What was found
DURING FLIGHT 1070 MKE TO SDF AT FL 210 THE CREW GOT A CABIN HIGH INDICATION. THE CREW DECLARED AN EMERGENCY AND DID AN EMERGENCY DESCENT. THE A/C DECOMPRESSED SLOWLY AND BY FL 100 THE A/C HAD NO PRESSURIZATION. BOTH THE CREW AND PASSENGER DONNED OXYGEN MASKS DURING DESCENT. THE CREW FLEW THE A/C BACK TO MKE WITH NO FURTHER INCIDENT. THE A/C PRESSURIZATION SYSTEM WAS PUT ON MEL AND THE A/C WAS RETURNED TO SERVICE. MORE INFORMATION WILL BE ADDED ON THE CLOSING OF THE MEL.