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Thread: late model C-180 Edo 2870 vs 2960

  1. #1
    CubDriver218's Avatar
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    late model C-180 Edo 2870 vs 2960

    Hello,

    We currently have EDO 2960 floats on our 1976 Robertson STOL equipped 180 As many of you know the heels are pretty long on these floats and they can dig in if you apply too much back pressure on take off which will prolong your take off run. Please correct me if I'm wrong but I believe the gross weight on 2870s is 3188# and the gross weight on 2960s is 3190. I also believe I read that I can have my 2960s converted into 2870s which is nice since our floats are custom painted to match our beautiful 180. There are a number of reasons I'm wondering about my options for better take off performance out of our floats or what my options are for switching floats. first and foremost the seaplane base I'll now be operating out of is a rather small pond. A lot of guys tell me not to worry about it, but those same guys aren't flying on 2960s and I do not have a ton of time on those floats. (Any STOL techniques are appreciated) I've also been looking at a few lake homes and some are on lakes with only 2000 - 3000 feet of water.
    I can't afford aerocets. I'm wondering what floats you guys would recommend for a reasonable price, or what I should do with mine to perhaps enhance performance a bit. I feel like after some time I'll obviously be able to pilot my ship better even with the 2960s but I still have to get out of said pond first.
    Thanks,
    Richard
    Fast or slow, always low, freedom of flight soothes the soul.

  2. #2

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    2870s aren't on the J model TCDS. Only 2960s for straight floats, and the gwt is 2950# unless you have a Kenmore gwt increase to 3190#. The last 180 model that listed 2870s was the H model and the gwt is 2820#. My J model had 2870s when I bought it. They were okay. I sold them and got 2960s instead. It made better sense for my 3190# gross. 2870s gross at 3190 on a 185 TCDS but not a 180.

    A trick to reduce the heel dragging is to clip the rear float struts a little. Or learn to do your run at 20* flaps and momentarily pull 30* to pop it off the water.
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    BC12D-4-85's Avatar
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    Rolling a float just prior to takeoff with 2960's helps. My time on them is admittedly limited but flying in a fellow pilot's 185 this summer we tried a variety of techniques. If close to takeoff and pulled off prematurely the plane dropped the heels and drug them...they flew away if speed was higher but it still wasn't a real clean getaway. That was with 20* flaps and not adding more to get off.

    We then tried partial power straight ahead takeoffs to make things worse. Lifting the right wing about 5 under Vr and it either accelerated and flew away or could be pulled off without much heel drag from the left float. So he practiced some and we later flew again. If the float lifts (right float mostly to use airframe torque and depending on crosswind) his plane was ready to fly and he's settled on that technique for now. Next summer we're going playing on rivers so that'll require turning on step in the channel and lifting either float followed by climbing in a turn until clear of trees.

    I flew PK 3500 and EDO 3430's which behave differently from what little time I've had with 2960's. Never flew 2870's so don't know the difference.

    Gary
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    skywagon8a's Avatar
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    Quote Originally Posted by BC12D-4-85 View Post
    Rolling a float just prior to takeoff with 2960's helps. My time on them is admittedly limited but flying in a fellow pilot's 185 this summer we tried a variety of techniques. If close to takeoff and pulled off prematurely the plane dropped the heels and drug them...they flew away if speed was higher but it still wasn't a real clean getaway. That was with 20* flaps and not adding more to get off.

    We then tried partial power straight ahead takeoffs to make things worse. Lifting the right wing about 5 under Vr and it either accelerated and flew away or could be pulled off without much heel drag from the left float. So he practiced some and we later flew again. If the float lifts (right float mostly to use airframe torque and depending on crosswind) his plane was ready to fly and he's settled on that technique for now.

    Gary
    At the same time as you roll the right float out of the water, pull more flaps and up elevator followed by reducing the extra flap. If you have crosswind, choose the wind from the right, still rolling the right float out of the water. I know your instructor taught you and everyone else to keep the wing down into the cross wind. When on floats you do the opposite to reduce water drag and to let the wind get under the wing for a bit more lift.

