FPL to IF Simbrief Generator

I was using this because I found it in one of the topics here in the Infinite Flight Community I had once used it before, but this time I was going to try my first-ever Long Haul flight from EGLL to KLAX but for some reason when I got to cruise altitude which was recommended for 38000 ft in a Air Force One Boeing V25 my aircraft went out of control it started to rapidly descend shortly after I added altitudes to my way points in order to use vnav it was also losing speed so I ended the flight to avoid any possible violations can someone please explain to me how to use this flight plan generator correctly up to and including using s i d and stars and assigning appropriate attitudes into the flight plan

🌟 Any advice would be appreciated greatly 🙏

Hello! This may have been due to your aircraft being too heavy for the given altitude. It is recommended to climb to a lower altitude first, as the aircraft consumes more fuel it becomes lighter and more suitable to climb to higher altitudes. I’d recommend checking out the step climbing page from the flying guide for further details :)


I’m sorry but I’m still a tad confused on that as well as the rest of my post


It is recommended to climb to a lower altitude at first. If your final cruising altitude was 38,000ft, it is recommended to have a lower initial cruising altitude, (32,000ft for example). This figure would depend on your aircraft’s weight. As you travel, your aircraft would lose fuel, which in turn makes it lighter, thus making it more suitable to climb to a higher altitude. This procedure is an idea of the term “Step Climbing”. Climbing directly to the final cruising altitude may cause your aircraft to stall if it is too heavy.

In regards to fpltoif.com assigning these altitudes, i believe they have assigned certain altitudes to each waypoint, also including the step climbing procedure if needed. If at any time you feel that your aircraft is not suitable to meet the recommended altitude, don’t hesitate to descend to a more suitable altitude and perform the step climb procedure to meet your final cruising altitude.

Hope this helps, please let me know if you have any further questions.


Your aircraft was too heavy and, at higher altitudes, aircrafts need more thrust and subsequently the heavier you are the higher your thrust needs to be set.

What I personally do (because, let’s be honest, I do overnight flights so I don’t have the time to do step climbing) is I go straight to my final altitude, checking if at cruise altitude my aircraft is stable ; if, at the bottom, the ‘ETE to Dest’ doesn’t read ‘FUEL’ and is not displayed in orange/red ; if the speed is not too low and corresponds to what’s indicated on my flight plan.

If one of those 3 points is not respected, I would descent 1,000 ft lower and see if it’s better, and that until I get stable.

If at any point during your climb your plane starts decelerating although you’ve put 100% thrust, try decreasing your vertical speed until its speed increases back again ; set the VS to 0 if your aircraft has lost too much speed.

Attention: What I’m saying is not the recommended procedures, but simply what I do personally during my flights (mainly overnight flights as I don’t monitor them from the beginning until the end).

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DM’d you Sir


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