What was found
DURING FLIGHT 3178 FROM RFD TO DTW, LANDING GEAR SELECTED DOWN, INTRANSIT REMAINED ILLUMINATED WITH NO GREEN LIGHTS. CHECKED CIRCUIT BREAKER, FOLLOWED QRH, IT CALLED FOR EMERGENCY EXTENSION AND THE GEAR (ALL THREE) CAME DOWN AND LOCKED. MAINTENANCE REPLACED THE LANDING GEAR CONTROL VALVE P/N HP848430-721, S/N OFF 1167 S/N ON 2059. FOR DETAILS ALL WORKED PERFORMED REFER 409 CARD 133427. ALL WORK PERFORMED IAW SAAB MM CHAP 32. ALL CHECKS GOOD.