Hi everyone, The same day Linda ended up in a field in the US, I had to make a precautionary¹ landing in the UK due to severe loss of power and rough running. This happened about 30 minutes into a flight in my Alon A2.
I had decided to climb from 2,000 to 2,500 feet, applied full power and my sweet running engine suddenly ran very roughly. After finding that application of carb. heat made the situation much worse, and not seeing any other immediate problem I looked for somewhere to land. I could just hold altitude at 70 mph and by luck there was a nearby farm strip on which I successfully landed. On throttling back in the flare the engine stopped. After pushing the aircraft off the strip I tried cranking with the mags off to check the engine was free, and we heard a sticking or hissing noise. Hand turning the prop seemed to indicate the compressions were fine and we could see nothing leaking, dripping or broken. Today I went to the farm strip with my engineer. He found the problem in around one minute (the time it took to open the left cowling plus 10 seconds) and another minute to repair. There is an induction pipe - a metal tube - connecting the carburettor to each cylinder inlet. The inlet manifold flange on the cylinder is larger than the pipe, so there is a short rubber sleeve slipped over the pipe to match the diameter and then a longer and larger diameter rubber sleeve fitting over both to form the seal. These are held in place with two hose clips. The lower of the hose clips on the rear port cylinder induction pipe was loose and the rubber spacer that side had slipped down the pipe. This meant that there was no mixture to that cylinder it was sucking air - and it would also imbalance the mixture to the other cylinders. This accounted for the sudden power loss and rough running. Therefore the various theories such as carb. icing, stuck inlet valve and cracked piston were all wrong, and a precautionary landing was definitely required. The engineer did a thorough inspection and ground check of the engine, and then I flew it away. So check those hose clips for tightness once in a while, and may it never happen to you! Best regards, Mike [email protected] www.ercoupe.co.uk Alon A2 Aircoupe A-188 G-HARY --
