[Theflexmaster]

Yeah that's pretty easy.

-First select a viewport you want to have it in
-Then hit alt+b and find the picture you want to use as the guide
-Finally click match bitmap, then click lock zoom/pan as long as you want the guide not to move.

Another way is to just use planes with textures on them. That's probably the best for your jet. It's best if you use blueprints to make the jet. So basically in your top viewport, make a plane with the top view picture on it. If you don't know how to do that, just go into the material editor and click on the diffuse map. From there select bitmap and find your top view picture. Repeat this process for the side picture just in another viewport.

-Good Luck!