31 July 2011 C1 CIVIL AVIATION DEPARTMENT HONG KONG ...

FAR/JAR 25.812(l)(1) requirement can be met even though, in a crash,there may be a considerable distance between the two verticallyseparated parts of the fuselage.3 Evaluations3.1 The means provided in showing compliance with the requirement of theAN(HK)O shall be the subject of an evaluation by the Director-General. Inaddition, all concepts not already approved shall be the subject of ademonstration to determine both the strengths and weaknesses of a particularsystem.3.2 Engineering evaluations and demonstration tests should be conducted inconditions of darkness either at night or where conditions have been simulatedby preventing daylight from entering through windows or through exits whetheropen or closed.3.3 Where it is intended that an aircraft's MEL is to permit continued operation ofthe aircraft with some elements of the system unserviceable, the test subjectdemonstration should be conducted with the system configured so as to simulatethe relevant MEL standard.3.4 A demonstration should clearly show, to the satisfaction of the Director-General, that test subjects, on leaving their seat in any part of the passengercompartment and entering the cabin aisle, can, using the visible signs andmarkings, immediately determine in which direction(s) exits are to be foundusing visual references only.3.5 The demonstration is intended to establish that there are adequate visualreferences which will provide the necessary orientation of the passengers. Itis not necessary to assess the passenger evacuation rate under these conditions.Obstructions created by loose cabin baggage, etc., need not, therefore, besimulated, except in so far as baggage might interfere with an illuminationsystem.3.6 In assessing the effectiveness of all visual cues, the existing emergency lightingsystem which provides illumination from locations more than 4 feet above thecabin aisle floor, must be switched off. It is not intended that the test shouldbe performed in conditions of smoke but simply taking into account itsblanketing effect. Therefore, care needs to be taken to ensure that, in theabsence of an overlaying smoke, the floor proximity system is prevented fromilluminating and hence reflecting light from parts of the cabin above the 4 feetlevel.3.7 Test subjects should not have detailed knowledge of the aircraft other than thatobtainable from a study of the normal Passenger Safety Leaflet. The totalnumber of test subjects is not critical but they should be adults and shouldinclude both males and females over 60 years of age.31 January 2002 AN-56 P.4