AirTalk.org Aviation discussions newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  water formation/condensation in 582 carby bowls in tropics          AirTalk.org Forum Index -> Light aircraft View previous topic :: View next topic   Author Message bock Guest Posted: Fri Nov 17, 2006 7:13 am    Post subject: water formation/condensation in 582 carby bowls in tropics I fly a 582 powered Airborne trike in tropical Northern Australia. Recently I had two engine failures caused by suspected carby icing when reducing from climb to cruise power.The landings were uneventful.Weather was around 30-32 deg C and 90% rel humidity-hot and humid. I am consistently finding small drops of water in the fuel bowls even after a 30 min flight. Its not the fuel as I have tried every combination of Premium/Avgas/mineral and synthetic premix in the aircraft.The fuel is run through a water separator each time I fuelup.There is a whitish oil film forming on the slides after every flight which must be emulsified oil.There is also water forming inside the body of the carb slides. My gut feeling is that the high humidity is causing water condensation inside the carbs as the carbs are wet externally on landing. Any other tropical flyers had this experience?My next move is to fit carb heaters to the aircraft. Back to top P.D. Guest Posted: Fri Nov 17, 2006 6:32 pm    Post subject: Re: water formation/condensation in 582 carby bowls in tropi If you have water droplets in your fuel bowls, they *have* to be coming from your tank. No matter how clean the fuel is that you put in, every time you fly warm, moisture-laden air enters your tank to displace the fuel you are using. When the tank cools (eg. at night) the moisture condenses and runs down into the fuel. In these conditions you have to mount a fuel drain valve at the lowest point in the tank so that you can drain off any water in the fuel before you take off as part of your pre-flight inspection. (Same valve that is found in all GA aircraft tanks, and for the same reasons.) You can also help avoid this condition by filling the tank completely full after every flight to minimize the amount of humid air in the tank. I would have to guess that you are not experiencing carb icing at the temps you describe. Water droplets in the fuel, however, can *seriously* mess things up. Water does not flow through the jets as fuel does, and it certainly doesn't burn very well! Right now (well, almost anytime actually) I would happily trade Northern Indiana's cold, wet, windy, cloudy weather for yours! Happy flying! Peter Back to top Q Guest Posted: Fri Nov 17, 2006 11:30 pm    Post subject: Re: water formation/condensation in 582 carby bowls in tropi I respectfully disagree with Peter about water in the float bowls having to come from the fuel tank. I've observed that ice in the venturi will melt and some of it will flow down through the needle jet into the float bowl. Here in frozen Central Oregon that is a problem because that tiny bit of water freezes into a pellet and blocks the main jet at high power settings. Q P.D. wrote: Quote: If you have water droplets in your fuel bowls, they *have* to be coming from your tank. No matter how clean the fuel is that you put in, every time you fly warm, moisture-laden air enters your tank to displace the fuel you are using. When the tank cools (eg. at night) the moisture condenses and runs down into the fuel. In these conditions you have to mount a fuel drain valve at the lowest point in the tank so that you can drain off any water in the fuel before you take off as part of your pre-flight inspection. (Same valve that is found in all GA aircraft tanks, and for the same reasons.) You can also help avoid this condition by filling the tank completely full after every flight to minimize the amount of humid air in the tank. I would have to guess that you are not experiencing carb icing at the temps you describe. Water droplets in the fuel, however, can *seriously* mess things up. Water does not flow through the jets as fuel does, and it certainly doesn't burn very well! Right now (well, almost anytime actually) I would happily trade Northern Indiana's cold, wet, windy, cloudy weather for yours! Happy flying! Peter Back to top P.D. Guest Posted: Sat Nov 18, 2006 12:57 am    Post subject: Re: water formation/condensation in 582 carby bowls in tropi And I will respectfully defer to experience! I think, though, in this situation, before going to the trouble and expense of adding carb heat, I would still want to eliminate the possibility of water in the fuel with a drain valve on the tank. Icing charts would seem to indicate that you wouldn't expect a problem at 30 degrees C, and then a gradual reduction in power, not a sudden engine out. But then I've never actually had an icing situation with my 582 here in Indiana which can get bloody hot and humid in the summer and high relative humidy in the