Originally a re-purposed light courier, these ships were first used in combat by the Maquis as attack fighters during their insurrection against the Cardassian Union. In 2370 a pair of such ships were upgraded, armed, and used by former Starfleet officer, Lieutenant Commander Calvin Hudson, in an attempted attack on a Cardassian weapons depot on Bryma, beginning the Maquis uprising. They were engaged by Benjamin Sisko on the USS Rio Grande forcing them into a strategic retreat. (DS9: "The Maquis, Part II"; TNG: "Preemptive Strike")
After seeing the effectiveness of the Maquis' improvised attack versions of the ship, a large number of these ships were built and used by Starfleet in the Dominion War. During Operation Return, eight successive waves of fighters were sent to attack the Cardassian ships of a Dominion fleet, hoping to provoke them into breaking formation and creating an opening for the Federation fleet. (DS9: "Sacrifice of Angels")
Although not originally designed for combat, the ship that became known as the attack fighter was capable of being modified to carry an impressive arsenal. Designed for a civilian role, and sized similarly to the starfleet Runabout, the original design was only lightly armed, primarily intended for personal and cargo transport.
When used by the Maquis, the fighters were armed with whatever weapons were available; there was no standard design, and various ships were modified in different ways according to the skill of the available engineers and the materials at hand. On most upgraded models, the improved weapons, engines, and shields took up most of the room on the ship, reducing the habitable space to just the cockpit. The first examples of the ships used by the Maquis were armed with Pygorian weapons, including photon torpedoes, pulse cannons, ship-mounted high-energy disruptors and particle accelerators; these were used when an attack was planned at a weapons depot on the Bryma colony. (DS9: "The Maquis, Part II") Later in 2370, another set of ships were, according to Gul Evek, armed with photon torpedoes and type 8 phasers acquired from an unknown source. (TNG: "Preemptive Strike")
When used by Starfleet from 2374 onward, the ship was equipped with several forward torpedo launchers and at least one phaser bank with two forward emitters. Captain Keogh referred to these vessels as "lightly armed shuttlecrafts," compared to the Dominion ships he expected to face. (DS9: "The Jem'Hadar") In keeping with it's heritage, the ship was also used as a testbed and as a way to utilize foreign and salvaged equipment, and various runs of the ship were produced with experimental, improvised, and/or nonstandard weaponry.
- TNG: "Preemptive Strike"
- VOY: (all appearances from display graphics, referenced as an "Academy flight trainer")
Background information Edit
The fighter cockpit interior, seen in "The Maquis, Part II", was a modification of the type 15 shuttlepod set. It was reused later from DS9: "The Search, Part I" onwards to represent the type 18 shuttlepod cockpit.
In the script of "The Maquis, Part II", the phasers used by the Maquis attack fighter are identified as the pulse cannons mentioned earlier in dialogue.  The initial phaser blasts in the episode however seems like regular phaser fire from the extended bank under the nose of the ship. Photon torpedoes are seen being fired from the tube at the nose of the ship. When the torpedo tubes are damaged, the fighter opens fire with pulse cannon phasers from two wing mounted banks that are not visible on the model.
Visual effects in "Preemptive Strike" show phaser fire pulses coming from the wings, where there are three visible tubes on each wing. Phaser fire is also seen coming from the front ends of the embedded warp nacelles. These banks seem to be targetable, instead of firing straight ahead like the Pygorian pulse cannons in "The Maquis, Part II."
The script of "Sacrifice of Angels" states that the attack fighters were firing a barrage of quantum torpedoes when attacking the Dominion lines.  The effects used for the phasers and quantum torpedoes of the fighters in this episode were not what is normally associated with these Starfleet weapons. The torpedo launchers were mounted on the wings and on the nose of the ship. In some shots, the wing torpedoes seem to be launched from the same spot where the pulse cannons were located in "The Maquis, Part II." In others, they seem to be coming from the three small visible tubes on each of the wings. These tubes would seem to be much too small to launch full-sized torpedoes.
In one shot of "Sacrifice of Angels," one of the fighters is seen firing a bluish-white beam from the one of the two forward phaser emitters, on the extended phaser bank, under the nose of the ship. When a fighter fired the phaser from the same location in "What You Leave Behind," the regular Starfleet phaser effect was used.
According to Original Starship Collection, the fighter is 25 meters long, and has 2 pilots.