I'm new to this forum and need your help.

I have got a classic arcade table with (amongst other games) the classic Scramble (the "Konami" version if I've spelt it correctly).  My problem is that I cannot get past the 5th stage (the caves?).  My "jet" will go vertical for a short while,. then go diagonal...and then crash.  There must be a way of getting through the caves to finish the game (and then start again).

Can anyone help ?