    Richard,
    Do not cut back your floats reducing the buoyancy. Less buoyancy causes the floats to sit lower in the water at the same loaded weight. When the floats are lower in the water it requires more horsepower and water distance to climb up on the step. Thus defeating your ability in flying out of a smaller pond.
    N1PA
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    mvivion's Avatar
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    ^^^ What those guys said. The 2960s will make you use some technique, but they’ll work fine. Load them heavy and they’ll take even more technique, usually involving some explicit language. Roll up on the left float (remember, that requires opposite rudder to keep the floats straight in the water), pull to 30 flaps and simultaneously apply some up elevator. As it launches, lower the nose to settle into low ground (water) effect, and accelerate.

    As Pete said, don’t consider cutting those floats, even if 2870s were approved on your plane.

    If you do want to go to different floats, CAP 3000 floats are great floats. I’ve seen them installed on 180s, but have never flown that combination, but I have flown a couple of 185s on CAP 3000. They are great performers, though a bit heavier than 2960s, if memory serves. Those are about the only older floats that I can think of, other than Aquas.

    2000 foot long float pond is getting pretty tight for a loaded 180 in any case.....I’d definitely be sure my technique was well practiced and comfortable with VERY short takeoffs. At that distance, even empty, just about every takeoff will be a one shot deal....with the only abort very early. I operated 185 and Beaver out of 2200 foot float pond, but only with the right wind, or no wind, and only empty launches. Landed next door in salt water to pick up loads. And with certain winds, that 2200 feet could provide some entertaining landings as well.

    Id practice, practice, practice, using the techniques noted here, till you’re consistent. See what that distance is, add 100 % and that’s a good starting point. Work your way down from there.

    MTV

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    BC12D-4-85's Avatar
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    One thing I like to do in an unknown plane is find the planing attitude that yields peak speed at partial power by using only elevator trim. Leave the elevator pressure alone for this test. Takes water room and patience to fly right below rotation speed while fussing with trim to get the most out of the reduced power. Pick a variety of loads and CG's and them mark the trim range for them. Then when near the previous loads and conditions preset the trim and let the plane do the work. Overuse of elevators can increase drag (float and airframe) and may slow the takeoff. Try it someday and see if works for you.

    Pilots that fly low powered aircraft on small floats soon find out how to make them do what's possible.

    Gary
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  7. #7

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    Is this short-ish lake wide enough to do a J hook step turn to takeoff? Or on glassy days with sticky water, a couple of circles to chop up the surface followed by a step turn to take off?

    Skywagons have one thing in common with Cubs. The best way to improve float takeoff and rate of climb is to add horsepower.

    Or.... if the lake's too short for the 180, put the -12 on floats and make the 180 a wheel plane.
    Last edited by stewartb; 02-19-2018 at 09:33 AM.

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    Most of my flying is out of Surfside and Crane Lake in MN and a few spots in Canada. I was a low time float pilot with about 80 hours on floats with a 90 hp PA-18 when I bought the 180 in 2009. One thing for sure, flying the 90 hp on water you learn patience, you just can't haul it off the water. My 1955 180 has an O-470K, a Horton Stall and it came with CAP3000's. I flew with them for 2 seasons. I sold the 3000's and now have 2960's. Both have/had a few bottom patches, which I believe can add a little drag. My experience suggests the 3000's and 2960's behaved about the same; a little tricky finding the sweet spot for either type, but very doable as Mike stated earlier. Just takes a little experience finding it. Also, taking off almost always appears a little long on the water from the pilot's perspective, especially when loaded heavy. We get antsy, pull back just a little, hoping to get in the air sooner and drag the heels, paying the penalty in time.

    In the air, the 3000's were about 5 knots faster than the 2960's. The only 2870's I flew were on a late model 182; a bit longer on the water and probably not comparable within this conversation.

