Merry christmas

A friend of mine has bought a second hand bi plane. Original the glow engine was placed upside, but after the first flight the plane crashed, and afterwards he inverted the engine. Now the center line of the propeller is located 1” above the center of the fuselage.

Will that affect the flight characteristics? - Because the plane is close to impossible to handle in the air.

Thanks

wow i would also be checking the indences on all surfaces.

It will change the way the plane flies, but it could change it for the better. Things like knife edges could change, with the plane pulling one way or the other but In normal flight it probably wont matter that much.

Thanks for your replies gentlemen :-)

Merry Christmas

The plane is most likely tail heavy

I don't understand why this would be. Can you elaborate ?

A plane must be balanced front to rear about a point 25% to 35% of the overall wing width from the front of the wig in order to fly correctly.

If the tail is heavy they are almost impossible to control. If they are very nose heavy they are hard to keep the nose up on landing

You have a biplane but you must treat both wings as one and find the point 25% back and you must support it by the top wing

I agree, but he hasn't changed anything but the position of the motor, ie, upright to inverted. How would this change the balance ?

It crashed the first time he flew it. The plane may have been tail heavy when he bought it?

Maybe he doesn't know how to fly?

On the internet it is hard to tell all the little details sometimes?

Hi!
The engine position will not change the planes flight characteristics (not much anyway).
Have you checked if the wing has wash-out (or worse... wash-in)? C of G, both lateral and axial? Wing loading ?

Merry Christmas gentlemen.

I'll post your replies to him. Hope he will get it fixed... He has only been flying electric, and perhaps not the most patient guy I have met...

Thanks

This thread is closed.