Bigglesworth

And rehab programs for those who think they are flying but are still on the ground. Life, be out of it:yin_yan:

Lets get this thread happening................ Serves you right for closing it. The revenge of the stubborn. It will and won't take off, depending on things such as whether the moon is in scorpio with venus rising or how much the pilot was drinking, hence how many moons there are. Makes sense to me, but I don't trust myself after spending last weekend at Thredbo wearing a Bundy apron to a Country music festival. I would like to say it was fun, but I can't remember.

Into bikes, and all sorts of planes, and windsurfing etc. I would even try base jumping but there aren't many tall buildings around here. I want to know how many pilots are into bull-riding?

Hold my beer, I want to try something. That was my sig. until others objected. By the way If you're faced with a forced landing, fly the thing as far into the crash as possible. (Bob Hoover - renowned aerobatic and test pilot) Is no joke. It can easily save your life. Fly it as in don't stall when trying to lose speed. it is better to miss a tree a 50kts than hit it at 30.

Ethanol dissolves the lining in the Jabiru tanks. This then gets caught in the fuel filter since Jab uses a very fine filter. And since the filter is also opaque, you won't see it being blocked, and next thing you know, the motor stops. Or so I have heard, from pretty reliable sources.

Good of you to pick it; it means at least someone is following. But N=zx+N IS part of the question. What 'fools' people into thinking that the plane would stand still? Its because the belt would make a car/ other wheel propelled vehicle stand still. Therefore the conveyor speed MUST be N=zx+N. That has been my point all the time. And if that follows, any acceleration on the part of the plane causes major problems.. I disagree with M Wrenford's statement. If the projectile is fired above the ground reference, i.e. the belt, then it has a velocity of 45kts period. If the belt is travelling at any speed/direction the velocity is still 45kts. Remember those earlier comments about the speed of the earth. The earth is moving, but we measure our speed in relation to it. So why should we do otherwise in a localised scenario of a belt?

Even I have to agree there, instructor, or at least practise at altitude ONCE you are confident of recovery from unusual attitudes. Interesting thing I found with a sideslip on final for short runways is: A sideslip needs more speed, not due to ASI/pitot, but because of the angle of the wing. Roll out from a slip, and you will be well above your final speed, and speed is just as bad as height. They are a powerful tool, and should be treated with respect due to their ability to catch the unwary. Also a slip needs a certain amount of height to roll out from, so a plane can't be slipped right to the ground to make a steep approach.

Calculus As I said, I am a bit rusty, and tired so this is a basic starter: Take the formula for a/c speed past the scenery to be f(x) Now, for the a/c to speed up, it must accelerate, i.e: f'(x)= z Where z is the acceleration. Thus f(x)=zx +c the constant can be disregarded since the movement of the plane is analysed from a rest. So the speed of the a/c over the conveyor is given by Vconv= zx+N Where N is the speed of the conveyor in the opposite direction. Thus, from the information in the question, the speed of the conveyor, N, can be found by: N=zx+N Solving for N N-N=zx 0=zx Hence z=0. Thus the a/c starts at a rest situation, and undergoes NO acceleration, since that would violate the conditions of the question, or the laws of mathematics. Thus the aircraft will not take off. Catfish? PS standing on the runway is fine, since the laws of math stop everything from moving. We'll write it on your headstone.

OK, you asked for it. How about we slightly change this thread to a competition for best/most confusing mathematical proof? I will pay the winner $100 provided I can use their equations to get the $150 off brentc ;). I'll start thinking soon, I have gotten rusty on calculus actually.

SAYS WHO?????????? where does it say that speed is relative to airmass? And where does it say that the air is stationary for that matter? The plane is still on the 'ground', and since when do you taxi on airspeed??? The velocity of the plane could be measured against the scenery/still air, BUT if that is the case, the conveyor belt is as useless as tits on a bull. It won't stop anything, whether it is wheel driven, or propellor driven or magnetic attraction or whatever. FOR THE QUESTION TO BE OF ANY SIGNIFICANCE, 'SPEED' MUST BE MEASURED AT THE WHEELS. I.E. RELATIVE TO THE SURFACE THAT THE PLANE TRAVELS OVER. And in that case, things go funny.

