Aaronp07 Posted May 21, 2020 Report Share Posted May 21, 2020 On 05-19-20, I completed a landing at my home airport after spending approximately 1.5 hours on a local flight doing full stop landings at various nearby airports in my 2009 Flight Design CTLS. After landing and turning onto the taxiway from the runway, I immediately saw a large amount of gray/white smoke billowing out of the front of my flight deck where the EFIS is located. I immediately shut the aircraft and all power down. After exiting the aircraft and gaining some distance (in a very quick manner) in case of a fire, I saw that the aircraft was not on fire at that time, and safe to approach. I examined the aircraft, but could not see any fire at that time in the darkness on the taxiway. After moving the plane back to my hanger, I removed the front top cowling as well as the passenger side EFIS in order to access the area where the smoke was coming from. I saw that the round hole where numerous wires entered the cockpit from the engine side of the firewall was charred black on both the inside and outside of the firewall. Upon examining this area, I saw that the wires had obviously rubbed the composite over time on the bottom side of the hole, and worn the wire sheathing out exposing the inside of the wires. The wires then shorted out, causing the smoke and igniting the composite on fire, causing the heavy charring. The wires in the aircraft were run through the firewall this way when I purchased it, as I have not manipulated or changed these wires in any way since I purchased the aircraft. I purchased the aircraft from a private seller in March of 2019. The fire sleeve on the wires stopped on the engine side of the firewall, and did not go though the hole in the fire wall to protect the wires. There also was no type of fire sleeve over the wires on the inside cockpit area of the firewall. I do not know the full extent of the electrical damage at this time, as I have not powered the aircraft back up after the shutdown on the taxiway when I first saw the large amount of smoke. I have also disconnected the battery. I am awaiting an avionics shop to take a look at it as soon as they are able to fit me in their schedule. I do know that at a minimum numerous wires will have to be replaced. I wanted to make everyone aware of this safety of flight issue so others can avoid the issue that I had. I was lucky that this smoke/fire occurred on the ground after landing, and not up at 10,000 feet. Also, I notified Flight Design USA this morning. They were very helpful, as usual. I have attached some photographs that I took below. Quote Link to comment Share on other sites More sharing options...
AGLyme Posted May 21, 2020 Report Share Posted May 21, 2020 Firstly, glad you are safe. Glad it happened on the ground. There was a recent AD from Flight Design re this very thing. I bought special tape from Aircraft Spruce and complied with the AD preventing wire abrasion against the composite wall. My fix was inspected and approved by FD USA. Evidently a similar event occurred and FD notified the fleet. Quote Link to comment Share on other sites More sharing options...
Aaronp07 Posted May 21, 2020 Author Report Share Posted May 21, 2020 Do you have any idea of the SB # for this that you mentioned? When I called FD today they did not mention that. I did provide them with a similar write up to this and the pics. Thanks in advance! Quote Link to comment Share on other sites More sharing options...
Aaronp07 Posted May 21, 2020 Author Report Share Posted May 21, 2020 I went to FD's website and just found the SB you mentioned. It is SB-ASTM-CTLS-17. I have attached a photo of it below. The SB only list a small # of the newer CTLS that have the newer metal ring in between the firewall. That must have been why I did not see it, as my aircraft was not affected per the SN's listed in the SB. Well it appears that the wire chaffing and short can still happen, even in our older mofel CT's without the metal ring. I bet a new SB will come out from FD addressing this now that they have been notified. Quote Link to comment Share on other sites More sharing options...
Mike Koerner Posted May 21, 2020 Report Share Posted May 21, 2020 Similar incident: 2004 CT2k. 2 am. Belen Airport, New Mexico. Returning from a trip to New York with my wife. Got her out of a warm motel bed with promise of a pleasant flight on calm, clear night. Or maybe it was the thought of getting home quicker? Either way, it was a big deal. Taxing for takeoff. Smell burning paper or an electrical fire. Shutdown and get out quick. Sniff all around. No fire. smell is gone. Convince my wife we didn't smell fire. Get back in a start up again. Run the engine and avionics on the ground for a good long while. No smell. Start to taxi for takeoff. Smell fire. Park the plane. Spend the rest of the night in the airport lobby. Look over the plane carefully in the morning. See no evidence of a fire and no smell during subsequent startup, taxi, takeoff and flight home. Later find that the landing light wire has rubbed on the unprotected edge of hole in the carbon fiber fire wall where the wire bundle passes through. Bare wire strands, burnt wire insulation and burnt edges of the hole. Replaced the landing light wire. Added a plastic wrap around the wire bundle. Squirted some silicon rubber around the edges of the hole. Posted incident to CT forum on Aug 24, 2017. Was told the wires should have been protected in a fire sleeve or flexible plastic tube. Don't know what happened. No further problem. The above Service Bulletin does not apply to my aircraft and I do not have the metal sleeve through the hole as it depicts. Mike Koerner Quote Link to comment Share on other sites More sharing options...
