What was found
AIRCRAFT WAS GROUNDED: AFTER TAKEOFF , UNABLE TO RETRACT FLAPS FROM 1 TO UP. AN EMERGENCY WAS DECLARED AND THE AIRCRAFT RETURNED TO DFW WHEERE IT LANDED SAFELY WITHOUT FURTHER INCIDENT.FLIGHT CREW FOLLOWED QRH. ALT FLAPS USED FOR F15 LANDING WITH A NORMAL TOUCH DOWN AND LIGHT BRAKING. MAINTENANCE REPLACED THE RIGHT TRAILING EDGE FLAP POSITION TRANSMITTER AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK PER AMM 27-58-01.