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Vertical Descent  

84 members have voted

  1. 1. What vertical descent rate do you use?

    • 200fpm or less
      2
    • 300fpm
      8
    • 400fpm
      5
    • 500fpm
      53
    • 600fpm
      2
    • 700fpm
      10
    • 800fpm
      0
    • 900-1000fpm
      1
    • 1000-1500fpm
      3
    • 1500-2000fpm
      0
    • 2000fm or more
      0


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Posted

I use my 430W to plan a 300fpm descent to arrive 1nm from the airport at 1000ft AGL. Since I pick up a little speed in the descent, I can vary the descent rate to still arrive at the same point. This will range between 300-400fpm. I usually bring the power back a little because going too fast in the descent adds a lot of parasitic drag and is inefficient. 300fpm is comfortable, allows me to maintain cruise or slightly higher speed at a lower fuel flow, and gives me a stable platform for the last portion of the flight.

Posted

I said 500fpm but it will vary.  In the summer time if ATC tells me to descend at pilot's discretion and I'm far enough out I will do 200fpm to stay in the cool air longer.

When told to descend to x altitude I will generally go 500fpm.

 

 

 

 

Posted

depending on route my airport lies right on the edge of mountains. I need to get from minimum 12,5 to 6500 in not too many miles. Less than 1k FPM isn't really feasible trucking along at 200+ knots.

Posted
1 hour ago, kortopates said:

 but IFR is often closer to 300'

AIM 4-4-10(d)

d. When ATC has not used the term “AT PILOT’S
DISCRETION” nor imposed any climb or descent
restrictions, pilots should initiate climb or descent
promptly on acknowledgement of the clearance.
Descend or climb at an optimum rate consistent with
the operating characteristics of the aircraft
to
1,000 feet above or below the assigned altitude, and
then attempt to descend or climb at a rate of between
500 and 1,500 fpm until the assigned altitude is
reached. If at anytime the pilot is unable to climb or
descend at a rate of at least 500 feet a minute, advise
ATC. If it is necessary to level off at an intermediate
altitude during climb or descent, advise ATC,
except
when leveling off at 10,000 feet MSL on descent, or
2,500 feet above airport elevation (prior to entering a
Class C or Class D surface area), when required for
speed reduction.

Posted
1 minute ago, peevee said:

AIM 4-4-10(d)

d. When ATC has not used the term “AT PILOT’S
DISCRETION” nor imposed any climb or descent
restrictions, pilots should initiate climb or descent
promptly on acknowledgement of the clearance.
Descend or climb at an optimum rate consistent with
the operating characteristics of the aircraft
to
1,000 feet above or below the assigned altitude, and
then attempt to descend or climb at a rate of between
500 and 1,500 fpm until the assigned altitude is
reached. If at anytime the pilot is unable to climb or
descend at a rate of at least 500 feet a minute, advise
ATC. If it is necessary to level off at an intermediate
altitude during climb or descent, advise ATC,
except
when leveling off at 10,000 feet MSL on descent, or
2,500 feet above airport elevation (prior to entering a
Class C or Class D surface area), when required for
speed reduction.

Yes, Its all about communicating. My point is even in busy airspace its not that hard to get a slow descent with the controllers Ok. Even in busy SOCAL airspace, even if I can't get pilots discretion for the entire descent, I'll most often get it after clearing some altitude he/she needs me below. Sometimes for example, I may be asked to expedite for opposite direction traffic to an altitude of x and then resume pilot discretion to y. I am often asking for an early pilot discretion descent and am familiar enough with the airspace to know where I am most able to get it. Just gotta talk and ask.

Who knows, maybe we'll eventually see more of the Next-Gen approaches geared to help make jet's make a continuous descent to the airport at near idle power get deployed to GA airports. RF-Leg capable GPS and EFIS capability make it possible for many of these.

  • Like 1
Posted
Just now, kortopates said:

 

Who knows, maybe we'll eventually see more of the Next-Gen approaches geared to help make jet's make a continuous descent to the airport at near idle power get deployed to GA airports. RF-Leg capable GPS and EFIS capability make it possible for many of these.

