Simbrief infinite flight

Hello! So i wanna understand and learn how to use simbrief for flight plan, but there are a few things i dont understand. Hope someone can clear things for me.

:on descent it says 80/300/250. what does the 80 stand for?
:on fuel factor it goes from (P00) to (P80) and the numbers is the same but it says (M) instead of (P)
Thats all. Thank in advance!


You dont necessarily need Simbrief at its fullest extent to apply it in Infinite Flight. uses Simbrief but it will simplify everything to the context of IF, so I’d give thats shot.

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Okay, thank you! But i still wan’t to learn what those things mean!:)

Mach number, 0.80 I think


Descent has three numbers: 80 = mach 80, 300 = kts, 250 is the speed in knts when below 10.000 feet.


Thank you for explaining PHMEL:)

Do you know what the p00/p80 means?

No, sorry. I’m curious too. Although I never use it.

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All good. Lets wait and see if anyone can tell us

Cost index: (time cost)/(fuel cost). Higher CI means higher time cost, resulting in shorter trip time. Lower CI means higher fuel cost, resulting in lower fuel burn. IRL the pilot will select a cost index and the FMC will calculate the optimum speed. This feature is not present in IF.

Climb profile: the speeds to follow during climb. For example, 250/300/78 means 250kt to 10000ft, then accelerate to 300kt and climb to Mach transition altitude (in IF it’s fixed at FL280), after that adjust to M0.78 and climb to cruise.

Fuel factor:

For the sake of flight planning in IF, you only need to fill the mandatory blank in red.

After that, this tool can take care of the rest for you.


Wow! Well explained, much appreciated! One thing tho… you said : after that adjust to M0.78 and climb to cruise. Can you explain that in a different way maybe? What does the (M0.78) mean?

In IF, when you pass FL280, the speed unit in your autopilot changes from knots to Mach, which is the ratio of your speed to the speed of sound at that altitude. M0.78 means your speed is 78% of the speed of sound.


I see, thank you for clearing it for me.

Simbrief also has a good user guide and tutorial video in the Help tap on the Home Page. I would suggest reading and watching the video.


Actually my opinion Simbrief Is way Better and more realistic!!

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