The Concorde arrived at the Museum of Flight on Wednesday. And it has a new hat: “the Concorde, when traveling at supersonic speeds, is heated by atmospheric friction. This causes the airframe to expand. Inside, the expansion is visible only as a gap that opens in the paneling behind the cockpit; then, as the aircraft slows and cools, the gap closes. So, while the jet streaked at 1,350 mph over Canada, one of the engineers aboard stuffed his hat into the gap. And there it remains.”