Random facts about planes..

[Ian Lancs]

Ayahuasca said:

There are, at any given moment, over 1,000 B737s in the air.

And here they are (if this link works) https://www.flightradar24.com/11.29,-46.04/2

[dr_gn]

Ayahuasca said:

AVV EM said:

dvs_dave said:

You've got that the wrong way round. Faster moving air is lower pressure air. Due to the aerofoil shape of the wing section, the air that flows over the wing has to travel faster than the air below it, as it has a greater distance to travel. That's what creates the pressure difference between the lower and upper surfaces of the wing, and hence lift.

Woops, my bad,

If it were, an aircraft would not be able to fly inverted.

It would - it all depends on the angle of attack. A flat plate at zero incidence produces no lift. Give it some relative incidence - either the right way up, or upside down, and it will produce lift. Same with a symmetrical aerofoil. Same with an asymmetrical aerofoil (although the efficiency decreases significantly with angle of attack when inverted in that case).

You could argue that a flat plate at positive angle of attack (the only way it produces lift) presents a longer flow path on the upper surface due to the flow becoming detached.

Not saying Bernoulli theory for lift is correct (there are videos out there that show smoke blips not meeting at the trailing edge), but the flat plate giving lift, and inability to fly upside down examples don't actually seem to prove its wrong in themselves.

[Dr Jekyll]

dr_gn said:

Not saying Bernoulli theory for lift is correct (there are videos out there that show smoke blips not meeting at the trailing edge), but the flat plate giving lift, and inability to fly upside down examples don't actually seem to prove its wrong in themselves.

Nobody is saying it's wrong in itself, just that is isn't the reason (or always even a reason) why aircraft fly.

[Atomic12C]

Ian Lancs said:

Ayahuasca said:

There are, at any given moment, over 1,000 B737s in the air.

And here they are (if this link works) https://www.flightradar24.com/11.29,-46.04/2

Flight radar always impresses me as to the sheer number of planes in the sky at any moment.

Even though flightradar is only providing a partial picture, it doesn't display all aircraft currently flying, there are many regions over land and water that flight radar does not receive data from.

https://www.youtube.com/watch?v=WAud8KpFyvM
Crazy just how many and much need people to move about these days.

[dr_gn]

Dr Jekyll said:

dr_gn said:

Not saying Bernoulli theory for lift is correct (there are videos out there that show smoke blips not meeting at the trailing edge), but the flat plate giving lift, and inability to fly upside down examples don't actually seem to prove its wrong in themselves.

Nobody is saying it's wrong in itself, just that is isn't the reason (or always even a reason) why aircraft fly.

I know the Bernoulli principle about velocity and pressure is correct, not saying anyone disagrees. I'm saying some of the *reasons* people give to demonstrate it's invalid for wing lift don't actually seem to prove its invalid for that application (flat plate lift and flying upside down).

[dvs_dave]

dr_gn said:

Dr Jekyll said:

dr_gn said:

Not saying Bernoulli theory for lift is correct (there are videos out there that show smoke blips not meeting at the trailing edge), but the flat plate giving lift, and inability to fly upside down examples don't actually seem to prove its wrong in themselves.

Nobody is saying it's wrong in itself, just that is isn't the reason (or always even a reason) why aircraft fly.

I know the Bernoulli principle about velocity and pressure is correct, not saying anyone disagrees. I'm saying some of the *reasons* people give to demonstrate it's invalid for wing lift don't actually seem to prove its invalid for that application (flat plate lift and flying upside down).

Indeed. Bernoulli effect coupled with wing angle of attack is what makes an efficient wing work. If Bernoulli wasn't important, then wing stall also wouldn't be, which is patently not true. Flip a wing upside down and change the angle if attack to suit, you can fly upside down. Bernoulli effect is still working, just the effect in the opposite direction as a result of AoA is greater.

Edited by dvs_dave on Saturday 22 April 14:15

[thebraketester]

I wish I hadn't said anything now

[5150]

Jump to 3:45 (but the whole thing is genius)

http://www.dailymotion.com/video/x59zq6s

[Eric Mc]

Who needs wings anyway?

[RizzoTheRat]

Eric Mc said:

Who needs wings anyway?

Bruce Peterson?

[Eric Mc]

He nearly ended up with a pair of these -

[db]

5150 said:

Jump to 3:45 (but the whole thing is genius)

http://www.dailymotion.com/video/x59zq6s

Brilliant
Nice find

[kurt535]

During the war ....some wag flew his Tiger Moth into barrage ballon wires and landed safely with the top set of wings missing......I wonder how that chat went with the OC.

[h0b0]

As the space shuttle and Concorde have been mentioned many times on this thread, it's prudent to remind those going to NYC you can see both in one place. The Intrepid Museum will allow you to walk through a Concorde and under a shuttle. There's an impressive collection of aircraft and a submarine as well. Get tickets ahead of time cheap or check corporate affiliates for free tickets.

I've been several times and I like seeing the blackbird while thinking of Will Smith's "I am legend".

[V8LM]

On approach to landing Concorde was on the back side of the drag curve so pulling the yoke back made the aircraft drop faster.

The number 3 engine on the 747 is often shutdown during taxi to the gate.

A experiment involving nematode worms was being returned to Earth from the ISS in Columbia. The researchers studied where the canisters were loaded, where approximately that part of Columbia was when it broke up, and projected the trajectory to model where the canisters would have impacted. They recovered the canisters and found the worms still alive. https://www.ncbi.nlm.nih.gov/pubmed/16379525

[maffski]

Eric Mc said:

Who needs wings anyway?

Wings are all you need.

[Dr Jekyll]

Random question that might throw up some random facts.

If a pilot couldn't see outside at all and was flying purely on instruments. Would it make any difference if the seat and controls were arranged so s/he was facing backwards? Or sideways?

[RizzoTheRat]

My guess is it would make them a lot more susceptible to motion sickness and disorientation. There's a tendency for people to trust thier senses more than the instruments, which can be lethal when flying on instruments. Presumably less of an issue among more experienced commercial pilots than amateurs (disclaimer: I've only ever flown VFR) but it's still an added complication. The only reason for doing it I suspect would be to reduce G loading on the pilot.

[Krikkit]

dvs_dave said:

dr_gn said:

Dr Jekyll said:

dr_gn said:

Not saying Bernoulli theory for lift is correct (there are videos out there that show smoke blips not meeting at the trailing edge), but the flat plate giving lift, and inability to fly upside down examples don't actually seem to prove its wrong in themselves.

Nobody is saying it's wrong in itself, just that is isn't the reason (or always even a reason) why aircraft fly.

I know the Bernoulli principle about velocity and pressure is correct, not saying anyone disagrees. I'm saying some of the *reasons* people give to demonstrate it's invalid for wing lift don't actually seem to prove its invalid for that application (flat plate lift and flying upside down).

Indeed. Bernoulli effect coupled with wing angle of attack is what makes an efficient wing work. If Bernoulli wasn't important, then wing stall also wouldn't be, which is patently not true. Flip a wing upside down and change the angle if attack to suit, you can fly upside down. Bernoulli effect is still working, just the effect in the opposite direction as a result of AoA is greater.

I think the important bit to think about is that in that particular case (that is an aerofoil wing) the Bernoulli effect is how the lift is generated due to the change in speed, but it isn't the only explanation or way to generate lift.

[Ayahuasca]

V8LM said:

On approach to landing Concorde was on the back side of the drag curve so pulling the yoke back made the aircraft drop faster.

I believe that, on approach, pulling the yoke back will make a lot of aircraft drop faster.