descending speed

[aliege 0]

Anyone knows what to do to reduce the speed when the plane starts descending with 2000 fpm??

Ispeeds runs up to 300.

Thanks

 

geert

 

[BillC 135]

Higher up, 2000fpm/300kts is fine but you wouldn't want it doing that below FL100. What level are you at when it's doing that?

As for slowing down and descending at the same time in a 737 it's never that easy (even though some Vatsim controllers seem to believe "go down, slow down" is easy). To slow down you either have to reduce your rate of descent or use the speedbrakes (or both). Often the best way to manage it is to lose the speed before starting to descend.

[vadriver 247]

2 hours ago, aliege said:

Ispeeds runs up to 300.

Ispeeds .... means what ?

IAS on the PFD (high mach at all levels  at 300kIAS) is not  ktas / kgsp??

it's all about kgsp groundspeed, not kIAS. not kTAS... 5fpm/kt of kgsp  is a 3^o fpa ... any more needs those speedbrakes !!

& 4fpm/kt of ground speed below F100 is better .. if it matches your arrival vnav.

[MarkJHarris 128]

Sounds far too complicated. 

Firstly, what is on your FMA? Which autopilot or Flight Director mode are you following. If you are using LVL CHG, then you should see at the top a target MACH of whatever was your cruise mach, plus the SPEED WINDOW will be open with the current MACH number showing. If you close the thrust levers, or the autothrottle does, you will maintain this MACH number and as you descend, your IAS will increase up to and into the red overspeed. There is no automatic changeover between IAS and MACH in V/S or LVL CHG modes.

If you select in the DESCent page of the FMC a high cost index, then the computed descent may be a high IAS. In VNAV, the aircraft begins to descend in MACH then transitions to IAS when the figure in the DESCent page is reached. Whichever is being tracked is in magenta.

So, what modes are you using, what's on the FMA and the MCP?

[aliege 0]

Sorry it was a quick Q but i am talking about below 10.000 ft!i found out that when i am using VNAV  it held the spd on 240.But are there other ways.i.e. Approach spd??

But thanks to all the replay sofar.

Geert

Edited August 16, 2018 by aliege

[Ephedrin 418]

On 8/15/2018 at 9:38 AM, aliege said:

Anyone knows what to do to reduce the speed when the plane starts descending with 2000 fpm??

Ispeeds runs up to 300.

Thanks

 

geert

 

Until 320kias (i believe) you can use the spoilers

 

edit: i love the mobile version of this forum... not. Have missed that there actually have been plenty answers.

Edited August 16, 2018 by Ephedrin
Badum tsss

[vadriver 247]

14 hours ago, aliege said:

Sorry it was a quick Q but i am talking about below 10.000 ft!i found out that when i am using VNAV  it held the spd on 240.But are there other ways.i.e. Approach spd??

But thanks to all the replay sofar.

Geert

geert

240kIAS is about 270kTAS + tailwind could = 300kG/S around 10,000' normally requiring 1200 to 1500fpm to match most VNAV profiles ..... unless you were above profile & the aircraft was "chasing" a lower altitude (within its abilities).