Managing Descent with ProATC/x

[cleonpack93 79]

Hey all,

I'm having some trouble managing the descent on the NGX when I'm flying with ProATC/x. Basically I'm trying to put in the altitudes assigned by ATC and using the Alt Intv, but usually I'm not descending fast enough and get a VNAV disconnect and/or a Des Path Unachievable warning. Then, by the time I get to the ground I'm too far above the glideslope and usually have to overspeed (above 250 knots below 10,000 ft) to descend rapidly enough to catch the slope. Apparently I'm not descending fast enough at higher altitudes. How can I better manage my descents?

[scandinavian13 5,192]

8 minutes ago, cleonpack93 said:

How can I better manage my descents?

Make sure that you have your throttles at idle. Additionally, quite honestly, I've never been a fan of these ATC apps. I've found them to be an amateur's programmed view of their idea of ATC, and not actually how ATC actually behaves.

[Chock 17,769]

With Pro ATC X, what I do is set it up in the options so that I initiate the descent myself (rather than having ATC decide when to do it based on my plan, because they almost always start you down too late). You can then use the ATC chat window to initiate the descent at a more suitable time.

Most of the time, a 737 is gonna need at least 50 miles to get down from a relatively high cruising altitude and probably more than that if you want a comfortable descent rate. If you want some rough rules of thumb to help you...

To know how far away from the airport you need to be when you start down: Mulltiply your cruise altitude by three, and that will give you how many nautical miles you will need to get down. i.e. if you are at 25,000 feet, 25x3=75, so you need to commence your descent 75 miles away from your destination.

To know your required descent rate to achieve a 3 degree descent angle: Divide your groundspeed by two, then times that result by ten, and that will give you a rough estimate of the required descent rate for a three degree glide angle. i.e. groundspeed 500 knots, divided by 2=250x10=2,500, so you need to descend at 2,500 feet per minute to be coming down at an angle of three degrees.

To know how long it will take you to descend: Divide your cruise altitude by your rate of descent. i.e. 30,000ft/2,000fpm=15, so it will take you fifteen minutes to get down to zero feet from 30,000 at that descent rate.

[SierraHotel 974]

32 minutes ago, cleonpack93 said:

Hey all,

I'm having some trouble managing the descent on the NGX when I'm flying with ProATC/x. Basically I'm trying to put in the altitudes assigned by ATC and using the Alt Intv, but usually I'm not descending fast enough and get a VNAV disconnect and/or a Des Path Unachievable warning. Then, by the time I get to the ground I'm too far above the glideslope and usually have to overspeed (above 250 knots below 10,000 ft) to descend rapidly enough to catch the slope. Apparently I'm not descending fast enough at higher altitudes. How can I better manage my descents?

Post your question here:- https://www.facebook.com/groups/1571953959750565/    Also what version are you using? There is now an ATC expert on the PATC team so things can only get better

[cleonpack93 79]

5 minutes ago, Chock said:

With Pro ATC X, what I do is set it up in the options so that I initiate the descent myself (rather than having ATC decide when to do it based on my plan, because they almost always start you down too late). You can then use the ATC chat window to initiate the descent at a more suitable time.

Most of the time, a 737 is gonna need at least 50 miles to get down from a relatively high cruising altitude and probably more than that if you want a comfortable descent rate. If you want some rough rules of thumb to help you...

To know how far away from the airport you need to be when you start down: Mulltiply your cruise altitude by three, and that will give you how many nautical miles you will need to get down. i.e. if you are at 25,000 feet, 25x3=75, so you need to commence your descent 75 miles away from your destination.

To know your required descent rate to achieve a 3 degree descent angle: Divide your groundspeed by two, then times that result by ten, and that will give you a rough estimate of the required descent rate for a three degree glide angle. i.e. groundspeed 500 knots, divided by 2=250x10=2,500, so you need to descend at 2,500 feet per minute to be coming down at an angle of three degrees.

To know how long it will take you to descend: Divide your cruise altitude by your rate of descent. i.e. 30,000ft/2,000fpm=15, so it will take you fifteen minutes to get down to zero feet from 30,000 at that descent rate.

This is great. Thank you!

5 minutes ago, SierraHotel said:

Post your question here:- https://www.facebook.com/groups/1571953959750565/    Also what version are you using? There is now an ATC expert on the PATC team so things can only get better

I think I'm using the latest (1.8.7?) Thanks for that info, that's great to know!

[andreh 125]

I used ProATC for a while. I just requested decent for arrival shortly before ToD in my plan then used Decend Now. It would just let me decend along the STAR. If I got vectors instead I went of the LNAV/VNAV and used Flight Level Change  and HDG Select instead. Can't recall ever having these problems. 

Andre

[Alan_A 1,650]

On 3/3/2017 at 10:55 AM, scandinavian13 said:

...quite honestly, I've never been a fan of these ATC apps. I've found them to be an amateur's programmed view of their idea of ATC, and not actually how ATC actually behaves.

Clearly online ATC (especially PilotEdge) is the gold standard.  But since that's not always a practical option (lots of household interruptions), what's second best?  Default ATC, which at least gives you a representative workload even if the procedures are insane?  Or plan the flight, fly the plan and ignore the AI?  I'm guessing it's the latter, but thought I'd ask.

