The Ostro was the LRI's main attack aircraft, and their most numerous warplane. An agile twin-seat fighter, it could carry a 27 mm cannon for anti-shipping and anti-fortification missions, but it was usually just fitted as a bomber or reconnaisance aircraft. In this configuration, it would often be used to target the CIR's Cuttlefish airships supplying the Tyrrhenian rebels, where it would often be supported by cannon-less Ostros. These airships were the lifeline for the rebels in the renewed war early on, and Cuttlefish freight was still a major element of Iberian logistics in the war.

This wasn't the only job of the Ostro: Thanks to it's performance, it was the Legion's standard light bomber, and also carried out reconnaisance missions and anti-shipping patrols. Cheaper than the Gregale, the Ostro was often used in CAS roles, where it made a name for itself thank to it's maneouverability, which made it a difficult target for gunners to hit and also a deadly opponent at low altitude.