As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE RIGHT HAND AIR PRESSURE PUMP FAILED ON A NORMAL FLIGHT. NO UNUSUAL CONDITIONS EXISTED AT THE TIME. WHEN THESE PUMPS FAIL, THEY NORMALLY SHEAR THE COUPLING SINCE THEY ARE DESIGNED TO DO THIS. IT IS NOT KNOWN WHY THIS PUMP FAILED PREMATURELY AT 400 HOURS. THEY NORMALLY GO TO 500 HOURS.