From Halopedia, the Halo wiki
The siege-hauler is a large aircraft employed by the Banished. The craft sports a layout broadly similar to the described appearances of the Griever fighter-bomber and "Super Spirit", employing three primary parallel hulls. The two outermost hulls are each equipped with two rotating thrusters, while the spaces linking the outermost and inner hulls are lined with lifting equipment. The siege-hauler appears not to be fitted with any sort of armaments, though is coated in a thick layer of armour plating.
Installation 07 conflict
Throughout the course of the war on Installation 07, numerous such craft were employed by the Banished during the xenoarchaeology digs across the ringworld. One such craft was stationed at the Banished outpost at Annex Ridge, where it was ultimately stolen by Spartans Jaide and Rosado. The craft was fitted with an autopilot system which prevented the Spartans from commandeering it fully, though the Spartans remained resolute to find out where the autopilot system was taking them and its cargo of three Forerunner artifacts. The vehicle was later reported as lost by Zeretus.
List of appearances