Garfly Posted August 18, 2021 Posted August 18, 2021 (edited) This video report is interesting for its mechanical insights but the footage of the accident itself is one of the best illustrations yet of that hard-to-resist instinct to pull-back to escape the ground rising to smite us. Note to self: a). Don't pull back! b). Go practise the big push with instructor! Note to pilot in video: thanks for making your mistake openly available for the rest of us to learn from. Also, there's much useful discussion in the YT comments. I thought this one on coolant systems in general seemed helpful: texasfly99 2 years ago First of all I would like to thank the fine folks at Rainbow Aviation for this very informative video. I would like to add some general knowledge to this thread in order to promote knowledge among all aviators. It really bothered me when the cooling system expansion tank was pointed out and the way it was installed. Clearly whoever had installed this cooling system did not have an idea at all about how a cooling system is supposed to work. The coolant recovery line that was improperly added at the top of the expansion tank was one of the causes of loss of coolant in the entire system. It is basically a brick at this point! The proper method of installing the recovery/overflow line is to go into the bottom of the tank. Is this video, it clearly shows that the outlet, the small nipple at the bottom of the tank, was plugged up. Completely wrong!! Now, if the line that was added at the top would have had a piece of tubing or piping that went to the bottom of the tank internally, it would've probably worked correctly. But all they had to do was hook it up to the already provided outlet nipple! In a liquid cooled engine, water needs to be surrounding every square inch of 'wetted' areas (cooling jackets around cylinders, water pump, hoses, and radiator) from bottom to top, with no air pockets. The water is what absorbs the heat. Now, as the engine heats up, the water expands...it also builds up a bit of pressure. The liquid flows right into the overflow/expansion tank. The radiator cap is spring loaded and is supposed to open when the pressure gets too high. Most systems are supposed to operate at about 4 or 5 pounds of pressure. This is only half, though, of what is supposed to happen. When the engine is shut down, everything cools off. The water condenses, taking up less space in the wetted areas previously mentioned. The net effect of this cooling down, is a pressure drop in the engine block area. A vacuum is actually created on the waterside of the block. Coolant can then flow FROM the overflow/ expansion tank back INTO the engine block!! The waterside should stay as sealed up as much as possible to allow the physics to work properly! The coolant level in the exp. tank should fluctuate as the system heats and cools. The expansion tank must be able to vent properly in order for the whole system to function correctly. There should be no leaks (as shown also in the video) in any hoses, pump, radiator, block etc. Air is the enemy in a sealed system!! Only the expansion tank should have air in and out of it! Your car cooling system works the same way! I hope this helps everyone!! Edited August 18, 2021 by Garfly 4
RFguy Posted August 21, 2021 Posted August 21, 2021 Really great that they spent the time to fully document and teach and educate. (putting aside company marketing benefit) . It's quite a good watch. Poor engine.
APenNameAndThatA Posted August 21, 2021 Posted August 21, 2021 This video illustrated why it annoys me that the first thing that pilots are taught is that if you pull back on the stick, the aircraft climbs. The things people learn first tend to stick.
Garfly Posted August 21, 2021 Author Posted August 21, 2021 TECHNIQUE: THE 'PANIC PULL' OUT OF YOUR COMFORT ZONE? DON'T YANK ON THE YOKE https://www.aopa.org/news-and-media/all-news/2011/june/01/technique-the-panic-pull
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