Shock Strut Covers

[Helidesigner]

I am looking for a clean and easy way to cover the holes in the bottom of the fuselage where the shock struts attach. If people could post some pictures with a short description it would be most appreciated. I was flying with the holes open and started to smell exhaust when I was doing slow flight testing. I carried a CO detector on the next flight and found the CO level got as high as 165 PPM in the cockpit. Not dangerous for a short period but surely needs to be fixed.

Thanks,
Mark
BHQB73

[Battson]

I used fabric boots around the gear legs to try and minimise how much air can get in. They are not an aerodynamic masterpiece like Bob's self-sealing streamlined fibreglass fairings, but they do work when you're on the ground as well as in-flight. I also thought that baffle material might do the job, if you wanted a more streamlined option.



When I built the plane, my plan wasn't to make it airtight, I wanted to make a long and difficult enough "labyrinth seal" to prevent the gas flowing inside in sufficient quantity to cause a build-up. I saw that there are two levels of protection to work with, the exterior and the interior skins. I made both an airtight as possible, to work together as a system.
I designed my interior to cover all 5 sides [except the firewall] so each side has a double-skin. I sealed up the interior corners / edges with bathroom type silicon sealant, sealed the flap handle with a boot, and minimised other openings and holes where possible. I also minimised all other openings in the exterior, and sealed up the gear legs with the boots shown.

There was news of a pilot was killed by CO asphyxiation during take-off just when I started building, so I had that in mind during the build.
I've never smelt anything like exhaust in the cockpit, not even the smallest amount. I've never had a digital CO detector accurate enough to give a reading other than "OK". After 7-8 months the chemical detector hasn't reacted at all. During flight testing we placed detectors in all corners of the cabin and never found any level of indication, even for the longest flights. So that was good enough for me.

[marcusofcotton]

Mark,
​Take a look at Bear Tracks July-Sept 2006 for Bob's Engineering change specifically addressing this.

Mark J