It should be to get 10 Kill Assists in each weight class for cockpit items.
However the Medium class one says 10 Kill Assists in a light rather than a medium. Haven't tested it to see how it works yet, will get back to that in a few minutes.
Edit: Nope, it is just a text error. The goal is 10 kill assists in a medium as intended.
Edited by IllCaesar, 15 June 2018 - 06:43 PM.