AGLyme Posted May 21, 2020 Report Share Posted May 21, 2020 I do have the metal sleeve. However while performing the preventative fix in the designated area, I decided to check the whole plane for other potential problem areas. I found another area in the baggage compartment where a wire bundle passed through the carbon layer without protection. I wrapped the wires with the "tape" specified in the AD. Metal sleeve or not, I think everyone with a CT or any other carbon plane should trace wire bundles and see if there are any sharp carbon edges that could potentially compromise the wire(s). I am flying today, I will take photos of the AD fix and my own fix and share. Quote Link to comment Share on other sites More sharing options...
GrassStripFlyBoy Posted May 21, 2020 Report Share Posted May 21, 2020 14 minutes ago, AGLyme said: However while performing the preventative fix in the designated area, I decided to check the whole plane for other potential problem areas. That is exactly what I thought, trace everything, and I'd also recommend taking a peek at pitot / static lines as I recently discovered one static line running to the mode C box having a rub & wear spot touching something at one time in it's past. It was almost to point of being a hole. My landing light wires are not factory, and I've not been happy with how someone ran them, more esthetic than concern but will take closer eye there. Good info Mike. When I did my panel project I was methodical to run new wires within existing bundles and such, and for the new wires to EFIS on pilot side I encased everything spiral wrap. The lower center panel was possible to have the wires not repackage in manner that did not "loop" correctly, with them being sort of bunched and close to touching the fuel shut off lever and rod, keep an eye on that area also. Quote Link to comment Share on other sites More sharing options...
GrassStripFlyBoy Posted May 26, 2020 Report Share Posted May 26, 2020 Looks like the site is back up! Was wondering if I broke the internet or something... Quote Link to comment Share on other sites More sharing options...
AGLyme Posted May 26, 2020 Report Share Posted May 26, 2020 As promised, here are photos of the latest AD applying to my CTLSi model... and others... it’s a simple procedure... apply silicon tape to the principal wire bundle going through the firewall to prevent eventual abrasion and wire shorting. While I was at it I reviewed other areas and found another bundle in the baggage compartment. I would suggest based on comments above that anyone with a CT review same. Quote Link to comment Share on other sites More sharing options...
AGLyme Posted May 26, 2020 Report Share Posted May 26, 2020 Aaron and Mike K thx for your stories... makes this precautionary stuff all real. Quote Link to comment Share on other sites More sharing options...
Aaronp07 Posted May 26, 2020 Author Report Share Posted May 26, 2020 I thought you broke ctflier.con to, lol. I was wondering what was going on with the site. My CTLS is currently in my avionics repair shop. He is having to trace and replace each individual wire that was frayed or burned. He also had to order some new connectors, which will not be in until next week. Thanks for sharing your stories. We shall see how much this is going to cost me. I still have not heard anything back from Flight Design as of today. Like I said before though, at least it occured right after landing instead of up in the air. Quote Link to comment Share on other sites More sharing options...
FlyingMonkey Posted May 28, 2020 Report Share Posted May 28, 2020 My CTSW just had the "bare hole" in the firewall when I got it. As soon as I noticed it I put a piece of fire sleeve around the wire bundle where it passed through, and then sealed the sleeve to the firewall with high temp RTV. It's been good to go that way for six years. I didn't know about silicone tape back then, I have used that since for a lot of things and I'd use the tape + RTV if I was doing it today. I like using the RTV as it fixes the tape/sleeve to the firewall so vibration can't cause the sharp edge of the firewall hole to wear through it. Quote Link to comment Share on other sites More sharing options...
Garrett Gee Posted September 1, 2020 Report Share Posted September 1, 2020 During the Condition Inspection today, we decided to look at this on my CTLS as well, even though the SB does not apply to my S/N. While the wires in question are covered in fire sleeve, the fire sleeve had evidently "slipped" down the wire bundle and was not actually protecting the wires. Only a tiny section at the top of the bundle was actually protected. As others have said, check your CT even if it doesn't fall in the serial number range. Quote Link to comment Share on other sites More sharing options...
johnr Posted September 17, 2020 Report Share Posted September 17, 2020 G'day All. It may not be general knowledge but carbon fibre will conduct power & is flammable. If there is sufficient amperage the resistance will cause combustion. Most earths are connected to the firewall. It would be an advantage if the carbon fibre firewall was not connected to earth, I am not sure how that could be achieved but if it could, it would give an extra layer of protection. A short between + & -- cable would normally trip a circuit breaker. The short between a live wire & the carbon fibre firewall can very quickly cause a fire with a current less than the trip value of a circuit breaker. John WA Quote Link to comment Share on other sites More sharing options...
Skunkworks85 Posted September 18, 2020 Report Share Posted September 18, 2020 On 9/17/2020 at 5:09 AM, johnr said: G'day All. It may not be general knowledge but carbon fibre will conduct power & is flammable. Just the clarify, the carbon fiber matrix that is suspended in a resin is not flammable. However it is conductive. The resin is the flammable part.. Quote Link to comment Share on other sites More sharing options...
Mike Koerner Posted September 19, 2020 Report Share Posted September 19, 2020 John, Skunk, This is good thinking. My sailplane is carbon fiber. The structure is not grounded. The battery ground is brought out to an insulated terminal strip which is mounted to the structure. The instruments are grounded to the terminal strip. This seems like a better approach. Mike Koerner Quote Link to comment Share on other sites More sharing options...
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