Exactly How Much Power do Infinite Flight Aircraft Really Have?

Hi everyone! Since Infinite Flight aircraft often have overpowered performance, I wanted to share a method for estimating their actual thrust using SimBrief.

Step 1: Locate Thrust Selection

In SimBrief, scroll to the bottom of your custom aircraft’s “Airframe Performance” section. Find the “T/O Thrust” entry. Set the unit to “LBF” (pounds of force) for easier adjustments.

Step 2: Select Flat Runways

Infinite Flight doesn’t simulate sloped runways, so choose ones with a 0.00% slope. In SimBrief, go to Performance and Tools and search for flat runways. Examples include KSFO’s 1R/19L and MKJS’s 7/25. Use Maximum Performance settings (full thrust, MTOW, etc.) to ensure accurate data. Note the calculated slope gradient and V1 speeds. Additionally, make sure your altimeter is set to 1013. It’s the standard used in IF and irl. If incorrect, it will mess up the data.

Step 3: Test in Infinite Flight

Spawn at your selected runway. Set the aircraft to MTOW, match all SimBrief settings, and use full thrust until V1. Then, perform a rejected takeoff (RTO):

Use MAX autobrakes (if available).

Apply max reverse thrust until it disengages, then manually brake to stop.


Step 4: Measure Stopping Distance

Estimate the remaining runway using the white aiming point markers (each is 150 feet long). Add their lengths and approximate any smaller gaps to the end of the runway threshold. Additionally, test on the other side of the runway as well and calculate (change runway settings in SimBrief too). Then, average them out.

Step 5: Adjust Thrust Numbers

Return to SimBrief and adjust the T/O Thrust in increments (e.g., 1,000 LBF, then smaller increments like 100 or 10) until your calculated stopping distance matches your in-game results.

Step 6: Repeat as Needed

Refine your numbers with further tests until they closely match SimBrief values.

Why This Helps
Once you’ve calculated accurate thrust, it becomes much easier to plan takeoffs and landings in Infinite Flight. Your performance calculations will be more realistic, helping you achieve smoother and more precise operations.

Good Luck!
P.S. let me know if there’s something wrong in this.

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Hi! Cool, I would check out @AndrewWu’s guide: it’s a similar concept as this!

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He did an excellent job on it and he actually did a lot more work and even came up with numbers compared to me. Maybe If I’m lucky, this method will complement his? Mine focused just on how to calculate thrust numbers. This is critical for determining power settings, which may or may not align with his.

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Yours adds a lot of value to the work I’ve already done. Actually very useful information to have and I might do some testing with this next time I get a sub. Great work!

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I will say, for a bit more precision you can use Google Maps to measure distance based on the surrounding airport infrastructure.

I think my only gripe is that there is a bit of a confounding variable in the brake power (we have no idea how IF brakes stack up to IRL brakes and there’s no way to test this). Simbrief gives you a distance with a V1 speed so perhaps you could note where this distance takes you (using Google Maps) and then compare that to the location where you actually hit V1. This would remove that variable.

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Is it safe to say IF brakes have much more bite than IRL?

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I presume so, but any experience I have is anecdotal (for example, I believe with max manual braking you can stop a CL35 within 1000 feet and if you go to a long runway like LAX 25R you can bring a 787 to a stop from 500+ knots).

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I think I might have made a small confusion towards the end of my initial post. Meeting the real world values wouldn’t really work perfectly for Infinite Flight given the small flaws. My problem is that the Infinite Flight runways lengths are a bit off. For example, Google says MKJS has 9646 feet of runway and Infinite Flight says it has 8737 feet. The most I can really do is tweak the runway length values in SimBrief and go off of that. For the brakes, I just used the autobrakes max since it’s the closest to if not the brake setting used for RTO. It may be close or far from irl, so I just keep that with the Simbrief calculations.

This is really cool! I would caution that it’s perhaps missing one thing: on some aircraft, especially smaller/lighter ones, V1 isn’t always necessarily the latest possible rejection point when relative to runway distance. I’ve noticed that sometimes my takeoff calculations kick back an equal V1/VR speed, because the runway is too long. Instead, it just has them equal because you can’t physically hit VR before V1, and you won’t reject a takeoff while you rotate. I know you have this at MTOW, but you also have it at full power, so it may not necessarily translate and you may, in a couple of cases, end up thinking it should have less power than it actually does.

All in all though, the fact that people keep coming up with ways to get data from a simulator that is generally pretty lacking in that regard is really awesome and I love all these topics. I’ll definitely give this a try at some point!

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I would’ve tested on a shorter runway and checked if the two v speeds were different, but I can’t exactly find any other airports in SimBrief perfectly flat. I want to test them at their limits where they use most of the runway. I have them at MTOW and full power because I want the SimBrief calculations to try and maximize performance over anything. I also forgot to mention that if there’s an option to disable flex, please do.

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I don’t know how short you need, but KBFI’s shorter runway is about 4000 feet and essentially flat. KALB’s Runway 28 is about 7000 feet and also almost flat.

Wow! Really impressive results. Is the calculated thrust anywhere near the real life value?

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I’m wondering if the person above me was referring to lighter aircraft like the GA fleet. If so, I would need shorter runway so the aircraft can hit the levels needed. Unfortunately, the airports you mentioned have a slope gradients of 0.06% and 0.03%. I’m hazardous of the slopes because they kinda mess up the caclulations and it’s harder to hit them. I used to test the 737 Max there and I couldn’t hit consistent numbers. I’d have to reduce throttle inputs by 1-2% to adhere there. I think I’m going to try and see if I can find one with 0.01% so it’s not that bad.

Ehmm. It’s kind of hit or miss.

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Here’s one for the A380 that I got.

The thrust is 109250 lbf per engine so that’s like 437,000 lbs. Doing the thrust to weight ratio math, its around 0.34. Normal would be around 0.22 - 0.24

This is some impressive science. Nice work.

You can also put the lat/long on the bottom bar, take note of where you start, and take note of where you stop. There are plenty of online calculators you can use to find the difference between these points.


How do you take into account the margin of error in your math? Without looking, I believe aircraft have to be able to accelerate to V1 and then come to a stop within 60% of the runway’s length. Is that the number you’re using, or the number simbrief uses?

I’d bet that the published numbers don’t perfectly reflect reality. An aircraft that can use a 6,000 foot runway will have to do that on the hottest possible day, and stop well short of having its front tire on the opposite threshold.

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Here’s a shock: in my A380 breakdown I had its takeoff distance marked down as 64% of IRL, which means 56% more power from the IF version controlling for rotation speed. Airbus’ brochure says the A380 has an effective thrust of 70,000 lbs of thrust per engine (the number is usually quoted higher, towards 75-80k depending on configuration, but this is official Airbus marketing material so I’m going to go with it). Your 109,250 lbs / 70,000 lbs is…almost to the dot 56% more. Quite interesting.

Yes, I know the percentages don’t control for drag since at the same speed an engine with less power is losing a larger proportion of its thrust to drag, but since in IF planes don’t experience statistically significant drag until 250+ kts IAS I think it’s alright.

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I was using what Simbrief uses.

I measured the thrust for the 757-200, which produced 46,500 lbf per engine (93,000 lbf total). This gives a thrust-to-weight ratio of about 0.36, slightly higher than the typical range of 0.29–0.34. I still need to calculate the rest of the fleet, so if anyone tests other aircraft, please share your results. My subscription just ended, so I need to renew it before continuing!

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