Then I focused my attention on the stall warning kit that came with my wing kit. There are electronic and fabricated aluminum parts that make up the attach bracket for this assembly, which is basically a micro switch with a flat metal vane that sticks out of the LE of the left wing at an angle such that, when the angle of the wing against the direction of flight gets too steep, the vane will move causing the microswitch to close which then sends an elecrical current to an audible warning circuit that gets piped to the audio panel, and finally to your headset. It is an early warning system designed to tell you when you about to stall the aircraft.
The only problem with installing such a devise on an aerobatic airplane such as mine is that it will be going off quite a bit as you enter different attitudes during various aerobatic maneuvers. So it basically can become more of a nuisance and distraction during aerobatic flight, and is not recommended.
The one interesting thing about this kit is that it contains a short support rib for the extreme leading edge of the wing that I may decide to use to help support that area since it is the same part of the LE that will house the fake machine gun fairings. One other thing I found interesting is that there is a slot that has to be created right on the lower portion of the leading edge of the wing for the vane to stick out into the airflow. According to the instructions, the slot is made by drilling 2 holes in an exact location determined by a drilling template, and then enlarging those holes with a number 10 drill bit, and then cutting the slit in between the two holes. This is a rather large hole, and I think it is more than large enough to fit two 16 ga. wires for the lights. More importantly, I was a little worried about drilling extra holes in the LE of the wing until I started looking at the stall warning kit.
The whole reason I started reviewing the details of this kit was that the holes are already predrilled for the mini support rib as well as the starter holes for the stall warning vane. Most builders not using this system will simply close the holes with a rivet or some other means. Those that will do alot of aerobatic flight or that will use an AOA system for stall warning indication instead of this system are the ones that typically will not use this kit. Vans provides it as a standard part of the wing kit, and it still makes a good backup system, if nothing else, so I may still assembly it and run wires for it except for installing the vane. The other reason I started looking at it is that the access panel opening has also already been cut out by the factory, and I will definitely be using this panel for access to the wiring for the machine guns and also possibly the stall warning switch assembly. Another added use will be for access to the wiring and fuel pump assembly for the extended range fuel tanks should I decide to install those later on. All of that stuff will also live in the same bay in the wing.
Now for some pics:
Here is the mounting bracket for the access panel clecoed into position in hole that is already cutout in the bottom of the left wing LE. There are two tabs on the left side that line up with holes for the rib flange on that side. Only problem is the instructions show this incorrectly, or they cut the aprt and drilled it incorrectly. Either way, the instructions and the actual alignment of the part do not jive with each other. Just another opportunity for Vans to straighten out some of their instructions I guess. Another part is just barely visible on the bottom of this pic. It is the template for drilling the holes in the LE of the wing for the support riblet and the slot for the vane. I guess they provide this template for those that may decide to add it later if they choose not to install it during the initial build, but in my case the holes and access panel are already cut and drilled, so I really did not need the template, but I am glad they provided it. The reason is that this template is made from .020 aluminum (or perhaps even thinner), and so it wraps around the the LE wing skin relatively easily. I went ahead and installed it for 2 reasons:
1. To see if the template holes lined up with the predrilled holes in the skin, which they did
2. To give me a sense for the same type of "boot" that I will be fabricating that will wrap around the top and bottom of the LE wing skin, jsut as this template does.
NExt pic shows the rest of the template as it wraps around the bottom of the LE wing skin. There are two sets if template holes - one for the RV9 and the other for the RV7 and 8. You need to be sure to use the correct hole pattern. You can just see the clecoes for the holes for the bottom of the support riblet on the bottom left side of the pic, adn the unclecoed holes for the RV9 on the right side.
Next is a side shot showing the clecoed template as it wraps around the nose. The bottom - most clecoes are for the two starter holes for the vane that sticks out into the airflow that actuates the micro switch when close to the critical angle of attack of the wing.
And finally the top side of the LE wing skin showing the last set of holes for the top of the support riblet clecoed in place. It was very easy for me to invision what the mounting bracket for the gun assembly will look like after viewing this template assembly. It will simply become a question of how many nut plates and screws to use on the top and the bottom, and how far back from the LE the mouting bracket will extend, and how wide to make it.
Here is the support riblet that mounts into the LE wing skin. The micro switch is assembled with some additional brackets, the microswitch, and mounting hardware that all comes with the kit.
And here it is clecoed into position. You can also see the two starter holes for the vane that actuates the microswitch. It's really kind of a neat setup.
And finally a couple of pics that show the template after I removed it from the LE (It was completely flat when I started):
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