Today's Message Index:
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1. 07:04 AM - Re: Re: !~ F.O.D. CHECK ~! (Roger Kemp)
2. 07:35 AM - Re: !~ F.O.D. CHECK ~! (Tim Gagnon)
3. 08:42 AM - Carbon Monoxide Filters (viperdoc)
4. 09:01 AM - Re: Carbon Monoxide Filters (Tim Gagnon)
5. 11:09 AM - Re: Re: Carbon Monoxide Filters (Roger Kemp)
Message 1
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| Subject: | Re: !~ F.O.D. CHECK ~! |
I found a small Phillips head (approx 3 mm) screw driver lodged next to the
control tube in my 50. When I questioned the avionics tech that installed my
radios and transponder if it was his, it was denied. Curious though. It was
not there before they worked on the plane because I had the floor panel off
chasing a sticking break cable a few days earlier.
Also found a roll of electrical tape lodged next to the tail wheel shock
absorber at the far aft bulkhead attachment point. Found it when I was
replacing the bearing in the end cap. I don't use electrical tape on
aircraft. I have not found any used in the AC either? Being black tape and
lodged below and behind the shock absorber, it was not seen on the digital
camera photo inspection of the empanage.
So much for the theory that FOD will fall out of the tail because there is a
big hole back there that the tail wheel strut sticks out of on the belly!
Anyway my point is, as is Tj's, check often and especially after someone
else has worked on your aircraft or you have had a stranger in the backseat.
I have all my pax empty their pockets before going flying anyway when I give
52 rides.
If one had been a bit more anal about cleaning out their pockets, wearing
pants/shorts with securable pockets or had worn that flight suit with
zippered pockets the below would hopefully not have been in the tail. Being
anal about checking for FOD would have turned this up before annual as a
surprise.
Not trying to start the why wear a flight suit issue here. They are not
worth a crap anyway if the zippers are left open and that gay shoulder flap
on the pin/pencil pocket has been removed anyway.
We have not lost one to FOD lately, but it sounds like we have been lucky.
Doc
During the annual, the following were removed from the tail:
Metal AA size flashlight
Metal ball point pen
several fuel receipts
and a few other small items that I can't quite recall.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=130929#130929
Message 2
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| Subject: | Re: !~ F.O.D. CHECK ~! |
Part of EVERY pre-flight should also include a personal one. Check your pockets
for loose change, keys, cell phones, pens, old chewing gum, the number of that
ugly chick from last night...her panties....you get the point.
I had interior panels made that have pockets built into them. I also bought a couple
of small zippered bags that are easily attached to one of the countless
lightening holes in the airplane. Use a small carabiner that can be had at any
Target, Walmart (the Devil)....
I also have a jug that has about $5.00 worth of change in it from emptying out
my pockets.....beer money...and something that keeps me from calling TJ and telling
him I will need a check for whats left of my airplane.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=131061#131061
Message 3
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| Subject: | Carbon Monoxide Filters |
Gentlemen:
I am in the process of developing a filter for removing carbon monoxide from
the cockpit air. I am working under license with the manufacturer of the
substrate (they hold the patent). Anyway before I sink any farther funds
into this project, I need to do a survey as to interest in this product.
The system takes ram and ambient cockpit air, passes it through the catalyst
that converts the Carbon Monoxide (CO) to Carbon Dioxide. This is farther
filtered to end up with Oxygen and Water. This system will require the wear
of an aviator's O2 mask to ensure that no ambient unfiltered air is
inspired. The CO substrate is refurbish able but the other filter substrates
have to be discarded (replaced) when the indicator turns color meaning the
converting ability of the medium has been exhausted.
The Carbon Monoxide testing I have done so far on the 52 and 50 have shown
that there is a significant problem. The average CO levels during start,
taxi and take off is on average 35 ppm (parts per million). Run up pushes
that number up to >50 ppm. I have seen numbers as high as 100 ppm,
especially on landing and at shut down. I have done all of the exhaust and
some of the cockpit seal modifications recommended. There is not a real
problem during flight. I have been seeing levels ranging from 2 to 5 ppm
during cruise. That number changes significantly during maneuvers at high
alpha. During stalls, loops, Cuban 8's ect., the number rises to around
20-30 ppm.
The levels are measured with a data logging portable professional CO
monitor from Draegar. I have measured the level at waist level, chest level,
and at nose level. With the canopy open and closed during start, taxi, run
up, TO, climb out, aerobatics, formation flight, landing, taxi, and run up
for shutdown. The problem is the worst on the ground and as already stated,
during slow or high alpha (angle of attach) flight.
I have also measured the levels outside the cockpit beginning at the wing
root, one half the way up the side of the fuselage, at the canopy rail and
at the top of the canopy during idle. I have not measured it during flight
since my probe will not stay in place! The level rises significantly as you
go from the top of the canopy down to the wing root.
