Thrust line

[Dave Bell]

Hi Guys,

As a newbe to kit bashing etc.,I can use some info on a plane thrust line;how do you locate it,effect of thrust line on flight(if any),effect of mounting engine above or below plane thrust line and anything else related to the subject.

Note that I'm not talking about engine thrust line offsets.If I am all wet and confused,don't be afraid to say so.

Thanks for any and all comments------------

Dave :confused:

[Brandano]

if you have the thrust line above the "center of drag" (on most plane this is close to the CG, but not on all) the plane will tend to pitch down when thrust is applied. if you have the thrust line below it, it will tend to pitch up... I think you can see where this all leads. Check the thrust lines on the old JU52 for an extreme example: http://richard.ferriere.free.fr/3vues/ju52_3v.jpg
Angling the engines like that brought their thrust lines closer to the center of drag and made the plane easier to fly on two engines only (or easier to crash land on one engine only, I guess)

[nmasters]

http://www.rcgroups.com/forums/showthread.php?t=704575&page=2

--Norm

[Dave Bell]

Thanks Guys-----

Thrust lines and C.G.'s are lots more complicated than I ever imagined.After re-reading the info several times,I think I am beginning to understand what has been said.The major point for me is to start thinking in three dimensions.I'm not well versed in aerodynamic fundimentals so much of the info goes right over my head.

Thanks again,guys.After I re-read the info and study more postings in this forum I hope to learn and understand more,and will more than likely pester everyone with more foolish question.

Dave :rolleyes: