5.2 Exits with Slides & Slide-Rafts: Arming, Disarming & Normal Operation

Ready for evacuation: the regulatory hook

Nig. CARs 8.9.2.6 states that no person may cause an aircraft to move on the surface, take off or land unless each automatically deployable emergency evacuation assisting means installed on the aircraft is ready for evacuation. In plain language: every slide that is supposed to be armed must be armed before the aircraft moves. This single regulation is the legal basis for the arming and cross-checking ritual performed on every sector.

How arming works

Two mechanisms are in common use, and both do the same thing — connect the slide's girt to the aircraft floor so that the opening door drags the pack out and fires the inflation bottle.

Armed means the door is in the emergency configuration: opening it deploys and inflates the slide within seconds. Disarmed means the door will open normally, as at the gate.

The cross-check discipline

Arming and disarming is never a private action. The sequence is:

1. Command. The senior cabin crew member or the flight deck gives the command — for example on the PA before departure and again on arrival at the stand.
2. Action. Each crew member arms or disarms their own door.
3. Cross-check. A second crew member physically looks at the door and confirms the indication. This is not a glance; it is a deliberate check of the mechanism and the flag.
4. Report. Each pair confirms to the senior cabin crew member, who confirms the cabin status to the flight deck.

The reason for the ritual is that the same physical action produces two opposite outcomes depending on state, and the person performing it is usually busy, tired or interrupted. Cross-checking is a barrier designed around a known human-factors failure.

A crew member who is not certain of the state stops and verifies. Never open a door "to see". The correct sequence is to confirm the indication first, and if the indication is ambiguous, to call the senior cabin crew member before touching the handle.

Pre-flight checks at a slide-equipped exit

1. Arming indication legible and consistent with the required state for the phase.
2. Girt bar or arming lever intact, undamaged, correctly stowed or engaged, with the retaining device in place.
3. Slide pressure gauge, where visible through an inspection window, with the needle in the green operable band. A needle in a low or high band is reported.
4. Slide pack properly seated in its container, the container door closed and latched, no visible fabric protruding.
5. Manual inflation handle present in its stowage, unobstructed and clearly identified.
6. Viewport clean; the exterior visible.
7. Escape path and door area clear, since Nig. CARs 8.9.2.7 prohibits carry-on baggage or other items from blocking access to emergency exits while the aircraft is moving on the surface, during take-off or landing, or while passengers remain on board on the ground.
8. Adjacent emergency equipment present and serviceable.

Normal operation: opening at the stand

1. Receive and acknowledge the disarm command; disarm and cross-check.
2. Check the viewport: is the airbridge or step in position, is the ground area clear of personnel and equipment.
3. Confirm the disarmed indication a final time.
4. Operate the handle through its full travel in the direction indicated.
5. Allow the door assist to open the door; guide it, do not fight it.
6. Latch the door fully open before releasing.

Closing before departure

1. Confirm the escape path and sill area are clear, and that no ground equipment is in contact with the aircraft.
2. Release the door latch and bring the door under control.
3. Close and latch fully; verify the door-closed and locked indication.
4. On the arm command, arm and cross-check, then report to the senior cabin crew member.

Inadvertent deployment

If a door is opened while armed, the slide deploys and inflates in a few seconds with considerable force.

Consequences: serious injury or fatality to ground personnel, damage to the airbridge or the aircraft, the aircraft removed from service until the slide is repacked and recertified, delays and diversions of the operation, and a reportable occurrence with an internal investigation.

Immediate actions if it happens: shout a warning to clear the door area, notify the flight deck immediately, prevent passengers from approaching the open exit, keep the door area clear, and preserve the position of the girt bar or lever exactly as found so that the investigation can establish what happened. Do not attempt to retract or repack the slide.

Prevention is entirely procedural: arm and disarm only on command, always cross-check, never open a door outside the standard sequence, and never allow an interruption to break the sequence part way through. If interrupted, restart the sequence from the beginning rather than assuming where you had reached.