SouthernAirboat.com   Pictures & Wallpapers   Classifieds   Forum   Weather & Water Data   Store   Calendar   Airboat Directory   Site Support  
 

By accessing or using this Site, you agree to be bound by the terms and conditions as stated in the SouthernAirboat.com Terms of Service

It is currently Wed Apr 23, 2014 2:35 pm

All times are UTC - 5 hours




Post new topic Reply to topic  [ 40 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: Flying airboats
PostPosted: Sat May 18, 2013 2:58 pm 
Offline
Southern Airboat Member

Joined: Sat Feb 11, 2012 11:43 pm
Posts: 241
Location: fairbanks,alaska
Was reading with interst on the other forum about flying an airboat. Is there any math formula or any feeling or indication when it might happen or are there just too many variables. I think this would be a good topic because with new technology boats are going to get faster and lighter wether it is a carmotor or aircraft. Would really like hear from some of the racers on here about this or just anybody on here that has knowledge or experience about this topic.

_________________
8 x 15 alumitech 383 mas from gto 3 blade r 2.3 belt


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Sat May 18, 2013 3:02 pm 
Offline
Site Supporter - IV
Site Supporter - IV

Joined: Tue Mar 06, 2012 9:14 am
Posts: 2546
Location: palm bay
Joey,aka Quikdesel said it best I think....put a sheet of plywood on the top of the truck and cut the straps at 80mph....wow....but I think this thread will get interesting.... 8)

_________________
DiamondBack, Benny Webb Sled/ Waterthunder, RHS 490CI,HOLLY EFI. Ballistic 2.7 10bl stagger Saber....


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Sat May 18, 2013 3:30 pm 
Offline
Site Supporter - II
Site Supporter - II

Joined: Thu Apr 13, 2006 10:55 am
Posts: 1615
Location: Ocala, FL USA
helms24 wrote:
Joey,aka Quikdesel said it best I think....put a sheet of plywood on the top of the truck and cut the straps at 80mph....wow....but I think this thread will get interesting.... 8)

Yep...pretty much describes it.

_________________
Keith ~~

Modern Performance Engines, LLC
Custom built engines for airboats, hotrods, mud trucks, buggies, circle track and drag racing!

352-282-6407
MPEKeith@gmail.com


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Sat May 18, 2013 5:13 pm 
Offline
Site Supporter - VIII
Site Supporter - VIII
User avatar

Joined: Thu Jan 05, 2006 7:49 pm
Posts: 15440
Location: Palm Bay, Fl
Much of it has to do with hull shape, hull weight and speed. It seems to me that most boats cruise around the 30-40 MPH range. With that in mind if you regularly run at 50 MPH you wont have much fun cause you will constantly be running away from the folks you ride with. Now I am sure there are some light boats that will be getting squirrely at 50 MPH and some will still have a degree of stability.

Wind direction and speed have much to do with it too. If you are cruising at 50 MPH in a 20MPH headwind you got 70MPH wind into the bow of the boat. Theres a LOT of boats won't handle 70 MPH.

Also, water surface condition will have an input as well. If you are up on top in waves, the bow gets pushed up at every wave. the faster you run onto the waves the more the boat gets tossed upward.

When and where the boat is actually going to become airborne is anybodies guess. How fast over the water, how fast through the air, how much wave, what direction the wind is from, how much the boat weighs, what is the shape of the hull and probably a couple hundred other factors.

Knowing how a wing on an airplane works, I would think that a full deck boat would get airborne sooner than an open boat. I would think that a boat with a lengthwise crown or rounded bottom with turn chines will remain stable a little longer than a purely flat bottom. No matter it takes a low air pressure area over the boat and a high air pressure under the boat to get airborne.

I'm sure the air temperature will have a defined effect on when the hull heads skyward as well. Cold dense air produces more lift than hot humid air.

Just thinking out loud here. Probably most folks that have survived flying a hull have no clue about all the details that came together at that exact moment when it took to the air. If they do they are a genius at multitasking.

_________________
"The Constitution is not so the government can restrain the people, it is so the people can restrain the government." Patrick Henry
The government cannot give anything --
that they have not first taken from someone else.


