Filming Aerobatics

[omcaree]

I've got a question for all the aerobatic people out there.

Beside the obvious use of making cool videos, is there any benefit to be had from filming aerobatics from inside the cockpit? If I ever get competant at flying a taildragger (struggling with a Cub at the moment :ugh:) I'm going to undergo plenty of aerobatic tuition in a Pitts with a long term aim of doing some competitions. Would I benefit by watching my mistakes on a big TV afterwards when I don't have the added pressure of flying?
Assuming it would be useful, am I best having a pilots eye view (small cam strapped to my head), or something forward looking attachted to the aircraft?
I have access to small/lightweight A/V equipment so I don't believe cockpit security would be an issue.

Thanks in advance,
Owen Mc (omcaree)

[BackPacker]

Well, if you eventually want to fly competition aerobatics, what would be most beneficial is if you can take videos somehow of the things that the jury would be interested in. Trouble is, those things are not necessarily visible from the cockpit.

Beside a couple of minor things, the jury system judges your maneuvers in two different ways: ZLA and CGT.

ZLA means Zero Lift Axis. They take an imaginary line through the cockpit (along the "zero lift axis" which is roughly the longitudinal axis) and look at that line in reference to the horizon. Essentially, all 45 degree up/down and 90 degree up/down parts of the sequence are treated as ZLA. ZLA is relatively easy to see from the cockpit: look sideways over your wing. So for ZLA bits you would need a video camera that can see the wingtip. Thoroughbred aerobatics planes have a little triangle at the end of the wingtip aligned with the ZLA axis so that it's easy to see angles.

CGT means Center-of-Gravity Track. The jury looks at an imaginary point where they think the CofG of the aircraft is (roughly between the wings) and then look at the track this point makes through space. So on a horizontal segment, the line that the CofG makes has to be horizontal. Even if the airplane is slowing down or speeding up - they don't look at the AoA but at the track the CofG makes. For horizontal lines (plus things like aileron rolls and hesitation rolls, if you have a video incorporating the altimeter you've got a fair idea on what you're doing. But for instance a loop is also a CGT maneuver and it is notoriously hard to judge from the cockpit. Especially since CGT maneuvers need to be wind corrected. The only way a video of a loop would be marginally useful is if you can see the stick position (or another way of measuring AoA) in combination with the G meter, the airspeed indicator, the altimeter, the real horizon (over the wingtip) and a timer. And it would be useful if the video wasn't mounted too tight, so that you can see the buffet from flying through your own wake as well.

So to have any benefit, I think you would need two video cameras. One would be looking sideways at and over your wingtip, the other would be somewhere near your eyes looking forward, mostly at the instruments. And you'd need a way to synchronize their streams so that you can flip back and forth between the two views, depending on the type of maneuver you're making.

I would definitely NOT attach something to my head. Apart from the blurry imagery (your head will be swiveling around a lot), any gram you add to your head will be four grams by the time you do a normal loop, and possibly even more with advanced maneuvers. Even with just a headset, if you move your head at the wrong time, during a relatively basic, low-g maneuver such as a loop initiated with 4g, you are already feeling the strain and dizzyness, especially if you haven't been training all that much.

[javelin]

Tanya & Bryan Duke's RV-6 (http://www.thedukes.org/rv/video.html)

[eharding]

50% (at least) of the essence of competition aerobatics is about where you're looking (or not looking) - hence, having an experienced aerobatic coach review what you're looking at during a sequence can be invaluable - particularly so if combined with a critique debrief. We've used various bullet camera/recorder combinations in the past, and the results have been very useful. The weight of a bullet camera mounted on the side of helmet or headset is negligable (you should see the brick of a video camera a certain Red Bull pilot used to strap to the side of his head!). You need a decent bullet camera (Helmet cameras (http://www.rfconcepts.co.uk/helmet_cameras.htm) for example), a power supply for the camera and recorder - avoid hard-disk based items as they can't cope with more than about 3G - mini DV or a good solid state recorder. Some example video from a couple of years ago in the Pitts (90 MBytes - best 'Save As...')

http://www.plus7minus5.co.uk/video/05-FEB-06/05-FEB-06-SPIN-DIVX.avi

[Flash0710]

Straighten up and fly right.....

luv

xxx

f

[eharding]

Straighten up and fly right.....

luv

xxx

f


Good point - you can go a bit overboard with the camera gadgets - the dreadful temptation is to go for a "Oooh look at me - I've got a new Gentex" video.

Larking about last September..... (http://video.google.com/videoplay?docid=-5448227753369858220)

Said Gentex, like it's owner, hasn't aged well - now very battered, and smells a bit funny.

