Newt, good morning mate. :)

You are more clever than I thought - you replied before I posted!!!!!

newt

lower mate, lower;)

Newt doesn't do low mate!!

Spent a lot of his time up at 100 feet. :E

Quality Banter
 

:D

Now that IS funny.

Clearly I'm still hypoxic from the experience!!

Must be all the clear air in Scotland:ok:

The sum of all lift in straight and level flight (positive and negative, from all parts of the plane) = gravity, otherwise you would be going up or down.

Owza fishin' mate?

Sorry buddy - lift is a FORCE and cannot equal gravity because that is an ACCELERATION.

Back to Sir Isacc Newton.

Lightning Mate is right.

Lift is defined as a force.

However, formally, 'g' is referred to as the "acceleration due to gravity" to avoid this kind of argument.

The force on a mass caused by the acceleration due to gravity is, formally, weight.

The forces on an aircraft are in balance in straight, UNACCELERATED flight, which fits a constant rate of climb or descent as well as straight and level.

I haven't seen anyone correctly use momentum yet.
If you want a clear physical explanation of any of this, please PM me. I do this for a living.

Now, can we get back to interesting stuff like victory roll trimming and LL jokes?

F3WMB
MRAeS, MInstP

not much time to trim here!! Mind you if he got it wrong!!

Fox3, ffs no more of that, it will go to his head and then we'll be right in the deep end.

SI Units. (Expressions to make you sigh)

The way I was tought is that Isaac Newton discovered Gravity when an Apple fell on his head. Four Apples = 1 Pound therefore 1 pound = four Newtons.

Kilowatts is what the Electric fire used to run on and a Litre's like a Metre only better 'cause it's wetter.

The dear old Frightening was so ancient that its ASI was calibrated in 'furlongs per fortnight'....;)

Is there any truth in the story that the fuel gauge read 'Empty....Fumes....Not enough....Still Not Enough....All you're getting but really not enough'

Or that the altimeter read 'Ground pounders....Mud movers....Learning Command....Truckies....Air Defence Sky Gods and V-bombers only'?

Close BEagle but no cigar!!:D

From what I've seen, the Altimeter should be

Groundpounders, Buccaneers, War, Falkland Islands, and then a biiig gap before mud movers. Americans are somewhere above Learning Command.

Lightning top speed 4 million furlongs per fortnight (though that's an awful lot of AARs in a fortnight!)

I think.... momentum is mass x velocity. Velocity is a vector, thus momentum is a vector too, i.e. it has both magnitude and direction.

What this means is that, even at constant "speed" momentum changes around the loop (it swings around with the aircraft's velocity). Newton said roughly that "the rate of change of momentum is directly proportional to the applied force and takes place in the direction of that force".

To loop the loop, we need an extra bit of force perpendicular to the momentum vector to unbalance the forces on the aeroplane, i.e. to accelerate the aircraft mass towards the centre of the loop. This is produced by pulling back on the stick to increase angle of attack, increasing the lift generated by the wings, whilst maintaining airspeed with the throttle.

Nobody's mentioned nibble (and flap) :ooh:

my go at answering.
 

FCSOveride has a great answer for you right there.

I always like to relate answers to real world examples. Therefore: talk to your son next time you go around a roundabout. Ok, it's lateral 'g', but the principle is the same (get him to lean 90 degrees to the right if it helps).

Before you his the roundabout, there is no lateral 'g', right? Start going round it and he will be thrown to the outside of the car. Keep going round, and the 'g' force will remain. A loop or a break is similar.

In the case of a loop though, we already at 1 (not zero) 'g'. If I pull up into a loop with 4 'g', then that's what I will feel (initially). At the top of the loop I will be doing the same thing with my aircraft but now the plus 1 'g' I would normally feel is acting the other way so I would feel about 2 'g'. (3 'g' in the vertical). You need to picture "plus 1 'g'" acting vertically downwards at all times.

