Amphibs- SS or Highlander

For general discussion of the Just Aircraft family of aircraft.
Includes: Highlander, Escapade, Summit and SuperSTOL.

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Re: Amphibs- SS or Highlander

Postby Jack L » Mon Jan 19, 2015 8:30 am

Paul,

Thanks for sharing those links with us. I am ready to install the bottom on my first Zenair 1450 straight float and after sealing everything the best I can I still have concerns for leaks. Once these floats are closed there is no way to get back into them without a lot of work so I am wondering if painting the exterior of the floats will help provide an additional worthwhile seal? I don't like the idea of adding weight to the floats but if the paint can help prevent leakage I will paint them rather than take on water.

I know of a structures guy that scratch builds floats in Northern Quebec that look absolutely amazing. Do you know what these floats are copied from? They have accessible compartments that allow repairs if necessary, the owner of the Savage Cub in the picture below has two storage lockers that hold a five gallon jerry can each. His only complaint is that the floats are heavy and maybe overkill for our aircraft. I looked over his floats and as far as construction goes they are far superior to the floats that I am building. What do you think?

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Re: Amphibs- SS or Highlander

Postby av8rps » Mon Jan 19, 2015 3:59 pm

I'm pretty sure the floats he's building are copies of the Czech 1300 amphib (from the pics they sure look like it), which are actually just a scaled down version of a Wipaire 2100 amphib. When you look at the CZ 1300 it is so exact to the Wip 2100 amphib it almost looks like you could buy replacement parts for it from Wipaire. But it is a smaller float, so I'm sure while it looks identical to the Wip 2100, the parts aren't actually the same. (and fwiw, a Wip 2100 amphib with rigging today is around 60k. So anything less than that for a similar float should be a bargain I guess :wink: )

So if he is building a copy of the CZ 1300 like I think he is, it should be a great float. Compared to the Zenairs the CZ 1300 will look more like a "Certified" float, appearing more professionally engineered, stronger structurally, uses bucked rivets, has a much sturdier full suspensension landing gear, and takes a lot more time to buid. Unfortunately, all that good stuff equates into more weight (and cost) so they are slightly heavier than the Zenair designs. But they do work well as the one thing they have going for them is that they are more properly sized for airplanes like the Highlander and the Rans. So many of the other float options (like the Aerocet and Clamar) are in my opinion too large for planes like ours, as those manufacturers (imho) primarily went after the more lucrative high-end Cub LSA market, which needs a 1550-1750+ lb float. And while those floats will work ok on our planes, generally you are flying around with too much float. (e.g.; I watched a 940+ lb [e.w. on wheels] Carbon Cub on Aerocet 1500's perform flawlessly. So an airplane like my 680 lb Highlander would be grossly overfloated, consequently flying around a float much larger than needed). Now don't misunderstand me, the Aerocet is a fantastic float, and is very light for it's size. But it is just not designed for the lighter LSA's in my opinion. Here's the specs to better show what I mean;
AEROCET MODEL 1500 SPECIFICATIONS: (From their partner "Cub Crafter's" website)

Weight: 245 lbs.
Gear retract system: Dual-action hydraulic hand pump
Buoyancy: 1,550 lbs.
Maximum flotation: 1,746 lbs.
Price: $49,990, installed


Your question about whether to paint your floats to seal them up is an easy one. Don't expect paint to seal seams on a float as the first time you hit any kind of rough water the paint will crack at the seam. Rather, use a sealer like Wipaire does (3m 5200 something or other? I think they tell you somewhere on their website what it is). Or just use marine sealer like Bostick. I sealed my Lake amphibian hull with Bostick and it worked like a dream. I also used float sealer from WagAero that I painted on the inside and it also worked well.
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Re: Amphibs- SS or Highlander

Postby Jack L » Mon Jan 19, 2015 4:54 pm

Paul,

Thanks for your responses to my questions. As far as I am concerned the Zenair floats are not a well built float and are no where near the quality of the floats in the pictures I posted. I don't know why Zenair decided to go with a rounded top as it doesn't allow a flat surface for access panels, pump outs and hatches. To make the tops round the bulkheads are fluted and it is difficult to get a good seal, fortunately the rounded part is above the water line on most of the bulkheads. The sealant they provide is 3M 5200 so perhaps it will work well and I am worrying for nothing.

I used Stewart Systems paint on my aircraft and it is very flexible but like you said it will likely crack... just thought I should ask.