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Sat May 18, 2013 5:25 pm 
Offline
Southern Airboat Member
User avatar

Joined: Mon Jan 11, 2010 7:58 pm
Posts: 2097
Location: GAINESVILLE
THIS IS WHY EDDIE HILL QUIT RUNNING TOP FUEL HYDRO. BOAT WOULD FLY AND THEY HAD NO EXPLANATION AS TO WHY. HE SAID AT LEAST WHEN HE WRECKED THE DRAGSTER THEY COULD ANALYZE WHAT HAPPENED! LOL


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Sat May 18, 2013 5:34 pm 
Offline
Site Supporter - I
Site Supporter - I
User avatar

Joined: Wed May 12, 2010 11:18 am
Posts: 166
Location: homosassa,fl
whitebear, well said, no matter what the conditions are i will bet it will create a big pucker factor. :dontknow:


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Sat May 18, 2013 8:33 pm 
Offline
Southern Airboat Member

Joined: Tue Feb 21, 2012 8:10 pm
Posts: 145
Location: Miami
I would have to say that when it starts coming up your first instinct is to let off the throttle and when you do you are done, you need to kind of pat the gas


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Sun May 19, 2013 9:17 pm 
Offline
Southern Airboat Member
User avatar

Joined: Thu Aug 16, 2012 5:39 pm
Posts: 316
Location: Brooksville, FL
look at wing in ground effect. Boat would have to be a deckover with a lifting body.

_________________
Alumitech 7136 IO-470-J


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Sun May 19, 2013 9:35 pm 
Offline
Southern Airboat Member
User avatar

Joined: Wed Aug 26, 2009 10:01 pm
Posts: 294
Location: South FLA Dammit!
I think you really got to be hauling _ss! to get one totally airborne. On a full deck the hull should act like an upside down airfoil because the camber is on the bottom. In theory with no grass rake the air going under the bottom has to travel faster to get to the back at the same time as the air going over the nearly flat upper part of the hull. Therefore the faster air has less pressure than it's counterpart going over the top. Like White bear said,the higher pressure heads to where the lower pressure is (Italian dudes principle of fluids in motion). Throw in grass rakes, cages and the like and it all probably equals out so it's most like letting that plywood fly off the top of the car! Man I'm glad I could clear that up! :florida: :rebel:


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Sun May 19, 2013 9:35 pm 
Offline
Site Supporter - III
Site Supporter - III
User avatar

Joined: Mon May 23, 2005 6:17 pm
Posts: 8646
Location: Port Saint Lucie Fl
there's not much difference in a hydroplane or a airboat lifting off an flying if you can't correct in the first few seconds it just to late prepare for a wild ride

Hull design of course effects lift and at a certain speed you boats hull lifts out of the water accept for a small portion , hydro's and AB's have that in common where a bay boat rides heavier in the water . at a certain point the hydro's or airboats lose that small water surface contact that stabilizes them and changes for water lift to air lift like a planes wing at that point its like letting that piece of plywood fly like earlier mentioned

_________________
.


Support our future , get a kid involved in the outdoors!!



.


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Sun May 19, 2013 9:41 pm 
Offline
Site Supporter - II
Site Supporter - II
User avatar

Joined: Fri Nov 30, 2012 5:03 am
Posts: 1201
Location: New Iberia, LA
goldhunter_2 wrote:
there's not much difference in a hydroplane or a airboat lifting off an flying if you can't correct in the first few seconds it just to late prepare for a wild ride

Hull design of course effects lift and at a certain speed you boats hull lifts out of the water accept for a small portion , hydro's and AB's have that in common where a bay boat rides heavier in the water . at a certain point the hydro's or airboats lose that small water surface contact that stabilizes them and changes for water lift to air lift like a planes wing at that point its like letting that piece of plywood fly like earlier mentioned


I see your point goldhunter, it's a good one. But, a hydroplane is designed to compress air which gives them lift, making them fly just above the water and landing everyone once in awhile when water gets in the way. On the other hand, a flat bottom hull will never give you any warning. It will just roll over when least expected.

All in all, you really can't get a warning from either style hull.

