162 replies to this topic

[Da_Man]

Penguin., on Jan 6 2007, 11:39 PM, said:

Dude! I own a boat! Dude! Boat's propel themselves by acting against the water. Aircraft MOVE AIR!.

Try again.

dude, don't be a moron okay, read what i said, read all the posts before hand, the reason an aircraft can take off from  a treadmill is , and i quote "the engines propel the aircraft, not the wheels, the wheels move freely, but will be moving twice as fast as normal on take off"
   think about that....do the floats spin freely? if your seaplane does.. u need a new one........
again, the water will push against  the seaplanes floats, causing.. hmm whats that word? DRAG?? or something like that, i don't know....... what happens when u have that??? explan to me that mister sea plane rating??

if the force of  the water is equal to the thrust of the prop.. u aren't going anywhere, think about it, what would happen if u shut off the engine on a seaplane? you would start to float away with the current correct?? why is that?? because the water pulls the plane with it....
   now i doubt ud ever come into that situation where the current was stronger then the thrust of the aircraft, but, in theory.. the water would stop it from happening if it could....

a sea plane has a rudder on each float does it not? why??? because the movemnt of the water flow affects the movment of the aircraft.......... same concept.... if the water is causing to much drag, then the plane isnt going anywhere......

[Penguin.]

Dude. You're being the moron, it's nearly physically impossible for the currents force on the minimal surface area of the float to impede the plane from moving.

The floats are ON TOP of the water, not within, like the oars, propeller, or the water rudders.

Yes, a current can move the aircraft, just like a treadmill rotating backwards will move the aircraft backwards until the thrust counteracts it, which doesn't take much in either case.

[Da_Man]

Penguin., on Jan 6 2007, 11:54 PM, said:

Dude. You're being the moron, it's nearly physically impossible for the currents force on the minimal surface area of the float to impede the plane from moving.

The floats are ON TOP of the water, not within, like the oars, propeller, or the water rudders.

Yes, a current can move the aircraft, just like a treadmill rotating backwards will move the aircraft backwards until the thrust counteracts it, which doesn't take much in either case.

so.. hmmm, the planes floats aren't touching the water now??? they are above the water?? sheesh, wow.. i didn't know that.... why does my boat have a waterline then?? why is it that a swimmer can float if he lays on his back and does a back stroke...

   i know it would be pretty impossible, but like i said, in theory if the current was stong enough, it would stop it from doing it...
K, i really have to work here, im trying to fix T1 lines and to busy laughing on the phone with customers about this, i have a real pilot here and he is laughing at this non-sense....

come on please, when the aircraft starts out from a dead stop the floats are in the water, as the plane builds speed they start to "plain" out, same with a boat, and a jet ski, but if the current was so strong, the aircraft would never be able to "plain" and ud be stuck......
pretty much what i said there is, if you cannot build up your speed you will not get the floats on top of the water, therefore you would get no airspeed out of it becuz you are limited to the water....


why would this site have warnings for high currents, if it didn't affect the aircraft??

http://www.airnav.com/airport/BNF

[Da_Man]

OKAY, FINALY!! Found something worth crediting...... the first part "water characteristics" says it all....
"Because of its wieght Water can exert a tremendous amount of force, this force, a result of resistance, produces drag, as the water flows around or under the object being propelled"



http://www.seaplanes...bs/AC61-21A.pdf

Edited by steve23guy, 07 January 2007 - 12:12 AM.

[Penguin.]

Yeah, sure you are big guy.

The floats aren't affected as much as the things you're trying to compare to. You're forgetting that all your comparison objects propel themselves by forcing against the water. Having spent a lot of time around air boats, I've never seen one that couldn't get upstream in a strong current that stopped jet boats.



Oh, BTW, the warning about currents is for those who are docking and taxiing, it has nothing to do with the 'takeoff', which IIRC, is what we're talking about.

