The Mark I Arwing was a stunt craft developed by Arspace Dynamics and served as the blueprint for the Arwing fighter craft.
The Arwing X-01 was originally designed as a reckless stunt craft and not for military use. The craft became very popular with Mercenaries however, in particular James McCloud. Eventually he would commision Arspace Dynamics to make the craft more combat worthly, leading to the development and production of the Arwing Mark II.
The Mark I Arwing is only available in the Tutorial missions and Battle Simulator. It is very lightly armed and can easily be destroyed by most other fighter craft.