On September 2011, Citilink as SBU Garuda Indonesia started to operate A 320, the first aircraft with fly by wire technologic. A 320 can be classified to narrow body aircraft such as B 737 Classic or B 737 Next Generation. A 320 has some difference with other narrow body that Garuda Indonesia operated. One of important thing to know by maintenance engineer when handling this aircraft is emergency exit door of A 320.
Emergency exit of A 320 such as B 737 NG, there are four overwing emergency exits as well as four regular passenger / crew doors. But the difference is emergency exit has escape slide mechanism. Each emergency exit hatch has a slide release mechanism with two operation modes. These are the NORMAL mode and the MAINTENANCE mode. During the NORMAL mode, the latch pin of the slide release mechanism is in the ARMED position (the latch pin is extended). When the emergency exit hatch is removed, the slide release mechanism operates the emergency escape slide automatically. As a maintenance engineer, we have to avoid escape slide release automatically without desirable. During the MAINTENANCE mode, the latch pin is in the DISARMED position (the latch pin is retracted). This prevents an operation of the emergency escape slide when the emergency exit hatch is removed during the maintenance procedure. A proximity switch monitors the ARMED/DISARMED position of the latch pin. If the latch pin is retracted, the proximity switch sends a signal to the Electronic Centralized Aircraft Monitoring (ECAM) system. To prevent accidental operation of the hatch locking mechanism, the release warning system gives two different warning signals. One signal is sent to the ECAM system and the other gives a visual warning in the cabin.
To open one of the two emergency exit hatches from the outside, a red panel has to be pushed in, the door falls into the cabin and activates the escape slide release mechanism. To open one of the two emergency exit hatches from the inside, pull down the cover flap from the recess. A slide armed indicator illuminates to show that the escape slide release mechanism is in the armed configuration. To disarm the mechanism, turn the retractable pin a quarter turn anticlockwise. This is confirmed by the extinguishing of the slide armed indicator. Pull the lever of the hatch control handle to the down position. Carefully let the top of the hatch fall inwards so that it comes clear of the structure. Take the lower handle and pull the hatch from the recess. A red manual handle can be used to activate the escape slide release mechanism manually. Install a rigging pin in the provision of the hatch frame. A ditching line attachment point housed in the door frame, and a dual point on the wing upper surface enable the ditching line to be connected.
So before engineer do maintenance check (remove / install) please caution this step :
1. make sure that the safety/lock pin is correctly installed in the regulator valve assembly of the inflation reservoir. this prevents accidental discharge of the inflation reservoir and deployment of the escape-slide. Which can cause injury and/or damage.
2. make sure that the latch pin is retracted in the disarmed position during the removal and installation procedure. this prevents an accidental operation of the escape slide mechanism during the removal/installation.
3. make sure that the safety pin is correctly installed in the hatch frame if the emergency exit hatch is removed. this prevents an accidental operation of the escape slide mechanism during the maintenance.
Ref :
AMM 51-21-00
AMM Task 52-21-11-000-001
A 320 Training manual Hanbook JCT-0124