Thats what I thought at first. But what is the plane's SPEED? If the wheels turn at 2kts, then its speed is 2kts over the belt, then the belt must also turn at 2kts, causing the wheels to turn at 3kts, belt speeds up........ etc. Next time you are taxiing, and the wheels turn at 2kts, would you say your speed is 2kts? If you are on a conveyor belt and wheels at 2kts, whats the difference?

Short question: Have all of you who disagree with me, studied the equations I gave earlier to back up my claims? Of course, in a real world situation the plane will take off. Thought about it for 2 seconds to realise that. Then wondered where the catch was. But we don't live in the real world. This is the internet where Geeks rule supreme. So: we have a convyor belt trying to halt any thing on it. Capische? If anything moves, the belt speeds up to try to stop it. Catfish? If the belt can't stop it (such as an aeroplane) it continues speeding up until it reaches infinity. THIS HAPPENS. we are online now.:big_grin: Now, can your plane handle a runway moving under it at infinite knots? Staying in the field of pure mathematics, To take off from a runway moving at infinite knots, the plane must move over the runway at infinity plus about 60kts. Which is not mathematically possible. So until someone starts fooling around with time dilation for when the speed reaches 3x10`8m/s (speed of light) that is the scenario. I really wanted to find a way that I could solve it using integral calculus, but that doesn't fit .

I follow all the physics easily (I got 90 something in HSC physics only a couple of years ago). The fact is that it will take off if: The speed of the conveyor is linked to the speed of the plane past the scenery which most people think it is, but that is a waste of time. 0r, if the conveyor belt is a practical one which isn't fast enough to destroy the wheels (such as in the video) My point is that the conveyor belt DOES have an effect on the aircraft. But only if it is fast enough to destroy the wheel bearings, which, as w3stie points out, only needs to be about 200kts. The video should show the plane at rest on the belt, then engine is on, plane rolls forwards and the belt speeds up until the wheels die and it brings the plane to a stop. Then it can't take off. <hand over the cash>

In slow motion for the non-physicists amongst us. And to claim the $100 off brentc:laugh: BTW, frame of reference problems can look very hard until you see the point and then they are obvious. I love them. Firstly we have to work out the speed of the conveyor belt. It moves backwards at the same speed as the plane but in reverse. What speed is the plane? Past the scenery it will go at the airspeed. Over the conveyor belt it goes at a "groundspeed". Think about this. If the belt tries to match the airspeed, it is pointless. it can't do any good to any form of vehicle, be it plane, car, boat, or UFO, other than make its wheels turn at double time. If it tries to match the groundspeed and keep the plane stationary, it is doomed to failure (as shown in videos etc). BUT, on the way to failure, it will speed up until it reaches breaking point. OR until the wheel bearings seize from overheating and the plane is gounded. So, brentc, if I can build a conveyor belt fast enough to seize your wheels up, that $100 is mine. A side note: A wind can stop a plane, but not a car, until it reaches breaking point; a conveyor can stop a car, but not a plane, until it reaches breaking point. PS. John's section is cool. if only it was about something better like performance tweaks:)

