Doug G. Posted December 30, 2013 Report Share Posted December 30, 2013 Am I right in assuming then that the putty holding the filler on the wing is also conductive? I realize that if there is conductivity through to the tires static will drain from my plane as it sits. I always place my conductive plastic containers on the floor of the hangar before fueling. And make physical contact with the plane in the process of refueling. ( In case anyone gets uptight, they containers draw air from inside the wing tank to displace the fuel that comes from the container so fumes aren't vented externally.) Link to comment Share on other sites More sharing options...
Anticept Posted December 30, 2013 Report Share Posted December 30, 2013 Hi Tom, I disagree. The spars do touch especially when you apply 200 in/lbs of torque on the pin retainers. The metal rings inside the spars where the pins go through touch when tightened down. Like I said, it really won't make a difference since the whole aircraft is linked in some way shape or form. Put a power supply on the right wing fuel insert then take a reading on the other wing insert or put the power supply on the exhaust pipe and take a reading on the fuel insert. There is conductivity. I think he meant they don't touch the fuselage in any place, that's the pins doing that. Link to comment Share on other sites More sharing options...
Roger Lee Posted December 30, 2013 Report Share Posted December 30, 2013 The spars do touch each other. The metal collard inserts in the spars touch when you torque down the retainer caps on the spar pins. The entire spar length may not touch, but they do touch on the metal pin collared insert. Then the metal spar pins are in contact with the fuselage and the two alignment pins on each wing are in their metal inserts embedded in the fuselage. I think we are playing with semantics. The wings are in contact with the fuselage at some point. The basis question is there conductivity between wings, engine and fuselage. The answer is yes. Link to comment Share on other sites More sharing options...
Tom Baker Posted December 30, 2013 Report Share Posted December 30, 2013 Roger, the spars do touch each other. The main pins go in the metal bushings in the spars, but none of this touches the fuselage. You could pin the wings together on a pair of saw horses and it would be the same. There are no metal inserts in the fuselage for the main pins. The alignment pins do touch the sides of the fuselage, this is where the conductive path is. Link to comment Share on other sites More sharing options...
Ed Cesnalis Posted December 30, 2013 Report Share Posted December 30, 2013 I guess I am wondering why question if Roger has tested the plane and says he shows a full circuit. Does it matter what all the glue, bolt, washer, rubber parts, hoses, links, lines, cables, tubes, carbon fiber shell, leather in the seats, glass in the panel, rubber in the tires do if there is conductivity end to end? No. What does matter is that you can indeed put a static ground on the tailpipe and fuel the plane without concern for static discharge and fire, UNLESS, you somehow managed to goof up putting the clamp on the tailpipe. We have continuity but at what level of resistance? Is it a reliable path that exists in all CTs including mine? Link to comment Share on other sites More sharing options...
Ed Cesnalis Posted December 30, 2013 Report Share Posted December 30, 2013 I used my multi-tester and found that I do have continuity from my gas fill to my gas nozzle when my bonding cable is attached from my fuel trailer to the exhaust. I guess I have no need to contact the fill with my nozzle. I have continuity from my gas fill to my hangar frame which is my ground. The airframe does does have continuity from metal part to metal part like exhaust to wheel pant fastener but there is none to painted surfaces. If you think you are discharging just by touching the painted wing when filling from cans I don't think so. Link to comment Share on other sites More sharing options...
sandpiper Posted December 30, 2013 Report Share Posted December 30, 2013 Am I right in assuming then that the putty holding the filler on the wing is also conductive? I realize that if there is conductivity through to the tires static will drain from my plane as it sits. I always place my conductive plastic containers on the floor of the hangar before fueling. And make physical contact with the plane in the process of refueling. ( In case anyone gets uptight, they containers draw air from inside the wing tank to displace the fuel that comes from the container so fumes aren't vented externally.) Doug - are you fueling inside your hangar? I always push my plane outside. Maybe that's not really necessary and I have only seen one fire which was during a de-fueling. I don't know of any others. Wiped out the hangar and 3 airplanes. That was enough to convince me to go outside especially since my hangar is attached to my house. Link to comment Share on other sites More sharing options...
Doug G. Posted December 30, 2013 Report Share Posted December 30, 2013 Yes, I usually do, but to clarify, the possibility of spilling is extremely small since it is only when the nozzle of the "can" is in the filler that the weight of the can opens the end of the nozzle which is already inside the wing, then a tube running from the top of the nozzle ( inside the wing) draws a volume of air/fumes equal to the volume of fuel back into the can. this also eliminates the possibility of over fill since once the fuel reaches the end of the nozzle the air line is cut off and the fuel stops. I never smell fumes from refueling. I suspect there is more danger from sticking my tanks. I always fuel before I go which means the plane has been sitting at least overnight. I am not allowed to store fuel containers (full or empty) in my hangar. I do at home and refill my mower and snow blower with less safe containers. That has not been an issue for my 64 years of life. The two incidents of similar fires I am aware of involved people working on motorcycles who were smoking. Link to comment Share on other sites More sharing options...
