A stock aircraft called AH-6 Little bird with autocannon. Built with 200 of the lightest faking parts, its root part is strutCube.
This thing barely flies before you start firing its missiles.
It will probably skim across the ground for about 3 minutes before taking off due to the weight of everything, so if you want to take off faster, fire off two of the missiles.
to use the cannon, you must make sure the cannon is Firing, and then press 2,3,4,5 in that order.
Press 1 to turn the cannon on.
you get about 5 seconds of cannon fuel, so use it wisely.
Built in the SPH in KSP version 1.4.5.