The flyover caused a "disturbance on the beach."
Members of the U.S. military have the legal right to refuse orders they believe are unlawful, but they risk violating military laws of obedience if the order is in fact lawful, experts in military law say.
All personnel were safe and in stable condition, after a Navy helicopter and a fighter jet both went down in the South China Sea, the U.S. Pacific Fleet said.
Navy and Coast Guard vessels that arrived last week set sail to return to their home ports.
The "Homecoming 250" fireworks show, originally delayed due to weather earlier in the week, drew crowds to both sides of the River for a vibrant celebration of military history and service.
The events culminate with a fireworks show over the Delaware River Wednesday night, and a sendoff for the ships on Thursday.