Published date: 1 November 2022


This AC describes an acceptable means of compliance with Civil Aviation Rule Part 121, which, if included in a certificate holder’s exposition, would support an application for Extended Diversion Time Operations (EDTO) and/or polar area operations authorisation. It explains means acceptable to the Director for a New Zealand-registered twin turbine engine Part 121 aeroplane to be eligible to operate over a route, or a designated polar area, that contains a point further than 60 minutes’ flying time from an adequate aerodrome at an approved one-engine inoperative cruise speed.

This Revision also includes provisions for the authorisation of Part 121 turbine engine aeroplane with more than two engines to operate over a route beyond 180 minutes from an adequate aerodrome. Specific criteria are included for deviations up to 180 minutes, up to 240 minutes, and greater than 240 minutes from an adequate aerodrome.

Related rules

This AC relates specifically to the rules regarding EDTO (Subpart G, rule 121.407, Maintenance elements for EDTO, and Subpart N, EDTO Authorisation and Operations, and rule 121.165, Route distance limitations, and those relating to the conduct of polar area operations: rule 121.171, Requirements for Air Operations in a Polar Area, rule 121.173, Application for Air Operations in a Polar Area, and rule 121.175, Authorisation for Air Operations in a Polar Area.

Change notice

Revision 2 makes minor updates to the Application (General) section in line with the recent forms refresh.

We have also made a marked-up copy [PDF 897 KB], so changes can be easily checked. As with other ACs, text in yellow highlight denotes insertions and text in strikethrough denotes deletions.