What was found
DURING TAKE OFF FOR A SCHEDULED TEST FLIGHT REQUIRED FOR THE REINSTALLATION OF THE #1 ENGINE. IT WAS NOTICED THERE WAS SMOKE COMING IN THE CABIN AND COCKPIT GASPERS. AN EMERGENCY WAS DECLARED AND RETURNED TO AIRPORT WITH NO OTHER INCIDENT. THE FOLLOWING DAY MAINTENANCE COMPLIED WITH ENGINE RUNS AND LIMITED THE SMOKE DOWN TO THE #2 ENGINE. STANDARDAERO CAME OUT AND BORESCOPED THE ENGINE FINDING NO DISCREPANCIES. IT WAS DETERMINED THAT IT WAS RESIDUAL OIL FROM THE #5 CARBON SEAL FAILING PREVIOUSLY ON THE #2 ENGINE. MAINTENANCE COMPLETED ADDITIONAL ENGINE RUNS AND NO ADDITIONAL SMOKE WAS FOUND. COMPLETED SUCCESSFUL TEST FLIGHT AND AIRCRAFT HAS BEEN RELEASED BACK TO SERVICE.