HahahaHa.. Arnold went on a bombing run. He lead one other Aviatik and the target assigned was a RR station. His rpms started to bounce just after he crossed the fronlines and he decided to head for home. He was about to pass over an observation balloon so he continued straight and level and let them drop.
He then thought twice about signaling his squadmate to continue with the mission and decided against it. Arnold barely made it home to Colmar, his engine rpms kept fluctuating and the high end kept falling. Both landed OK and he filed a balloon claim that was confirmed.