_________________
Great minds discuss ideas, Average minds discuss events, small minds discuss people.
Adm. Hyman G. Rickover


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Sun May 19, 2013 9:46 pm 
Offline
Site Supporter - VIII
Site Supporter - VIII
User avatar

Joined: Thu Jan 05, 2006 7:49 pm
Posts: 15440
Location: Palm Bay, Fl
Cutler mentioned above about not letting off the gas as it begins. That is exactly right, that prop when ya take your foot off the gas is like throwing a parachute out behind the boat. The point is that that parachute is attached to the center line of thrust which is 3 or so feet above the center line of drag. Now all of a sudden the center line of drag is above the hull. So with the bow already coming up and you throw out that parachute so high above the hull it literally pulls the stern down and helps the bow climb even more and as stated its all over from there. A water brake might help at any point before the stern lifts off. Maybe.

_________________
"The Constitution is not so the government can restrain the people, it is so the people can restrain the government." Patrick Henry
The government cannot give anything --
that they have not first taken from someone else.


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Sun May 19, 2013 9:55 pm 
Offline
Site Supporter - II
Site Supporter - II
User avatar

Joined: Fri Nov 30, 2012 5:03 am
Posts: 1201
Location: New Iberia, LA
Whitebear wrote:
Cutler mentioned above about not letting off the gas as it begins. That is exactly right, that prop when ya take your foot off the gas is like throwing a parachute out behind the boat. The point is that that parachute is attached to the center line of thrust which is 3 or so feet above the center line of drag. Now all of a sudden the center line of drag is above the hull. So with the bow already coming up and you throw out that parachute so high above the hull it literally pulls the stern down and helps the bow climb even more and as stated its all over from there. A water brake might help at any point before the stern lifts off. Maybe.


Well if you are as slow as I am Whitebear, by the time she lifts off it's too late. I would get the pucker factor, say a prayer, and scream on the way over. FML!

_________________
Great minds discuss ideas, Average minds discuss events, small minds discuss people.
Adm. Hyman G. Rickover


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Sun May 19, 2013 10:09 pm 
Offline
Site Supporter - VIII
Site Supporter - VIII
User avatar

Joined: Thu Jan 05, 2006 7:49 pm
Posts: 15440
Location: Palm Bay, Fl
Sorry, not trying to scare anyone. The question posed is what causes it. Just contributing what seems to me to be important.

_________________
"The Constitution is not so the government can restrain the people, it is so the people can restrain the government." Patrick Henry
The government cannot give anything --
that they have not first taken from someone else.


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Sun May 19, 2013 10:18 pm 
Offline
Site Supporter - II
Site Supporter - II
User avatar

Joined: Fri Nov 30, 2012 5:03 am
Posts: 1201
Location: New Iberia, LA
Nah, not scared, I just know how slow my reaction time is. I'm the guy that gets in everybody's way on the road hahahahaha!

_________________
Great minds discuss ideas, Average minds discuss events, small minds discuss people.
Adm. Hyman G. Rickover


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Sun May 19, 2013 10:27 pm 
Offline
Site Supporter - VIII
Site Supporter - VIII
User avatar

Joined: Thu Jan 05, 2006 7:49 pm
Posts: 15440
Location: Palm Bay, Fl
Remember the caution we are always giving new airboaters. "When your out of throttle your out of control."

There is no reason for a new airboater to try and see how fast he can make his boat go.

Also in the safety threads were interested in preventing disaster, not how close you can get to disaster and survive it.

Guys who race know the odds, new airboaters may have little or no knowledge about the Darwin Awards.

_________________
"The Constitution is not so the government can restrain the people, it is so the people can restrain the government." Patrick Henry
The government cannot give anything --
that they have not first taken from someone else.


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Sun May 19, 2013 10:35 pm 
Offline
Site Supporter - II
Site Supporter - II
User avatar

Joined: Fri Nov 30, 2012 5:03 am
Posts: 1201
Location: New Iberia, LA
Whitebear wrote:
Remember the caution we are always giving new airboaters. "When your out of throttle your out of control."

There is no reason for a new airboater to try and see how fast he can make his boat go.

Also in the safety threads were interested in preventing disaster, not how close you can get to disaster and survive it.

Guys who race know the odds, new airboaters may have little or no knowledge about the Darwin Awards.


Darwin awards = Murphey's Law..........If it can happen.........It WILL happen.

