A ramming pilot could use his entire aircraft as a ram or he could try to destroy the enemy's controls using the propeller or wing to chop into the enemy's tail or wing. Ramming took place when a pilot ran out of ammunition yet was still intent on destroying an enemy, or when his plane had already been damaged beyond saving. Most rammings occurred when the attacker's aircraft was economically, strategically or tactically less valuable than the enemy's, such as by pilots flying obsolescent aircraft against superior ones or by single-engine aircraft against multiple-engine bombers. Defenders rammed more often than attackers.