The incident yesterday of an Air Canada Jazz pilot who found himself trapped outside the cockpit of a Bombardier CRJ-100 after a trip to the toilet has awoken debate into the effectiveness of security measures as we head towards the fifth anniversary of 9/11.

Yesterday, passengers on the Jazz service from the Canadian capital Ottawa-Hull to Winnipeg, Manitoba watchjed in amazement as the captain was trapped in the cabin after the door locks on the reinforced cockpit doors malfunctioned. Crew members were forced to take the door off its hinges to let him back in after the incident, which happened 30min before the scheduled arrival of the aircraft in Winnipeg.

Air Canada Jazz spokeswoman says the first officer had remained on the flight deck throughout, and that the CRJ-100 had not started its descent when the incident occurred. Jazz says the first officer could have landed the flight by himself, and there had been no danger.

Transport Canada is not investigating the minor incident, which is the first reported malfunction of cockpit doors. The bullet-proof barriers to the flightdeck were introduced in the aftermath of the 11 September 2001 airborne terrorist attacks in a bid to prevent intruder access to the aircraft controls. Canadian federal funding was provided to help air carriers install fortified cockpit doors on around 500 aircraft under the Canadian Air Carrier Protective Programme.

Jazz stresses that the safety and security of the passengers was never compromised, but questions are being asked in aviation safety blogs about the redundancy of the locking mechanisms and procedures in place in case of inability to re-open the doors.

The Ontario daily newspaper Toronto Star reports that Peter St John, an anti-terrorism lecturer at the University of Manitoba, says the incident "sends a message to terrorists" that hijacking aircraft is still "fairly easy to do".