As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAIN DOOR: WITH APU RUNNING AND BLEED AIR ON THE MAIN CABIN DOOR WOULD NOT CLOSE. THE DOOR SEAL WAS INFLATED. SHUT OFF THE BLEED AIR WITH NO CHANGE. WHEN WE SHUT OFF THE APU THE SEAL DEFLATED AND THE DOOR CLOSES NORMALLY. /// CORRECTIVE ACTION /// OPS CHECKED MAIN CABIN DOOR SEAL IAW CESSNA 560XL AMM CH 52-10-04, OPS CHECK SATISFACTORY.