Carbon Monoxide Problems
CARBON MONOXIDE IN THE SWIFT...(5199)
Subj: Carbon monoxide
From: Jim Shosted <Jim2swift>
On a recent flight with my Swift my passenger and I thought we smelled
the scent of exhaust. We opened the fresh air vent and that took care
of it. However soon after that flight I found myself at my nearby home
improvement store where I purchased a Nighthawk battery powered digital
readout C O detector. It works great. I took it flying with me over the
weekend and found with the cabin vents closed I had 28 PPM (parts per
mill) of C O in the air. 50 PPM is max for an adult in an 8 hr period.
When we opened the fresh air vent or cabin heat vent C O returned to 0.
I was a little surprised since I have the tail wheel opening covered.
We did find some gaps in the left wheel well to put some tape on. I never
did feel good about the old C O detector disc. This unit shows you on
a LCD window. If you would like to try it out in your plane let me know.
Every pilot should know if they are being exposed to carbon monoxide.
See you around the airport. Jim2swift.
MIGRATING CARBON MONOXIDE...
Thanks for the explanation of the cylinder bushings. You seem to have
the answers so I will ask you directly: (Editor's note: That's why we
call him the "Answer Man" Steve...) I am considering installing the Temco-designed
partition/bulkhead that installs in the tailcone and is supposed to stop/reduce
carbon monoxide from coming into the tail wheel area and migrating to
the cabin. I got a tracing of the bulkhead from Joe during the National.
My question is -- how best to fasten the bulkhead to the fuselage? What
material should I fabricate it of? I have been considering thin "temperboard".
For my current annual I took out
the partition behind the seats, as well as a fabricated aluminum cover
for the area in front of the seats (C-152) and which covers the vent lines
and the emergency crank system. I have found out there are so many leak
holes in the Swift that I can't possibly plug them. Fortunately, it made
running my cables for the new strobe system easy! Now, if I can only find
a three foot "munchkin" who is willing to do A&P work, I will have
my forays in the tail cone only as bad memories (I am 6'2").
What type (make and model) of twist
fasteners were used for the original inspection ports? They have a blade
screw head and a pin which twists into a corresponding female receptacle
riveted into the wing skin. Steve Roth <email@example.com>
You can use duct tape or sheet metal screws to hold that draft seal in.
Fabricate it out of any light cardboard or hardboard. Those fasteners
are "airlocks" and I believe they have them at Swift. -- Jim
CARBON MONOXIDE PROBLEMS... (12299)
From: Jerry J. Adams <firstname.lastname@example.org>
Tested for Carbine Monozide on my 210 Swift, with a single collector exhaust,
and tested positive. It didn't take long turning dark, about 10 minutes.
I do not have a heater and think It my be coming through the tail. Is
there a boot arrangement to block access, or does the false bulkhead work
best? Does the single exhaust 210 more prone to this problem. The belly
skins really look tight.
I would suggest installation of the bulkhead seal. I do not know if the
single exhaust is more prone to this or not. (I presume this is the center
exhaust from a Cessna 336) Contact Jim Shostead at: Jim2swift@aol.com
CARBON MONOXIDE PROBLEMS AND SWIFTS...
From: Rick Stroud <Rick.Stroud@tbe.com>
Subject: Old Song-New Emphasis
I recently read an article on carbon monoxide problems in aircraft on
avweb (avweb.com) under their aeromedical heading. The article was very
detailed and reviewed a couple of carbon monoxide detectors. I purchased
the one recommended (AIM Model 935 available from Aeromedix.com, about
$79 with shipping) and found both our Swifts were pumping carbon monoxide
into the cockpit. My Swift (210 HP w/bubble) peaked at 150 PPM on takeoff
and Lana's Swift (145, mostly stock) peaked at around 45 PPM. Since I
was headed over to Jim Thomason's for annuals for the Swifts, the first
thing we did was seal the tail on both birds. That dropped the readings
to 'Lo" to 5 PPM for both birds. The following table from the article
indicates the levels and their effects.
35 PPM No obvious symptoms after
8 hours exposure
200 PPM Mild headache after 2 hours
400 PPM Headache, nausea and dizziness
after 2 hours exposure
800 PPM Headache, nausea and dizziness
after 45 minutes exposure, collapse after 2 hours exposure
1000 PPM Unconsciousness after 1
1600 PPM Unconsciousness after 30
The article indicted that there have
not been any published "tolerance level" for aircraft but that the original
OHSA regulations was 35 PPM continuous in the workplace but was subsequently
raised to 50 PPM. The author's recommendation for aircraft was 5 PPM -
worry; 10 to 20 PPM land immediately; and 35 PPM - you have an emergency.
I believe the author was a bit conservative but will readily agree that
any exposure is not good.
We also checked both our birds with
the heater on. Our heat muffs appear to be OK as the heater did not raise
the readings for either bird. Guess the case in point is that Swifts have
a known problem with airflow forward from the tail and if not sealed you
are probably getting some carbon monoxide in the cockpit. Of course, that
would be even worse if the exhaust stacks are leaking into the heat muff.
We are planning on using the detector on all of the aircraft (even other
brands!) around the home field to possibly head off problems. Now that
I really know what is in the cockpit with me, I would certainly recommend
checking the CO level in any aircraft (especially Swifts) with the heater
both on and off. -- Rick Stroud
TAILWHEEL HOLE COVER DRAWINGS...
Subj: Tailwheel cover
From: Dennis Friedrich <email@example.com>
Does anyone have any drawings etc. on how to cover the tailwheel hole?
Do they run a strip on the inside to fasten it...or the outside? I had
a cloth piece made and spent an hour under the airplane trying to decide
on just how to attach it. Am trying to make sure it is sealed tight. Thanks.
The factory installed a draft seal bulkhead made of cardboard at sta.
145.33, it was just screwed to the existing bulkhead with wood screws.
If you are closing up the hole where the shock strut and steering cables
exit, you are on your own. Look some Swifts over at a fly-in and you may
find one to give you an idea. -- Jim
COVERING THE TAILWHEEL AREA TO
KEEP THE EXHUAST OUT... (110100)
From: Larry Owen <T081763@sphn.com>
Subject: Tailwheel hole -Reply
Denis, you got me on my soapbox again (just kidding) or how I covered
my tailwheel hole story #934. This may not be what Dennis Friedrich is
looking at, but here is what I did. I sewed a three sided piece of heavy
cloth with a vinyl type covering, (the stuff you use for sofa's). Cut
to taper into a cone, with Velcro along the back seam. Sort of a upside
down, three-sided pyramid. The top "hole" is big enough to over
lap the skin by 1/2 inch. Bottom hole is just big enough for the tailwheel
to come out. Velcro closes it up. Sewed into the inside, heavy plastic
"rub guards" for the tailwheel control arms so they can not
rub on the cloth. Cut a 1/2 inch ribbon of alum from some thicker stock
(32?) and bent it into the shape of the skin hole. Sort of like a chrome
strip for you car. Paint to match. Put the cloth between the skin and
the strip. Drill small mounting holes (plan this out so not to interfere
with anything !!) and assemble. I used short flat-headed sheet metal screws
(sorry), but a better idea would be mounting nut-plates. The cover keeps
the grime off the tailwheel. The Velcro opens in the back for inspection.
The vinyl cleans easily. The color matches the swift. Never had any problems.
Larry Owen N78287