They don't work that well for the jets, why would they work any better for GA?

Posted
3 minutes ago, peevee said:

They don't work that well for the jets, why would they work any better for GA?

I don't know, but my impression as an observer has been the controllers don't like them much yet since when the old ILS is still getting the majority of the traffic the new longer approaches kinds tie up your hands for vectoring them to final and probably create a headache for fitting them onto final with other traffic. If more of the traffic was using the new approach I imagine it would make it a lot easier for everyone. But I could be way off. What do you see as the issues?

Posted

Assuming IFR, I shoot for a 500 fpm rate of decent. It keeps ATC happy and the math simple.

  • Like 1
Posted (edited)

500 for the math,

but 400 fit my preferred route over water at the primary destination...

I had a portable G that would warn of the TOD and give a virtual glide slope for guidance... no math required.

any higher the airspeed is blistering...

This is for my NA engine.  Max power available, staying off redline, while descending...

Getting to the airfield with the targeted amount of energy.  Not arrive 3000' high or be three miles out at TPA...

Fun engineering energy calculations, no wrong answers...

Best regards,

-a-

Edited by carusoam
Posted

I set the Avidynes up for a 600fpm descent, and when it chimes then dial in 700fpm without touching the throttle - the increased speed more or less cancels out the difference. Still takes 20 odd minutes and ~100nm to get down from FL200!

For mental planning without the GPS I use 200ft/nm, or 5nm per 1000'

Posted

I prefer 500 fpm, but I've also had plenty at 1500 fpm.  It's what happens when a controller hands you off late, or terrain gets in the way.  

  • Like 1
Posted
14 minutes ago, chrisk said:

I prefer 500 fpm, but I've also had plenty at 1500 fpm.  It's what happens when a controller hands you off late, or terrain gets in the way.  

+1

Posted

Another general 500 FPM target here. It's easy math if I don't want to use the calculator and is quick enough without bothering some passengers.

obviously, there are situations in which I might do more or less. 

Posted

The answer's are assumed your IFR within the system, I've cancelled often going into KILG 80 miles out so descend and go direct to the airport on my terms, I lose speed going into the teens I would like to gain it back on my descent,when in the system I set 600 FPM in the box unless a different descent profile is asked l'll cross Money at 8000 then pilots discretion.

Posted

Here is a good example of a slam dunk from Tuesday, visiting DMax.  Somewhat my fault for asking for not asking the controller earlier.

Capture.thumb.JPG.4a041502fbd307d07d3d7358d010ab14.JPG

Posted
3 hours ago, Awful_Charlie said:

I set the Avidynes up for a 600fpm descent, and when it chimes then dial in 700fpm without touching the throttle - the increased speed more or less cancels out the difference. Still takes 20 odd minutes and ~100nm to get down from FL200!

For mental planning without the GPS I use 200ft/nm, or 5nm per 1000'

I feel your pain. Reducing at 1" per minute from 31 or 32 inches to 25" adds time to the process plus controllers don't really understand we can't go down like the jets.

Posted

When cruising with a tailwind, I tend to try to stay up at the optimum altitude longer and accept a higher rate of descent at the lower altitudes.  Same thing if I know the lower altitudes are bumpy.  Stay in the tailwind/smooth air longer, hurry through the adverse wind/bumpy air.  -_-

Interesting that my POH recommends maintaining cruise airspeed in the descent, but doesn't differentiated between cruise indicated, or cruise TAS. :wacko:  I presume it means indicated, but I generally allow the indicated to creep up to maintain cruise TAS.

Using the Vertical nav feature of the 430W allows me to see where I am in relation to my programmed 500' descent.

Posted (edited)

Clearly any good pilot should look to carry maximum kinetic energy to the point of impact and achieve this on each and every approach to landing to avoid operating at reduced power settings where every single engine failure happens:

Image result for slam dunk jordan

Edited by jkhirsch

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