Anyone have a Zenith 701 or similar, on floats, that they land at high altitude on tiny lakes?

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wktaylor

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VB... reminder...

The 'mission statement' was for water-landing/TO on high altitude [6000/8000-Ft?] tiny [way-less-than 1000-ft across] mountain lakes, with unspecified obstacles/terrain.

I have to assume that the OP was 'thinking' summertime conditions = perfectly 'calm WX' day VFR @ 85F-to-100F[?]. Problem with mountain flying is that it is rarely without adverse weather [WX], such as wind/gusts, up/down-drafts, summer-storms, etc.

War-Story.
One late-summer/early-fall afternoon [hey it was 1980] I took a lowly [but new] Piper Tomahawk to Flagstaff AZ Airport, 7000-Ft ASL on a warm 80F afternoon with only a slight breeze across the RW. My takeoff distance was slightly longer than 1/2-the 8800-Ft RW... and max climb rate [just skinny me and topped-off fuel] was not-quite 350-FPM. However, I had plenty of time/room to climb in good conditions and sailed-away. NO SWEAT. Lesson learned.

Anyone taken formal mountain flying training? please speak-up.

Anyone here ever operated out of Flagstaff AZ... or better yet... Leadville CO airport?? Airport | Lake County, CO

Just saying... these adventures deserve consideration of the family.
 

Victor Bravo

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The landplane version of Steve Henry's competition STOL airplane takes off and lands in approximately 20 feet. This is an extreme competition situation of course.

So let's triple that for non-competition use, and say 60 feet.

Then let's multiply that 60 feet by 5, to account for the density altitude. So we get 300 feet.

Then let's double that to account for the drag and step issues of floats instead of wheels. That gives us 600 feet.

Now any experienced pilot will testify that mountain weather and micrometeorology can immediately invalidate any assumptions, and they can render any amount of lift or power irrelevant. But you can't quantify that, and you can't remove common sense from any equation involving air safety. So just like every other flight, the OP would have to include mountain realities in his decision every time he puts the throttle forward.

I certainly do not have any formal training in mountain flying, but I have a reasonable amount of direct experience, most of which was flying sailplanes in very close proximity to the mountains, making use out of those gusts while preventing them from having me for dinner.
 

Rhino

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So I will summarize after 22 posts.

This is probably not a good idea, and quite possibly a very bad one.

Now at lower altitudes on bigger lakes.......meh. Schmaybe.
 

wktaylor

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I presume that Zenith company engineers would have a clear-eyed perspective as to how to get the 701/mod to perform safely in this environment. Or NOT.

VB... I think You are dancing on thin ice with Your linear-multiplicative assumptions [X3 X5 X2]... especially extrapolating from a 701 tail dragger {??} with large balloon tires to a float equipped 701/mod. Experience tells me there are relatively 'few' linear interpolations that would work in this case.

Hmmm... perhaps exotic float designs and engines exist that I'm unaware of... just to get off the water quickly... in ideal conditions.

OH, DANG. I forgot to mention lake-water obstacles such as shallows/rocks/branches and 'wave-chop'. This is a tough scenario.
 

Victor Bravo

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My comments were all based on an airplane that is not the Zenith 701. I was talking about the Just Aircraft SuperSTOL, specifically because it has shorter takeoff and landing capability than any of the Zenith series.

My earliest comment was that the 701 is likely not the right airplane for this particular mission. Since the original poster kindly opened up the discussion to aircraft that were similar but not specifically the 701, I steered my part of the discussion towards an airplane that at least has some chance to achieve this difficult (and perhaps not wise) mission.

All of my subsequent comments were based on the SuperSTOL. If you have any better or more appropriate ideas how he can achieve his stated mission, I would like to hear it. Of course it's a higher risk mission, and of course he might be better off not attempting it. But we are discussing how he could technically pull this off if he were willing to take XYZ risk.

Floats are designed for several things, all balanced against each other for some compromise. In this case the float design 'balance' would be shifted towards rapid step transition, sacrificing some amount of drag or other things in the process.

The engine I was mentioning is the Yamaha snow sled engine which is now becoming very popular and noteworthy in the STOL community. The larger version I believe makes 150 HP in normal use and 250+ in "racing" competition tune like what Steve does. I believe you should take a moment to look for the youtube videos of him taking off with this engine.

It would seem to me that shallow water obstacles, rocks, and other water hazards would be the same at low altitude lakes or high altitude lakes. Meaning that the same care would have to be taken in a High Sierra lake as it would be in a low altitude lake. Is this not correct?
 
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TFF

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I have a friend who has a Backcountry Super Cub on floats. IO-390 three blade Whirlwind prop. It is spec for one lake in Alaska near Cook Inlet that none of his friends can get in and out of. It’s not a big lake at any stretch, most people wouldn’t try. It’s got every trick in the book.

No guarantees except you would need to test what you can do on a large lake and start honing it down to what it can do.
 

wktaylor

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VB... OK, anything is possible.😳

The Just Aircraft SuperSTOL Is a candidate. A float version has flown and seems fast onto the step and initial climb on a low altitude lake. Now lets find a big-enough high-altitude lake, legal for float planes, to try it out... at a reasonable GW/CG and summer-day conditions... say density altitude 8000-to-10000-ft to see if it will hack the implied operational constraints. MAYBE Big Bear Lake CA is a good starting point??

TFF... '...lake near Cook Inlet AK...'. Does that lake often have density altitude 8000-to-10000-ft @80F?

PS: I agree with MW... landing/TO on a frozen-solid 'pond' is probably workable, winter WX permitting.

'Never fly with anyone braver that yourself.'
 

