Yesterday I did some work on my plane. I got and inner tube and cut gap seals for the landing gear legs. I put those in and stuffed 2 holes in the belly near each door post with foam insulation. I also added some felt to an opening in the back part of the engine baffle.
This made some inprovement.
Cruise is down to 5 (was at 7 - 9) acceptable is 9 or below.
TO is now down to 48 (was up to 55)
Landing and taxi in was also lower.
Other ideas I have.
Gap seal the strut connection to the fueslage.
Extend the exhaust tubes some inches. (maybe 4)
Seal with foam insulation the gas line that comes from the cabin.
I looked at the new Cessna's and they have a full seal at the strut connections.
Any other good ideas to get the tempory high values down?
Tom Arsenault
N4163V
CO in the cockpit
Moderators: GAHorn, Karl Towle, Bruce Fenstermacher
I'd avoid the use of foam as an insulation material because it will absorb water and promote corrosion. I'd suggest either neoprene gasket material (available from Spruce and local hardware stores) or silicone engine baffle material, also available from Spruce. Cutting a gasket for the landing gear leg seal (if yours is damaged/missing) and making one for the lower strut attach similar to later 172's shouldn't be hard. Keep in mind also exhaust gases may enter the tailcone area and travel forward to the cabin. I spent a lot of time tracing that source down in a 182 once. the cure was to install a missing bulkhead above the hat shelf. (I fabricated a bulkhead for above/aft of my baggage shelf, and soundproof insulated it on it's backside. It made a big difference in perceived noise for my rear passengers, especially when taxiing. Previously without headsets on, we could all hear oil-canning and cable-slapping when taxiing on rough terrain and whenever the tailwheel crossed over a tar-strip on paved taxiways. That tailcone makes quite a sound-tube!)
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David Laseter
- Posts: 156
- Joined: Sun Oct 13, 2002 11:24 am
We arrived at the Airport at Ft Nelson early, trying to get a jump on the weather. It was cold. We started the plane, tail still tied down and Traci wanted to sit in the plane while it warmed up, to fiddle with the GPS. She knows how to use the breaks!
I went in and filed a flight plan. Then untied the tail, jumped in, and saw the CO detector was Black. NO odor or anything!
I've rarely warmed the plane up without me in it and cabin heat off probably, never thought about it. I immediately opened all the windows to ventilate and closed the cabin heat and the louver down by the rudder pedals. The dot started turning back proper color. We decided that I had just learned a new No/No. We took off and 10 mins later it was back to original color. Course we were freezing and opened the cabin heat again and never had anymore problems. From then on I closed the cabin heat before landing. Am I thinking straight or did the CO get to me?
Dave
I went in and filed a flight plan. Then untied the tail, jumped in, and saw the CO detector was Black. NO odor or anything!
I've rarely warmed the plane up without me in it and cabin heat off probably, never thought about it. I immediately opened all the windows to ventilate and closed the cabin heat and the louver down by the rudder pedals. The dot started turning back proper color. We decided that I had just learned a new No/No. We took off and 10 mins later it was back to original color. Course we were freezing and opened the cabin heat again and never had anymore problems. From then on I closed the cabin heat before landing. Am I thinking straight or did the CO get to me?
Dave
Last edited by David Laseter on Sun Dec 15, 2002 2:29 pm, edited 1 time in total.
You could have simply experienced exhaust gases surrounding the cabin at low idle sitting at the chocks entering the cabin.
BUT-you could also have an exhaust leak in your cabin heat system that inflight is diluted with fresh air also entering the cabin. I'd suggest you inspect your exhausts and heater-muffs for cracks and leaks. Also try to seal up your exhaust riser clamps which notoriously dump exhaust into the aft cowl ....exactly where your heat mixing valve is allowing air to enter the cabin. When not in flight, there's no ram air to encourage that exhaust clamp-leak to discharge out the bottom cowl, so a CO-enriched firewall area results. Without the ram-air entering the heater muff (and also not pressurising the heater mixing valve discharge duct) and forcing on thru the heat system, that CO-enriched air can more easily enter the heat mixing valve and into the cabin. (It's a lousy location and design for a heat mixing valve, but Cessna didn't change it until well into the 172 line. It's also a lousy design for exhaust riser clamps but that also wasn't changed for the entire Cont. engine production.)
