All helicopters and levels:
     To  get  all helicopters and levels just put in R, C-Left, Right,
Up in the password screen.

Level Passwords:
02 - Up, Down, Left, Right 
03 - Up, Down, Left, Up 
04 - Down, Up, Left, Right 
05 - Down, Up, Left, Down 
06 - Down, Up, Right, Down 
07 - Left, Down, L, Up 
08 - Left, Down, L, Down 
09 - Left, Up, L, Down 
10 - L, Up, Left, Down 
11 - L, Up, Left, Up 
12 - L, Up, L, Down 
13 - L, Down, Up, Left 
14 - R, C-Left, Up, Right 
15 - C-Down, L, Down, Down 
16 - R, C-Left, Right, Up