So, if it's pretty much impossible, why try to argue the point. A conveyor large enough to hold an aircraft isn't impossible, just improbable.

Your 'source' is mostly about wave action (among other aspects of float flying, I like the part where they compare Alaska training to the 'lower 48') and not much about currents.

[Da_Man]

Penguin., on Jan 7 2007, 12:15 AM, said:

Yeah, sure you are big guy.

The floats aren't affected as much as the things you're trying to compare to. You're forgetting that all your comparison objects propel themselves by forcing against the water. Having spent a lot of time around air boats, I've never seen one that couldn't get upstream in a strong current that stopped jet boats.



Oh, BTW, the warning about currents is for those who are docking and taxiing, it has nothing to do with the 'takeoff', which IIRC, is what we're talking about.

So, if it's pretty much impossible, why try to argue the point. A conveyor large enough to hold an aircraft isn't impossible, just improbable.

Your 'source' is mostly about wave action (among other aspects of float flying, I like the part where they compare Alaska training to the 'lower 48') and not much about currents.

This is all in theory...... again, if the floats had props on the bottom, it would be a differnt story, but they do not.
what did u get in physics? seriously.. this is all about drag, if the current was "strong enough" the plane wouldnt move.....
Im done, later..

[Penguin.]

We've agreed on that already.  

Considering that this has only come close to happening a few times that I've ever read about (Don Sheldon in Devil's Canyon is one that comes to mind, but he was in a 90hp Aeronca Sedan in rapids), we should chalk it up to 'probable'.

Anyhow, go to work.

[dolbinau]

I hate to sound redundant, but, A Seaplane will takeoff in a strong current!

Think:

Current = Conveyor

Wheels = Floats

---

A Boat on water is like a car on a road, it is just..different than an aircraft.

Look at this ride:

http://en.wikipedia.org/wiki/FlowRider

You will go no where on your board, but if someone were to pull you along with a rope (Assuming it was all flat ) you would pull forward no matter how fast the water/current is going under you. Same with an aircraft.. I just don't know how to explain it.

Edited by dolbinau, 09 January 2007 - 04:42 AM.

[FL050]

A seaplane will take off no matter the current.  All the floats do is allow the aircraft to float, they have no bearing on what the aircraft does or how it gets it power/thrust.

[Chief_Bean]

steve23guy, on Jan 7 2007, 04:47 AM, said:

Penguin., on Jan 6 2007, 11:39 PM, said:

Dude! I own a boat! Dude! Boat's propel themselves by acting against the water. Aircraft MOVE AIR!.

Try again.

dude, don't be a moron okay, read what i said, read all the posts before hand, the reason an aircraft can take off from  a treadmill is , and i quote "the engines propel the aircraft, not the wheels, the wheels move freely, but will be moving twice as fast as normal on take off"
   think about that....do the floats spin freely? if your seaplane does.. u need a new one........
again, the water will push against  the seaplanes floats, causing.. hmm whats that word? DRAG?? or something like that, i don't know....... what happens when u have that??? explan to me that mister sea plane rating??

if the force of  the water is equal to the thrust of the prop.. u aren't going anywhere, think about it, what would happen if u shut off the engine on a seaplane? you would start to float away with the current correct?? why is that?? because the water pulls the plane with it....
   now i doubt ud ever come into that situation where the current was stronger then the thrust of the aircraft, but, in theory.. the water would stop it from happening if it could....

a sea plane has a rudder on each float does it not? why??? because the movemnt of the water flow affects the movment of the aircraft.......... same concept.... if the water is causing to much drag, then the plane isnt going anywhere......

Uhh, you're the only one being a moron here

Just face it that you're wrong, you're embarrassing yourself by arguing your point again and again  

[TomohawK]

Ummm, no it won't take off, no airflow over wings = no lift.

