I am not sure if this is a subject that really belongs in the maintenance forum or if I should have put it in the other forum but I'll start here. As the subject asks I am curious to ask what most people think is the best grounding point on the Comanche aircraft when refueling. In my case I have a Twin but some points will be common to singles.

In the past I've always grounded to a bolt or area of the nose gear trunnion that was bare metal. However I've just refinished my gear and really don't want to use those places anymore. I don't want to use the heater exhaust as I fear it will crack over time. I've been thinking maybe I will use a bolt head way up in the gear well or perhaps the wing tie down which does have a spot of bare metal due to use with tie-down ropes.

Any suggestions or recommendations?

Thanks,

- Charles

When I took flight instruction I was taught to use the exhaust pipe and I did that through 2 aircraft no problem. Then one day as I was refueling the Comanche a guy walked up, identified himself as with the FAA, and told me that my practice was a bad idea as it would damage the the pipe. He recommended the tie down ring and I have used it ever since.

Don

I clamp it on a nut on the steering damper. When I feel like it gets too marked up, I replace it. Easy place to get to and keeps from putting scratches on the exhaust pipe, or any surface that should be painted which my tie down rings are.

Steve

The idea behind grounding is to have absolute assurance of electrical conductivity through to the airframe in the area surrounding the fuel fillers. No part of a retractable gear is guaranteed to have perfect conductivity through to the main airframe because the electricity (static or otherwise) needs to go through at least one bushing/bearing which is (hopefully) coated with grease which itself is an insulator. I would strongly suggest "don't bother". An exhaust stack will USUALLY (but not always) give one an assurance of conductivity. And remember it is the airframe - not the engine - that one is counting on being grounded. It can be a long path through several components from the stack to the airframe. Using the tiedown ring gives one that assurance. I painted my plane a year ago and, yes, I cringed the first time a lineman put a chain through my tiedown rings but then I remembered that's what they are for. So, once again, I attach the ground clamp to a tiedown ring secure in the knowledge that I've probably got the best possible ground.
Don Ostergard ICS 3263

I also use tie down. I'm goosey about anybody touching the exhaust stacks - except on pre-flight. Actually I don't let anybody fuel except me or Ken, same for towing - at out of town airports, I walk with the tow vehicle.

Thanks for all these posts. Right now I think I'm going to start using the tie-down ring for all the reasons stated in the other posts. Currently my tie-down rings have paint missing due to use so I see no reason to not use that point (for now) and I do agree with the comment that ground connectivity is the #1 concern. Like Pat I do not leave the plane while it's being fueled. I either fuel it myself or insist on being involved and supervise what is done. I always make sure that I am the one who opens the fuel door and removes the fuel cap. It burns me when some line people will rest a cap straight on a wing - I just don't allow that and I don't hesitate to say something if things are not being done properly. Happily we have very good line folks here at HEF and I know them all well. Nevertheless the plane is NEVER fueled without my watching the process or doing it myself. I am used to this because we require it for our charter aircraft - pilot must observe fueling.

Thanks for all the responses on this topic

- Charles

Charles,

I got a WalMart white towel, cut a hole for the fuel door and put that on the wing for fueling so I can set the fuel cap on it. I used blanket binding to keep the towel from unraveling around the hole. So when it gets dirty, I just toss it in the wash. It also gives me something to use to wipe up the occasional fuel spill in the fueling area.

Fantastic idea Pat. The line guys here all use rubber fuel mats but they don't always work well with the hinged fuel door. I like your idea a lot better...

- Charles

I do the tie down ring..

I also put a drapery weight in each forward corner to help it stay on the wing ... then because it was in the winter, i accented it with the aircraft colors. That way when I do wash - it gets back to the airplane instead of in the closet.

There is a photo of it in one of the three Comanche Care articles I wrote.

I also use the Tie Down ring.

Jeff Aryan

 

Thanks, but I'd rather be flying.