CO poisioning takes much longer than while "on final" to clear out of your body. CO binds with the hemoglobin in your blood and it takes almost 3 times as long to clear out as it did to enter your bloodstream, and even then is only completely cleared out when on 100% oxygen.
The little paper "dot"-style CO detectors perform so poorly that they are worthless in an airplane. If yours showed CO then the actual concentration was very high indeed. Too high! Also the paper detectors have a 2-3 month life, once opened.
The best CO-detectors are the ones specifically designed for aircraft, or made in Canada, because the US-made ones available down at WalMart have warning thresholds set too high for aircraft use. (Fire dept's got tired of false house-hold alarms so they lobbied for raising the alarm-levels of the detectors. The Canadians are more realistic, probably because they have more occurence of kerosene-fired cabins/homes etc.)
BUT-you could also have an exhaust leak in your cabin heat system that inflight is diluted with fresh air also entering the cabin. I'd suggest you inspect your exhausts and heater-muffs for cracks and leaks. Also try to seal up your exhaust riser clamps which notoriously dump exhaust into the aft cowl ....exactly where your heat mixing valve is allowing air to enter the cabin. When not in flight, there's no ram air to encourage that exhaust clamp-leak to discharge out the bottom cowl, so a CO-enriched firewall area results. Without the ram-air entering the heater muff (and also not pressurising the heater mixing valve discharge duct) and forcing on thru the heat system, that CO-enriched air can more easily enter the heat mixing valve and into the cabin. (It's a lousy location and design for a heat mixing valve, but Cessna didn't change it until well into the 172 line. It's also a lousy design for exhaust riser clamps but that also wasn't changed for the entire Cont. engine production.)
CO poisioning takes much longer than while "on final" to clear out of your body. CO binds with the hemoglobin in your blood and it takes almost 3 times as long to clear out as it did to enter your bloodstream, and even then is only completely cleared out when on 100% oxygen.
The little paper "dot"-style CO detectors perform so poorly that they are worthless in an airplane. If yours showed CO then the actual concentration was very high indeed. Too high! Also the paper detectors have a 2-3 month life, once opened.
The best CO-detectors are the ones specifically designed for aircraft, or made in Canada, because the US-made ones available down at WalMart have warning thresholds set too high for aircraft use. (Fire dept's got tired of false house-hold alarms so they lobbied for raising the alarm-levels of the detectors. The Canadians are more realistic, probably because they have more occurence of kerosene-fired cabins/homes etc.)
Dave, CO gas has no odor. Now and then you can get an "exhaust" smell, I get it now and then when I pull the carb heat at lower RPM's and rich mixture, with the heat on. CO is certainly present with the exhaust gases, but can be there without the smell. CO gets into the bloodstream and takes a very long time to be "filtered" out of your system. You should get your exhaust system inspected and review the symptoms of CO poisoning. If you are flying with someone else, use the buddy system as you would for frost bite; look for slurred speach, light headedness, slow reactions, etc. If flying long legs alone, keep active reviewing track, ETA, instruments, emergency lists (whatever routines work for you) and if you find you can't perform those tasks, land as soon as practical. I plug in the CD player on long VFR trips, but still keep up my routines and monitor enroute frequencies when not on radar following, which is not as good here as in the US. On IFR, there is more interaction with the outside and someone would notice if you can't repeat or keep on track. JD
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David Laseter
- Posts: 156
- Joined: Sun Oct 13, 2002 11:24 am
Very good info..
That's some very good information about CO to have posted here.
I deal with diff gases, H2S, & CO, here at work. At least we go through training a lot. I have to use monitors and check LEL's and etc.. Enough to where I'm very concerned about this CO in my plane. Being a rookie with these planes, I've just thought of them like cars - Don't stand by the exhaust pipes.
OR be necking for a long time with the engine running.
Alright then, I've got to get the right monitor ($ N/A) ASAP!
I pay extra for the best mechanics, but I'm not sure how detailed they've been checking the exhaust and heater muffs for leaks. I've never heard of this vacuum technique.
Now that we've moved to Ark, I'll need a new mechanic,
Any recommendations on a mechanic that really knows these 170's and to check out all these things that I'm learning about? Preferrably in the South.
