Engine Thrust 10ft BN2 Islander

[Andrew Brown]

Hi All.
I'm after a bit of advice regarding thrust lines for a scratch built 10ft BN2 Islander.
A good friend of mine is in the process of finishing off two of these, suited for 2x DLE 20s and we're unsure of what degree of down/out-thrust (if any!) we should be using when mounting the engines.

The original plan is a 60" which has been doubled up to 120", however on the original plan there is no down-thrust built into the firewall, there is however 3 degrees of out-thrust on the left engine, and 4 degrees of out-thrust on the right engine, which is assumed to help with a potential engine failure.

Is it safe to assume that the same applies to the doubled up versions - i.e no down-thrust at all?
Any advice would be greatly appreciated!

I know there are a couple of larger Islanders on the circuit and would be interested to know what has been built into these models.

Many Thanks for your help!
Andy

[Paul Savage 1568]

Hi Andy,

I designed and built a semi scale Islander which was around the same size as the project you're currently working on.
It was adequately powered by a pair of SC 120 FS engines with no down or side thrust. It flew really nicely. The video link shows the model after I finally gave up with the vulnerable wing mounted under cart and replaced it with a more practical arrangement.
Hope this helps in some way and good luck with your project.

https://www.youtube.com/watch?v=gIGaQxFmOfQ



Paul.