In truth no-one flies constant 'g' loops - it wouldn't look like a loop. A barrel roll is different.

For breaks, if you have the power, 4 'g' will remain the same forever. Depending on aircraft type and power available, it may reduce as, has already been pointed out, increased lift increases drag, reducing speed (unless you have more power).

Watch out Jindy as you can be banned for being rude!! Nibbles and flaps is very close to the edge!:\

And if, by chance, you have a helium balloon in the back of the car as you drive your son around the roundabout (traffic circle), he (and you) may be surprised at the way IT leans.........

Did I detect a bit of roll/yaw coupling?

S'all abaht B/A ratio innit.

Morning Newt.

Not sure you could get roll/yaw coupling in a F104 LM. More like a dart than an aeroplane!:ok:

In a loop or a roll or a turn, what's the difference between centrifugal force and centripetal force; or are they the same?

On the one occasion I flew it, Newt, I was briefed carefully on max roll rate at high incidence.

"....watch the china, alpha..." ;)

SOSL
Centripetal force is that required to keep an object moving in a circle, in an Inertial Reference Frame,i.e. seen from outside the aircraft. It acts towards the centre of the circle, and is usually generated by a component of lift (Bona mates can VIFF too).

Centrifugal force is that experienced by the crew, who are accelerating and thus in a non-inertial reference frame. Newton's Laws do not work directly in non-inertial reference frames (Einstein's do). This force acts outwards.

Or, in a thousand words....
http://imgs.xkcd.com/comics/centrifugal_force.png

There are only three forces acting on an aircraft in flight. Thrust, weight and total reaction. Lift and drag are just 'lies told to children'. They are artificially defined components of total reaction (a much more valid and useful concept). Of course, take away thrust and there are only two.

....and I presume you believe that lift, sorry total reaction, is generated because of the venturi effect between a wing upper surface and the free stream air above it. :E

Now then - I know that even an elephant can fly

....seen Dumbo......?

Arthur:

1 Aircrew ARE children. Groundcrew, in my experience, have always referred to the aircrew crewroom as the 'playpen'. Quoth the sign-in desk Sergeant, "What have the children done NOW?".

2 Since the use of physics in this case is to explain, then pontificating about total reaction is worse than useless if it doesn't lead to understanding.

3 Most reference data is provided as separate lift and drag data, so reassembling it into total reaction is inefficient.

4 Acting all superior about it ("lies") does nothing for the reputation of physicists as people worth listening to.

newt - it's all about B over A ratio and the 104 has a lot of one and hardly any of the other, so you could get into trouble more easily in a 104 than in most aircraft. That is unless you are a god like you and me mate! :E;)

The clean Jaguar spinning (tumbling more like:eek:) video was a goodie - I think it went unstable in all 3 axes at the same alpha, 17 IIRC.

Don't talk about newt like that;)

And you and I know different:O;

About newt yeah jindy! :E

Oh no you don't:ok:


And I really thought you guys were being nice to me these days:{

How do flies land inverted on a ceiling?!
 

teeteringhead....here is a link regardin' your flyin' fly question...cool!
BBC - Bang Goes the Theory - Ask Yan - How does a fly turn upside down to land on a ceiling?
:)

The real answer is that all flys are really QFIs in the afterlife still looking for an answer to the question....

The real answer is ... Nobody knows!:confused::confused::confused:

But, Newt, I do of course. :p

The biggest problem in the 104 (apart from no lift) was actually negative g and a high roll rate. Bugging out of a fight was always interesting.

Just make sure you never have to bug out mate! ;)

How you doing T?

Good, still flying. :)

Murdock - many thanks, that's a brilliant piece of film, but to me it seemed he (or possibly she) was still "wingborne" when the landing spot was grabbed.......:confused:

And as for ... then they aren't flies, they are "walks"! Tata boom!

Lucky you ktk and good on you. Ageism struck with me sadly.