As the role of air traffic controllers comes under scrutiny in the deadly mid-air collision between a U.S. Army helicopter and an American Airlines regional jet, payouts by the federal government for past crashes show both the scope and limits of government liability.

The skaters who were aboard American Airlines Flight 5342 when it collided with an Army helicopter and crashed into the Potomac River were traveling back from Wichita, Kan., where they attended a national development camp held after the U.