What was found
(CAN) AT INSPECTION OBSERVED THE FRONT DOOR HANDLE IN OPEN POSITION BUT STILL ABLE TO START ENGINE. UPON INSPECTION, FOUND WITH DOOR OPEN MANUALLY OPERATING PLUNGER ON FORWARD DOOR LOCK OUT SWITCH ON LOWER DOOR SILL, FOUND SWITCH PLUNGER SEIZED IN CLOSED POSITION. THIS CAN ALLOW AIRCRAFT TO BE STARTED WITH FORWARD DOOR NOT LATCHED PROPERLY. RECTIFICATION IS TO REPLACE SEIZED SWITCH PLUNGER AND LUBRICATE SWITCHES ON A REGULAR BASIS. (TC NR 20070717019)