Frontier Airlines Holdings is reporting a net profit of $2.4M for April, compared to a net loss of $26.9M for April 2008. Frontier President & CEO Sean Menke says the airline is seeing the payoff of restructuring & cost-cutting the past year since it sought Chapter 11 bankruptcy protection. It will report net income of $3.4M for May, excluding $1.1M in expenses directly associated with bankruptcy. Menke credits Frontier's 3-level fare offerings & ancillary fees for helping boost revenue figures. Frontier's main hub is in Denver.