As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKE OFF FROM KPHL TO KTOL, DURING GEAR RETRACTION A NOISE AND VIBRATION OCCURRED. WHEN GEAR WAS LOWERED NOISE AND VIBRATION DISSIPATED SLIGHTLY. GEAR WAS CYCLED AND NO CHANGE OCCURRED. MAINTENANCE FOUND DUCT SEPERATED AT COUPLING. RESECURED DUCT, RESECURED CANVAS CURTAIN IN NOSE WHEEL WELL, IAW MM. INSPECTION OF NOSE WHEEL FRICTION BRAKES FOUND NO DEFECTS. AIRCRAFT WAS RETURNED TO SERVICE.