    My typical technique is set the trim slightly nose down from neutral, pull the flaps two notches on step and gently feel for the sweet spot and fly it level off the water. The trim setting is about right most of the time. Like most of us, my loads vary from light to heavy.

    I've rolled the right float up for a season or two and finally settled on just flying it off the water level. Never really timed either method, but from the lake we are on, we get airborne at about the same spot on our lake.

    Rolling a float, popping the flaps takes good timing and coordination in my opinion. Gary's idea about partial power and trim is another great idea. I kinda did what he suggested, but I did it on departures with various loads one season, noticing how the back pressure changed with the trim. Finally settled on a little nose down from neutral. However, I'm going to practice with these ideas a little more this season.

    So, I need a minimum of about 1/2+ mile to get airborne on most days; there are 50+ft trees another 1/2 mile or so farther on the shorter of the two typical departure directions of our lake. Wind and load appear the biggest factors regardless of which method I used.

    Skywagon8a mentioned about lifting the wing and let the wind lift the wing, actually did it on my seaplane check ride. It was a light wind and a hot August day in a 185. Worked just fine then and later on as well.

    Mike, according to my paper work, the CAP 3000's where 404 lbs. and the 2960's are 425 lbs. The placard on the panel limits me to 2820 lbs. max gross weight.

    Richard, all of these ideas and methods are very workable. My suggestion is try them with lighter loads until you gain experience on short water and use what works best for you.

    MartyC
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  9. #9
    Paul Jackson's Avatar
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    I owned a 185 with 2790's and now a 180H with 2870's and have spent time in airplanes with two of the best float instructors around Waldo Anderson and Mark Mathison. Mark taught me to not just use the ailerons to lift a float out but to sense when the wing wanted to fly (it gets lighter). It is a good way to let your butt feel the aerodynamics while your eye gets you the hydrodynamics to get to flying speed. Waldo taught me to glance down at that spray pattern on step and move it forward and back to find the slippery spot again feeling it like you do with the wing. He would drive me around the lake at 3/4 power and make me find that slippery spot and note the spray pattern and actually get me to flying speed at 3/4 power. If your eye gets trained you can almost catch the right spray pattern in your peripheral vision while your looking ahead (as you obviously should be). To me the 3/4 power once on step drill really got me to play with the and learn hydrodynamics and "fly" the float on the water while the wings get me ready to fly aerodynamically.

    I can't hold a candle to most of the high time float guys but I have a bit of time in a variety of float planes. The challenge with a STOL kit is the wing wants to fly (lift using Mathison's method) before the floats are even close to going flying hydrodynamically. It's why a Helio Courier isn't a great selling float plane; it isn't going flying until the floats are ready to "fly" too so why drag that much wing around? Accelerating with a clean wing (little or no flaps) and then adding them helps the hydrodynamics without increasing lift and therefore drag. You can pop a float out of the water with the techniques listed here. I have popped a float out in everything up to a Caravan on amphibs, it works and obviously getting rid of half the hydrodynamic drag of a float is a good thing when the trees are getting big. On the contrary you will use a lot of lake trying to use a wing that feels ready to fly and floats that aren't (draggin the keels). You have to resist the feeling to pull back when the wing gets light and drive the floats until they unstick with Edo's Caps and the older floats. Glassy water take offs suck you to the water and Edo's just suck (at getting unstuck).

    I attached what my be the best/worst display of how not too fly edos. I know it's been seen a 1000 times but rewatch it to see those keels drag and the float spray pattern from them. Also note the nose never moves even when the floats want to go on step. The Beaver wants to fly at about 70 knots loaded or even a little slower with wing mods. The floats need to get on step and then get unstuck (from lift and overcoming hydrodynamics). In this video the nose never comes back down and the floats never really "fly" they are popped out too late with raw lift. Beavers talk to you through your butt and let you know when the wing is ready to fly and then you need to get the floats unstuck with more speed and getting the floats to "flying" plane. Heavy Beavers need quiet hands and they fly out of the water they don't pop out very well.
    Last edited by Paul Jackson; 02-24-2018 at 01:34 PM.
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  10. #10
    aktango58's Avatar
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    Save $$$, buy Aerocets.

