Ok, so I'm a newb and I can't figure out how to bomb a base. I've tried bombing the runways and I've tried the buildings. Nothing seems to work and I get chickenscratch for cash and xp, maybe 10-15. I spent nearly 15 whole minutes bombing the shinolla out of an enemy base with 250kg bombs and was rewarded with 155xp for my efforts. The base seems to have something like a health meter and it barely moved. Maybe 5%.
What am I doing wrong?