AMC to Appendix S, S25.20(b)(1) Ensuring removal of in-flight obstructions before take-off and landing

This paragraph provides guidelines regarding the criteria under which an item, although constituting an obstruction that does not comply to CS 25.813(c), may be considered acceptable because per design and procedure, there can be high confidence that the obstruction will be removed when needed for safety (S25.20(b)(1)). In addition to the exceptions set in Section 2 — Deployable features of AMC 25.813(c), an item which can be deployed by a crew member or passenger into the region defined by CS 25.813 (c)(4)(i) or into the passageway required by CS 25.813 (c)(1), (2) or (3), but which, when stowed, is no longer in either of these areas, is acceptable if there is enough assurance that the item will be stowed when needed. Such assurance may be assumed when all following conditions are met:

(1)A position monitoring system is installed, which detects that the item is not properly stowed, and triggers both alerts in the passenger cabin and a visual indication to the flight crew if the item is not properly stowed before entering any of the taxiing, take-off, approach, and landing phases.

(2)The alerts in the cabin, required in paragraph (1), include an aural device which sounds continuously in all areas of the passenger cabin (it should be loud enough to clearly act as an irritant, thus assuring that occupants will stow the obstruction, but not so loud as to distract the flight crew), as well as a conspicuous electrically illuminated sign showing an appropriate text message or pictogram, in the immediate proximity of the relevant emergency exit.

(3)The alerts described in paragraph (2), are triggered without delay if the deployable item is moved away from the safe position during any of the taxiing, take-off, approach, and landing flight phases, or, if upon entering these phases, the item is not stowed in the safe position. When preparing for landing, the alerts are triggered at a point that allows ample time for a cabin occupant to re-stow the deployable item before landing. It should be considered that the cabin occupant needs to move within the cabin to reach the deployable item, therefore, the alerts should be triggered during descent, allowing enough time prior to entering the approach phase, unless the aeroplane is required to have at least one cabin crew member on board; The aural and visual alerts should both remain on until the obstacle is properly stowed.

(4)The visual indication provided to the flight crew, described in paragraph (1), is triggered without delay if the deployable item is moved away from the safe position during any of the taxiing, take-off, approach, and landing flight phases, or, if upon entering these phases, the deployable item is not stowed in the safe position. When preparing for landing, the visual indication is triggered during the descent phase, early enough to enable the crew to take appropriate action before entering the approach phase.

(5)The failure to alert in the cabin or cockpit that an item is not properly stowed is demonstrated to have an average probability per flight hour of the order of 1 x 10-3 or less.

(6)Instructions are given to the passengers and cabin crew (if any), by means of appropriate placards and a pre-flight briefing, that the obstacle should be stowed before entering any of the taxiing, take-off, approach, and landing phases. The pre-flight briefing (which could be part of a regular briefing) should describe the position monitoring and alerting system, as well as the necessary response by the passengers. The requirement for this briefing should be part of the AFM.

(7)A description of the position monitoring and alerting system is made available to the flight crew. The AFM should also include the appropriate normal procedure ensuring that the cabin is ready (i.e. a check that no visual indication, as defined in paragraph (4), being present) prior to landing, and an instruction that the crew takes all necessary actions when the visual indication, as defined in paragraph (4), is triggered.

(8)The emergency exit provided when the obstruction in its most adverse position(s) is at least as effective as a Type IV emergency exit, unless it can be shown that following any single failure an exit at least as effective as a Type IV emergency exit can be obtained by simple and obvious means. If the obstructing item is a seat, the normal seat operating controls (e.g. track, swivel, recline etc.) may be considered as means meeting the simple and obvious requirement, provided that the controls remain visible to a person approaching the seat and are easily useable without sitting on the seat, when the seat is in any possible obstructing condition. If movement of the obstructing item to meet the above requires electrical power, it should be substantiated that the required power source(s) will remain available following an emergency landing.

[Amdt 25/19]