[Pattyboy10]

I have been trying to follow this quite some time now, and never posted something. I am a certified pilot, and the first thing that ALWAYS comes up to me, offcourse it won't fly, because you need airflow over the wings to create drag. The plane won't move forward, thus not creating any airspeed... (leave the wind out of this please)

But its really stupid man, i don't get it... Why would it fly ???????? THE IS NO AIR OVER THE WINGS IT won't CREATE LIFT!!!!!!!

please don't get mad at me, only bringing in my point  

[Tim.]

TomohawK, on Jan 9 2007, 08:03 PM, said:

Ummm, no it won't take off, no airflow over wings = no lift.

Yes, I knew I was always right with this question!

The engines are producing a force which is keeping the plane in a stationary posisiton, so the plane would not take off.

People seem to go on about how it would take off, but are talking about when the forward motive force is greater than that force of the conveyor belt so the plane would move forward and would have enough speed to take off.

[N3123V]

The three of you that posted above me need to go back and get your facts straight. Read the whole topic and the links that were included.

The engines have no effect on the ground. Therefore the wheels are independent of the ground. The wheels have NOTHING to do with how much air is going over the wings. The engines effect the air, NOT THE GROUND. The engines push the air, which is independent of the ground. The force acting on the air PUSHES THE PLANE FORWARD. I'm not sure how many times this has to be repeated before everyone understands.

Edited by N3123V, 09 January 2007 - 03:38 PM.

[Chaos81]

Tim., on Jan 9 2007, 02:18 PM, said:

The engines are producing a force which is keeping the plane in a stationary posisiton, so the plane would not take off.

What's keeping the plane stationary? Is there some magic force stopping it from moving forward?

[Chief_Bean]

I can't believe this is annoying me so much

Just face it TomohawK, Pattyboy10 and Tim. The plane will take off. For God's sake, we even had a ###### video to prove it. How much more evidence do you need?

Chaos81: [sarcasm]No ###### Sherlock.[/sarcasm]   

Edited by Chief_Bean, 09 January 2007 - 03:55 PM.

[TomohawK]

I am referring to these conditions as i believed were asked. A plane on a surface which increased resistance to the equal opposing force supplied by the engines.

OK so no matter how much thrust the engines produce, the aircraft willl not move forward or backwars. the forces are balance.
The engines have jack ###### to with the actual lifting of a plane.

LIFT = cl*p/2*v2*a

With no velocity or airflow over the wing, no high presure beneath the surface of the wing it will no rise, not when the planes is stationary and there is no wind!

[Chief_Bean]

TomohawK, on Jan 9 2007, 09:09 PM, said:

I am referring to these conditions as i believed were asked. A plane on a surface which increased resistance to the equal opposing force supplied by the engines.

OK so no matter how much thrust the engines produce, the aircraft willl not move forward or backwars. the forces are balance.
The engines have jack ###### to with the actual lifting of a plane.

LIFT = cl*p/2*v2*a

With no velocity or airflow over the wing, no high presure beneath the surface of the wing it will no rise, not when the planes is stationary and there is no wind!

But the forces aren't balanced, that's what you're missing. OK, if the plane wasn't moving it's obvious that it won't gain any lift. However, in this scenario, it would move. The undercarriage is free of the aircraft and that isn't where the drive comes from like in a car. An aircraft propels itself through the air, not the ground.  

You need to take into account our opinion [the truth] because talking to you "non-believers" is comparative to talking to a brick wall

[TomohawK]

Cant help but laught at some of you guys  

Explain how the forces aren't balanced buddy?

Right, so you admitted that the initial question's answer is NO it will not lift. And doh, aint it obvious an aircraft doesnt propel itself through the ground.

Im sorry if the "scenario" was changed in this thread. I have better things to do with my life than sift through topics for hours every day  

[Chaos81]

Chief_Bean, on Jan 9 2007, 02:54 PM, said:

Chaos81: [sarcasm]No ###### Sherlock.[/sarcasm]   

I only said it because certain people just don't seem to get that.