slow speeds/high AOA attitudes. If all this talk of increased performance is comparing stock wings to extended/slotted wings, I've misunderstood. I thought we were talking about the merits of slots.

Did your "old" plane have extended wings?

Stewart
 
mvivion said:
Crash,

What kind of fuel burn do you run at that power setting, and have you strobed your prop to verify the accuracy of your tach?

Just curious.

As Brian says--those are pretty exceptional Cub numbers in my experience. I don't have a lot of experience in 180 Cubs, though.

MTV

Mike, some Cubs are just faster then others. This Cub has always been fast for an Alaskan Cub. I also lean out no matter what altitude or rpm. If I am going a long way by myself I run at 2450. If I am with other Cubs I pull back to 2200-2250 and poke along at around 90 mph. At this rpm I burn about 10% less then an O-320 which has to run at 2450-2500 rpm to keep up. A critical eye towards rigging also helps the flight envelope at both ends. There are a lot of poorly rigged Cubs flying around out there.

Take care. Crash
 
There was a slotted (standard length round tips) wing cub that flew up from Soldotna a few years back for a flight test. A friend flew it in a test compared with another well rigged stock cub. I know he was real impressed and it has sparked my interest ever since.

There is a set of them being covered in the hanger next to mine so I know they sold them in the standard wing version at one point but now I don't see them on Dakota's website. They now only advertise the extended wing from what I can see.

I'm going to call them and see what's up. If all they have now is the extended wing version that will end my curiosity since I have no interest in extended wings. I run into enough stuff with my standard length wings.

Jerry
 
Crash,

I'm well aware that there's a lot of variability in Cub speeds, and especially in Cub fuel burns. The differences in fuel burn rates is one of the little mysteries I've never quite been able to figure out.

But--you didn't answer either of my questions:

Has your tach been verified for accuracy?

What fuel burn are you seeing, leaned or not, at that power setting?

Saying you are burning less than an O-320 in another Cub means nothing to me, cause I've seen those that burn anywhere from 7.8 up to nearly 10 gph at that power setting, which is my point.

If I were to run a Husky at that rpm setting, I'd be burning a lot of gas, like 9 +, even if I pull the throttle back.

Again, I'm just curious, and not doubting, just trying to calibrate.

These things tend to be all over the place.

MTV
 
Lance said:
Steve,

Have you gone up to the 4-7000 ft range to see what that constant speed will true out at? Any better than 100kts?

I would imagine you would open up the spread between your and Crashes speed even more as you go up.

Lance

Lance, sure it makes a big difference, and fuel burn is obviously better than it used to be (not saying it is better than Crash's... 8) ) but at 100kts leaned at 3K I am buring 8 - 9 gph, and much better up higher (although I rarely go there).

For most folks to get the kinds of speeds crash is talking about with a fixed pitch (at least the legal ones) they are running 2650 rpm, which gets pretty noisy after a while. The CS prop can be dialed back real nice to just purr along at the same speeds.

I'm not saying they are for everybody, never have, but I sure like it and I think there are distinct advantages to it over the fixed pitch, otherwise barons, bonanzas, and skywagons would have P235's on them..

sj
 
StewartB,
There are three things that have the 'potential' to work for you, if used correctly at the correct time, on the extended wing that are above and beyond what the old VG'd straight wing I had could do. None of those three are magic or work all the time. Those three can work together in certain limited circumstances.
It is nice to have big flaps and extra ailerons when you get behind the power curve on landing, I think it would be dangerous to get behind the power curve on departure w/o the bigger flaps and extended ailerons. The slotted wing excels at allowing you to get behind the power curve :crazyeyes:
 
In the experiences I've had where bad things have almost happened....it wasn't a lack of flaps or ailerons or lift that made the situation dicey. It was the lack of velocity. To make an airplane fly at slower speeds is nice if the wind's on your nose. It's not so nice when the wind's at your side and big physical obstructions are on your other side. I think the stock wing provides adequate take-off potential, acceptable landing potential, and allows these things with enough forward velocity to handle crosswinds well. Upsetting that balance isn't something I'm interested in. Improving that balance is. Thus my questions.

Stewart
 
StewartB,
I would agree that you can put this wing out of balance and fly it outside the envelope. It ain't magic. It is, however, a whole lot better than a straight wing with VG's. As the flying season went on, it kept increasing the gap of superiority over the straight wing as I learned to use it better. It is way more forgiving of mistakes when you are learning.
That being said , I think the potential for trouble with a straight slotted wing and 0-320 combo would be much greater. Extra flap, extra aileron , extra thrust, all have there time to shine after you have rolled around in the stupid puddle for a while.
 
loop,

You never aswered my earlier question about flying your plane on wheels and/or skis. Are you going to drydock it or fly it this winter?

Stewart
 
mvivion said:
Crash,

I'm well aware that there's a lot of variability in Cub speeds, and especially in Cub fuel burns. The differences in fuel burn rates is one of the little mysteries I've never quite been able to figure out.

But--you didn't answer either of my questions:

Has your tach been verified for accuracy?

What fuel burn are you seeing, leaned or not, at that power setting?

Saying you are burning less than an O-320 in another Cub means nothing to me, cause I've seen those that burn anywhere from 7.8 up to nearly 10 gph at that power setting, which is my point.

If I were to run a Husky at that rpm setting, I'd be burning a lot of gas, like 9 +, even if I pull the throttle back.

Again, I'm just curious, and not doubting, just trying to calibrate.

These things tend to be all over the place.

MTV

Yes Mike I did check my tach for accuracy. When I had the prop balanced the guy put a strobe patch on the prop and I had him call out the various RPM's as I powered up. It was very close for a mechanical tach. As you can see it's a brand new tach with only 227 hours on it.

My fuel burn running 2200, leaned is around 7.3 to 7.5 GPH. Running at 2450 leaned, is around 8.5. I've never been one to check burn rates very closely. The big tank at the airport never seems to run out so I just go get more when my balls are getting low. Crash
 
StewartB,
With latest news from Airglas, I am drydocking. You can fill in the emotions I have making that statement.
 
Crash,

Thanks, those are pretty impressive numbers. If I was you, I'd patent that sucker, and not sell the prototype. :p

She's a good un.

MTV
 
Another big advantage of the 18 has been the wide-body. It stores a lot more than I thought it would. The weight and balance seems to work well with extra weight going further back. A lot of the extra empty weight is on the leading edge of the wing, which seems to counter balance the extended baggage well, w/o giving to nose heavy of a feeling.
I didn't fly with the cargo pod this year and never missed it. I am going to sell it, because there is no reason to have it with all the extra baggage room. It is also a lot easier to get stuff in and out. It is more comfortable for me and my enlarged midsection to fly, but the flap handle is in a goofy spot and occasionally I wish I could move it. In my opinion, the flap handle location is the only screw up of the whole set-up. I think (not really sure) it is the same spot as the standard body, but it seems awkward when you have the extra space.
 
Back
Top