Victor 933
From Halopedia, the Halo wiki
Summary
A Pelican dropship attatched to the Pillar of Autumn. Captain Keyes, Sergeant Johnson, and Private Wallace Jenkins traveled to an area where they hoped to discover a cache of weapons aboard Victor 933. Twelve hours after the last transmission from the pelican, the Master Chief dropped into the swamp aboard Echo 419 and discovered Victor 933 crashed in a swamp, sending a garbled distress signal. Whether the vessel was brought down by hostile fire from the Covenant or the Flood is unknown.