Talk:Falling leaf

Photos[edit]

Neither picture shows a spin, or falling leaf. The first looks like a fighter jet doing a missile avoidance procedure and is not an aircraft type that likely to ever be in this configuration anyway. The second shows an aircraft that is clearly in a spiral dive not a spin.

Sorry, but I'm not sure what you mean. Missile avoidance procedure? That seems seriously unlikely with the elevators at full back-stick and the throttle clearly off. The smoke flares used are not the same as the heat flares used for missile evasion, but they're used for showing the airflow produced by a moving object, such a wingtip vortices. They were obviously launched from a separate plane, or else the smoke would be behind, not ahead of and following the plane. You can just as easily do the maneuver in a fighter plane as you can a stunt plane, or a Cessna for that matter. It's a very good maneuver to learn. but each aircraft responds a little differently. (Very good for landing skills, especially when approaching in a slip or a crab.) I have no reason to doubt the photographer.

I am not sure what I am looking at with this picture, or how it is demonstrating a spin, if indeed it is. To be used it needs some explanation. I cannot reliably see where the elevators are or if it is powered on on not or its speed relative to a stall. I would have assumed that the flares were fired by the plane but I could be wrong, it is hard to tell where the smoke or the flares are in relation to the plane and if it has indeed just passed through the smoke then what is it telling us? This is not a practice I have heard of although I have seen a leading plane laying a smoke trail for the following plane to fly through. Those flares are hot and hard, if they really have been fired by another, and our plane is flying through them it looks unacceptably dangerous and completely unnecessary. Maybe a jet fighter can be spun this way, I haven't flown one, but I understood that they stall in quite a different way. Maybe what you say is all true, if it then I think it all needs more explanation. E x nihil ^(talk) 03:13, 12 August 2015 (UTC)[reply]

As for the other photo, that is definitely a spin, which is distinctly different from a flat spin. A spiral dive, on the other hand, is a barrel roll in the purely vertical direction. It is much wider in diameter. A spin is more akin to a rudder roll in the vertical, but even tighter still in diameter. You can't pull a turn that tight in normal flight because the laws of physics forbid it. The plane will stall out. For example, compare these diagrams by some very reliable sources. Zaereth (talk) 01:36, 12 August 2015 (UTC)[reply]

I won't stand in your way but in that picture its doesn't look like the inside wing is stalled. I think we could find better ones that make it clear that it is not in a spiral dive. E x nihil ^(talk) 03:13, 12 August 2015 (UTC)[reply]

A fighter stalls pretty much the same way any other plane stalls. The main difference is stability. Fighters are highly unstable, which provides good agility, but not at all stable in flight like a Cessna is. In a falling leaf, there is no developed spin. To an observer standing on the ground, there is no discernible spin at all. From the cockpit, there is a constant swaying motion from side to side, accompanied by rocking and a stomach-dropping slip to the side. During the maneuver, the nose should stay roughly 20 to 30 degrees from the projected flightpath.

If the throttle were on, the jet nozzle would e all lit up. To see the elevators, you may need to open the largest version of the file and try looking at it on a large screen. (I have mine on a 50 inch plasma TV.) Use of these smoke flares is quite common in the aeronautical industry. You can find many photos on the internet of planes flying through the smoke, from fighters to jumbo jets. The smoke pattern is quite different for a plane in flight as opposed to a falling plane. This is done because some things just cannot be simulated in a wind tunnel, and led to the development of air liners with those upward-bent wingtips. (It turns out a lot of energy is lost in the wingtip vortices, which show up well with smoke flares, and the bent wingtips help reduce them, so much that the millions of dollars it costs to convert to them pays for itself in just a few years.)

I'm not too worried about pictures. I just picked the only related photos that commons had on the subjects. If you think we need better ones, then we can wait until better ones come along. Zaereth (talk) 04:55, 12 August 2015 (UTC)[reply]