Warrant Officer Shiela Polaski was a UNSC Warrant Officer assigned to the 23rd Naval Air Squadron in 2552. She was stationed aboard UNSC Pillar of Autumn as a Pelican pilot. When Pillar of Autumn fled the Battle of Reach, crash landing on Installation 04, Polaski survived.
Polaski was among the handful of survivors who fled in a Pelican when Installation 04 was destroyed. She, Lieutenant Elias Haverson, Staff Sergeant Avery Johnson, and Corporal Locklear hid in the debris field until they met with John-117 and Cortana in their Longsword fighter.
Polaski helped the Chief capture the Covenant flagship Ascendant Justice. She then learned to pilot its Covenant Dropships, and when they returned to Reach, she piloted the ship to the surface so they could locate the SPARTAN-IIs who had survived the fall of Reach.
When they returned to Ascendant Justice, they were caught in an anomalous Slipspace bubble. Polaski volunteered to pilot the Spartans outside the vessel to conduct extra-vehicular repairs. A renegade charge of plasma flash-vaporized the dropship's cockpit, killing her along with Anton-044 and Li-008.
- Polaski was relatively levelheaded.
- At some point, Locklear developed a crush on her. She apparently reciprocated his feelings.