 

[SirBismuth 9]

8 hours ago, Alan_A said:

Clearly online ATC (especially PilotEdge) is the gold standard.  But since that's not always a practical option (lots of household interruptions), what's second best?  Default ATC, which at least gives you a representative workload even if the procedures are insane?  Or plan the flight, fly the plan and ignore the AI?  I'm guessing it's the latter, but thought I'd ask.

 

I liked the idea of PilotEdge, but doesn't cover the areas I like to fly the most (Europe and Africa).  Default ATC generally are ok, but have some strange ideas sometimes.  What I like about PATC, is that it assigns SIDs/STARs, and is fairly realistic (I only fly GA IRL, so can't speak on RL airline-type ATC experience).  For descents, I normally request manual descent 10-20nm before TOD, that gets me down fine usually. What I have enjoyed with PATC is that it doesn't just assign bog-standard ILS-type approaches, on my last five flights I have had two RNAV, two NDB-DMEs and a Visual (EHAM 18L at night was interesting).  Default ATC only assigns ILS or visual in my experience.

When PATC has crashed, or just stopped talking to me, I fly the flight plan (in conjunction with AIController it keeps AI aircraft out of my way).  Boring, but am not quitting a flight just because ATC went on extended leave.  Sometimes will revert to default ATC for ground guidance and gate allocation on arrival (If PATC is not available), but that's only if I don't know the airport or where I am supposed to park.  Even then, will sometimes just use GSX, they usually have a guy with a van to guide you to a parking bay.

 

 

[scandinavian13 5,192]

13 hours ago, Alan_A said:

Clearly online ATC (especially PilotEdge) is the gold standard.  But since that's not always a practical option (lots of household interruptions), what's second best?  Default ATC, which at least gives you a representative workload even if the procedures are insane?  Or plan the flight, fly the plan and ignore the AI?  I'm guessing it's the latter, but thought I'd ask.

I'm online or bust. If you need to log off, it's not huge issue, just log off. You can also coordinate logging back in if you'd like, or you can just log back in if the airspace isn't currently being controlled (or even if it's controlled - particularly if you're at cruise or near T/D).

MSFS adds in a whole bunch of junk that's antiquated, superfluous, or just plane bad technique: "request clearance, as filed," as an example. If you file a flight plan, you're implicitly asking to be cleared as filed, else you wouldn't have submitted a plan. It's not like you're going to call up "request clearance, but spin the wheel of flight plans and assign me a random one, please." There are a few spots in the books that reference reporting your type of plan - VFR or IFR - but it's not currently appropriate to "request taxi - IFR," as the MSFS ATC will 'speak' for you if you request taxi instructions. There are a few other things that are just plain odd about it. The vectors are worse than a new trainee working a sequencing sector, too.

If I'm not in the mood for online, I just ignore ATC entirely and kinda just go through the dialogue in my own head. MSFS ATC is awful. The add-ons are pretty weak. Online can even be pretty bad, but it's usually at least passable or closer to reality than the other options.

[pcubine 143]

On ‎3‎/‎3‎/‎2017 at 11:22 AM, Chock said:

so you need to descend at 2,500 feet per minute to be coming down at an angle of three degrees.

Sounds like you are trying to break the sound barrier. The NGX would be like a run away freight train at 2500 fpm.

[cleonpack93 79]

So I actually found the best solution to the problem is to NOT push the "alt intv" button each time ATC assigns me an altitude. The altitudes they are giving me follow the STAR, but they sometimes give them a little early and hitting the Alt Intv makes the FMC think you're trying to get to that altitude too quickly, hence the VNAV disconnects and yadda yadda. So if I start the descent a bit earlier and just adjust the MCP altitude as we go without hitting the Alt Intv button (except at first when starting the descent) I now seem to follow the plan just fine. I'll continue to monitor how it goes with more flights.

[pcubine 143]

4 hours ago, cleonpack93 said:

hitting the Alt Intv button (except at first when starting the descent)

You can also start the descent early by pressing the DES button to bring up the bring up the DESCENT page, click on DES NOW, and execute. You will start to descend at 1000 FPM until the airplane reaches the descent profile and then it will resume a normal VNAV descent. I usually click and execute about 10 mile from T/D. The plane will descend to about 1200-1300 feet below profile at T/D and then start to narrow the gap between VNAV profile the airplanes altitude until they are the same. The profile might be 1700 FPM and the airplane is still descending at 1000 FPM so they are going to eventually meet.

[Alan_A 1,650]

16 hours ago, scandinavian13 said:

If you need to log off, it's not huge issue, just log off. You can also coordinate logging back in if you'd like...

Did not know that.  Definitely opens up the possibility for me.  I'll check out the options.  Thanks for the vector...

[scandinavian13 5,192]

6 hours ago, Alan_A said:

Did not know that.  Definitely opens up the possibility for me.  I'll check out the options.  Thanks for the vector...

Welcome. I do that all the time. I'll take off with ATC and then drop off soon after the last controller drops me, or when I enter an (unstaffed) oceanic sector, and then log back in just prior to exiting the oceanic sector, which is usually closer to when I'd be landing anyway. There are sites like VATTASTIC that allow you to see which sectors are staffed/unstaffed, so you can log in just prior to entering their airspace and call them up (if you've been off for more than 30ish min though, you should re-file your flight plan when you log back in, just to be sure you're still in the system).

[Alan_A 1,650]

5 hours ago, scandinavian13 said:

Welcome.

Thanks again.  Will head off and do some research now on basics (using VATSIM) and advanced techniques (e.g. the correct transponder code for "cockpit intrusion, cat, burmese")...