What was found
AIRCRAFT WAS GROUNDED: CREW REPORTED PRESSURIZATION UNCONTROLLABLE IN AUTO SYSTEM 1, AUTO SYSTEM 2,AND MANUAL. AN EMERGENCY WAS DECLARED AND THE AIRCRAFT RETURNED TO CLT WHERE IT LANDED SAFELY WITHOUT FURTHER INCIDENT. MAINTENANCE ACCOMPLISHED PRESSURIZATION TEST AND WAS UNABLE TO PRESSURIZE THE AIRCRAFT ABOVE 4 PSI. FOUND FORWARD CARGO DOOR SEAL INCORRECTLY INSTALLED AND LEAKING. MAINTENANCE REPLACED THE SEAL PER AMM 52-31-18. AND A SATISFACTORY LEAK CHECK WAS ACCOMPLISHED.