Navy Petty Officer 2nd Class Carren McMillan adjusts and aligns an Identification Friend or Foe transponder. Navy Petty Officer 2nd Class Carren McMillan adjusts and aligns an Identification Friend or Foe transponder for an aircraft aboard the USS Theodore Roosevelt (CVN 71) while underway in the Atlantic Ocean on April 3, 2005. Identification Friend or Foe, known as IFF enables a pilot to distinguish enemies in flight. McMillan, of Mission Hills, Calif., is a Navy aviation electronics technician. SHARE: Download: Full Size (0.05 MB) Credit: VIRIN: 950793-M-UON85-963.jpg Photo Gallery