Jack
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Re: Amphibs- SS or Highlander

Postby av8rps » Mon Jan 19, 2015 6:12 pm

In defense of the Zenair design, the float does what it needs to do for the least amount of weight, and money. But I do agree that the round top idea is somewhat problematic. It's too bad you don't have a set of CZ 1200/1250 amphibs to look at as it probably would help you to see how nice a well built Zenair can be, as well as seeing some of the tricks the Czechs did to improve the Zenair design (like access compartments - because they hard riveted them they had to have access to get inside each compartment to buck the rivets). I believe they did the best job possible to improve the round top design, while still retaining the light weight nature of the Zenair design. It would be nice if Zenair could do the same, but I'm guessing it would add a lot of cost to their floats, and since what they have works, why change it?

There's been a lot of those Zenair floats used over the years, and I can reassure you as many people as I have known to use them, I never recall hearing issues with severe leaking. So I tend to believe you might be over-thnking the sealing issues. Although I will admit one of my friends installed an electric bilge pump in each float. But he's rather eccentric, and his floats were built in 1984 and consequently have been hammered in a lot in rough water as well as salt / brakish water conditions. Plus I think his motivation to install electric bilge pumps is more because he thinks its stupid to pump floats when electric pumps are so readily available and inexpensive. And honestly, I tend to agree with him. He says two small bilge pumps weigh what one manual float pump weighs, and he doesn't have to have anywhere to store them...

Keep building those floats. I think after you get through all the hard parts of building and rigging, once you have your plane operating on floats you will grow to really like the Zenairs. The Rans S7 I flew on the CZ 1200/1250's (which remember are essentially just a very well built Zenair) I really liked. So much in fact that I bought a set of those before I found my CZ 1300's. Yes, the CZ 1300 flat top design is a better float overall, but the Zenair designs work very well for the money. In fact my CZ 1200/1250's weigh less than the little Aerocet 1100's (which are way, way smaller) I fly on my Kitfox. As you get more into this floatplane thing you will learn that there are a lot of compromises typically required to be made when putting together a good seaplane. But I can assure you compared to most other options out there for floats, the Zenairs will work better than most all the others. And frankly, for what the others cost, the Zenair is truly a good value. So again, keep building...it's going to be worth all the effort.
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Re: Amphibs- SS or Highlander

Postby MarkZ » Fri Jan 23, 2015 9:29 am

Paul, in your opinion, where would be a great place and time of the year to add on a float ticket? I'm giving this some serious consideration and really think I'd like to do it in an LSA of better caliber. What would be the ultimate airplane/float setup to accomplish this? I'll need an instructor that has ice water running through his veins. :shock:
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Re: Amphibs- SS or Highlander

Postby av8rps » Fri Jan 23, 2015 1:42 pm

I wondered how long it would be before that Highlander got you thinking about floats? :)

Since you are an instructor, I would make sure to get a standard float plane rating from an instructor that is not just a Sport Pilot guy that uses an LSA, as the SP float endorsement only allows you to fly that specific model seaplane. I'm not 100% sure of that exact rule verbage, but I'm sure you either already know what I am talking about, or you can look it up to verify what I am saying.

Personally, I would recommend learning to fly a float plane in something like a J-3 Cub as it will make you a really good seaplane pilot. Jack Browns in Florida is probably the most common place to get a float rating in America. But I really like a guy that I met last year at the Oshkosh Seaplane Base that flew from Louisana to Oshkosh in his straight float PA-11. So he truly has seaplane flying running through his veins. And he has huge experience in other aircraft, but does seaplane training because he loves it. That's the guy I would want to train me if I had it to do all over again. I don't have his info available right now, but I can get it to you if you are interested.

And that PA-11 he flies is about the perfect trainer in my opinion. It has enough power to fly two grown men around, but you are going to have to learn really good technique to make it perform. Granted, there are a lot of really fun to fly seaplanes out there to train in, but high powered seaplanes like a Super Cub, a Husky, or a C- 185 (or a Highlander) are honestly just too easy to fly. If you want to learn to be a really good seaplane pilot, that airplane with that instructor would be a winning combination. And personally, even though I've never flown with him, I think it would be a blast because he is so passionate about it, and does it so regularly for his own enjoyment. He also teaches bush stuff with big wheels on beaches and sandbars, etc. So he is definitely the kind of guy that most of us would like to hang with.

BTW - I am really glad to hear you are enjoying that Highlander. Yes, Howard built a really nice airplane. I know he misses it. The Highlander is truly one of the best LSA's a guy can fly!

