Hello all, just after some guidance regarding the need for an alternate when utilising dual TSO C129a GNSS in RPT and charter operations.
My understanding previously was that a C129a unit could not be utilised for the purpose of meeting the radio navigation aid requirements for alternate planning at either the destination nor the alternate, however this appears to have been changed (perhaps quite sometime ago without my realising).
CAO 20.91 Appendix 13 (page 95 of 95) states:
6.6 For the purposes of flight planning, any required alternate aerodrome must have an available instrument approach procedure that meets the requirements of this Appendix for the equipment installed in the aircraft.
6.7 For aircraft equipped with (E)TSO-C129 ( ) GNSS systems, the alternate
aerodrome must have a non-GNSS approach procedure available and the aircraft must have the requisite equipment installed and operative.
The AIP and Jeppesen mention extracts from CAO 20.91 regarding this as well (AIP ENR 3.3 para 2 / Jepp (electronic) Pacific - page 371 para 6).
Additionally the AIP and Jeppesen state under "Radio Navigation Systems" (AIP GEN 1.5 para 2 / Jepp Pacific - page 790 para 5.12):
If GNSS equipment in accordance with (E)TSO-C129 is used and if an alternate aerodrome must be planned:
a. navigation to the alternate aerodrome should be accomplished by use of ground-based navigation aids;
and
b. the alternate aerodrome should have a suitable approach that uses groundbased navigation aids, or the alternate aerodrome must be suitable for approach in VMC.
So my questions are as follows:
1. If the aircraft is fitted with 2 x TSO-C129 GNSS units, provided that all other non nav-aid conditions are met regarding alternate planning, does the destination not require an alternate?
2. If the destination requires an alternate due to conditions not relating to nav-aids, does the nominated alternate require ground based nav-aid(s)?
I apologise for the long post and if it seems like I have answered my own questions, however I am just after clarification and guidance.