U.S. Army and Air Force personnel paint a yellow cross over the runway number at Howard. U.S. Army and Air Force personnel paint a giant yellow cross over the runway number at Howard Air Force Base, Panama, on June 16, 1999. The yellow cross over the runway number indicates the air field is closed to traffic. The closing of the field is one of the steps in the turnover of U.S. bases and the Panama Canal to the Panamanian government. SHARE: Download: Full Size (0.05 MB) Credit: VIRIN: 090515-M-CIF61-917.jpg Photo Gallery