What is this thing for? (not dick related)

[BoostedNihilist]

Yeah, this thing.. I have two guesses, one way cooler than the other..
#1 some sort of antenna? Looks like it would get the hockey game but doesn't look like such a shithot VHF setup
#2 (my favorite) some kind of reference for aerobatics?

[Chuck Ellsworth]

Its a tracking antenna.

[BoostedNihilist]

Really, that thing is an antenna? Crazy. Is it some sort of passive deal? which unit does it plug in to? Don't see a wire but it could be hidden in the strut.

[Pratt X 3]

'Fish' Finder

[L1011]

which unit does it plug in to?

I thought you said this was NOT dick related!

[MichaelP]

Note that it is precisely at pilot eye level and the angles are forty five and ninety degrees.
The Decathlon has a symetrical wing too.
It is related to angles, how far you can or should get it up or down depending on your orientation so to speak!

[Chuck Ellsworth]

M.P....god damn it you ruined it.....

...I almost had them convinced it was a tracking antenna.

[MichaelP]

Khor toht!
It is a tracking device, but it is only accurate in zero wind... the real skill is correcting for that wind!

[BoostedNihilist]

(sarcasm on) damn you .!

I was going to come back and post how obviously it must be a moose tracking antenna for finding tagged moose... the antlers have to come from somewhere eh?

seriously though hahaha

This was gold, I really did laugh

I thought you said this was NOT dick related!

Really, perfect lol.
sucks to accidently plug the wrong antenna into the wrong output... I'm thinking diode

Anyways,

I did notice it was at pilot eye level which is what lead me to the conclusion it was some sort of attitude aide. Is it angle of attack oriented?

What does a symmetrical wing have to do with that thing?

The only way that thing makes sense to me is if I look left and go inverted or vertical... or if I bank 90 degrees and aim for something on the ground.. such as a moose...

[MichaelP]

The aerial harassment of moose is contrary to the CARS... Be careful!

A symetrical wing allows for many more positions to be achieved, different ways to penetrate the air. You are as good on top as on the bottom so to speak....
Even girls can do it in a Decathlon!

The device allows you to increase the accuracy of your figure!

[Blakey]

If it's mounted on a blue Decathalon, it may be a millionaire tracking device.


It's not working.

[sky's the limit]

If pilots are involved - it IS "dick related....."


stl

[BoostedNihilist]

The aerial harassment of moose is contrary to the CARS... Be careful!

I got that one right on the PSTAR

A symetrical wing allows for many more positions to be achieved, different ways to penetrate the air. You are as good on top as on the bottom so to speak....
Even girls can do it in a Decathlon!

okay, so you have your artificial horizon and turn/bank indicator to help you with the roll, but the gyro horizon doesn't work too well inverted, and it's not as accurate for judging an ascent as your IAS... the moose tracker though would definitely help with that .. I just see that thing out the window and can't help but associate it with the horizon... and things you might want to do with the horizon... fun things.

I also thought that if you were fully sideslipped and coming at the runway sideways you could use it to help with the approach...

Though I enjoy cryptic word problems I would really like to know the application of that thing Right now I feel like an ignorant baby following a stream to civilization... and I don't see my instructor until sunday!


mmmm girls doin it in a decathalon... schwing

[MichaelP]

I would really like to know the application of that thing

When doing competition aerobatics you score points with the accuracy of your figures.
Cubans require forty five degree up lines (reverse half Cuban) and down lines (half Cuban) and so a quick glance through the device at the horizon will tell you how close you are to the ideal.
You must take the wind into account... Doing a forty five up line into the wind means you need a more shallow angle than the exact angle in the device.
Doing it downwind means a steeper angle is required.
It's how it looks from the ground that counts in competition rather than the actual air accuracy of the manoeuvre.

Likewise the vertical up and down lines for the stall turn (Hammerhead) are easier to judge with this device, and likewise you need to adjust for the wind.
It's ideal if you do the turn into the wind, then the aeroplane appears to pivot around the normal axis.
Doing the turn downwind makes the manoeuvre look like a bridge.

Artificial Horizons

The Russians make a gyro based on a ball. The gyro is in the ball and is driven by an electric motor that is powered by induction (no wires). An air system keeps the ball floating in the instrument case.
The top of the ball is brown and the bottom is blue and this confuses people to start with.
But pitch down and you see the top of the ball, brown earth, pitch up and the bottom of the ball shows blue sky.
This gyro is fully aerobatic.

[SkyWolfe]

Thats super confusing to comprehend but its really neat...

[cgzro]

You can see one in use here:

http://www.youtube.com/watch?v=1bZcQBvgg6U

The camera is mounted not quite in line with my eye so it looks a bit off but you can see how it is used to judge 45's verticals etc. Look at 1:30 and beyond.

They are called aerobatic sight gauges and the one for the Decathalon is made by a guy in Montreal.

Here is a shot of an MX2 during an airshow shot from a helmet cam. You can see the gauge and the string that is attached and you can see him using it to keep his vertical rolls nicely lined up. The string has a different purpose ... can anybody guess? (no its not a slip indicator)

http://www.airshowbuzz.com/videos/view.php?v=6ee40fd7

[360montana]

The string is to gauge the relative air flow... like on a glider.