_________________
Great minds discuss ideas, Average minds discuss events, small minds discuss people.
Adm. Hyman G. Rickover


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Mon May 20, 2013 1:19 am 
Offline
Site Supporter - VIII
Site Supporter - VIII
User avatar

Joined: Thu Jan 05, 2006 7:49 pm
Posts: 15440
Location: Palm Bay, Fl
Darwin awards are given to those who insist on thinning the gene pool when even a moderate amount of caution, or simply doing something else might have prevented it. A simple example is those who insist on going fast before they learn to go slow. Those who want to modify a gun before they understand how a gun works to begin with. Those who buy a new sport bike and want to haul ass down the interstate before they learn how to ride with traffic first. Those who would go ride bulls before they learn how to ride a horse. Those who would buy a 16 foot airboat with 750+ HP and want to go riding and playing before they learn to run a 10-12 footer with 100 HP.

The Darwin awards are given to those who blindly ignore or are totally ignorant of Murphy's Law.

Those who go do things that nearly any old fool even could predict a fatal outcome.

_________________
"The Constitution is not so the government can restrain the people, it is so the people can restrain the government." Patrick Henry
The government cannot give anything --
that they have not first taken from someone else.


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Mon May 20, 2013 2:53 am 
Offline
Site Supporter - VIII
Site Supporter - VIII
User avatar

Joined: Sun Jul 24, 2011 12:58 am
Posts: 816
Location: singapore
Whitebear wrote:
Much of it has to do with hull shape, hull weight and speed. It seems to me that most boats cruise around the 30-40 MPH range. With that in mind if you regularly run at 50 MPH you wont have much fun cause you will constantly be running away from the folks you ride with. Now I am sure there are some light boats that will be getting squirrely at 50 MPH and some will still have a degree of stability.

Wind direction and speed have much to do with it too. If you are cruising at 50 MPH in a 20MPH headwind you got 70MPH wind into the bow of the boat. Theres a LOT of boats won't handle 70 MPH.

Also, water surface condition will have an input as well. If you are up on top in waves, the bow gets pushed up at every wave. the faster you run onto the waves the more the boat gets tossed upward.

When and where the boat is actually going to become airborne is anybodies guess. How fast over the water, how fast through the air, how much wave, what direction the wind is from, how much the boat weighs, what is the shape of the hull and probably a couple hundred other factors.

Knowing how a wing on an airplane works, I would think that a full deck boat would get airborne sooner than an open boat. I would think that a boat with a lengthwise crown or rounded bottom with turn chines will remain stable a little longer than a purely flat bottom. No matter it takes a low air pressure area over the boat and a high air pressure under the boat to get airborne.

I'm sure the air temperature will have a defined effect on when the hull heads skyward as well. Cold dense air produces more lift than hot humid air.

Just thinking out loud here. Probably most folks that have survived flying a hull have no clue about all the details that came together at that exact moment when it took to the air. If they do they are a genius at multitasking.



Hey, Whitebear,

You sure you are just a moderator?

Looks like you are more a aeronautical expert !

Strange we dont see this kind of comment or advice this part of my world !! :lol: :lol: :lol: :lol:


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Mon May 20, 2013 5:02 am 
Offline
Site Supporter - VIII
Site Supporter - VIII
User avatar

Joined: Thu Jan 05, 2006 7:49 pm
Posts: 15440
Location: Palm Bay, Fl
Mascara my Engineering is in Satellite Communications. I did have a Pilots license a couple of decades back though. Most of the aerodynamic stuff I mentioned comes from flying airplanes, not airboats. LOL Now I do have some expertise teaching a 13 year old rebelious kid how to safely run an airboat though. Started him off in a deckover WPB 10' boat with a 90 HP GPU and no electrical system. He wanted to ride he had to learn to hand prop it without getting hurt. One good knuckle rap from the prop and he decided he best pay attention to how I told him to do it. After that things went incredibly smooth. He was safely running my 455 Buick boat before he made 14. By the time he had his own family he was riding them around like he was a professional Coast Guard Captain. Started my twins out on 250 cc Honda dirt bikes instead of fire breathers and they got it down pat in a very short time. Started them all out on small .22 rifles until they had the fundamentals of safety and shooting before they moved up. One of them now carries a gun and badge for a living. They all got a good explanation of the Darwin Awards LONG before they go to do anything by themselves. Before any of them learned to run the torches and weld, we first taught them how to safely light a match......Grinn ;)

_________________
"The Constitution is not so the government can restrain the people, it is so the people can restrain the government." Patrick Henry
The government cannot give anything --
that they have not first taken from someone else.


