Brief Description: IFD-440 GPS antenna mount extensioin
During my test flights I've been having problems with the IFD440 losing GPS position in turns. The antenna is mounted to the front of the firewall under the cowl. From what I've read, the fiberglass cowl shouldn't affect the signal but the bracket that I built positioned the antenna partially under the aluminum tabs for the Skybolt receptacles and I suspect that they are partially blocking the signal. To test the theory, I fabricated an extension to move the antenna forward a few inches. The extension is an aluminum "C" channel that slips over the top of the antenna bracket and bolts to the antenna hole pattern in the top of the bracket. The Antenna is then mounted to the extension in such a way that the screws in the two aft holes of the antenna fit into the two holes in the bracket that previously were used for the forward antenna screws.
I bolted the bracket, extension and antenna to the firewall, rolled the airplane out to the ramp and switched on the IFD440. After power up it acquired eight satellites which should be more than enough. With the IFD440 still on, I re-installed the upper cowl, and there was no difference in GPS signal. I need to flight test it to verify the fix but based on this test, I'm optimistic that the issue will be resolved. If so, I'll make the extension permanent by priming and painting it and possibly adding a brace at the forward end to attach it to the engine mount.
UPDATE: Flew a 1.3 hour test flight on Jan 4th and the IFD440 never lost the signal so it looks like moving the bracket forward solved the problem.
