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Canopy Fun

I find the prop fascinating to watch...

I assume that the frame rate on the camera is very precise, the perceived changes in the rotation of the prop must be small changes in the RPM of the engine. This must be due to the changes in the pitch of the plane.

Fun to watch and of course great music to go with it.:)

Kent
 
Nice vid, Jon. I have one question for your consideration, however. On the VAF home page, the intro for this thread stated that the aft canopy does not lift as previously thought, but is compressed.

Ignoring aerodynamic principles of high/low pressure caused by airflow and accepting your premise, how do you explain the phenomenon experienced by just about every RV-8 passenger that gobs of air flows in from that area? If the canopy aft area is actually being compressed and not lifted, it would seem that the seal should improve and that would be the least likely area for air inflow.

Got any hypotheses for us?
 
N8RV said:
Nice vid, Jon. I have one question for your consideration, however. On the VAF home page, the intro for this thread stated that the aft canopy does not lift as previously thought, but is compressed.

Ignoring aerodynamic principles of high/low pressure caused by airflow and accepting your premise, how do you explain the phenomenon experienced by just about every RV-8 passenger that gobs of air flows in from that area? If the canopy aft area is actually being compressed and not lifted, it would seem that the seal should improve and that would be the least likely area for air inflow.

Got any hypotheses for us?
Click to expand...

Don,
It makes my head hurt too much, to try to figure out why the aft canopy area, does not always seal well. I believe there are a couple of factors involved, among those are; temperature( causes the canopy to expand and contract, thus changing the aft shape slightly), and the downward pressure causing the aft area to flatten out (causing the skin to flare away from the turtledeck).
Also, using the incorrect primer during the early stages of construction of the empennage may contribute slightly to the problem.:rolleyes:
 
jthocker said:
Don,
It makes my head hurt too much, to try to figure out why the aft canopy area, does not always seal well. I believe there are a couple of factors involved, among those are; temperature( causes the canopy to expand and contract, thus changing the aft shape slightly), and the downward pressure causing the aft area to flatten out (causing the skin to flare away from the turtledeck).
Also, using the incorrect primer during the early stages of construction of the empennage may contribute slightly to the problem.:rolleyes:
Click to expand...

Fair enough. Just something to chew on.

As for the primer contribution, I've always suspected that as a root cause of some pesky issues that crop up from time to time. Thanks for reminding us all of the hazards of priming ... :D

[NOTE: For any newbies reading that and wondering, it's a JOKE. The whole primer discussion is only a red herring to divert attention away from the real culprit -- figure-eight holes.]
 
What's the deal with the flaps?

As I was watching the video the flaps were deploying and retracting. Almost like speed brakes. Does this RV-8 have manual flaps? What as the formation speed during the filming?
 
Pmerems said:
As I was watching the video the flaps were deploying and retracting. Almost like speed brakes. Does this RV-8 have manual flaps? What as the formation speed during the filming?
Click to expand...

Must be an optical illusion, flaps were deployed on final approach, never retracted til landing.
Standard formation maneuvering speed is about 130-140 knots.
 
prporter said:
That was SUPER footage. Can you shed some light on your camera/mount?
Click to expand...

Camera mount was a Mark I RV-8, with an integral 15 year old male installed in the rear seat, acting as a sub-mount. The sub mount had a fully articulating grasping apparatus that the camera was then mounted to.

The sub mount is a particularly expensive piece of equipment and not usually very dependable, but proved somewhat useful in this instance. ;)

The camera is a Kodak Zi8.
 
jthocker said:
Camera mount was a Mark I RV-8, with an integral 15 year old male installed in the rear seat, acting as a sub-mount. The sub mount had a fully articulating grasping apparatus that the camera was then mounted to.

The sub mount is a particularly expensive piece of equipment and not usually very dependable, but proved somewhat useful in this instance. ;)

The camera is a Kodak Zi8.
Click to expand...

Jon, be advised that those 15-year-old sub-mounts have an AD issued on them. An attitude adjustment is required almost daily until they reach 18 years of service. After that, maintennance costs usually skyrocket for another four years, then drop off dramatically.

In the short term, at around the 16-year mark, it's hard to keep them around -- they tend to disappear when you need them most.

Good luck with your sub-mount. :D
 
jthocker said:
Camera mount was a Mark I RV-8, with an integral 15 year old male installed in the rear seat, acting as a sub-mount. The sub mount had a fully articulating grasping apparatus that the camera was then mounted to.

The sub mount is a particularly expensive piece of equipment and not usually very dependable, but proved somewhat useful in this instance. ;)

The camera is a Kodak Zi8.
Click to expand...

What mount did you use for the landing shots? Did you attach your "sub-mount" with a bungee cord on the gear leg to get the shots under the wing? ;)
 
I assume that the frame rate on the camera is very precise, the perceived changes in the rotation of the prop must be small changes in the RPM of the engine.
Click to expand...

I think you're right Kent. I see the same thing when using an accurate variable rate strobe light on a prop. On some airplanes you can freeze the blade and it will remain pretty steady. Others go in and out of sync with the strobe and appear to rotate at a variable rate. This is done on the ground of course, and my assumption has been the steady ones are nicely in tune (mixture delivery and spark) while the others are less so.

What you don't see with a strobe is the "bending blade" illusion. I have no idea how that works.

Thocker, you're a lucky man.
 
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