winter too. Peter Back to top bock Guest Posted: Sat Nov 18, 2006 4:13 am    Post subject: Re: water formation/condensation in 582 carby bowls in tropi P.D. wrote: Quote: If you have water droplets in your fuel bowls, they *have* to be coming from your tank. No matter how clean the fuel is that you put in, every time you fly warm, moisture-laden air enters your tank to displace the fuel you are using. When the tank cools (eg. at night) the moisture condenses and runs down into the fuel. In these conditions you have to mount a fuel drain valve at the lowest point in the tank so that you can drain off any water in the fuel before you take off as part of your pre-flight inspection. (Same valve that is found in all GA aircraft tanks, and for the same reasons.) You can also help avoid this condition by filling the tank completely full after every flight to minimize the amount of humid air in the tank. I would have to guess that you are not experiencing carb icing at the temps you describe. Water droplets in the fuel, however, can *seriously* mess things up. Water does not flow through the jets as fuel does, and it certainly doesn't burn very well! Right now (well, almost anytime actually) I would happily trade Northern Indiana's cold, wet, windy, cloudy weather for yours! Happy flying! Peter Back to top bock Guest Posted: Sat Nov 18, 2006 4:15 am    Post subject: Re: water formation/condensation in 582 carby bowls in tropi P.D. wrote: Quote: If you have water droplets in your fuel bowls, they *have* to be coming from your tank. No matter how clean the fuel is that you put in, every time you fly warm, moisture-laden air enters your tank to displace the fuel you are using. When the tank cools (eg. at night) the moisture condenses and runs down into the fuel. In these conditions you have to mount a fuel drain valve at the lowest point in the tank so that you can drain off any water in the fuel before you take off as part of your pre-flight inspection. (Same valve that is found in all GA aircraft tanks, and for the same reasons.) You can also help avoid this condition by filling the tank completely full after every flight to minimize the amount of humid air in the tank. I would have to guess that you are not experiencing carb icing at the temps you describe. Water droplets in the fuel, however, can *seriously* mess things up. Water does not flow through the jets as fuel does, and it certainly doesn't burn very well! Right now (well, almost anytime actually) I would happily trade Northern Indiana's cold, wet, windy, cloudy weather for yours! Happy flying! Peter Back to top bock Guest Posted: Sat Nov 18, 2006 4:43 am    Post subject: Re: water formation/condensation in 582 carby bowls in tropi Q wrote: Quote: I respectfully disagree with Peter about water in the float bowls having to come from the fuel tank. I've observed that ice in the venturi will melt and some of it will flow down through the needle jet into the float bowl. Here in frozen Central Oregon that is a problem because that tiny bit of water freezes into a pellet and blocks the main jet at high power settings. Q P.D. wrote: If you have water droplets in your fuel bowls, they *have* to be coming from your tank. No matter how clean the fuel is that you put in, every time you fly warm, moisture-laden air enters your tank to displace the fuel you are using. When the tank cools (eg. at night) the moisture condenses and runs down into the fuel. In these conditions you have to mount a fuel drain valve at the lowest point in the tank so that you can drain off any water in the fuel before you take off as part of your Q. Tend to agree with you.Tank and lines were drained and avgas tried and still the oily builup on the slides and water drops in bowls. I do a drain /check before every flight. (Come on PD......this is basic stuff) Until you have flown in this tropical evironment it can be hard for some to come to terms with the heat and humidity that we encounter here.......try flying through a sauna and you will no what I mean.A 2000 hour trike CFI was helping me trying to sort out the issue so no corners were cut troubleshooting this problem.I would ask PD to explain water buildup inside the slides........... Bock Quote: pre-flight inspection. (Same valve that is found in all GA aircraft tanks, and for the same reasons.) You can also help avoid this condition by filling the tank completely full after every flight to minimize the amount of humid air in the tank. I would have to guess that you are not experiencing carb icing at the temps you describe. Water droplets in the fuel, however, can *seriously* mess things up. Water does not flow through the jets as fuel does, and it certainly doesn't burn very well! Right now (well, almost anytime actually) I would happily trade Northern Indiana's cold, wet, windy, cloudy weather for yours! Happy flying! 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