Dave
I deal with diff gases, H2S, & CO, here at work. At least we go through training a lot. I have to use monitors and check LEL's and etc.. Enough to where I'm very concerned about this CO in my plane. Being a rookie with these planes, I've just thought of them like cars - Don't stand by the exhaust pipes.
OR be necking for a long time with the engine running.Alright then, I've got to get the right monitor ($ N/A) ASAP!
I pay extra for the best mechanics, but I'm not sure how detailed they've been checking the exhaust and heater muffs for leaks. I've never heard of this vacuum technique.
Now that we've moved to Ark, I'll need a new mechanic,
Any recommendations on a mechanic that really knows these 170's and to check out all these things that I'm learning about? Preferrably in the South.
Dave
Last edited by David Laseter on Sun Dec 15, 2002 2:28 pm, edited 1 time in total.
All this talk of CO has me a bit worried 
I fly a lot with my 2 year old girl in a car seat secured to the rear seat. She does like to take long naps and sleep deeply. Now that heater season is here, I find myself scared to let her sleep too long. I may feel fine, but is she sleeping deeply because she is tired, or is her little body already overcome with CO? Last extended flight we took was the aborted attempt to get over the Appalachians without ample ceilings. 2.4 hours and she slept a great deal of that time, sometimes so deeply that I could not wake her by yelling and popping her on her legs. I panicked and turned the heater off, directed cold air from the wing root on her, and she eventually moved her fingers and woke up. WHEW! Are there guide lines concerning outward physical appearance when CO is present in a person and dangerous levels? Blue lips, etc? Especially important when the little person can't tell you exactly how they are feeling.
I just bought the $49 CO detector from Sporty's that uses a 9 volt battery for power up to one year. I have not had a chance to test it in the plane yet. Wonder if this unit is good enough? Now I see panel and remote mount models in TAP. Any advice?
I fly a lot with my 2 year old girl in a car seat secured to the rear seat. She does like to take long naps and sleep deeply. Now that heater season is here, I find myself scared to let her sleep too long. I may feel fine, but is she sleeping deeply because she is tired, or is her little body already overcome with CO? Last extended flight we took was the aborted attempt to get over the Appalachians without ample ceilings. 2.4 hours and she slept a great deal of that time, sometimes so deeply that I could not wake her by yelling and popping her on her legs. I panicked and turned the heater off, directed cold air from the wing root on her, and she eventually moved her fingers and woke up. WHEW! Are there guide lines concerning outward physical appearance when CO is present in a person and dangerous levels? Blue lips, etc? Especially important when the little person can't tell you exactly how they are feeling.I just bought the $49 CO detector from Sporty's that uses a 9 volt battery for power up to one year. I have not had a chance to test it in the plane yet. Wonder if this unit is good enough? Now I see panel and remote mount models in TAP. Any advice?
John, 2734C in Summit Point, WV
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David Laseter
- Posts: 156
- Joined: Sun Oct 13, 2002 11:24 am
Book Report
Talked with our Medic and researched CO in one of his HUGE Medical Books. As usual everything written in these post are pretty much, right on the money.
CO being a clear gas, odorless, with a density of 0.97 that of air.
CO does actually have a lavender odor at extremely high concentrations.
Like was stated, CO competes with Oxygen (O2) for binding sites in your hemoglobin. CO bonds at 210 to 280 times more tenaciously as O2. After CO exposure 100% O2 is administered to try and get the CO to release from the hemoglobin, so O2 can be carried.
Mild CO toxicity - Weakness, Nausea, Dizziness, Headache, Impaired Judgement.
The Medic is an advocate of routine Carboxyhemoglobin Testing. He says that anytime there is an incident with unknown variables, the Carboxyhemoglobin Test should be given. He said it is quick and easy!
Of course the sooner the test is given after CO exposure, the better.
Wa4jr - CO intoxication is especially harsh on the very young and very old. He didn't seem too concerned about you're situation at this point, but cautioned me not to say that a medical person said, not to worry. He said, if you want peace of mind then go get the Carboxyhemoglobin Test or call your Pediatrician. How's your new CO Detector working?
The Medic suggested that planes should have audible alarm detectors because of the judgement impairment symptom. We might not comprehend the readings correctly.
What gahorn said about "the best CO detectors are the ones specifically designed for aircraft" makes sense to me.
