13th July 2023

Evacuation Alarm

Initial Report

The Forward Attendant Panel (FAP) had been inoperative for 8 days, I was assured this is OK for up to 10 days, but unable to sound evacuation alarm from cabin either FAP or AAP (Additional Attendant Panel), also not able to use toilet lights or pax reading lights also unable to adjust cabin lighting for take-off landing in darkness.

Company Comment

The MEL is created and approved by the UK CAA to comply with all required regulations. As such, when the FAP is inoperative, it is permissible by the regulator not to dim the lights for take-off and landing if an AAP is not fitted, or inoperative.

With regard to the EMER EVAC from the cabin this would only ever be used in line with our procedures:

“The only occasion when the cabin crew will initiate an evacuation is when the situation is clearly catastrophic. In a clearly catastrophic situation the evacuation of passengers must be initiated without delay immediately the aircraft has finally come to rest.”

In such circumstances the evaluation would normally be initiated by the Flight Crew or by any other means e.g. loud hailer, as it is clearly a requirement to leave the aircraft.

CAA Comment

There is no mandatory requirement for aircraft to have an evacuation alarm installed and the rectification interval for an unserviceable system will be determined by the Minimum Equipment List (MEL) for the aircraft in question. UK operators tend not to rely on an evacuation alarm as the only indication of evacuation, but also use evacuation commands, which may also be used in the event of system unserviceability.

Cabin lighting, such as passenger reading lights, are not mandatory airworthiness items and will therefore have a longer rectification interval.

The Operator creates the MEL based on, and no less restrictive than, the master minimum equipment list (MMEL).  This MEL is then internally reviewed and approved before submission to the CAA for final approval.

CHIRP Comment

Manufacturers’ risk assessments determine what is and what isn’t a no-go item and these items are specified in the aircrafts’ Minimum Equipment List (MEL) . It is not ideal for aircraft to be dispatched with inoperative equipment, but such operations are permitted only as a result of careful analysis of each item to ensure that an acceptable level of safety is maintained. The Minimum Equipment List (MEL) also lists the equipment that may be temporarily inoperative, subject to certain conditions, at the commencement of a flight. In the event of any defects being notified or arising before take-off, the Commander must review them against the MEL to ensure the aircraft can still be safely dispatched.

Defects in the cabin are less than desirable especially when they impact the comfort of the passengers on board. If there is a defect in the cabin mitigations or alternative measures may be in place, for example, if the FAP is in-op (and there is no other method available) it is permissible not to dim the cabin lights for take-off and landing.

Regarding the evacuation alarm, if the this was suddenly in-op during the flight, and then in the event of an evacuation, what would you do? If a loud-hailer is available, use it. Otherwise, shout; while automation has many advantages, it shouldn’t always be relied upon. Alternative measures should be discussed with the crew during the briefing, if the defect only becomes apparent onboard, make sure you take the opportunity to address any alternative measures to aid your situational awareness.

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