Paul
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Re: Amphibs- SS or Highlander

Postby MarkZ » Fri Jan 23, 2015 6:40 pm

LA isn't all that far from me. If you think about it, get me that guy's info and I'll call him. Are you planning to go to OSH? We go every year with the TX group and stay at Gruenhagen right next to Kelley's. I'd love to meet up with you at some point. If you are ever in the DFW metro mess let me know, our place is open and there's 2800' of good turf in the backyard. I'm going on a trip for the next week but will be ack soon.
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Re: Amphibs- SS or Highlander

Postby av8rps » Sun Jan 25, 2015 10:58 pm

MarkZ wrote:LA isn't all that far from me. If you think about it, get me that guy's info and I'll call him. Are you planning to go to OSH? We go every year with the TX group and stay at Gruenhagen right next to Kelley's. I'd love to meet up with you at some point. If you are ever in the DFW metro mess let me know, our place is open and there's 2800' of good turf in the backyard. I'm going on a trip for the next week but will be ack soon.


Mark,

You're gonna feel like you just won the lottery! Well, maybe not quite that big, but I just dug up Dave Lewis' card and guess what? He's from Tomball Texas, not Louisana. So you have a lot less miles to travel. Attached below are copies of both sides of his business card. I think you will really like working with him. Oh, and his son (who is in the photo on his card with him next to the Cub) and his wife are equally passionate about aviation from what I was able to tell when I met them at Oshkosh. I just think they are a really cool family, and would be a blast to hang out with and do some training. And check out his credentials on his card...I think it's safe to say he is pretty well qualified :wink: But yet you'd never know it by talking with him. The pictures on his card tell you what it is that he really likes to do... :D

And to answer your question; YES, I go to Oshkosh too every year. I'm there for approx 2 weeks 24/7 (3-4 days before and after the convention), as I run EAA's Seaplane Base on Lake Winnebago during the airshow, so if you can find some time to stop by the EAA SPB I'd love to meet you. If you've never seen EAA's Seaplane Base you need to. I might be a bit biased, but many consider it EAA's Crown Jewel.

Paul
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Back of Dave's biz card
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Front of Dave's Biz Card
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Re: Amphibs- SS or Highlander

Postby Jack L » Fri Jan 30, 2015 9:36 am

Paul,

I am just finishing up my first float and dreaming about all the places to go and was wandering if our little aircraft could carry a fishing Kayak strapped to the floats or spreader bars? I am permitted to fly at a gross weight of 1430 on floats and with my straight floats the weight should not be a consideration, my concern is mainly about the effects of drag and disruption of air flow. Have you ever tried this or know of anyone who has?

Also, do you know of anyone who has used something like this for extra luggage?
http://www.thule.com/en-us/ca/products/ ... -_-1680041

Please say I don't need a DeHaviland Beaver!

Jack
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Re: Amphibs- SS or Highlander

Postby av8rps » Fri Jan 30, 2015 3:50 pm

Jack,

I personally have never strapped anything to the spreader bars or the struts of a Highlander float plane (I'd prefer an inflatable in the baggage area), but based on what I know of the Highlander as a seaplane I can't see any reason that you shouldn't be able to carry a Kayak, small boat, or a baggage pod. And I would say that about a Highlander even if the floats were amphibious. The most limiting factor in my opinion would be your gross weight limitations, how efficient your powerplant and prop are, and the efficiency of the float design to get you off the water at heavy weights.

That old Dean Wilson-Avid airfoil that our Highlanders use will lift a lot of weight (A friend flew his Avid Magnum [basically the same wing as ours, just slightly longer] regularly at 2,000 lbs on floats and even at that weight still took off as short or shorter than the SuperCubs on EDO 2000's). What I do know firsthand about the Highlander is that an amphib Highlander can be flown even 100 lbs heavier than the gross you stated, and have no issues other than probably an extended takeoff run. I'm confident it will always get off the water. And performance could be improved if you plan to regularly fly heavy by finding a way to give it a bit more wing area (one day I'm going to mess with extended wingtip/aux fuel tanks, and/or fowler flaps). The Rotax 912s generally provides plenty of power as long as the prop is reasonably efficient (and I think you have that covered with either the Sensenich or the Kiev. But I would suggest if you order a Kiev to get the 75 incher if you want to fly it heavy on floats, as I'm pretty sure the longer blades will produce more thrust than the shorter, faster Sensenich).

