Plane not working

[Resand]

Soo... I'm hoping some of you might be able to point me in the right direction here.

I got two almost identical planes. One flies just fine, the other not at all.

This flies: http://imgur.com/BID5sjr,oxFH8Fo#0

This does not: http://imgur.com/BID5sjr,oxFH8Fo#1

The only difference is that the second one has a service bay. I just detached the fuselage, added the service bay, and reattached it.

Crossfeed is enabled, and the engine does start. But it start to skip along the runway for a while. At around 50% higher speed it does take off, but only just, and if I stop pointing it upwards it does a nosedive.

Edited May 16, 2015 by Resand
Changed prefix

[Tex_NL]

Move the rear landing gear further forward to just behind the centre of mass on both designs. The landing gear forms a fulcrum, the further behind the centres of mass and lift the harder it will be to lift the nose.

[Geschosskopf]

Do you have SAS turned on? That usually keeps planes pointed the way you want.

As to landing gear position, there are 2 things to keep in mind here. First is that having landing gear as far aft as possible is usually a good idea because it keeps you from dragging your tail during takeoff and, especially rough landings. The wheels have suspension and the plane flexes, which can lead to the engine hitting the ground. But as Tex_NL says, this makes it harder to take off. So to solve that, make sure you arrange the wheels so the plane sits slightly nose-up when it's on the ground. For instance, if you're using all the same type of landing gear, put the nose wheel on the fuselage and the main gear on the wiings. If the wings are mounted on the centerline of the fuselage, its wheels won't stick down as far as the nosewheel and the plane will sit nose-up. Then the plane will usually fly itself off the ground without control input.

[Resand]

I moved the landing wheels forward a bit, did help on the design, but it's not the problem as such. Good thing is that trying the plane a bunch more times, I finally figured out what's wrong.

Turns out the control surface on the second plane is inverted. So up is down as vis versa. So both me and SAS gets it wrong while flying. But I can't find a way to fix it, and I have no clue why it happens. It's the same wings as the first plane:huh:

I tried just picking them up and turn them around, delete and add new ones and start them deployed and inverted through the right click menu. Nothing seems to help

[Red Iron Crown]

Resand, I believe the game is looking at the attachment point of your wings to determine the control surfaces' relationship to the CoM, in your first pic it's slightly behind the CoM and in your second it is slightly ahead of it. I suspect if you move the attachment point just aft of the CoM your surfaces will work correctly.

[Resand]

Resand, I believe the game is looking at the attachment point of your wings to determine the control surfaces' relationship to the CoM, in your first pic it's slightly behind the CoM and in your second it is slightly ahead of it. I suspect if you move the attachment point just aft of the CoM your surfaces will work correctly.

Thank you! That did it. I literally moved the wings back a couple of pixels and it fixed the plane