Do pattern planes normally have an engine offset (eg; slightly down and to the right)

or are they normally mounted in a direct line with the fuselage producing exactly forward thrust.

Depends on the plane/engine/prop combination. Flight testing/trimming will more than likely reveal the need to make changes however you set it up initially. Sorry for not being more specific but neither was the question.

Terry in LP

Most setups will have very slight down and right thrust. An exact measurement can't be given because every design is different, and will require different amounts. There are some who will try to set up their aircraft with 0 down and 0 right thrust, but the trimming process will reveal the need for a little (very little) in each direction.

hi their

you need to trim your pattern plane as follows

assuming your aircraft does not have endless power you need to set ur airplane up as per the kit then hit the fieald then fly tha aircraft vertically upwards ( not so that it flies out of site but you need to see weather or not it turns to the left or the right as it slows to zero knots in the vertical.\

Thanks for the replies.

The instructions for my (cheaper) pattern plane do not specify engine mounting offset.

I have converted the plane to a nosewheel config due to the dusty an very rough field I fly off.

I felt the plane had too much offset after my mods (i had repostioned the engine).

I have reduced the offset and applied a little down thrust since posting this post.

Just interested if the more expensive pattern planes instructions actually specified how much engine offset and down thrust (if any) should be set.

It has been windy conditions during the flight test today, so difficult to tell if the mods are an improvement over the previous setup. Even with vertical climbs (was blown off the vertical).

Do the more expensive pattern planes specify offset.

My plane is a Phoenix Atlantis (poor mans pattern plane)

Cheers.

Some right, a hair of down usually. the theories on this abound, and none is right or wrong.

if you want to be safe, shoot for 2-3 degrees of right and .5 of down. the smaller the plane, the less it needs generally speaking, so long as the tail moment isn't too short in relation to everything else. Then you will need more. this has more to do with the prop than it does with the plane itself if this is not a short coupled plane. A high diameter low pitch prop will need slightly more than a smaller higher pitch prop turning faster.

Keep in mind this is just generally speaking, you can get away with none at all if your plane is properly designed, trimmed and set up otherwise, and you may still need a little mixing. if you start with a little default right thrust, say 2 degrees, that should be a good starting point on a cheapie plane. Flight trim from there....

-Mike

All my pattern planes have had down and right thrust built in, and so have all the top dollar planes I've seen.
Even my old Hyde Out had one deg' of each and that was from a guy like Chip Hyde that didn't believe in right thrust! That plane needed the typical Hyde rudder to throttle mixing in place of engine thrust. After a couple of years I just dropped the mixes and added 3 deg engine offset instead and a swear to god it few considerably better!
I wouldn't hesitate to build in 1deg down and 3deg right thrust into your model and trim from there.

Only one way to trim a plane and this is the definitive trimming chart: http://www.mini-iac.com/Portals/57ad...20trimming.pdf read and inwardly digest, then go out and try it, it can transform a medioca plane into something desirable.

Mike