I won't tell you that you need a de Havilland Beaver to do what you want done...as in some regards you already have one :wink: Our Highlanders are just a smaller, homebuilt LSA version of a Beaver in my opinion. Here's why I say that;

Just look at what our planes will carry; A light Highlander if max grossed as an experimental can carry about 130% of what it weighs empty! There are very few planes that can make that claim. In fact, a Beaver can only carry 70% of its empty weight (and it's mostly known for it's hauling capability). So technically our Highlanders have better load hauling (relative to their size) than a DHC-2 Beaver (How cool is that?). And our planes are for sure a lot more efficient (ever buy the fuel for a Beaver? :cry: )

Plus, even though we think our planes are slow... I haven't heard anyone berating a Highlander for the bird strike issues the DHC-2 Beavers suffers from. :lol:
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Re: Amphibs- SS or Highlander

Postby Jack L » Fri Jan 30, 2015 6:03 pm

Thanks Paul,

The 1430 lbs I stated is the max allowable on floats on my Certificate of Airworthiness, having said that there is a Canadian Highlander registered at 1550 lbs so when the time comes I may ask for an increase. I guess the thing to do regarding a kayak or baggage pod is flight testing... fortunately I live on a lake that is close to four miles long so I can do some progressive hops.

The Kiev propeller I have coming is a 75" diameter 3 blade model so it should provide a fair bit of thrust.

Thanks for the input and we (3 guys building Zenair floats for our Highlanders) will be seeking your guidance throughout our float build.

Jack
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Re: Amphibs- SS or Highlander

Postby av8rps » Sat Jan 31, 2015 10:46 am

I think doing some testing on your big lake is a really smart approach. I also would suggest researching and/or talking with those that fly floatplanes with external loads to learn what you can from them (might try that question on Supercubs.org?) I have never done any external loads, so I can't offer any personal experience on that subject. I 'm guessing the most obvious thing is to keep the air from being too disturbed over the tail. The Highlander does have a shorter distance from the back of the wing to the tail than most airplanes in its horsepower class, so it is probably a good idea to be extra careful with that. But again, I can't believe it won't work well. Especially considering how large and effective the tail feathers are on the Highlander.

I am really looking forward to hearing your opinion of that Kiev vs your Sensenich. But I'm guessing with everything going on in that part of the world right now it may be awhile before you see it at your door?

I'm happy to help you guys get your Highlander floatplanes going. But for the record, there are a lot of much smarter guys than me out there on that subject. But they aren't on forums much, so I try to fill in when I can for them :wink:
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Re: Amphibs- SS or Highlander

Postby Jack L » Sat Jan 31, 2015 12:06 pm

Paul,

I will keep you and others informed with performance figures from both the Sensenich and Kiev propellers. I have to say that when all is working well it is easy to forget about the propeller, point in case, I now have 10.3 hours on skis and I haven't taken the time to record and compare performance figures to what I had posted in the past. All I can say is that the climb and speed just keeps me smiling and all I want to do is fly.

The forecast is for cold weather so I won't get out for at least a week but the next time I do get out I will focus on numbers and post them to the forum.

Jack
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Re: Amphibs- SS or Highlander

Postby MarkZ » Mon Feb 02, 2015 3:57 pm

Thanks Paul, .... Just getting in from a 7 day cruise out of Galveston. I wish I knew this last week and would have made a stop in Tomball on the way down there and set something up. Oh well, I'm good with procrastinating also. I did go to the seaplane base this year and try to make it out there every year. Now that I know you'll be there I'll stop in for sure. Do you fly in and camp there? I find the tranquility out there phenomenal and it's nice to get away from the rat race pace out at the convention. I'll certainly file the info and will make contact to explore my options. Thanks again.
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Re: Amphibs- SS or Highlander

Postby av8rps » Mon Feb 02, 2015 10:51 pm

Mark,

Man, a cruise sounds good to me. This winter up north has been dragging on, and on, and on...

Yes, I stay at the seaplane base, I have to since I'm in charge of it. Unfortunately I never get to take my airplane as I have to drive my motorhome with a large trailer full of things we need to operate the base, plus another car that my wife drives with another trailer full of stuff. But please do make a point to hang out with us if you can. And that goes for any of you on this forum. Troy Woodland comes out to hang out with us too when he can break away from the airport activities. If you are an Eaa member, the seaplane base is part of your membership, just like the warbirds, vintage, homebuilts, etc. are. So try to enjoy it like you do the other areas. But I will warn you: hang out with the seaplane crowd too long and you're likely to get completely sucked in. Thats why I today own three seaplanes, and run the place ... It's safe to say I got sucked in big time. And that was way back in the mid eighties, and I still haven't had enough :wink:
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