A-wings are the space ships that often crash during series 1. It is revealed in series 2 that these are martians trying to move to Earth, unfortunatly most die on impact.
Here is a list of A-wings appearences in series 1:
Pilot- 1. Crashes into and kill's Jar Jar Binks. 2. Kills Zombie Jar Jar at the end of the episode.
Episode 1: Lunar Lunatics 3. Flies past Sam and the gang when they are in space.
Episode 4: Phillip's Message on Weapon Safety 4. After Phillip has been severly wounded by the dodgy weapons an A-wing crashes into him which finishes him off.
Episode 5: Octan 5. After the credits Sam Grant and Harry Kane say about how something feels unfinished and then an A-wing kills Jar JAr Binks.