As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SPS - FLT 3635 - CREW REPORTED THE MAIN HYDRAULIC ACCUMULATOR PRESSURE WENT TO ZERO IN FLIGHT. LANDING GEAR WAS PUMPED DOWN AFTER GETTING NO RESPONSE FROM HYDRAULIC OVERRIDE. EMERGENCY WAS DECLARED AND AIRCRAFT WAS LANDED SAFELY IN SPS. MAINTENANCE REMOVED AND REPLACED THE MAIN HYDRAULIC PUMP IAW SAAB MM. OPERATIONAL CHECK WAS GOOD AND AIRCRAFT WAS RETURNED TO SERVICE. (M)