As a warning, you definitely do not want to taxi the 50 with the canopy
closed or sit idling for a period of time with the it closed. I saw numbers
climbing to over 100 ppm while idling for about 10 minutes waiting for a
rain shower to pass over. I was literally sitting in a bath of CO!
OSHA (US) defines exposure as based on concentration inspired over time
exposed. PMEL is the permissible exposure limit and MEL is maximum exposure
limit. These limits are defined as the average exposure for a worker in the
environment for 8 hours a day and 40 hours per week. PMEL is set at 35 ppm
and MEL is set at 50 ppm. That is given for a worker working at 1 ATM
(atmosphere), the equivalent of sea level.
As aviators or divers for that matter, the Atmospheric pressure decreases as
we climb in altitude, as does our inspired Oxygen concentration. The problem
is that CO binds to Hb (hemoglobin) 200 times stronger than Oxygen. Where
the release time from Hb by oxygen is on the order of milliseconds, CO hangs
on for hours. So you have a relative hypoxia at altitude as compared to the
pilot that is breathing air free of CO. (As a technicality, for the divers,
the Atmospheric pressure increases as you descend in depth). The physiology
of the CO induced hypoxia is essentially the same for both the aviator and
the diver but not technically.
My question is, what is such a system worth to you? I have an estimate on
what it will cost to produce the basic system. It will be more if certain
bells and whistles are included like the aviator's 02 mask, bayonet fittings
for the mask/helmet and on board in line CO and 02 monitor (not cheap)
$ (US) 500-1000
$1000-1500
$1500-2000
$2000-2500
$2500-3000
$3000-3500
$3500-4000
I know this is an open ended question but.. I need to know if it is worth
going forward with this project.
I have a scuba system that I have designed that I currently use with the 50.
I can make available if you want to go that route. It entails using a scuba
tank that has to be refilled after each flight. That can be a bit of a pain
as well as there is the issue of increased weight.
I have investigated the cost of instillation of a diluter demand 02 system
also. The cheapest that I can get the components for that system is $3300.
Those are mil surplus that have been remanufactured. The problem with the
diluter demand system is that you are still breathing ambient air which is
contaminated with CO. I have talked to the manufacturer of the new systems
(CRU-121) as to acquisition cost for their products. They want $10000 for
their consol and it is only sold to military contractors for use in (active
duty) military aircraft. They will not sell the product to a civilian (non
DOD contractor). That system does not include any of the additional
components like, the mask, tubing, fittings, or 02 tank. Seems they want no
part of the liability that goes with dealing with the civilian world. Our
litigious societies strike again.
Thanks for your time and feed back in advance.
Doc
Message 4
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| Subject: | Re: Carbon Monoxide Filters |
Doc,
I appreciate you looking into this. I know after a long day of flying, I have
a bit of a headache.
Has anyone looked at the exhaust system and what can be done there? Extending the
pipes back a few feet or something along those lines? There are other airplanes
with similar set-ups as ours that don't have the problems we do...or they
are ignorant to it.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=131069#131069
Message 5
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| Subject: | Re: Carbon Monoxide Filters |
Craig did a lot of this on the exhaust system already. Replacing the steel
wraps on the exhaust sections is one place to begin. Sealing the oil cooler
on the inside of the fuselage. I used the firewall pad from Wag Aero. That
did not lower the CO levels in the 50 though. I think the open tail wheel
opening is a major culprit for why the levels are still up.
If you noticed, your face may be flushed at the end of 3 sorties along with
that headache. Dehydration is one reason for the headache also. As well as
that washed out feeling especially if the temperature is in the 90-100's
too.
Since I have been flying the 50 with the scuba system, I have not been
nearly as tired after a sortie. I use it for all ground ops and acro.
Otherwise the system does not have enough air for a full hour. The problem
is that it has to be refilled at the end of each sortie. I have looked at
the new spun aluminum kevalar wrapped tanks. They hold 5000 psi (roughly 1.2
hours) and are light, 39 lbs, but are expensive at ~$900. Yes you can get
used ones on ebay for less but again is on ebay because it failed it's
hydro?
Doc
-----Original Message-----
From: owner-yak-list-server@matronics.com
[mailto:owner-yak-list-server@matronics.com] On Behalf Of Tim Gagnon
Sent: Sunday, August 26, 2007 11:01 AM
Subject: Yak-List: Re: Carbon Monoxide Filters
Doc,
I appreciate you looking into this. I know after a long day of flying, I
have a bit of a headache.
Has anyone looked at the exhaust system and what can be done there?
Extending the pipes back a few feet or something along those lines? There
are other airplanes with similar set-ups as ours that don't have the
problems we do...or they are ignorant to it.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=131069#131069
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