Vertical Speed Indicator

[juanca]

HI!

Im having trouble in my manual descents.

for example when I begin my descent (727) in a clean configuration, (autopilot disengaged) and I want to maintain for example 1500 fpm rate of descent; its very hard (if not impossible) to maintain that specific rate. I have to keep trimming up or down the whole way down
because the needle keeps moving up or down.

I dont think im doing anything wrong,(or am I?) I also use the throttle to try to control the VS.  but still cant accomplish a constant VS.

Im no pilot, but I dont think its like that, can you please tell me the correct procedure.

thanks

Juanca

[ozzy72]

You shouldn't be using the trim to control to set the rate of descent. You should control it manually.
The trim is there to ensure straight and level flight with minimal control input. Best bet set the elevator trim to neutral and then push the stick forwards, you'll soon get the feel for it.
Also 1500fpm descent is a little bit steep for an airliner!

[Nexus]

Ozzy he's talking about the initial descent and in this case, 1500ft is not a steep descent at all.

Infact around 2000ft is considered normal, and that's not even an idle throttle descent, if you did that the V/S would drop to nearly 4000ft per minute (Now that's more like it eh Ozman )

[microlight]

Heh ... heh ... he said 'juanca' ... heh ... heh

Good name, dude!

[ozzy72]

You know me Nexus, if it doesn't have a shiny spinny thing, then its foreign to me
Barring certain HEAVY stunt planes

[Nexus]

Haha, there's only one Ozwaldo, and I think that's enough  :)
I'd never touch an AN 225 with a 50ft pole - let alone fly it  ;D

Loved your screens though  8)

[juanca]

thanks for your replies, although  my question is ..how to maintain a constant rate of decent? (manually)

because the needle on the VS dont seem to stay put! even if I use throttle to try to "balance" rate of decent.

Oh yes i'm a 737

[Nexus]

Unless flying approaches, pilots never do something call constant rate of descent because
a) It's hard to accomplish (without autopilot)
b) it's not economical to do

The descent techniques are idle throttle, partial throttle or partial throttle/constant angle descents.

These three are different styles but all relates to SPEED, and by that I don't mean vertical speed.

"But we have a vertical speed mode in the autopilot of the 737?", you might ask.
Yes that's true but in the real world. V/S mode is generally only used below 10.000ft since you lose control of speed management. Speed, or especially

[juanca]

maybe i'm not explainig myself properly...

for example: I'm 27000 ft and 90 miles to KMIA
                  270/3 =90

Start me descent  at a rate of 1350  270*5=1350

If I dont maintain these rate of descend I will end to high or to low (ok? of course I know I have to keep calculating the rate of descend as I slow down and so on)

My problem is with the needle in the VS; I cant seem to keep it in that specific rate (I want to fly manally), because it keeps increasing or decresing...  I try to maintain that rate of descent for that specific part of the descent  with trim, and trying to balance with the throttle,  but the darn needle has a mind of its own, and I have to keep  tapping the trim all the way down, wich causes fatige, and I was wondering if this is so on real aircrafts???

thanks for your tips

Juanca

[Lux13]

Hi!
Just try to use the Flight director.....it helps a lot!!!
Cheers!

[juanca]

I use FD!

I just cant get the needle in the VS to stay at a specific and constant rate of descent for long.........

Lets say you are descending  at 2000 fpm......,  you can only maintain that rate with the autopilot, but if you try it manually you have to keep trimming and trimming and trimming to maintain that specific rate of descent.


I want to know the technic applied to avoid this

[chomp_rock]

real airline pilots use autopilot to decend, try it.  It will get easier if you move the joystick very little to make necessary corrections.

[oldhorse]

  HI
Well I Have Read  All Pro Con, So thought I tell you how I do it.
Don`t know about those Axial Flow Blow Torch  So will Used My A26.
When you power down from cruse setting, Some thing change The
Elevator does more then just set pitch, It Also control SPEED (I know
you thought the throttles did that) An now used Power To control
Rate of decent or VSI.  In my A26 I know that 30 inch MP And 28
click of up trim Will net me 150 mph An 2000 Fpm decent on VSI
Every Time.  You Will Haft to Play with Number to get what you want.
  [ Elevator TRIM TO CONTROL SPEED  POWER TO CONTROL Rate of decent ]
HO that Also works on all real airplane I have Flown to
     Rich

[oldhorse]

Well Did It Work  

[OTTOL]

How are you adjusting your pitch trim Juanca?

Contrary to popular public simviation opinion, constant RATE descents are not only possible, they are taught at the most