[rtl_flyer]

Get a bullet camera and DV-500, what I have and works well.

DV500 solid state video recorder (http://www.dogcamsport.co.uk/solid-state-mp4-recorder.htm)

Tim

[Zulu Alpha]

A bullet camera and Mini Digital Video or good solid state recorder will give the best results.

However you can get quite reasonable results by using your still digital camera in video mode. You can buy a clamp on swivel mount and clamp it to a fuselage tube. Or make your own by buying two or three different size plastic armoured cable clamps from your local electrical wholesaler. This will allow you to review your flights and if you have the camera it will only cost a few £s.

The bullet camera and DV recorder will cost £300-400, the results will be DVD quality, whereas the digital camera will only be a bit better than youtube.

As Ed says its a good tool to help you review the flight afterwards.

ZA

[omcaree]

Cheers for the replies guys!

I have a couple of different bullet cams and the use of a solid state DV recorder (records onto miniSD, not sure of the quality), but will probably invest in my own recorder shortly. I agree with eharding about the head mounted bullet cam, having used them for other applications, the increase in weight is unnoticeable. So even at 6g, 6 x Nothing isn't likely to be noticeable in comparison with 6 x the weight of my head!

Having looked at the videos posted here, and various others, I am not convinced of any real training value. I will definitely be filming some flights, just because the videos look cool. But the question is, is it worth filming all flights. In the event that all goes perfectly, the video isn't needed. But in the event of a recurring mistake could it be used to diagnose the cause afterwards, without relying solely on memory (obviously more applicable to practising solo, which I won't be doing for a while!).

BackPacker,
Cheers for the detailed post. When (if!) I get into competition flying, I can see the benefit in having a ground based spotter who knows what to look for from a judging perspective, as I'm sure this is quite difficult to determine from inside the cockpit. At the moment I'm more focused on the time between becoming competent at aeros (following the required tuition) and becoming competition ready (as a beginner, initially). Obviously I will require coaching during this period to make sure I'm concentrating on the right things, but I can forsee a large amount of solo practise were identifying my mistakes may prove difficult.

Thanks to all so far, and I welcome further opinions!

[GSXR1K]

Having someone film you from the ground is probably the best option, and the one you can most benefit from, as that perspective is the one that can most easyly show any area for improvement, specialy if you are flying a pre-determined set of maneuvers (as would happen in competition).

Sometimes, specialy at the beggining in competition, you have this idea as to how it probably looked from the ground (where the judges are...) and then you watch it on screen and it´s very different (in my case, i allways seem to think i did worse, and then score acceptably).

Anyway, different angles are a plus, as you might be busy looking outside and, for example, let the airspeed drop too much (cue hammer-head followed by unvoluntary tailslide or spin) and then the whole sequence goes out the window, wich an inside camera showing the instruments would make clear.

A wing mounted camera is also good, as is a tail one looking forward.

[Elix]

omcaree,

I use three bullet cams connected to a PIP unit and SSR. I've made a nice setup for the S-2C so that I only remove the external batteries (I use 3) everytime I put her back to sleep (only because of the fire hazard).

I have one mounted on the avionics rack pointing straight up. Essentially, this one captures stick and rudder movement, with some external visual cues. I've set the PIP unit to display this as a window in the bottom right corner of the screen.

YouTube - Wheelie Landing (http://www.youtube.com/watch?v=WMWGyAGXBbc)

The other is mounted on my hat's visor, and points where I turn my head. This one takes the whole screen and switchable in-cockpit with the third.

The third has two mounting positions. One is on the canopy rail, pointing back, the other is behind me pointing toward the instrument panel. The first mounting is mainly just for fun, with some training use as it is the only one that is steady and can give an indication of accuracy and balance. The other mounting (toward instruments) I have only used for some flight tests.

The way I see it, 1 is absolutely necessary for proper debriefing, 2 (mounted in this way) are an even greater help, and 3 are only good if you care about making more elaborate films and perhaps promotional material.

Since you want to fly a Pitts, having stick movement and the pilot's POV on tape will assist greatly in everything from landings to aerobatics. You don't realize how big a push forward a Pitts will need on touchdown until you see it on tape.

You can obviously fly without cameras and the like, and I sometimes do fly with everything off, but once you get into tumbles and the weirder gyroscopic maneuvers, you'll realize you need the video to even get a sense of what happened.

As the other guys mentioned, once you get your sequences down you will care more about the judges' perspective than anything else, but I still think there's valuable insight to be drawn from in-cockpit footage.

Hope this helps.