As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BEZEL GASKET ROLLED FROM SEAT ALLOWING PRESSURIZATION TO ENTER AIRSPEED INDICATOR. THIS CUASED LARGE ERROR IN AIRSPEED, ALTIMETER, AND V.S.I. DURING FLIGHT. UNIT HAD BEEN REPAIRED PRIOR TO FLIGHT. RECOMMEND A POST-ASSEMBLY INSPECTION TO DESIGN PRESSURE LIMITS TO DETECT SIGNS OF INTERNAL LEAKS.