TFF

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Exactly. It’s going to be hard to do at 7000 ft when at sea level a real hot rod can just do it. It was an example of draw the conclusion yourself.
 

Mad MAC

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I am surprised no one has mentioned the rotax 915*, rated power (135 hp) to 15,000 ft, probadly the best off the shelf engine available for this mission profile. A lower prop RPM would be nice as running the largest possible prop disc area will help with initial acceleration etc.

The quick back of the envelope check for an airframe (with a turbo normalized engine) would be that its meets the required performance take off etc at sea level, then reduce the operating weight by aleast 25% (not payload), plus allowing for marketing's performance figures effects. then it might be worth a closer look.

* I see there is a rotax 916 that makes 160 hp for take off but otherwise same as 915 but that's worth another thread.
 

Gregory Perkins

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Around 1999 or 2000 at Sun N Fun they held a short takeoff contest for seaplanes at the nearby lake. I Watched a 701 with a Rotax 914 win the contest with what appeared to be a takeoff distance equal to a wingspan. I'll never forget it. The pilot with the initial application of throttle went way nose hi when going over the initial bow wave then the nose went way down on the downside of the bow wave and when the nose came up again, it kept going right out of the water as if the bow wave was a takeoff ramp. Of course the pilot was a skinny short guy with no payload and probably only a few gallons of gas.
 

speedracer

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VB... reminder...

The 'mission statement' was for water-landing/TO on high altitude [6000/8000-Ft?] tiny [way-less-than 1000-ft across] mountain lakes, with unspecified obstacles/terrain.

I have to assume that the OP was 'thinking' summertime conditions = perfectly 'calm WX' day VFR @ 85F-to-100F[?]. Problem with mountain flying is that it is rarely without adverse weather [WX], such as wind/gusts, up/down-drafts, summer-storms, etc.

War-Story.
One late-summer/early-fall afternoon [hey it was 1980] I took a lowly [but new] Piper Tomahawk to Flagstaff AZ Airport, 7000-Ft ASL on a warm 80F afternoon with only a slight breeze across the RW. My takeoff distance was slightly longer than 1/2-the 8800-Ft RW... and max climb rate [just skinny me and topped-off fuel] was not-quite 350-FPM. However, I had plenty of time/room to climb in good conditions and sailed-away. NO SWEAT. Lesson learned.

Anyone taken formal mountain flying training? please speak-up.

Anyone here ever operated out of Flagstaff AZ... or better yet... Leadville CO airport?? Airport | Lake County, CO

Just saying... these adventures deserve consideration of the family.
A friend with a 160 HP Long EZ took advantage of cheap fuel prices at Leadville and took on 45 gallons of fuel there in summer. He said he used about 6,300' of the 6,400' runway getting off. My Kingfisher amphibian (135 HP) needed at least 1/4 mile to get off the Columbia River (40' MSL) with a passenger. Less than half that single place.
 

TheToad

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I consider that lake to be "northern california" it's name is Loch Leven Lake, it's a tributary of the south fork of the Yuba river.. Near I-80 @ Cisco Grove... Not sure of that's north enough or not... There's many others I want to also try out... That's just a personal favorite...

There are very friendly black bears that will definitely try to steal your food at night... A good squirt teaches them a lesson and saves your food... Also works for cougars (the cat) which occasionally attack hikers in California... Better to have OT and not need it than the inverse... 😁😉👉

I love doing things nobody has done before... As long as Im confident it's possible...
 

davidb

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I just took a look at the maps. There is actually three lakes. The longest one affords about 1500 feet of straight water run. With a light breeze aligned with the lake, a takeoff and landing is doable but the climb out is questionable because of the terrain. The thing is that there is no margin between success and death. You can still have fun at other beautiful lakes like Loon Lake should you decide on this type of flying.
 

Victor Bravo

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Google maps gave me about 950 feet of water on the one that was marked Loch Leven. There are full grown trees all around it in the Google Maps photo.

For whatever the opinion of one guy is worth, landing and taking off at that lake is definitely possible. But you will need an airplane that is fairly exotic, which was pretty much my original suggestion in my first post in the thread.

IMHO you need the Just Aircraft Super STOL, a turbocharged or supercharged engine that is going to make 150-180 HP at that density altitude, and you still will need to be on your A game using very high levels of pilot skill.

One good gust of wind from behind you at the wrong moment in your takeoff roll, and you're gonna be the guest of honor at the coyotes' and bears' dinner table.
 

davidb

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Just looked at the photo again and noticed the glassy water. Glassy and confined don’t mix well for landing. You’d need a breeze to break up that mirror or a lot more water to execute a successful glassy water approach.
 

REVAN

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Oh sure, the zenith will do it but you'll get thrown in jail... CA has seriously tight laws on amphib operations. Look into it, I'm pretty sure Sierra lakes are a no go...
Has anyone looked into this in any detail? Follow-on comments were made that there are many lakes in N-Cal that are amphib-friendly, but the lakes the OP wants to go to are not those lakes. Legalities aside, they are not amphib-friendly from the physical conditions of being small and high altitude.

I'm curious if a Part 103 ultralight on floats would have more leeway to access those small alpine lakes from both a legal and operational perspective. What if it were an electric powered ultralight on floats? Many lakes prohibit IC engines, but allow man power, wind power and electric. Would electric propulsion legally open more lakes for Part 103 access? Also, electric motors don't lose power with altitude.

Anyone have any input on this? I'm still trying to get an answer from the state of California to my question on whether I can operate a paramotor off the beaches in California; been waiting 2 months so far. I'm not so inclined to try again with getting information from their dysfunctional government agencies.
 
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