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CARBON MONOXIDE RISK IN SUPERSTOL

PostPosted: Fri Jun 05, 2015 1:17 pm
by Jeremy
I suggest that all Superstol owners check their carbon monoxide levels with an accurate meter. Personally I use a Sensorcon unit available on Amazon. My initial readings on my plane on climb out were between 800-1000 ppm, which are deadly after 30 minutes. It took me a couple months to fix the problem and I am still making modifications. Here is a list of the changes that I made:
1 Firewall. My plane had a rubber piece that sealed against the cowling, leaving a gaping hole between the boot cowl and the seal. Any exhaust blew past the seal ended up inside the plane. I threw out the rubber seal and sealed the firewall completely.
2 Caulking. I ran a bead of high temperature furnace caulking around the inside of the firewall (pilot side), as well as all of the holes that carried cables and wires through the firewall.
3 I welded a 12” stainless extension onto the exhaust, which releases the exhaust gas farther away from the fuselage. This was a huge help.
4 Exhaust System. I found a myriad of leaks on my exhaust headers and sockets through the use of a soapy solution sprayed on the pressurized exhaust system. Run a vacuum cleaner in reverse and route the positive air pressure up into the exhaust stack. You’ll be amazed at how leaky these systems are. Tighten down the sockets. I even used fiberglass tape and hose clamps to seal leaks.
5 I noticed a cover over the tailwheel section of another Superstol being worked on at Magnum Aviation in San Martin, CA (Steve Lamb, www.MagnumAviation.com). He fabricated this boot because the owner of the other Superstol complained about . . .you guessed it . . . exhaust in the cockpit. According to Steve, the negative pressure in the cockpit draws exhaust in from the tail. He feels that the cover solves this problem.
My recommendation is please don’t rely on your nose. Get one of these meters and monitor it during all phases of flight. Be proactive. Save a brain cell or two.

Re: CARBON MONOXIDE RISK IN SUPERSTOL

PostPosted: Sat Jun 06, 2015 8:49 pm
by User GDS
I use those stick-on indicators on my Highlander and have never had a positive indication, but would like to measure it with a good meter to confirm.

Are you located in CA? Steve Lamb's father is my hangar neighbor at L35, he told me Steve was working on a SS for somebody up in the Bay Area.

Re: CARBON MONOXIDE RISK IN SUPERSTOL

PostPosted: Sun Jun 07, 2015 7:27 am
by Johnny C!
I haven't thought about checking the CO2 levels
in Lima Charlie since I have her flying, but I
think it's a good idea, even though I haven't
had any headaches or other indicators.

Would something like this be an effective and
less expensive alternative?

Image


http://www.amazon.com/Kidde-KN-COPP-B-LPM-Battery-Operated-Monoxide-Digital/dp/B004Y6V5CI/ref=pd_sim_60_1?ie=UTF8&refRID=09YJ6WSHDYY7WTW38D7P

Thanks!

John

Re: CARBON MONOXIDE RISK IN SUPERSTOL

PostPosted: Sun Jun 07, 2015 4:48 pm
by taildrgfun
I got a good meter and found high levels of carbon monoxide in the SuperStol. It was basically all coming in around the tailwheel opening. I got it closed up good and it fixed the problem.
At very high angles of attack it can come in around the doors some too. The place to put door vents is in the bottom corner of the TOP section of Lexan.

Re: CARBON MONOXIDE RISK IN SUPERSTOL

PostPosted: Sun Jun 07, 2015 5:57 pm
by 957DK
Hi Johnny,

I used exactly the same thing when I picked up a Navion in Phoenix a few years ago. When we took off, all was fine. Once at altitude we turned on the cabin heat and immediately saw a rise in CO. We turned off the heat, cracked the canopy and the meter went back to zero. We landed in Santa Fe, New Mexico and gave the mechanic that had been maintaining this aircraft a call. Long story short, we ended up disconnecting the cabin heat and continued on to Minnesota. Did I mention it was January... Coldest damn flight I've ever been on. We ended up putting on all the survival gear we had brought along (long johns, hat, gloves, sweaters and both coats). It saved our lives that day as the exhaust had a crack that was only visible by taking the whole exhaust apart. In my opinion, it's pretty cheap insurance.

Dan Kretchmer
N957DK
Alaska mod Highlander currently in phase I

Re: CARBON MONOXIDE RISK IN SUPERSTOL

PostPosted: Sun Jun 07, 2015 8:51 pm
by Johnny C!
Dan,
I'll pick one of those up.

Thanks!

Steve,
What is this tail wheel you speak of?

John



957DK wrote:Hi Johnny,

I used exactly the same thing when I picked up a Navion in Phoenix a few years ago. When we took off, all was fine. Once at altitude we turned on the cabin heat and immediately saw a rise in CO. We turned off the heat, cracked the canopy and the meter went back to zero. We landed in Santa Fe, New Mexico and gave the mechanic that had been maintaining this aircraft a call. Long story short, we ended up disconnecting the cabin heat and continued on to Minnesota. Did I mention it was January... Coldest damn flight I've ever been on. We ended up putting on all the survival gear we had brought along (long johns, hat, gloves, sweaters and both coats). It saved our lives that day as the exhaust had a crack that was only visible by taking the whole exhaust apart. In my opinion, it's pretty cheap insurance.

Dan Kretchmer
N957DK
Alaska mod Highlander currently in phase I

Re: CARBON MONOXIDE RISK IN SUPERSTOL

PostPosted: Mon Jun 08, 2015 8:52 am
by taildrgfun
I have a Tundra Lite (jim Pekola) tailwheel which by the way is an excellent tailwheel. The big opening where the shock comes down to the tw swingarm needs to be sealed up really well. Don't be afraid to use some tape along with as good of a hard cover that you come up with. The little plate cover from the factory does not begin to keep the exhaust from sucking back in. The hole needs to be sealed up much better than that will do by itself.

Re: CARBON MONOXIDE RISK IN SUPERSTOL

PostPosted: Tue Jun 16, 2015 12:57 pm
by Jeremy
IMHO this is the best unit at the right price for any airplane: http://www.amazon.com/gp/product/B004YU ... ge_o03_s00

It has the cool feature of recording the peak CO level, which is important to know. As I mentioned, I made a number of mods to almost eliminate CO in the Superstol. It was so bad in the beginning that I couldn't safely fly the plane (800-1000 ppm). There is one simple mod that I highly recommend: a tail boot cover provided by Magnum Aviation ((408) 683-4102 Steve Lamb, [email protected]) that, as Steve Henry mentioned, keeps the exhaust from getting sucked into the tail area. You could spend a few weeks trying to figure out the right pattern for this boot . . . or you could simply order it from Magnum and it will work immediately for you. Highly recommended.

This obviously isn't something to take lightly. CO is a silent killer. The fact that you haven't experienced headaches isn't enough. Get the meter and confirm that you're safe.

Re: CARBON MONOXIDE RISK IN SUPERSTOL

PostPosted: Tue Jun 16, 2015 5:46 pm
by SheepdogRD
Jeremy wrote:... There is one simple mod that I highly recommend: a tail boot cover provided by Magnum Aviation ((408) 683-4102 Steve Lamb, [email protected]) that, as Steve Henry mentioned, keeps the exhaust from getting sucked into the tail area. You could spend a few weeks trying to figure out the right pattern for this boot . . . or you could simply order it from Magnum and it will work immediately for you. Highly recommended.

I don't see anything about the boot at http://www.magnumaviation.com. Do you have pictures of your installation, cost, etc.?