# Understanding FSX Flight Planner's Fuel and Heading Calculations

Teemu Guest

I was trying to fly from Crown Point TTCP to Piarco TTPP (somewhere in Trinidad, Caribbean)  a number of times to find out an accurate fuel consumption. I deliberately wanted to run out of fuel when taxiing out at the destination.

The FSX flight planner gave me a fuel estimation of around 50 % of what I estimated. So I used my own estimation and ran out of fuel on the final at the exact moment when I got the clearance to land.
Also, the FSX flight planner gave me a heading to fly, I assume with all the corrections made, but after 20 minutes I was around 10 nautical miles off the waypoint. I had a constant heading error during that leg. I think I did a pretty good job with maintaining the compass heading and energy.

My question is, how does the FSX flight planner estimate the fuel amounts without knowing my power settings and my aircraft-specific performance table?
And how does it calculate the "fly heading" angle, especially the wind correction?
And at the end of the day: how can I get precisely to my waypoint and how can I run out of fuel when taxiing to the refuel at destination?

Ian Stephens (ianstephens) Captain
Ian Stephens is an expert on this topic. Read his bio here.

Your query about the fuel consumption estimations and heading calculations in Microsoft Flight Simulator X (FSX) is a multifaceted one, so let's break it down.

Firstly, regarding the FSX flight planner's fuel estimation, it's essential to recognize that the system employs a generalized algorithm. This algorithm, although sophisticated, doesn't account for the unique characteristics of different aircraft models, such as specific power settings and performance tables. Therefore, the estimations provided are based on a set of standard assumptions which may not align with your aircraft's actual performance. This is why your own calculations, which presumably took more specific factors into account, proved to be more accurate.

When it comes to the issue of the heading, the FSX planner calculates the initial heading based on a direct path between your departure and arrival points. However, this doesn't factor in the nuances of real-world navigation, like magnetic variation or wind drift, which can lead to deviations from your intended course. To counteract this, regular course corrections based on navigational aids or GPS (if your aircraft is equipped with it) are necessary. Additionally, understanding and applying wind correction angles can significantly improve your navigation accuracy.

For a precise waypoint navigation and fuel exhaustion timing, here are a few tips:

• Utilize real-world flight planning tools or software for more accurate fuel calculations. These tools often allow you to input specific aircraft performance data, which can yield more realistic estimates.
• Frequently update your heading in-flight based on real-time navigational data. This could involve the use of VOR tracking, GPS, or even old-school dead reckoning.
• Practice wind correction techniques. Calculating and applying the appropriate wind correction angle can be critical in maintaining your intended track, especially over longer distances.
• To time your fuel exhaustion accurately, consider using an external fuel calculation tool that lets you factor in variables like wind, weight, and cruise settings specific to your aircraft.

In summary, while FSX offers a solid foundation for flight simulation, it does have its limitations. Augmenting its in-built systems with real-world navigation techniques and external tools can significantly enhance your simulation experience.

Keep in mind that these insights apply to other platforms like Microsoft Flight Simulator (2020) and X-Plane 12, especially in terms of navigation and fuel calculation accuracy.

Feel free to reach out if you have more specific scenarios or need further clarification on any point.

Safe skies!