Expected rate of descent?
- Thread starter Pachong
- Start date
spades9048
Well-Known Member
I'm a little confused by your question. You said your first fix with a hard altitude is 220. If you were given a descend via clearance than there is no expectation what-so-ever other than you cross that first fix at 220. If you stay up until 360 until your 20 miles from the fix then so be it so long as you cross it as expected because a descend via clearance is a pilots discretion descent. If you were just given a flat out descent than I don't really have any expectation. I don't expect you to go 100fpm but if I need you to be somewhere then I'm going to give you a time restriction or just flat out ask you how long it's going to take. If it takes you more than 5 seconds to tell me then I'm going to assume hesitation and come up with a Plan B so neither of us are filling out paperwork later that day.
Pachong
Well-Known Member
I just mentioned the hard alt. because that's what I'm using to figure out if I need to hurry down or not.
I've put 500 FPM as a decent rate cuz I saw no hurry to get down and burn up fuel and go slower. Occasionally I'll have a captain tell me "You should pick up the pace, ATC expects "_____" for planning."
Not like I'm going to start a fight over it with the captain but just wanted to make sure that as long as I don't get a time restriction or a specific FPM in the descent, 500 FPM or greater will do the trick.
Thanks for the response.
I've put 500 FPM as a decent rate cuz I saw no hurry to get down and burn up fuel and go slower. Occasionally I'll have a captain tell me "You should pick up the pace, ATC expects "_____" for planning."
Not like I'm going to start a fight over it with the captain but just wanted to make sure that as long as I don't get a time restriction or a specific FPM in the descent, 500 FPM or greater will do the trick.
Thanks for the response.
Here's what the AIM says about that:
4-4-10
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.
4-4-10
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.
In a terminal environment, I'd expect at least 1,000 feet a minute for descent. So if you're doing 250 knots, I'd expect you to descend 1,000 roughly every 4-5 miles. At 210 knots, I expect that descent rate to be slightly better than at 250 knots. I know every aircraft is different, but this is pretty much what I've observed in a real life environment. As far an an enroute environment, I can't help you there.
z987k
Well-Known Member
They should expect at least 500fpm like sigler posted from the AIM. If that's all you give them and they need more, they will ask for more.
Autothrust Blue
”…trusting ze process…”
500-1000 feet/min until I hit the descent angle for the arrival we've been filed/cleared/are expecting, then a more "optimal" rate (usually more like 2000-2500ft/min most of the time is what the descents are figured at) after that.
I'm capable of steeper; I'll do steeper too, with the expectation that we're going to (1) go faster, and consequently (2) will require room to slow down should it become necessary.
Incidentally, for me, non-RNAV path descents in the terminal area are flown at 250 knots, clean, idle, and I'll note the rate today. 210 knots for this airplane works too, as we can hang the first notch of flaps out without any real fear of overspeeding them, along with the speedbrakes and really get down. (Gear too, if it's needed.)
Blackhawk
Well-Known Member
A rate of descent that gives me a 3 degree glide path until 10,000', sometimes lower. If I'm going to need to slow down at the fix then I lead it by about 5 miles.
Once I start getting vectored I try to smooth out my descent rates in order to intercept localizer and glideslope simultaneously. Just makes for a smoother ride verses being a throttle jockey.
Once I start getting vectored I try to smooth out my descent rates in order to intercept localizer and glideslope simultaneously. Just makes for a smoother ride verses being a throttle jockey.
I don't really care what you descend at 500-1000fpm would be what I expect in a straight descent. If its getting close i'll ask you to increase it. When I point out traffic at an altitude and say 30 miles, I expect you to increase even more, and miss those guys by 1000ft in the next 2 minutes...and when all those warnings fail, i'll turn you. If I need you down (turning isn't an option) I'll give you a restriction or a rate to descend at.
With a pilot discretion descent I expect you to be looking at that next hard altitude like you said, and start going down when you think you need to so when you pass the traffic I have well below you, and give you the cross XXXXX at XXX you can do it. I hate when I give a pilot discretion descent with an expect to cross XXXX at XXX and then they hold it up, the traffic passes, and I give the descent and they are like whoa we can't make that. Well I tried...nothing a delaying vector won't solve.
With a pilot discretion descent I expect you to be looking at that next hard altitude like you said, and start going down when you think you need to so when you pass the traffic I have well below you, and give you the cross XXXXX at XXX you can do it. I hate when I give a pilot discretion descent with an expect to cross XXXX at XXX and then they hold it up, the traffic passes, and I give the descent and they are like whoa we can't make that. Well I tried...nothing a delaying vector won't solve.
Bernoulli Fan
Controller
Surprisingly, once you throw out the "Roger, expect vectors shortly," very often they suddenly calculate that they CAN make that restriction!
Vector4Food
This job would be easier without all the airplanes
This is a bs answer I know...
What we expect is that you descend at the "normal" rate for your aircraft type, and how your company normally operates...
Confused enough? Sorry, but that's what we "expect"
Certain airlines climb/descend differently obviously, so when lets say Company A usually waits until after the "average" TOD and drops like a rock, then when another aircraft from Company A comes along and descends at 500FPM, it is unexpected and may or may not affect our plan
Don't worry however there's always plan b,c,d,e... Plan F is never an option
What we expect is that you descend at the "normal" rate for your aircraft type, and how your company normally operates...
Confused enough? Sorry, but that's what we "expect"
Certain airlines climb/descend differently obviously, so when lets say Company A usually waits until after the "average" TOD and drops like a rock, then when another aircraft from Company A comes along and descends at 500FPM, it is unexpected and may or may not affect our plan
Don't worry however there's always plan b,c,d,e... Plan F is never an option
genot
Well-Known Member
Plan B: Give me a good rate,
Plan C: Expedite
Plan D: Turn left/right
Plan E: Immediately
Plan F: Contact the next guy ie frequency separation
Plan G: Squawk Standby.
Good thing I still have plan G.
Crockrocket94
Well-Known Member
Unless your Washington center then they want you to do at least 2000fpm 400 nm out to fl240 so you can burn all your fuel 
GypsyPilot
Mohawk Town
Ha. Yeah, like that's never gone wrong before...
Autothrust Blue
”…trusting ze process…”
"We've got the field and all the airplanes in sight, cancel IFR, request flight following and to transition the Bravo to San Francisco, sir."
Only problem I have noticed with this is you guys do just that and miss the plane (well done) but don't do so 5 miles prior that I need!