Obviously planes and Physics don't occur together This is an interesting question. It is also a very stupid question. It is interesting that no-one else realises this. Consider: 2 possible scenarios: 1 The conveyor reference ground (VcrefG) = -VprefG (plane refence ground) 2 Or,VcrefG = -VprefC (plane refence conveyor) In scenario 1, any vehicle will move to any speed providing that it can tun its wheels twice as fast as it is traveling. Disagree? Take VvrefG=x (vehicle reference ground) Then VcrefG=-x The difference between them is |VvrefG-VcrefG|=2x And that holds true for any value of x. Therefore scenario 1 would not hold a car in position. And I think that is the scenario that most people envisage. So, scenario 2: VprefC (plane ref. conveyor) = -VcrefG I.E the conveyor belt will do its best to hold the vehicle in position. In a car scenario: VvregC=x where x is any speed up to about 200km/h depending on vehicle. Vcrefg=-x which is feasible. Therefore VvrefG= x+-x=0 i.e. vehicle is stationary (I hate to think of the driver getting out to push:black_eye:) Now The Finale A plane is on the belt. Where x=0 the situation is the same as for a car. BUT, when the plane applies power: VprefG=>0 which means that VcrefG increases (or, to be exact, decreases {goes backward}) in order to put the situation back to equilibrium. But since the speed of the plane is not influenced by the belt, VprefC>-VcrefG. This holds true for any value of VcrefG and so the conveyor will continue to increase its speed until it reaches infinity. (or self-destructs first). Either that of the wheels fall off the plane which would mean it would not take off. So it comes to a structual contest between the plane and conveyor. And, as such, the question is stupid, because it cannot be solved theoretically.

What do you call a man with a block of wood on his head? 'Edward What do you call a man with 2 blocks of wood on his head? I don't know, but 'Edward would.

Sorry Disperse, I didn't want to stop anyone's fun, I know this is the jokes section, but as an email purist, if we let this past, soon someone with teenage daughters will post a thread called "LOL FUNNY, Pass this on" ending with "and if you don't pass it on to 5 people within 4 minutes, you will have bad luck for the next 21 years 2 days and 5 minutes" I have gotten a fair few of those, and have lost friends by returning them with scathing comments. Another form of SPAM:censored:. Have a funny new year

Question, How come these are identical for the last few years? Answer: They are fake. http://www.stellaawards.com/bogus.html The true stella awards are even more interesting, since they are real.

I am thinking of flying to my annual holiday to the Tamworth Country Music Festival. Only problem is that Tamworth is a major airport and as such would not let in a recreational plane without a transponder etc. Does any one know of a nearby strip or useable paddock where I could land and park my plane for about 5 days for a reasonable cost? All come along, its one really good party there. (come to think of it; all the clubs let you wear hats during the festival, so maybe the airport will also relax rules to allow all the farmers to fly in, some hopes:sad:)

So what was the cost/weight/ looks? Sounds along the lines of what I wanted.

Air is supplied extra; in self-inflateable form.

I wish customers also had that sense of humour, I charged them for some of those parts. ;)

My plane was designed to be hangared for most of the time, UV would not agree too well with it. But on odd occasions, it may have to be parked outside, and I would like to have a lightweight uv resistant cover I could carry with me and put over it when I park it. Is anything like this being sold? or if I have to get it custom made by the local upholsterer, what material would I use? I though maybe along the lines of what they use for car covers.

Yes, easy to think about Dana Lyons' song "cows with guns" it it almost possible... watch out. I hosed the offending material off, and found that while is is sealed from the top, a pressure cleaner from the bottom is a different matter. D*mn. But as to the other part of my question; do cows still lick the fabric of planes if it is doped and painted fabric? and if they do, it there anything I could do to prevent it if a few strays get through the fence. Such as spray it with pepper spray. or wire it to the electric fence, he he he,,,, along comes dog to pollute my wheels,,,,, yelp yelp yelp ;)

Getting back to the topic, ( and to calm some earlier commentors down) I think the cheetah will really benefit from flaps, since it normally (as yet I can only speak about light loading) refuses to: a: descend b: slow down c: stall (not really related to flaps) All 3 of these situations it has to be forced into and doesn't like to stay that way. Someone earlier said that 40kts over the fence sounded dangerous, it isn't. It still floats 200 metres, and with a 400m strip, that is a long way. Take off no problem, but to get those wheels to touch the ground, that is a bit harder. Also, having done comprehensive stall/slow practice at height, I would be confident that a stall due to wind gusts would still be that gentle that it would be a piece of cake to pick it back up. Not that I ever want to try. Also with one up and half fuel I am about 180kgs below max (stacks of payload here) and that is below the earlier graph and into very low stall speeds. PS, don't try to land a Saratoga down home, I won't be answerable. Sounds like fun to land, engine failures must be dangerous, when you try for low speed in a short paddock,and then............