CE-680A flight crew reported uncontrollable cabin pressure on climb out. The flight crew requested a lower altitude for troubleshooting; but was unable to regain control of the cabin altitude. The flight crew performed a return to the departure airport.
Synopsis
CE-680A flight crew reported uncontrollable cabin pressure on climb out. The flight crew requested a lower altitude for troubleshooting; but was unable to regain control of the cabin altitude. The flight crew performed a return to the departure airport.
Narrative
Upon picking the airplane out of maintenance I noticed in the logbook that the airplane was previously written up for multiple pressurization issues. Once the door was closed to depart before briefing the passengers; I noticed a slight change physically in the cabin; nothing out of the ordinary. After; everything seemed just fine; takeoff was fine; and climb out was fine; up until we realized the cabin was climbing faster than it was supposed to. It kept climbing beyond normal pressurization for cruise when the airplane was at FL180. We then decided to level off at FL180. Normal cabin pressure is 4800 to 5000 ft. The cabin pressurization continued to climb beyond 8000 ft. until we got an amber CAS message and then we decided to descend to a lower altitude and proceeded to run the proper checklist. The cabin never got above 10000 feet so we decided not to Don mask or declare an emergency. We asked for a lower altitude and delayed vectors before landing to burn off extra fuel so we did not exceed landing weight limitations. Landing was normal.
Second reporter narrative
During preflight I noted the aircraft had multiple write ups for pressurization issues since it came out of dual engine change and complete paint on date. Ground operations seemed normal with small pressure changes noted but not outside of normal operations. After takeoff the climb felt normal but I noted it was climbing at 1300 fpm when the aircraft was climbing at 3000 fpm. Normal cabin climb rate should be 300-400 fpm. The normal climb schedule for the aircraft at FL 410 would be below 5000 ft. and out FL 180 it was already through 7000 ft. We asked ATC to maintain FL180 and they approved that. We proceeded to run the cabin altitude amber checklist and the cabin continued to climb in both auto and manual modes. As the cabin approached 9000 ft. we asked for a descent and return to ZZZ. ATC cleared us to 4000 ft. and direct to the airport. We didn't declare an emergency nor donned masks as we didn't exceed 10000 ft. cabin altitude and we're already back down to that altitude with a normal descent as the cabin approached that altitude. The cabin descended with us back to landing. We did use delay vectors to burn fuel to landing weight. The landing was normal. Maintenance appeared to be taking positive action to fix the aircraft after the previous events but it didn't appear Maintenance had considered that these issues could be connected to the previous heavy Maintenance event the week prior.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.