Any metal that runs parallel to the antenna can and will cause inteference or reduction in the received signal or both. It's always best to run the antenna as far away as possible from any metal pushrods... of course, within limitations.

What I often do is make a small channel right behind the wing in the wing saddle area, right in the middle of the fuselage, run the antenna up this channel and out. Then I put a little tape over that channel to keep the antenna centered and in the channel. I then run the antenna along the very bottom of the fuselage and tape it with blenderm or clear packing tape.. or even clear or matching color monocoat all the way back as far as I can get it. This will keep it centered and out of the way and, most importantly, in direct view of the transmitter for most maneuvers. I have NEVER encountered a problem running it this way.

One thing you want to make sure you do, no matter what you do or how you run the antenna. Never shorten the antenna. Use some sort of strain relief to prevent the antenna from snaking back into the fuselage. If this happens, well, what you will have on your hands is a rebuilding or repairing process on your hands. If the antenna snakes back in (caused by the inevitable vibration in any plane), it will probably bunch up right behind the receiver and will be totally useless.

I hope this helps a bit.

DS.