ETLB Squawk Forums — Archive

Trying to sort out the differences between the 1030F (Max 103) and an 1100R.  Sounds like the 103 has a lighter structure, but then adds on some creature comforts and aesthetics like cowlings and turtle deck.  Would that be a correct assessment?

If one was going to build a Part 103 machine, are there any differences in performance or handling between the two?  Other pro's con's?

I built a basic 1100 fuselage, but used the wing and tail plans of the 1030. As far as I can tell, the biggest differences are that the 1030 wings use slightly lighter compression and anti-drag braces, and the 1030 tail is the "light tail" version. The 1030 also has a different design for the engine mount area, but I built my fuselage per 1100 plans. I used a 277 Rotax and my plane ended up flirting with being tail heavy even with the light tail. I believe the 1030 engine mount plan would position the engine slightly forward by comparison which would help the W&B when using a lightweight engine.

The cowling and turtledeck do add a more finished look to the 1030, but I didn't want to add the extra work of building all of that, so I opted for the simpler 1100 flat-top.  

Hope this helps.

Lynn

Weight constraints will leave you with few options if building a legal Part 103 airplane. Most of the other traditional Experimental versions all share one thing: High structural drag, which limits performance. It doesn't really matter much what you use for power. All that drag is going to translate into a relatively limited range of efficient cruising speeds. Higher power-to-weight ratios provided by engines like the Rotax 503 will probably be felt mostly in climb rates and the ability to respond more quickly and authoritatively in marginal situations, such as a last second go-around in a gusty wind, which, IMO is far more important than raw speed. In the ultralight version I would shoot for the lightest airframe possible, coupled with the most powerful (able to turn the largest prop) engine available to you.

LSaupe,

My understanding is that the lighter wing of the 1030 has less drag braces per wing than the 1100. The 1030 has 3 per wing, the 1100 has 4 per wing. Also, on the 1030, the first of the three drag struts, i.e. the one nearest the root, is made of 3/4" X 3/4". The second one is made of 5/8" X 3/4", and the outermost one is made of 1/2" X 3/4". Whereas on the 1100, the first and second of the four drag struts are made of 3/4" X 3/4" and the third and fourth are made of 5/8" X 3/4".

I was also told the rear spar on the 1030 is weaker than that on the 1100. The front and rear spars for both models are made from the same stuff at the same dimensions. However, on the 1030, the doubler that runs along under the upper spar cap at the rear strut attachment is made of 1/2" X 3/4", whereas on the 1100 it's made of 5/8" X 3/4".

Thanks for all the feedback.  Much appreciated.