Flight Deck Security

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Article Information
Category:	Loss of Control
Content source:	SKYbrary
Content control:	EUROCONTROL

Contents 1 Description 2 Flight Deck Access 3 Flight Safety Issues 4 Solutions

Description

Following the events of 11 September 2001, when terrorists seized control of 4 airborne aircraft over the United States and demonstrated a new potential consequence of aircraft hijacking, the air transport industry and airlines in particular have instituted a range of physical and procedural defences to deter and prevent such acts.

Editor's Note: This article is intended to specifically highlight the operational flight safety issues associated with flight deck security and does not cover procedures, protocols and operational aspects of the overall security system

Flight Deck Access

Controlling access to the flight deck is part of the process of ensuring that legitimate control of an aircraft can be maintained. The door must be lockable and of reinforced construction so that access is only possible if it is opened normally and such that it is resistant to penetration (e.g. with a bullet) or intrusion (e.g. by being hit by a trolley) when closed. Access through the door to the flight deck should be procedurally controlled both in the air and on the ground and should be limited to personnel for whom entry is essential.

On the ground, this means that only designated flight crew and maintenance personnel should normally have access; if cleaners need to enter, then they should have already been subject to an identity validation check at aircraft boarding and be directly supervised by authorised operational or security personnel whilst in the flight deck.

In the air procedures vary from airline to airline and from region to region, but the principle that only those with legitimate need must be permitted flight deck access must be paramount. Beyond the flight crew at the controls, this will include relief, check and training pilots and may include other approved flight crew on duty, cabin crew who are part of the operating crew and maintenance crew who have need to carry out observational or other tasks in flight. Flight Operations Inspectors carrying out observations on behalf of the State Regulatory Body may also be permitted access subject to valid identification being presented to the aircraft commander before entry.

In flight, the door should always remain locked unless there is a legitimate reason to open it and it should remain open only long enough for someone to pass through it. There must be clear criteria in place for the door to be opened at any time between the completion of engine start at the beginning of the flight and engine shutdown after it is complete.

Flight Crew Cabin Surveillance Systems and electronic or manual locks which can be operated by the flight crew without leaving their seats, and sometimes also from the passenger cabin, are essential and often exist as Regulatory Requirements. Appropriate procedures must be in place to minimise the possibility of system abuse and unauthorised entry onto the flight deck.

If any form of disturbance occurs within the aircraft passenger cabin, e.g. an unruly passenger incident, then access to the flight deck should cease immediately in case the disturbance is a deliberate attempt to distract the crew.

Flight Safety Issues

• Communication. A locked flight deck door reduces the situational awareness of the flight deck crew in respect of conditions in the passenger cabin in the event of an onboard emergency. Also, the situational awareness of the cabin crew is reduced in respect of conditions on the flight deck in the event of an emergency.

• Crew Incapacitation. Should all the flight crew become incapacitated, cabin crew may not be aware and may not have access to the flight deck to assist.

• CRM. The locking of the flight deck door reduces routine interaction between the flight crew and the cabin crew during the flight. This emphasises the importance of the aircraft commander using pre flight preparation and turnround time to ensure that they have made preparations for effective CRM in whatever circumstances may ultimately prevail.

• Physiological Need. Naturally, the need for flight crew to use toilets, access designated crew rest facilities or be supplied with food and drink, requires access through the flight deck door during flight. Procedures for door opening mean that egress and access will take longer with the result that the flight deck crew are not always able to go to the toilet at a time of their choosing, which may cause them to be distracted and, occasionally, exacerbate existing medical problems or encourage the onset of new ones.

Solutions

• Communications protocols. Cabin crew should avoid routinely contacting the flight deck during times when they are likely to be occupied with a high workload. Most airlines use a signalling system for the flight crew to indicate to their cabin crew that it is safe to commence cabin service after take off. In some airlines, subject to this call being received, the cabin crew make no intercom calls to the flight deck until top of climb, when they will make a courtesy call to confirm that the pilots are not incapacitated. More commonly, a maximum time interval is set between intercom calls from the cabin crew to the flight deck which applies throughout the en route phase of the flight and is typically 30 minutes. In the event of an emergency, the senior cabin crew member will normally take personal responsibilty for liason with the flight crew who may be especially in need of intercom reports of conditions in the passenger cabin in order to decide on their course of action.

• Emergency Flight Deck Access. Most security systems have the facility for emergency access to the flight deck; such systems have safeguards built in to allow the flight crew to prevent access, for example by building in delays to the door opening such that the flight crew, if not incapcitated, can overide the lock release.

• Double Door system. Some aircraft have an "air lock" type door system, with 2 doors and a toilet in between. The airlock system ensures that there is never an open door to the flight deck. However, such systems take up space and are therefore only found on some larger aircraft.

• Door Construction. Strong, lightweight, composite materials often provide the required security with minimal increase in weight, which makes the door no more difficult to operate once unlocked than a non-security door.

• CRM. The flight crew should make the most of any incidental time shared with their cabin crew such as on the crew bus to get to know the crew. While there may be no requirement to carry out a pre flight internal inspection, it can be beneficial to make a point of walking down to the back of the aircraft to briefly re-establish personal contact with all the cabin crew team.