As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) WHILE ON A ROUTINE LOCAL TRAINING FLIGHT, THE PILOT EXPERIENCED SEVERE VIBRATION FROM THE ENGINE/PROPELLER. RETURNING TO THE AIRFIELD THE AIRCRAFT WAS LANDED SAFELY. INSPECTION REVEALED THAT ONE PROPELLER BLADE DE-ICER BOOT HAD DETACHED FROM THE BLADE AND WAS MISSING. THE MISSING BOOT HAD BEEN INSTALLED ON SEPT 9/2005 AND HAD ACCRUED 343.7 HRS TSN. (TC NR 20060207004)