Wish we could get some suggestions on which CO Detectors to buy
AIM, model 935, Hand Held, life 3 yrs, ~ $70.
Sporty's CO Detector - $49, 9 volt battery last 1 yr..
CO being a clear gas, odorless, with a density of 0.97 that of air.
CO does actually have a lavender odor at extremely high concentrations.
Like was stated, CO competes with Oxygen (O2) for binding sites in your hemoglobin. CO bonds at 210 to 280 times more tenaciously as O2. After CO exposure 100% O2 is administered to try and get the CO to release from the hemoglobin, so O2 can be carried.
Mild CO toxicity - Weakness, Nausea, Dizziness, Headache, Impaired Judgement.
The Medic is an advocate of routine Carboxyhemoglobin Testing. He says that anytime there is an incident with unknown variables, the Carboxyhemoglobin Test should be given. He said it is quick and easy!
Of course the sooner the test is given after CO exposure, the better.
Wa4jr - CO intoxication is especially harsh on the very young and very old. He didn't seem too concerned about you're situation at this point, but cautioned me not to say that a medical person said, not to worry. He said, if you want peace of mind then go get the Carboxyhemoglobin Test or call your Pediatrician. How's your new CO Detector working?
The Medic suggested that planes should have audible alarm detectors because of the judgement impairment symptom. We might not comprehend the readings correctly.
What gahorn said about "the best CO detectors are the ones specifically designed for aircraft" makes sense to me.
Wish we could get some suggestions on which CO Detectors to buy
AIM, model 935, Hand Held, life 3 yrs, ~ $70. Sporty's CO Detector - $49, 9 volt battery last 1 yr..-
Thomas Arsenault
- Posts: 29
- Joined: Fri May 03, 2002 11:51 am
CO monitor
I have the AIM 935 meter. After putting in all the gap seals around the wing struts and landing gear openings, sealing around the gas line, pluging the 2 holes behind the gas line entry, closing off the air intake ports for the winter, I now have my maxium CO during taxi/TO down to 21 - 23. Cruise now goes into the low reading (4 or under). While doing the commerical manuvers with my instructor the readings would go up.
This meter has a warning beep and I would recomend it.
Tom Arsenault
N4163V
This meter has a warning beep and I would recomend it.
Tom Arsenault
N4163V
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David Laseter
- Posts: 156
- Joined: Sun Oct 13, 2002 11:24 am
CO Detectors
The Hand Held could be used around the house, vehicle, etc., as well!Dave
I still have not had a chance to fly with my Sporty's $49 CO detector yet. Seems all the rain from the Texas and Louisiana rain forest region has moved up here trying to turn the Shenandoah Valley into a rain forest.
No, my little girl is not the nail polish type at 2 years old
Am I to assume that the pink color is an indication of a normal condition? Or will her nail color change to some other color with CO in her bloodstream?
Concerning the folks who are making seals for the landing gear and strut entrances...how about just using a nice heathy bead of clear silicone sealer? I was about ready to take the caulk gun out to the airport, but will wait lest everyone else knows some reason I should not seal my gaps with silicone sealer
No, my little girl is not the nail polish type at 2 years old
Am I to assume that the pink color is an indication of a normal condition? Or will her nail color change to some other color with CO in her bloodstream?Concerning the folks who are making seals for the landing gear and strut entrances...how about just using a nice heathy bead of clear silicone sealer? I was about ready to take the caulk gun out to the airport, but will wait lest everyone else knows some reason I should not seal my gaps with silicone sealer
John, 2734C in Summit Point, WV
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Thomas Arsenault
- Posts: 29
- Joined: Fri May 03, 2002 11:51 am
AIM meter and gap seals
For Bob (Flyer170) Most of the info is in these posts. Aim 935, cost about $70, works for about 3 years, very sensitive, self contained and portable. I put the address in previous posts.
John (w4jr) Silicone sounds great. Why didn't I think of that. We should check with George Horn to see if there are problems using silicone. Silicone plugs that could be pulled out later would be great.
Tom Arsenault
N4163V
John (w4jr) Silicone sounds great. Why didn't I think of that. We should check with George Horn to see if there are problems using silicone. Silicone plugs that could be pulled out later would be great.
Tom Arsenault
N4163V