Thread: Discussion Let's talk thrust lines
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Old Aug 09, 2012, 07:51 PM
GreenAce92_v2 is offline
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United States, NY, Buffalo
Joined Aug 2011
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Let's talk thrust lines

OK so my aircraft is not normal, it does not have any vertical stabilizers rather relies on the high sweep angle as well as the Gull shape to fly straight. It is a flying wing.

I had no problems flying it with a 10 x 3.8 SF APC propeller but then when switching to a different higher rpm motor with a 7 x 5 APC E propeller, I had troubles. The aircraft now yaws and wants to turn so I needed to re-do all the trim.

I'm just curious why the yawing effect was so noticeable. Other gull wing models would use the same motor and not have a problem.

It could be the servos I am using / bad receiver / glitches if one of the 6 surfaces is twitching then I could see.

I was able to fly straight with the flaps down.

My reasoning about the thrust lines was the "denser, faster flow of air" from the smaller higher rpm propeller made any slight angles much more drastic than a larger slower less dense mass of airflow from the bigger propeller.

I streamlined this airplane today and I was curious if this may have had an addition to the odd behavior.

Usually I fly it as this ugly stick looking thing and I have no problems with directivity however when streamlining it seems that I lost some of the straight flying stability.

Is it possible that a turbulent central leading area followed by high sweep wings with smooth airflow leads to a straight flying aircraft? It doesn't seem like it would make sense. I mean, rudders are at the back of airplanes not the front, then again rudders aren't really meant to cause turbulence are they?

This is the craft.



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