    When it gets hot, you are going to be looking for more water with Edo's. Even with Aerocets, so work that short larea light.

    2870s you can pull off before she wants to fly using flaps, and keep the tails out; 2960s not so much. Roll her over on one float, (even pull flap on her to help the right float out- then back down), ride one float gentle like until she flies off.

    Don't rush a float plane- they only take longer. You can try using full flaps until you get onto step, then go down to 20 degrees. You will gain elevator authority. Good is you might save a few feet because you can pull the nose up quicker. The bad is that it takes more monkey motion and your attention is not on the yoke and keeping her in the sweet spot.

    Not sure your mission and plane meet the desired outcome. Using a 12 for water and 180 on wheels makes a whole lot more sense for 2,000 feet, especially if you have anything to clear on the end.

    Dillingham guys, how long is Shannon's pond?
    I don't know where you've been me lad, but I see you won first Prize!

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    skywagon8a's Avatar
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    Quote Originally Posted by aktango58 View Post
    You can try using full flaps until you get onto step, then go down to 20 degrees.
    Only when the wind is blowing. In light winds this procedure extends the take off run.
    N1PA

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    55-PA18A's Avatar
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    Dillingham guys, how long is Shannon's pond?[/QUOTE]

    Sometimes, not long enough:
    Click image for larger version. 

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    (note the S-turn tracks across the tundra. He's not the first one that's been out there !!)

    According to the Airnav site; 1,400 ft.

    http://www.airnav.com/airport/0z3

    Jim

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    At the Lake Hood Complex from the normal start position near the Millennium Hotel shore to the beginning of the E-W canal is 2050'. I could operate my 180 on and off Lake Spenard without using the canal unless I was heavy or the water was glassy. With a little wind or at mid weight or lighter? Easy. But that departure has no obstacles. Would I want to take an intersection east over the hotel? Not in a Skywagon, I wouldn't. In a Cub? No problem. As I recall the southeast in Lake Hood is about 1500' if you don't use the east option. That's pretty easy, too, but it favors a gentle LH turn so a roll up on the left float is in play. Also no obstacles.
    Last edited by stewartb; 02-26-2018 at 12:48 PM.

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    aktango58's Avatar
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    I am of the opinion, which may be wrong, that that midwest area gets mighty hot and humid, making performance of good aircraft very poor.

    lake Hood is often moderate weather compared to other parts of the country. We perform well in Alaska most days.

    But you hit the obstacle issue square on the nose. Sometimes a 10' high object is 3' more than you want to try.
    I don't know where you've been me lad, but I see you won first Prize!

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    TurboBeaver's Avatar
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    For your airplane, PK 3000's would have been the best choice, in an aft loaded configuration, because they back ends of the PK's are vastly superior to 2960's/Caps
    In floation they come up on step much better than the other two, when loaded.........
    Walk all the way back to the rudders on 2960/Caps and see what happens, walk back to same spot on PK 3000's and you will be amazed how much difference there
    is in aft floatation. Light the 3000's are similar in performance to 2870's, but being a flat top float with huge hatches, then compared to 2870/2960 with round tops and narrow hatches the PK's are a hands down the better all around floats.
    About the only one that will commonly dispute this is pilot that has NEVER flown
    The PK 3000's..........
    There is still a lot of rumor left in Alaska from the old days of the early "PK 3500 A model floats" from the 70's that still exists today.
    Good Luck with your 180 they are a wonderful bird
    E

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    BC12D-4-85's Avatar
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    Floats?-Waaaa! It's pouring snow in Fairbanks and my 1320's are completely covered. The 135 op next to me flys C-185 with belly pod on PK 3000's and long 3-blade Mac. He's high time and experienced beyond most but the combination carries a load day after day. Pretty amazing actually.

