What was found
CREW REPORTED, AFTER TAKEOFF RECEIVED LANDING GEAR AIR/GROUND FAILURE WARNING, UNABLE TO RETRACT LANDING GEAR. AIR RETURNED, AND LANDED UNEVENTFULLY. AIRCRAFT MAINTENANCE FERRIED TO RIC. MAINTENANCE TIGHTENED NR 2 (RIGHTHAND) MAIN LANDING GEAR WOW PROXIMITY SWITCH IAW EMB145 AMM 32-61-02. OPS CHECKED GOOD (SEE M-602 677475), AIRCRAFT RELEASED FOR TEST FLIGHT, AIRCRAFT TEST FLOWN SATISFACTORILY, AIRCRAFT RETURNED TO SERVICE.