Wrong power settings of airliners

Hey guys,

Real life Boeing 737 pilot and flight instructor here. Just started getting into IF and been really enjoying it so far!

I know that the flight model in IF and the characteristics of the airliners are of course not like in reality but I couldn’t help but notice one very unrealistic thing that’s been bugging me.

In IF, with all the bigger aircraft, the faster you go, the less thrust you need. For example: Let’s say you’re going 200 knots and you need 55% N1 to maintain speed and altitude. And when you’re going 300 knots, you only need 50% N1 or even less to require speed and altitude, thus burning less fuel while simultaneously flying faster.

That is exactly opposite to reality. In reality, flying faster generally means needing more thrust in order to counteract the increased drag (Drag increases by the square of the velocity). Which is also why aircraft in holdings fly slower than normal; to burn less fuel.

Did anybody else notice this also? This may also be a reason why the aircraft have so unrealistically high ranges and accelerations as mentioned in another post.

Do you guys think this will be fixed maybe at some point in the upcoming future?

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Hey @Markus1311, there’s a cool thread by @AndrewWu that analyzes the power of aircraft in Infinite Flight and compares it to their real-world counterparts. Not an answer to your question but it’s some cool info to look at!

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Thank you! That’s exactly the post I was talking about but couldn’t find it :)

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As a pilot, how do you find the deceleration characteristics? Some planes seem to take forever to slow down, and others lose speed super fast. The 737 in particular seems to lose speed on short final really quickly when you just slightly reduce power.

Also, how close are the power settings to what they would be on short final?

Thanks for sharing your insights! I’m sure the physics aren’t super easy to program and model accurately but I still feel like they are close enough to be enjoy the experience, for a non pilot like me at least.

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I can agree with that it annoys me a lot. It causes hard and rough landings in which irl wouldn’t happen.

I also agree with this statement especially with the A380. It loses speed really fast so you really need a reduced reverse thrust setting for landing. In smaller airports where the A380 flies irl like Manchester it would most and maybe in rare cases all of the runway to stop

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It definitely is true that aircraft in real life also do have different deceleration characteristics. For example the A330 or the newer Boeing 737 MAXs just don’t want to slow down. However, the differences in IF are a little too big in my opinion. The A380 is exaggerated a bit and the 737 slows down too quickly, there should be more inertia.

The power settings on final are accurate as long as you’re not too picky. As a reference: The Boeing 737-800 with a landing weight of 60 tons approaches on a 3° glideslope with a nose up attitude of 1° to 2° at Flaps 30 and 58% N1. With Flaps 40° it flies at an attitude of 0° and about 63% N1.

But I agree, it definitely is close enough to be enjoyable, especially for a mobile sim!

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Thanks for the insight! I guess I’m also wondering if the power settings are so sensitive in real life, like there are times I’m established and have a stabilized approach speed and as the wind or something changes, and I need to add power, just adding a percent or two N1 results in rapid acceleration, or vice versa. How often and how much do you have to vary power on approach, or is it set it and forget it?

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In real-life 737 there’s a difference between flight idle and ground idle - the former still has about 30% N1 of thrust. This isn’t a thing in IF yet so I usually manually adjust the throttle during approach.

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Indeed, eventhough I understand it is not a 737 feature but rather something to see with the engine and its fast spooling capability in case of a go around.

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It’s definitely not like that in real life. Of course you also vary your thrust based on the conditions, airspeed and turbulence, but adding a few percent does not result in a rapid acceleration like in IF. The engines need a few seconds to spool up or down and an aircraft that weighs 60 tons also has a lot of inertia. In real life the plane doesn’t decelerate or accelerate as quickly as you see it in IF.

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That’s helpful, and what I expected. Thanks for your real world perspective!

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