    Gary
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    aktango58's Avatar
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    Just saw two crates sitting next to the hangar with Aerocett stickers. Someone has gotten the very best valentines day gift EVER!

    Flying the 185 with the 550, Sportsman's, X-wing, VG's and Aerocett amdphibs spoiled me.

    I can tell you the 185 platform with power is incredible. The slippery floats show themselves in airspeed and water runs. Takes a little time to learn when to shut the engine down and not slide past your parking spot though.

    Trying to spit snow today here also. Runway has some bare patches now, yesterday they were mud, leaving Mauley, (Lyn named her), looking like I spent an entire day on "Muddy Miss Daisy" beach.

    Reading about Dan Dufault's new float plugs, (https://www.youtube.com/watch?v=6WFJ...2FQxDyak1HrybY) I am getting the itch to be back on a float plane.

    Six more weeks if all goes well. Six more weeks.
    I don't know where you've been me lad, but I see you won first Prize!

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    BC12D-4-85's Avatar
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    Those new float plugs look promising. Now if curious Ravens will just leave them alone. After winter make sure your pump out tubes are still attached and not split from freezing.

    Gary

  19. #19
    CamTom12's Avatar
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    My only float time is in a 185 with Aerocets. It was a ton of fun, but I'm interested to see what a lower power, less slippery float feels like. I may have ruined myself, haha!

  20. #20
    mvivion's Avatar
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    Yes, the midwest gets pretty warm. Humidity as well, but humidity actually increases air density, not the opposite.

    As others have noted, the 2960s don't tolerate an increase of pitch when trying to break water. The OP also noted that this particular 180 is equipped with a Robertson STOL kit. Some folks don't like them, but I LOVE them. And, they'll help launching a bit.

    I can't recall the information in the 180 Flight Manual supplement for the RSTOL, but the one from the 185 actually calls for 30 flaps for takeoff.

    That kit also changes the stall speed of the airplane to ~ 37 knots, as I recall. That can be a big advantage on floats. The key is to get the wing moving through the air fast enough to provide enough lift to fly, plus some. I do agree that the floats have to be up clean on the step for the airplane to fly, but the EDO 2960s at say 40 knots, are nice and clean on the water. They should fly from there just fine.

    My technique for 2960s is get it in a big lake, where you can step taxi a ways, practicing to find the "step" attitude. Once up on the step, but slow enough the plane won't fly, move the yoke GENTLY fore and aft, and FEEL the drag of the floats change as pitch attitude changes.

    Now, once stable on the step, VERY GENTLY push the yoke forward until you feel the bows of the floats snub. At some point, you'll feel a distinct deceleration. Now, come back on the pitch so that you're almost to that snub, but not quite. This puts those looooong heels up out of the water. And this is where those floats will accelerate best. After doing this a while, you'll get them up on step, and continue with the nose down pitch until you're just about there.

    Wetted area of a vessel's hull generates a lot of drag. Wetted area is that portion of the hull that's in the water. Hydrodynamic drag is, as someone noted earlier, MUCH stronger than aerodynamic drag. This is why racing hydroplanes are veyr nearly flying when they are at speed.....just three small patches of their hull in the water.

    So our goal is to reduce the Hydrodynamic drag to the extent possible, while we're getting the wing at or above it's stalling speed. EDO 2960s, with their long tails, wind up somewhat more nose down than a lot of other floats when clean on the step......get those long afterbodies out of the water.

    I agree that there are better floats than the EDO 2960s for a 180. I've flown the PK 3000s and as noted by turbobeaver, they are great floats, as are the Aerocets.

    In either of those cases, finding a used set for sale is next to impossible....PK certainly has build VERY few 3000s. A good set of 2960s can be had for on the order of $10 K. Bring $35 K plus for new floats.

    As I noted at the beginning of this thread, the EDO 2960s can work well on a 180, but they'll make the pilot develop some good skills on the step.

    MTV
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  21. #21

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    MTV, thank you for that excellent post. As the new owner of C-182 "Sealane" on Edo 2960s I will print this out for future reference.

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