How to launch missle from a plane?

I have an aircraft object parented to a bezier curve, and I have another bezier curve with an empty parented to it; that curve is called “bomber vector”. I use “bomber vector” curve to change the aircraft’s orientation when it is doing a turn, or a yaw. (By making the aircraft track the empty using, ‘track to’ constraint). Originally, the aircraft couldn’t do roll maneuvers because the ‘track to’ constraint wouldn’t permit it. So I used 2 ‘locked track’ constraints and the aircraft could roll. The problem? Having the missle objects stay put under the wing of the aircraft, (tried parenting missles to the aircraft but the missles would go to the object origin of the aircraft.) The second problem? Launching the missles, (I tried making a new bezier curve, and placed the beginning of the curve exactly on where the the missles origins would be at the frame the missles would launch at. But how do you tell blender, I want you to start animating the missles on ‘X’ bezier curve at ‘X’ frame? Here is the blend file: Bombing test.blend (1.81 MB)

Update: I fixed problem 1, turned out I had auto insert key frame on and it was making some unwanted key frames in the beginning of the animation. I still need to know how to make a curve animation start at a certain frame.

Free-thinking here, it seems to me that maybe the curve, always pointing upward, needs to somehow be made to follow the plane but not be attached to it. (An empty at the bomb-bay door, say, with a constraint that has the curve following it.) The curve, meanwhile, maybe has an empty that’s set to animate along its length on-cue, and the bomb (only in its local Y / Z axes, say) is constrained to follow it.

So, the plane is rolling left-and-right at hyperspeed, with a curve-object chasing it. The empty’s at the top of the curve and maybe the constraint’s not yet turned-on. Then, “bombs away!” The constraint is turned on to follow the empty, and turned-off to follow the plane, perhaps animating that transition-of-influence over a handful of frames. (The curve must also be told to stop following the plane.) Now, the bomb, chasing the empty, falls to the ground.

Another way to do it might be to use a Python script, which takes-over control of the bomb when it is released and issues (dX, dY, dZ) influences upon it a la Physics. Or maybe you use Physics.

In a real-time game situation, you gotta do it one way. In a “movie,” though, you have many ways to cheat.

The demo file heremight help you a bit.

How do you set the empty to animate along the curves length on cue?