|
Download your free copy of the award winning ForPilots LogBook program today! |
On Wed, 03 Jan 2001 17:35:56 -0600, Scrappman wrote: > Sounds more like fuel contamination with water. To close the opening of a >side draft would be tough. Not saying its not possible, just not likely. > Scrappman > I had an Austin Mini with an SU sidedraft that iced unmercifully, and a Rover 2 litre TC that did the same under the right conditions. About 40 F and highhumidity - ground fog at steady speeds. With the air cleaner snout turned down to get warm air off the manifold, no problem. >Ken Kennedy wrote: > >> Mark Smith wrote: >> >> > I have heard of it but never seen it and I still believe that our carbs, >> > slide types, are not prone to internal icing, especially with the oily >> > mess we call fuel mix. >> >> Might other factors also be vibration and heat from engine (via proximity >> and/or blowback?)? >> >> > Also, most people think it occurs when it is cold. >> >> Conventional aviation engines are certainly prone to carb ice in warm humid >> conditions, but I am convinced it never happens to our Rotaxes in similar >> conditions. >> > >> > Ill bet all manner of two stroke ills have been missed and the >> > problem attributed to carb ice. >> >> No doubt this is so. However, I am also sure I have witnessed it. >> >> The conditions were just above freezing, with about a mile or two >> visibility in fog. After maybe twenty minutes of flight, there was a >> gradual loss of power. Limped back to base where engine barely ran. >> Shutdown. Then frost appeared on outside of carbs. Removing the air cleaner >> showed ice inside the carbs. Let it sit, then ice disappeared. Dropped >> bowls and found a little water (melted in carb, then drained down thru the >> jet?). Drained water and went again. (This was foolish, of course, >> swans that had buggered off from his wing, and whom he couldnt chase down >> when the engine misbehaved). Twice more in the next hour, he had to make >> precautionary landings with the same results. For several months before >> these occurrences, the 503 had operated perfectly. During the next month on >> the actual migration, the engine also worked perfectly, altho we never >> flew in the same meteorological conditions again. >> >> Given the above, I am totally convinced that the 503 can experience carb >> icing in moist conditions near freezing. (Conditions in which, Rotax pilots >> rarely operate). Maybe Mark could do some research by making a few flights >> in similar conditions and reporting the results. This is an area where we >> could all benefit from a little research. >> >> BTW, we found the swans late that night in a nearby river, having been >> tipped off by a hiker who had seen them, then later heard our plea on the >> local radio station. >> kk |
| [BACK] | Return to the ForPilots.com archive page |