Sterling P-51 D Strange Trimming problem Follow Up

[Phil Spillman]

Several weeks ago I posed a problem I was having with my very old and well used Sterling P-51D model. At that time it had a tendency to pourpose around on hard inside maneuvers. One of the suggestions I received here was to move the elevator horn mounting point to a lesser throw position. This I did but had to Waite for 24 days to encounter a day where I wasn't working and it wasn't raining or blowing gale force winds! Well today was that lucky day and out I went! Well my little Mustang flew like a true pro-stunter! It has no right to fly so well but it does! No more pourposing nor chatterring around the insides and very smooth other maneuvers! I am a happy guy!

The solution to my prior problems was to move the push rod at the elevator 3 holes down toward the ground. The horn used on this plane, which has been in continuous use since 1992 is a Top Flite medium one usually found in RC use. The linkage is from a right angled piece of 3/32 piano wire which is inserted into a carbon fibre tube which runs to a similar end at the flaps in a similar horn!

So often suggestions are made here with no report on which ones were actually used or tried with what result! Well... Here's the rest of the Story with my sincere Thanks to all and whom ever responded to my cry for HELP! It worked!!!!

 

[RknRusty]

That's great, Phil. I have a Sterling Mustang in the box that I've put off building for fixing crashes. I want it to be the hangar-mate in to my Sterling Yak-9. I imagine they fly much alike, and the Yak flies like a squirrelly 1/2A, twitching and bobbing. I thought maybe that's because I defied advice and hooked up the flaps despite being told they weren't needed. I put the longest Sullivan steel horns I could buy on it but it's still pretty jumpy. I'm interested to see how they compare whenever I do get around to building the Mustang.
Rusty

[Phil Spillman]

Hi Rusty, Sorry the Yak isn't up to standard! I am using an FP .20 swinging a 9 X 4 APC prop and 10 11:11 fuel. Perhaps some nose weight would help the Mustang. Back in 1985 I was flying some Core House Profiles powered by either Fox .35's or OS 35S's. One plane in particular, the Zero, need me to fill the back[plate cavity of the 35's with lead in order for it to perform well and not squirly! I added some tissue, as in Kleenex with the lead and a piece of brass for covering, to make the plane more stable. It flew well enough to get me booted to Intermediate! Love to hear how this works out for you!

Phil Spillman