Captain Paul D. McCarthy is an Attorney and former representative of the International Federation of Air Line Pilots Associations at ICAO. For him, unruly passengers present a significant challenge to airlines with several different types that have to be dealt with.

An unstable passenger presents a problem that may require a more nuanced approach from the cabin crew. Alcohol induced misbehavior, often due to consumption prior to boarding, has always played a significant role in bad behavior, but has usually been manageable by the cabin crew.

A more difficult type is akin to road rage, which the cabin environment may contribute too. This is particularly difficult for the cabin crew to defuse as they may be perceived as a cause of the problem.

Since 9/11, there is also the ever-present threat that unruly behavior is in fact a diversion for an action against the aircraft. In all of these cases it is left to the aircraft commander to manage the situation and decide if restraint or an off schedule landing is necessary.

Since 2001, the industry has rethought the procedures in place to address unruly passenger events. No longer is it permissible for a member of the crew to leave the flight deck to control the situation. The flight deck door must remain locked as long as there is a disturbance in the cabin.

This final defense against appropriation of the aircraft for bad purposes must remain in place at all costs. It has proven to be the most effective protection we have against a repeat of the events of 11 September. This procedure does have adverse consequences for the management of unruly passenger incidents. The aircraft commander must rely on the verbal reports of the cabin staff for any decision making.

Cabin staff can become directly involved in the unruly passenger event. Will this color the way in which events are reported to the flight deck? Will the seriousness of the situation be objectively assessed? Will the appropriate course of action be endorsed?

Unless there is effective training for this situation, reinforced at recurrent intervals, it is possible that events, which might have been manageable, lead to an overreaction, such as restraints or an off schedule landing. In the case of an off schedule landing, the costs to the airline and inconvenience to the passengers are obvious.

If the consequences to an unruly individual are known and appreciated by passengers, generally the threat of an off schedule landing may have a significant deterrent effect during any confrontation with the cabin crew. However, given the current patchwork of laws found around the world concerning unruly behavior in-flight, this threat may be no more than a wish on the part of the crew.

Where an off schedule landing is made, but the local authorities refuse to act, a difficult situation is created which may have broader consequences for the airline and the crew. More importantly, if the State of landing determines that the unruly passenger will not be allowed into the State, the airline may be forced to re-board the individual. It does not take an active imagination to see the difficulties this would present.

The international effort to strengthen local laws concerning prosecution of unruly behavior on aircraft needs to be supported. Cabin crew training needs to focus on effective responses to the various types of unruly behavior presented. These actions will not stop unruly behavior, but will help to control them.