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Mon May 20, 2013 5:04 am 
Offline
Southern Airboat Member

Joined: Mon Aug 15, 2011 5:31 am
Posts: 177
Location: Inverness, FL
So who is going to be the first to take their lightweight deckover, redesign the hull, add some small wings and an elevator, and make an
airboat that is really designed to fly a foot or so off of the water? I know some of you guys would do it just for the challenge of the project!
And think of the looks you would get as you "fly" down the lake!


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Mon May 20, 2013 7:40 am 
Offline
Southern Airboat Member
User avatar

Joined: Mon Jan 11, 2010 7:58 pm
Posts: 2097
Location: GAINESVILLE
What causes it is pretty simple, air getting under the boat with more lift than what the boat weighs. What to do when it happens is debatable. Everyone I have talked to that have flown a boat says it happened so fast they could not react, anyone that has driven a really fast boat knows it feels like you are flying to begin with. Lol. As for patting the gas or giving throttle, ifyou are already in the gas and the boat comes up I'm not sure that is the solution not to mention its hard to to either when your flying out of the seat. The only thing I think will help is a water brake set low enough it doesn't drag when running but does drag if the bow begins to lift, the problem with this is unloading the boat on dry ground you have to un hook the brake cable everytime. Its inconveinient but its lake someone said to me this weekend, they said ain't that fiesuit hot and I said not as hot as it can get without it! Lol


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Mon May 20, 2013 7:55 am 
Offline
Southern Airboat Member
User avatar

Joined: Tue Dec 04, 2007 7:53 pm
Posts: 57
Location: Miami FL
Water brake should be #1 if your raceing, Ive seen a few go over and dont have time to do anything.

Im glad I have the slowest boat out there. :bom:

_________________
Cecil Pierce


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Mon May 20, 2013 9:23 am 
Offline
Site Supporter - III
Site Supporter - III
User avatar

Joined: Mon May 23, 2005 6:17 pm
Posts: 8646
Location: Port Saint Lucie Fl
kajunoutlaw wrote:
I see your point goldhunter, it's a good one. But, a hydroplane is designed to compress air which gives them lift, making them fly just above the water and landing everyone once in awhile when water gets in the way. On the other hand, a flat bottom hull will never give you any warning. It will just roll over when least expected.

All in all, you really can't get a warning from either style hull.



yes they compress air both for lift and down force at the same time But they still require some portion in the water for stabilization may of the hydos back when I raced had skags those and the prop was about all that stays in the water , boats may have changed over the yeas but still the design theory remains the same. I have been in a 2.5 liter when it lifted off luckily I happen to be on the outside at the time but the scariest for me was during another race as I started to pass inside and the boat I was passing lifted off in front of me and went over top me, that kinda makes a lasting impression on a person :shock: (this was back before the fancy driver pods required in modern hydro's now)
To some degree a airboat does the same thing you either ride on the nose or the stern but once its takes to the air you lose all dreams of any kin of control and with the weight in the rear the bow lifts higher while the transom wants to find its way down causing the flip rotation to begin then speed just decides how far it goes


The best option is for experienced an new drivers not to go faster then they can SAFELY handle

_________________
.


Support our future , get a kid involved in the outdoors!!



.


Top
 Profile  
 
 Post subject: Re: Flying airboats
PostPosted: Mon May 20, 2013 10:27 am 
Offline
Site Supporter - III
Site Supporter - III
User avatar

Joined: Mon Jul 28, 2008 11:33 am
Posts: 387
I have personally flew a peanut gore haul ass boat back in 2001 and destroyed it, i have also put a deck over on its rudders, and had countless step boats flutter at 90+. This thread really dosnt apply to the average boat owner with the average round bottom boat do to the fact it isnt gonna run fast enough nor pack enough air to get it to lift...yes most of you guys boats act wierd at top speed of maybe 50mph and you think its gonna fly but it is going anywhere i promise you, the only thing you need to be concerned about is it taking a hard left when running that fast, not flying.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 40 posts ]  Go to page 1, 2  Next






All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group
 Page and Content Copyright ©2014 • SouthernAirboat.com, Inc. • All Rights Reserved