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

CIVIL AVIATION DEPARTMENTHONG KONG, CHINAAirworthiness NoticeTHIS NOTICE GIVES DETAILS OF A MANDATORY ACTIONNo. 79Issue 530 May 2006ACCESS TO AND OPENING OF TYPE III AND TYPE IV EMERGENCY EXITS1 Applicability1.1 This Airworthiness Notice is applicable to all Hong Kong registeredaeroplanes over 5700 kg MTWA, certificated in the Transport Category(Passenger) and configured to carry 20 or more passengers and equipped withType III emergency exits and/or Type IV emergency exits or their equivalent.Exits considered to be equivalent to Type IV exits are referred to as Type IVexits in this Notice.1.2 For the purpose of this Notice, exits that are smaller in size than Type IIIemergency exits (including elliptical exits) shall be deemed to be Type IVemergency exits, even though they are not formally classified as such.2 Introduction2.1 From a review of accidents, where rapid evacuation of the aeroplane was acritical factor governing passenger survival, Issue 1 of this Notice stated that itappeared that mid-cabin Type III emergency exits, although only rated for arelatively small number of passengers, could, in certain circumstances,become a major escape route.2.2 Following further reviews it has been decided to extend the applicability ofthis Notice to include Type IV exits (Issue 2) and to specify the requirementsfor face-to-face seating configurations.2.3 Current requirements governing the access to Type III and Type IVemergency exits do not quote specific dimensions for the minimum width ofaccess to such exits between adjacent seat rows. Tests have demonstratedthat, with typical economy class seats, seat pitches down to approximately 30inches have little or no effect on the rate of exit egress. The major constrainton the location of seats relative to such exits is the need to ensure that the seatsdo not impede the removal and disposal of the exit hatches.2.4 The Director-General believes that Type III and Type IV emergency exitsAN-79 P.130 May 2006