Simbrief says to descend to FL140 randomly during cruise, then climb back up again

Hello everyone!
I simulate on Infinite flight and a friend reported that he had scheduled a flight from Dubai to London with B777. He scheduled a step climb, but during the cruise the Simbrief told him to descend to FL140 and return to the attitude he was in before.

It’s already happened to me and I took the opportunity to find out if it’s a bug or some restriction.

Thank you very much and I’m waiting.

Hi, it’s due to an airway restriction. Normally trying a different route will fix it.

In this particular case, L768 is restricted to FL145. but only on the default (outdated) AIRAC cycle. Cycle 2110 no longer has that restriction and would not have caused a step-down.

Best regards,

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Hello @SimBrief First thanks for your attention. I understand, taking advantage of where I can see this restriction airway?

The easiest way I can think of to see airway restrictions would be in Navigraph Charts. You can click an airway to view the minimum/maximum altitudes and other information:

Otherwise, it often requires digging through the AIP for the country in question.

Best regards,

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I have a subscription and I had never seen it in front of me :grin:
Thank you very much and have a nice weekend.

Greetings :flight_departure:

A note of warning regarding a long standing issue ( and as a reminder to the posted issue :wink: ) with the NG data regarding differing FL availability in opposite directions. The FL range may not be equal and the NG data will contain the lower figure.

As NG are now apparently using the data to drive their own depiction of airways on the map the problem is replicated there.

As an example L60 in the UK has differing availability between OTBED and MAMUL. In this instance the NG AIRAC data will restrict planning to FL230 which actually only applies westbound. This obviously can also lead to descents within the planned flight if travelling eastbound and not corrected.

Reference to the AIP is really the only resolution:


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