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  #11  
Old 06-16-2014, 07:48 AM
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zilik zilik is offline
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Quote:
Originally Posted by scard View Post
little brain.
I think not!
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  #12  
Old 06-16-2014, 08:10 AM
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The first time I mounted the GoPro was underneath the right wing to get a glimpse of my gear legs during all flight phases. I mounted it on the inspection cover for the bellcrank. I did not notice any flight characteristic changes but then I did not test for any. WiFi control of the unit was not good in this position.

I then moved it to the left wingtip for some inflight pics/movies. First thing I noticed during the takeoff roll was the need for more right rudder. The same with all stages of flight. Stalls were normal with a slight tendency to drop the left wing first with the feet off the rudder. Using normal rudder technique stalls were a non issue.
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  #13  
Old 06-16-2014, 08:29 AM
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Greg Arehart Greg Arehart is offline
 
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Thanks for the post. When I read it this morning, I though you were joking about the change in stall speed! Very interesting to read that is was not a joke and the effect is real.

Greg
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  #14  
Old 06-16-2014, 08:40 AM
humptybump humptybump is offline
 
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Scott - thanks for the report. I've mounted a camera to my wing on a few occurrences.

You're reminder is that these things affect the performance of our aircraft. Often we have more than enough performance margin but a camera can reduce that envelope.

Imagine that vacation into a back country air strip in the mountains. Sounds like a great chance to record video. Mountain flight, short grass runways, passenger and cargo, and altitude all push the airplane toward the edges of the envelope. The camera(s) may have shrunk that same envelope.
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  #15  
Old 06-16-2014, 10:04 AM
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Flyin'Bryan Flyin'Bryan is offline
 
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Default Interesting that you should mention this scenario...

Quote:
Originally Posted by humptybump View Post
You're reminder is that these things affect the performance of our aircraft. Often we have more than enough performance margin but a camera can reduce that envelope.

Imagine that vacation into a back country air strip in the mountains. Sounds like a great chance to record video. Mountain flight, short grass runways, passenger and cargo, and altitude all push the airplane toward the edges of the envelope. The camera(s) may have shrunk that same envelope.
Just to provide some additional emphasis to your point, for many years the CAP here in Colorado has used a training video to train its search and rescue aircrews. The video was taken from a restored L-19 Bird Dog with a wing-strut-mounted video camera, that unfortunately recorded their own demise in the 1970s, after departing a mountain airport for a sight seeing trip. The crash site and the video footage from the camera were not discovered/recovered until many years later.

The resulting crash was attributed to several factors - mostly from climbing into rising terrain and getting into a position they could not safely get out of, but I never really stopped to think about the potential impact of the camera mount on the aircraft's performance, and how that may have contributed to the crash. And this occurred back in the '70s when the Go Pro was perhaps a thought in someone's imagination, so the camera equipment was most definitely larger that what we have available to us today.

Scott - thanks for posting your results, because this is real eye opener about how seemingly small the change might be, and how dramatically it may affect flight performance in different flight configurations. I too will be making some mods that will require extensive flight testing, so I find this sort of info very helpful.
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  #16  
Old 06-16-2014, 10:37 AM
g zero g zero is offline
 
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Default Go Pro

There was a Formation Aerobatic Team , the French Connection ( flew Cap 10s)
A camera was added to one of the planes wingtip and the cable duct taped to the wing going back to the fuselage, changed the stall speed/characteristics . One plane stalled before the pivot turn on a formation hammerhead and hit the other ,ending the French Connection .
Shows that small changes to the airfoil can make a big change in airflow .
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  #17  
Old 06-16-2014, 11:09 AM
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flyboy1963 flyboy1963 is offline
 
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Default not just cameras......

I often wish I had a nice video of 'someone' who has tuft tested an entire Rv.

frequently in magazines ( you know, those glossy, paper...never mind!)

you'd see someone wind yarn around the wing, run long lines of tape from root to tip, and then snip the yarn, giving nice, long, even patterns to show the flow.
I always wondered if they took into account how all the spanwise tapes altered the flow over the wing!!!

No doubt best to make very small, incremental changes when doing that type of thing, as you are truly a 'test pilot' each time!

kudos to Scott for taking note, and sharing with us 'old, not-so-bold' pilots.
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  #18  
Old 06-16-2014, 12:38 PM
rockwoodrv9 rockwoodrv9 is offline
 
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Default Vortex Videos

I found the post I was looking for. Steve M posted a link to a video showing strings as they move in flight and stalls. These two videos are very interesting and give a whole new thought process for mounting a camera or anything for that matter.

http://www.vansairforce.com/communit...ghlight=vortex

http://www.youtube.com/watch?v=qeSoO...ature=youtu.be

http://www.youtube.com/watch?v=ECTCV...ature=youtu.be

Those two videos are well worth watching if you are going to stick a camera on your wing. Maybe a fairing around the camera would help. Maybe building it into the front edge of the wing tip? It is about the same size as a landing light - mount the camera behind the lens?

Great thread - thanks Scott. This may save one of us from learning the hard way.
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  #19  
Old 06-16-2014, 12:46 PM
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Airshow pilots have been advised by various FAA personnel that any addition of cameras to the aircraft exterior must be logged and flight tested in and out of phase 1.
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  #20  
Old 06-16-2014, 04:42 PM
JSOliveira JSOliveira is offline
 
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Think of it as a spoiler, that is right where it is siting, down close to where the attached flow is for the top of the airfoil. You could probably put it on a streamlined pylon that raised it a few inches above the wing with negligible impact on aerodynamics, although the drag component would still be there. Even less impact on bottom of wing.

In any case, they should be tested exhaustively.
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