RCU Forums - View Single Post - CMPro/Chief/GSP 72.5 Extra 300s Build thread
Old 06-05-2006 | 02:03 PM
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andyjayh
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From: Crawley Down, UNITED KINGDOM
Default RE: CMPro/Chief/GSP 72.5 Extra 300s Build thread

Thought I would pitch in with my experience of this plane.

Bought it as an unfinished project from a club member a month or so ago. Most of the work had been done even down to fitting the engine, an ASP120 2s. Wouldn't of been my choice but I thought I would give it a go as it was cheap

Finished it all off last week so took it for its maiden over the weekend. I was worried about the CofG as I had to mount the battery on the engine box AND add another 80g of weight to the engine mount!! I hate adding weight to models. I tried to weigh it before I added any fuel but my scales only go up to 11.5lbs and it was over this [] This is not a light plane by any stretch.

Anyway, first flight was very uneventful and everything checked out fine. CofG was good and it hardly needed any down elevator to keep it level in the invert. Landing was quick but well behaved. A sigh of relief and a little jump for joy as this is my first large plane

So a couple more flights and I pushed it a bit harder and still everything was in order and I was really enjoying flying a large plane at last. Still coming in fast and finding it hard to slow down but then there is a lot of weight coming in!

Next flight and the trims were all over the place!! No idea why but I carried on and re trimmed. Just didn't feel right in the sky but I thought it was just me. When it came to landing it went all wrong. All or nothing on the controls, really had difficulty in bringing it in. Went around a couple of times before I decided to just cut the motor and get it down. It came down hard although I had full elevator in. So hard on the undercarriage and then flipped over onto the rudder []

Went and inspected the crash site and found one answer straight away, one of the aileron control linkages were off so I only had one aileron!! Kicked myself over this as I was going to replace these as I had the elevator ones. I really didn't like the kit solder jointed control linkages and the elevator ones were really loose. Replaces these with some nice carbon/alloy ones to take out all off the slop. Looked at the aileron ones and I didn't have anything to replace them with so just checked them over to ensure they were tight. So I obviously missed something here as one still managed to get away [>:] My own fault I know and I still haven't finished kicking myself yet [&o]

So damage report;

The alloy plate the the under cart fixes to took a bit of a pounding! This is now bent up into the fuse and all the surrounding wood is smashed. Not sure if this is worse due to the alloy plate or better?? I think it is better but it's just going to be a pain to fix. I think I need to create some more damage first to actually remove the alloy plate before I can straighten it. I can't see a way of getting to the fixing bolts that hold it to the fuse without having to cut an opening in the underside of the plane []

The only other damage is to the rudder. This took a hit when the plane flipped over and it has broken the hinges. This can probably be repair fairly easily but I think I will pin the hinges before flying again.

On the whole I enjoyed the few flights I had with this model although it is heavy. I am just really miffed that I now have it back in the workshop requiring some major repair work which I might of been able to avoid [>:]

Andy