Alphe: Imperial Navy defeats Chaos air force.

Percival's first offensive act on Alphe was dreamt up by his Naval attache. Alphe was a temperature world experiencing a planet wide summer, ideal conditions for flying, and the Imperial Navy commander reckoned the Imperium was superior in numbers and training to the forces opposing them. After presenting his logic, the Naval commander proposed a series of bombing raids, destroying vital resources and paving the way for a renewed offensive.

The strategy was to concentrate on holding the Catechism while wiping out the Dusk Raiders in the north. To contain the Catechism the air war against them was launched. Thousands of aircraft were sent against Merridale and other installations in Eastby, against the protestations of governor Torak, who argued laying waste to towns was tantamount to the murder of innocent civilians, his civilians. Percival argued they were now guilty of being corrupted by Chaos, and the bombings began.

Despite sending up strong resistance the Imperial fighter pilots were skilled and their shooting accurate, in contrast to the performance of air units on Tarsis. hundreds of Chaos planes were downed and the bombers were able to get through to their targets. Merridale was severely damaged and several vital supply dumps were destroyed or damaged beyond immediate repair. After three days of maximum effort the air campaign died down with Percival confident the Catechism would not be making significant gains in the near future. His attention now turned to the north.