L29 FLT CREW HAS THE CANOPY DEPART THE ACFT INFLT.

Narrative

10 MINS AFTER TKOF; WHILE CLBING THROUGH 5000 FT; COCKPIT PRESSURE LIGHT ILLUMINATED. I THEN NOTICED THE FRONT L CANOPY LATCH WAS NOT IN PLACE. CANOPY HANDLE WAS LOCKED AND CANOPY AJAR LIGHT WAS OUT. I THEN ATTEMPTED TO MOVE THE CANOPY INTO THE LOCKING MECHANISM AND THE CANOPY DEPARTED THE ACFT. I SHOULD HAVE RETURNED FOR LNDG AND ADJUSTED THE CANOPY ON DECK. A CONTRIBUTING FACTOR WAS THE TIME LINE NEEDED TO JOIN 3 OTHER ACFT FOR FORMATION TRAINING. WHILE I VISUALLY CHKED THE CANOPY LEVER FULL FORWARD AND LOCKED; AND THE CANOPY AJAR LIGHT OUT; I DO NOT RECALL VISUALLY CHKING THE FRONT L CANOPY LOCK IN PLACE. THE UNDERLYING LESSON LEARNED WAS THAT IF THE CANOPY WERE IN PLACE; IT WOULD LIKELY STAY IN PLACE FOR A SLOW SPD RETURN TO THE AIRFIELD TO RE-LOCK THE CANOPY. 702649: CABIN PRESSURE WAS NOT AN ISSUE. THE LIGHT INDICATED THAT THERE WAS A POOR SEAL BTWN THE CANOPY AND THE FUSELAGE. AT LOW ALT; SUCH A CONDITION PRESENTS NO HAZARD TO FLT. BETTER CRM WOULD HAVE PREVENTED THE OCCURRENCE.