Don't know what your talking about DS, that's not a Luscombe...

Help me out, I thought you had a Luscombe. The air speed intake resembles a early Cessna. Did you switch?
I guess a Cessna is still a departure from a Beach.

whee wrote:

aktahoe1 wrote:Also no disrespect here but I am not certain I agree with the square root / tire pressure concept. Where did that come from anyhow?

It is Horne's Equation. Used to predict the hydroplaning speed of aircraft tires but it doesn't really apply hear because of some of the assumptions made. You can read about it here : http://www.nlr-atsi.nl/downloads/hydroplaning-of-modern-aircraft-tires.pdf

Guess my "friend" will have to find someone to give him a lesson on skiing. Lots of gravel bars around here that are long enough to land but pretty marginal for takeoff.

I respect your opinion Rob and agree with the landing part but if skiing speed can be reached before you hit the water on takeoff then I don't see why it would be a big deal even on small tires.

Gonna post the vid of the departure in a bit but will only leave it active for a couple hours to protect my friend from his wife...

I think the margin for error is just too small when you're playing on the water with small tires. There would be no accurate way to assure you have enough distance to reach hydroplaning speed before you hit the water. I'm not a guy who is afraid to ski on the water, I've done it many times on bushwheels and 8.00x6s. But I've also inadvertently used water for takeoff before and it scared the shit out of me! I was 18 and flying my dads 125hp C-120 on 8.00s. I was dragging a beach to feel the firmness of the sand with the intention of going around. The sand was a little softer than expected and slowed me down quite a bit. I applied full power for the go around but ran out of beach before I hit the water. I was on the water at least 200 feet before I got airborne. I think if that plane had the C-85 I wouldn't have enough power to overcome the drag of the water and I would have been swimming to shore. After experiencing that I would NEVER plan to use water to takeoff with small tires. Even the thought of it on bushwheels still scares me.

I watched the vid, looked like a Maule, Whee flys a Luscombe.......so it had to be one of his buddy's.

Terry wrote:I watched the vid, looked like a Maule, Whee flys a Luscombe.......so it had to be one of his buddy's.

Maule on the first one. My mistake.

I think Whee's buddy is trying to stay out of trouble on the home front......I'm sure the vid he posted was a Maule.

robw56 wrote:I think the margin for error is just too small when you're playing on the water with small tires.

I agree that the margin for error would be very small, much smaller than when on bushwheels.

There would be no accurate way to assure you have enough distance to reach hydroplaning speed before you hit the water.

Same way it is done on BW. Just have to know your plane and how long it will take to reach hydroplaning speed. Right?

I'm not a guy who is afraid to ski on the water, I've done it many times on bushwheels and 8.00x6s. But I've also inadvertently used water for takeoff before and it scared the shit out of me! I was 18 and flying my dads 125hp C-120 on 8.00s. I was dragging a beach to feel the firmness of the sand with the intention of going around. The sand was a little softer than expected and slowed me down quite a bit. I applied full power for the go around but ran out of beach before I hit the water. I was on the water at least 200 feet before I got airborne. I think if that plane had the C-85 I wouldn't have enough power to overcome the drag of the water and I would have been swimming to shore. After experiencing that I would NEVER plan to use water to takeoff with small tires. Even the thought of it on bushwheels still scares me.

Any idea how fast you were going when you hit the water? I'd have to agree that if it took 200ft to get in the air then you'd be swimming if the plane had a C-85.

I don't mean to sound like I am picking your post apart; I'm just searching for info and finding it hard to come by.

I wish I could remember how fast I was going, but that was about 10 years ago when it happened. I guess there's only one way to find the information you seek. It will be an expensive question to answer though

The video was an example of why I'm interested in the water skiing departure technique. This guy said he hit the water at 50mph which is fast enough to get the plane in the air but he would have had to stay in ground effect, which is fine. The reason he didn't get in the air before the water is because the plane took a bounce before it could fly and if he had tried to keep it in the air it would have likely settled right into the lake. He thought it was better kill the bounce and get more speed even if it meant using some water, but he really really wanted to get in the air before he reached water.

I'm not looking to get in and out of 300ft gravel bars but there are tons of 5 and 600 foot bars around that are just long enough, no skiing required. If I had this departure technique in my tool box I'd be able to take my flying to the next level because it would give me the extra margin I need.

robw56 wrote:I wish I could remember how fast I was going, but that was about 10 years ago when it happened. I guess there's only one way to find the information you seek. It will be an expensive question to answer though

Yeah figured it was a while back but I had to ask.

What is you're flying speed whee? I think if you were just a couple mph short when you hit the water you'll probably be fine.... try it (just a guess)10mph slower and maybe not so much.

Stall is ~53mph. Will fly in ground effect at ~50. Most times I wait till 55 before lifting off. IAS

Bet your right, 10mph slower would not be good.

whee wrote:My buddy estimates he hit the water at about 50mpg

We have to think about our fuel economy now, to learn how to hydroplaning the wheels?? Too complicated for me I think
(trolling ends)

I do have an actual question:

whee wrote:[Guess my "friend" will have to find someone to give him a lesson on skiing. Lots of gravel bars around here that are long enough to land but pretty marginal for takeoff.

I am used to hearing it the other way around. That is, you need more to room to land than to get airborne again, STOL comp numbers & other experience etc.
Does riverbed gravel have that much extra drag that you get in heaps shorter than you get out?
Maybe I am just too used to slippery grass.

Battson wrote:

whee wrote:My buddy estimates he hit the water at about 50mpg

We have to think about our fuel economy now, to learn how to hydroplaning the wheels?? Too complicated for me I think
(trolling ends)

haha...this stay at home dad stuff is killing my typing skills

Battson wrote:I do have an actual question:

whee wrote:[Guess my "friend" will have to find someone to give him a lesson on skiing. Lots of gravel bars around here that are long enough to land but pretty marginal for takeoff.

I am used to hearing it the other way around. That is, you need more to room to land than to get airborne again, STOL comp numbers & other experience etc.
Does riverbed gravel have that much extra drag that you get in heaps shorter than you get out?
Maybe I am just too used to slippery grass.

In low hp planes like I am talking about it typically takes longer to takeoff than land. Higher hp planes it can be the other way around.

Thanks, I was clearly having a slow morning...

whee wrote:In low hp planes like I am talking about it typically takes longer to takeoff than land. Higher hp planes it can be the other way around.

Do I dare ask? How low hp is your Maule?

My plane has a C-85 which is 85hp.

Getting to be that time of year when all us backcountry guys want to drag something in the water. I've seen a few videos of some wingtips dragging in the water (bad floatplane landings, bad Red Bull racing), but hats off to the guys that do it for fun.

Hey y'all, watch this.......

What kind of aircraft is that?