[BoostedNihilist]

Excellent! Thank you guys so much for the information. Lots of interesting stuff here.

I am curious about a few of the statements I have read.

The gyro is in the ball and is driven by an electric motor that is powered by induction (no wires)

I would *LOVE* to take one of these things apart. So, the ball must be surrounded by a coil of some sort. Very cool. I would love a cross section of this beast. What an interesting concept. I also love the idea of brown is earth and blue is sky...

The camera is mounted not quite in line with my eye so it looks a bit off but you can see how it is used to judge 45's verticals etc. Look at 1:30 and beyond

.

Wicked video! Is there anywhere in Canada a guy could go for some dual pitts action? I would love to get my hands on a few hours with one of those puppies.

Again, thanks for the useful information. I really don't like to guess when it comes to airplane things and I am a curious beast.

[cgzro]

Actually the string is used to indicate direction. I.e. forward/reverse. When an aerobatic plane is flying straight up, stops and reverses in the air, the 'exact' moment that the plane starts backing up is pretty important because the controls all work backwards. Its also useful for knowning when to kick for a hammerhead since the string will go slack as you come to a dead stop.

Its not much use for yaw indication because its way out there on the wing and you cannot see yaw easily from a side angle. Yaw is very easily felt in these kinds of planes since you get pushed to one side of the plane. I don't have a ball in my plane and I used to use the compass to indicate slip.

[BoostedNihilist]

This thread has got me thinking... which is pretty fun/rare actually.

It's now obvious to me why the moose tracker wouldn't be much use in wind conditions

you could have a 45 degree nose up attitude, you could have the moose tracker nailed at 45 but still be ascending at some other angle. Even though your attitude would be locked in, from the ground it might look like a 50 degree up line.

MichaelP... the symmetrical wing thing really got me thinking too. So I searched and searched and came to a page that actually explained the concept of lift, not the bernoulli concept (which now seems horribly inadequate to me). Inverted flight is actually pretty amazing and has lead me off in a bunch of other physics-y directions.

Basically thanks guys, I have SO much to learn it's actually quite mind boggling.

[cgzro]

Yup, and two other problems.

a) you practice and practice on calm days with a flat horizon, then you go to contest in the mountains and its windy. You pull vertical and set that perfect vertical ... hmm so much for that theory.

b) you tweak it perfectly so that it gives perfect verticals / 45s etc. then some yahooo walks up to the plane, grabs it, bends it a bit and asks .. whats this here thingamajiggy fer?

[MichaelP]

I fly a red white and blue Decathlon... can't afford a new blue one with the moose angle dangle thingy...
I like the symmetrical wing but it is not as fast as a Citabria with the same engine...
But when an Indian student asked me what a bunt was I showed him!
The Decathlon is too much fun, don't ask me to fly it too often I might get sick like eating too much chocolate cake.
Anyway, I wish people wouldn't broadcast that I'm upside down on the common frequency, there's no upside down with a symmetrical wing and in any case dangling from the lapstrap is good therapy for the back!
It's better to do aerobatics from the back seat of the Decathlon, there's more points of reference including the straight trailing edge.
Solo and in the front seat (where you're supposed to be), it's more difficult, there are less points of reference and the CG is too far forward...

[Hedley]

symmetrical wing ... searched and searched
and came to a page that actually explained the concept
of lift, not the bernoulli concept

Sigh. Please remember that most people involved in flight training
don't have a clue about physics. Why people fixate, like a baby
duck, upon bernoulli is mystifying.

Lift is simple. Stick your hand out the window of a car driving
down the road, put on 10 degrees angle of attack, and feel
the lift.

Air has mass. A wing works by accelerating a mass of air
downwards. One formula says it all:

F = M x A

or, force equals mass times acceleration. Air has mass.
you accelerate it (or push it) down, you get an equal
and opposite force up. That's it.

No, there are no giant vacuum cleaners in the sky.

So, a symmetrical wing creates lift. So does a 4x8
piece of plywood on a windy day. This is not hard
to understand.

Heck, you can create lift, and sustain inverted flight,
with an upside down FLAT-BOTTOM wing, if you
put enough AOA on it. So much for the giant
vacuum cleaners in the sky, sucking wings upwards


Back on the subject of wing sights ... I am in the
rare minority of north american aerobatic pilots that
don't use a wing sight.

Most pilots over here hang truly enormous wing
sights on both sides, and paint them black (!!) so
people walk into them on the ramp. I think they
look like crap. Some russian and french pilots
figured out that you can put a couple pieces
of thin tape on the inside of the canopy and get
rid of all that junk out there, that really spoils
the look of the aircraft. That's what I do. Just
one like, for the vertical. The 45 isn't hard to
figger out from it, and keeps the canopy from
being too cluttered. Here's a pic, note the
vertical lines for both the front and rear seats:

[Cat Driver]

No, there are no giant vacuum cleaners in the sky.

Hedley you are missing something if you believe that.

I had one that I met in Bracebridge that would have changed your mind forever about that statement.

[BoostedNihilist]

She's gone from suck to blow!