While planning some flight over P500 airways, I realize that some MORA informations does not match together between Charts cloud and Simbrief dispatch.
If I look at the OFP, I got this information : “MOST CRITICAL MORA 23000 FEET AT MOTMO”
If I look at the High IFR enroute chart, the MORA around MOTMO is 27600.
Hi, MORAs in SimBrief navlogs are not the same as the grid MORAs in Charts.
Grid MORAs consider terrain within the entire grid, whereas SimBrief navlog MORAs only consider terrain which is within 5 miles of the planned route. The additional buffer provided above the highest terrain point might also differ from the method used for the grid MORAs, especially in the case of very high terrain such as this.
Note how the highest point within the grid is outside of the 5 mile corridor of your route:
Thanks for the reply. I was misled by the term MORA.
In this case, what you explain looks more like an MTCA than a MORA strictly speaking.
But then, the MTCA 5nm alone is only partially relevant, it should be completed by a greater MTCA (basically, MTCA 25nm), because in case of emergency 180° turn in cruise, there is no chance to complete it in 5nm… and in-cruise hallf-turns are exactly the purpose of this information on the OFP
Hi, in this case we are simply emulating the methodology used by the real-world flight planning software that SimBrief is based on. Why they chose a 5nm corridor is not really clear. It’s also possible this is an airline-specific setting.
Most OFPs still use the acronym MORA, despite it being based on a corridor. In this particular case we feel it’s more important to emulate real-world OFPs rather than devise our own parameters and acronyms.
