Lee Wilson Posted April 7, 2012 Share Posted April 7, 2012 I was very lucky to get a Global RC Extra for Christmas which I finally got down to the field today for it's maiden. Was in the progress of tuning the Zenoah 20 and was at the point of taking out to the pilot box when the right aileron was spotted to be hanging down. First thought was that the linkage had come loose when running the engine at full throttle, was a bit peeved because I thought I had put plenty of thread lock on. Turned the model over to find that the M2 bolt through the ball link had sheared . I was so glad the engine needed tuning, if it had ran sweet first time the bolt would have sheared in the air. Now I dont trust any of the linkages and plan to replace the lot before a second attempt at a maiden. PS I didnt win the lottery tonight so I guess I used all my luck earlier. Quote Link to comment Share on other sites More sharing options...
jpreou Posted April 7, 2012 Share Posted April 7, 2012 Lucky! One of our members today did the maiden on a large aerobat with a big petrol engine up front. Not sure of make / model of plane or engine. Took off and after a minute or two we heard a string of expletives. Throttle server intermittent, apparantly. Would surge unexpectedly and this was making the approach to landing difficult. Eventually cut the engine and came in for a greaser so all good. Throttle servo dodgy? Nah-ah. Investigation showed the entire engine mount had sheared loose from the firewall. Very small glue area, possible also incorrect glue chosen by the builder and not bolts or screws. Our member didn't build this model; bought it as was. Anyway, that big old petrol engine was only held on by the ignition lead (servo wire), fuel tube and throttle servo linkagage. The cowl has helping but was cutaway at the bottom so if the engine had come properly loose it would certainly have fallen clear. So, $1500 model saved! Phew! Lucky man Quote Link to comment Share on other sites More sharing options...
Paul Marsh Posted April 7, 2012 Share Posted April 7, 2012 I test fly my Super Skybolt. The 2nd flight, the wing strut came off, and upset the trim. Got down ok, but found the screw came out, as the top wing lifted, slipped from it's tongue and ripped the bottom tongue out. As the top wing flexed, caused the top aileron to change angle, due the torque rod connected to the bottom aileron. Throttled back, and got down ok. Quote Link to comment Share on other sites More sharing options...
Lee Wilson Posted April 7, 2012 Author Share Posted April 7, 2012 Hi jpreou I saw similar happen at our field. The mounting screws came loose and the engine fell forward and was only held in by the throttle linkage and the cowl. Pilot said there was a major change in trim and he did a pass down the strip where we spotted his prop at a rather odd angle. Throttle cut wouldn't work and he had to fly it until it ran out of fuel and he did a greaser dead stick. Quote Link to comment Share on other sites More sharing options...
Lee Wilson Posted April 7, 2012 Author Share Posted April 7, 2012 Another day when I got lucky, just a touch of yaw after this happened at the bottom of a loop. Looks a bit different now Quote Link to comment Share on other sites More sharing options...
David Ashby - Moderator Posted April 8, 2012 Share Posted April 8, 2012 Posted by Paul Marsh on 07/04/2012 21:38:03: I test fly my Super Skybolt. The 2nd flight, the wing strut came off, and upset the trim. Got down ok, but found the screw came out, as the top wing lifted, slipped from it's tongue and ripped the bottom tongue out. As the top wing flexed, caused the top aileron to change angle, due the torque rod connected to the bottom aileron. Throttled back, and got down ok. Clubmate had the same thing happen a few weeks back but his story didn't end happily...... Edited By David Ashby on 08/04/2012 13:38:24 Quote Link to comment Share on other sites More sharing options...
Paul Marsh Posted April 8, 2012 Share Posted April 8, 2012 It went into a spin, but got out, even though there was a different feel. Had to slow down, to lesson load on the top wing, as it has lost some strength, and could fail. Once it slowed down, wasn't too bad, but if it had carried on spinning, the end... Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted April 8, 2012 Share Posted April 8, 2012 Posted by Lee Wilson on 07/04/2012 22:07:31: Looks a bit different now Excellent looking job on the recover Lee Quote Link to comment Share on other sites More sharing options...
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