# Feedback on Vertical Speed

Thanks in advance. I have done my research on IFC on climb to cruise rates and the message I get is VS of anywhere between 2800 to 3800 per minute. All good but when I complete in detail Simbreif I get a V/S climd rate of 1300 per minute. I see many flights around me smashing out to ceiling heights quickly but it don’t feel right. I need some expert advice.
Thanks

2500-2800 fpm is a good climb rate.

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For bigger planes, but for a 737 and the A320 family isn’t that a little high?

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No, 737s go up to 3000fpm

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I regularly fly a 787 9 should I trust the Simbreif rate or be guided elsewhere

As ll good found details on wiki thanks fir replying this can close now

Yeah and as for the A320 family they also known for pitching 15 degrees sometimes

All depends on your aircraft, weight and flight time. As you can do step climbs at different FPM

Here’s what works for me:
From take off to 10000ft, I go 3500fpm. That is with a speed of 240kts.
After 10000ft I reduce v/s to 3000 and increasing speed up to either 290 or 320 depending on my desired mach speed. (Either .78 for 737/320, or .84/.85 for A350/787/777)
After that I decrease down to 2500 when crossing FL200 and then again down to 2000 when crossing FL280. My V/S after that depends on the load, but generally around 1000-1500fpm.

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It’s unfortunate that IF does not have a FMC. The flight management computer would automatically calculate the right FPM and thrust required.

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I always just set my power to 88-96%, then adjust my VS to maintain a certain speed (255 under 10000, around 300 till 28000, mach 0.78-0.86 after 28000). This will make your plane climb at around 3000fpm at first, and will slowly bring it down to 400-800.

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Is the reason that you decrease vertical speed as you go up oh, because the air density is less?

Yes, exactly. Less suction, but more efficient.

Thanks @Olivier999 did read N1 is the key reference point then adjust VS . Your feedback confirms that Cheers!

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Exactly, that’s how you do it.

You base your climb on an efficient N1 and adjust you VS constantly, vertical speed isn’t the focus.

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@Q-ENAN Cheers!

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This tutorial might be helpful.

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Yeah, use that tutorial. Don’t use a fixed vertical speed. Use a fixed thrust setting and airspeed. But, a light 737 can climb up at +6000FPM, so don’t be surprised!

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You won’t see planes going up with 6000fpm irl. That would happen when the aircraft is very light, and in that case you would use a lower power setting.

I hear that . Thanks