Doug G. Posted December 30, 2013 Report Share Posted December 30, 2013 So, Andy, you and I might be a slight bit safer by making certain we touch the filler ring when we refuel, or some other metal part. Judging by the number of fueling accidents, even in the bush, this is probably much ado about nothing. Link to comment Share on other sites More sharing options...
sandpiper Posted December 30, 2013 Report Share Posted December 30, 2013 Doug - I have two of the containers you describe. They are great! Link to comment Share on other sites More sharing options...
Anticept Posted December 30, 2013 Report Share Posted December 30, 2013 The spars do touch each other. The metal collard inserts in the spars touch when you torque down the retainer caps on the spar pins. The entire spar length may not touch, but they do touch on the metal pin collared insert. Then the metal spar pins are in contact with the fuselage and the two alignment pins on each wing are in their metal inserts embedded in the fuselage. I think we are playing with semantics. The wings are in contact with the fuselage at some point. The basis question is there conductivity between wings, engine and fuselage. The answer is yes. No no, i meant the spars don't touch the fuselage. They do touch each other. It is the alignment pins that have the most relaible ground path. Link to comment Share on other sites More sharing options...
Jim Posted December 31, 2013 Report Share Posted December 31, 2013 How many ohms is it from the exhaust pipe to the filter neck, Roger? (Sorry, I missed your reply above.) This it's what I have been trying to find out. I appreciate someone having the capability to do this. I measured this years ago, and probably posted the value on the old ctflyer forum. I seem to recall it was around 100k ohms. Enough to bleed off any static charge in a few seconds. Link to comment Share on other sites More sharing options...
Doug G. Posted December 31, 2013 Report Share Posted December 31, 2013 Yeah, a bit pricey for a "gas can" but they work extremely well. Link to comment Share on other sites More sharing options...
Ed Cesnalis Posted December 31, 2013 Report Share Posted December 31, 2013 I measured this years ago, and probably posted the value on the old ctflyer forum. I seem to recall it was around 100k ohms. Enough to bleed off any static charge in a few seconds. My tester shows 1.8k ohms from filler to exhaust or even to nozzle. Link to comment Share on other sites More sharing options...
Doug G. Posted January 2, 2014 Report Share Posted January 2, 2014 Thanks CT, that (finally) answers my question. Link to comment Share on other sites More sharing options...
FastEddieB Posted January 2, 2014 Report Share Posted January 2, 2014 Data point... ...my Sky Arrow has a white plastic gas cap assembly. Hard to imagine its conductive in any significant fashion, but I will check next time I think of it. Oh, and my POH calls for grounding via the exhaust. Link to comment Share on other sites More sharing options...
mocfly Posted January 2, 2014 Report Share Posted January 2, 2014 Yeah how many! Link to comment Share on other sites More sharing options...
FastEddieB Posted January 2, 2014 Report Share Posted January 2, 2014 Yeah how many! Let's set the groundrules before I start my exhaustive count... 1) Does each individual battery in my ELT count separately? Makes a big difference. 2) Do I count the batteries in portable devices? In my headsets? 3) Is my AirGizmo mounted 496 a "portable device" once it's snapped into place? Let me know. For now, my answer has to be "a whole bunch"! Link to comment Share on other sites More sharing options...
Tom Baker Posted January 2, 2014 Report Share Posted January 2, 2014 Yeah, but how many are dual redundant? Link to comment Share on other sites More sharing options...
FlyingMonkey Posted January 2, 2014 Report Share Posted January 2, 2014 Let's do it this way...how many are REQUIRED for flight? You can count the ELT as one. Link to comment Share on other sites More sharing options...
mocfly Posted January 2, 2014 Report Share Posted January 2, 2014 Here's a question about ELT's You depart from your local airport fly an uneventful flight to your next stop which is a high density airport, taxi to your FBO shut down and while securing the plane are greeted by a FRIENDLY member of the local FSDO. He is curious about your funny looking plane and would like to educate himself about it...You show him all the goodies explain about the range, useful load etc..You pop open the baggage door and as he looks in the space he asks how you pack everything in without damage to the ELT? You explain that you are careful packing the plane...FRIENDLY response, can you demonstrate to me that it is working? Now there is a sticker clearly showing that the battery replacement isn't due for another month. Question: Do you demonstrate that it is operational? Question: What is your response? We may want to move this to a more appropriate forum.. Link to comment Share on other sites More sharing options...
Tom Baker Posted January 2, 2014 Report Share Posted January 2, 2014 Let's do it this way...how many are REQUIRED for flight? You can count the ELT as one. Day or night? Link to comment Share on other sites More sharing options...
S3flyer Posted January 2, 2014 Report Share Posted January 2, 2014 Question: Do you demonstrate that it is operational? Heck no! ][/color]Question: What is your response? I'd say that the ELT is tested annually in accordance with 91.207d and leave it at that. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted January 2, 2014 Report Share Posted January 2, 2014 Day or night? Do you have extra "night only" batteries?? Link to comment Share on other sites More sharing options...
Tom Baker Posted January 3, 2014 Report Share Posted January 3, 2014 Do you have extra "night only" batteries?? Not all Dynons have the back up battery, my first CT set up just like yours didn't. The battery is required if you are going to fly at night per ASTM, or at least that is my understanding. Link to comment Share on other sites More sharing options...
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