# Vnav descending early

Why is my vnav descending with 37 minutes of the flight to go?

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Because you have to hit an altitude by a certain fix at the default V/S of -1500fpm to -2000fpm.

Just activate it later if you wanna descend later and faster. đź™‚

it says itâ€™s going to descend with 37 mins to go that isnâ€™t right is it?

VNAV is not broken. Just remove that altitude if you donâ€™t want it descending so early.

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Well said toaster

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Manually change them according to the altitudes you want when you reach a certain waypoint

I believe the answer to what youâ€™re actually asking about (not what everyone else has answered) is that the time youâ€™re seeing is the time until it starts descending, not how much time is left in the flight.

VNAV descent is shown in nautical miles, not minutes.

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thereâ€™s a timer in the VNAV status bar instrument thing and I believe thatâ€™s what heâ€™s referring to

I think heâ€™s talking about 37 minutes to go before he @Lewis_Ryan reaches his destination which is when the VNAV caused the plane to descend. Of course VNAV is NM left before descent but he was referring to the time left before he reaches his destination aka ETE.

Yeah i was 37 minutes away for landing and the landing just took forever

like everyone else said, you probably put the descent by altitude on a really early waypoint OR youâ€™re cruising at like 41k ft or smth

i was at fl350 and using a star

then itâ€™s the problem of the star

There are no problems with IF or STARâ€™S, in some STARâ€™S there is maximum and minimum altitude and the IF system as you can only enter one altitude it sets the minimum altitude, what you can do is when you notice â€śa problemâ€ť in the STAR is to go see the chart on the internet and make the changes or do it according to an estimate of -2000fpm (feet per minute)
See the photo below showing STARâ€™s with maximum and minimum limit.

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yeah, i tbink i put the wrong approach in and deleted someone of the star and approach could that be why?

Did you just takeoff

In addition, the IFâ€™s VNAV has an FPA of 2Â° (source), which makes the descent start a little â€śearlyâ€ť since it is customary to use 3Â°.

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