27 minutes ago, Farlis said:

Also how would ATC know what idle descent gives you on different airframes? It's the same with TOD. They don't know when it is, that's the pilot's job.

I think some people expect ATC to fly their aircraft. 😉

5 minutes ago, Bobsk8 said:

I think some people expect ATC to fly their aircraft. 😉

It came from decades of default ATC which did always provide descent steps and I assumed that was the way it worked.   Since default ATC is what it is I finally stopped using it a few years into 2020 and just recently picked up BATC.   Just misaligned expectations of how ATC typically works. 😉

10 hours ago, Speedbird 217 said:

Not sure if people have seen it, but there's currently a poll on the BATC Discord to vote on the next Community feature. You can cast your vote until Sunday.

As it stands it looks like this:

1. GSX Integration - 42%
2. CPDLC - 21%
3. Seamless Turnaround - 19%
4. Divert to Simbrief Alternate - 10%
5. Queued Button Replies - 8%

I struggle a bit with the current ranking but apparently that's what people want. Not sure how much benefit GSX integration is, I mean what is that even supposed to do? Link with the gate I'm assigned by BATC? I'm usually requesting a different one anyway...all this to save me pressing 2 buttons in GSX, great "feature".

I also really don't get seamless turnaround. It's literally going to BATC, pressing ESC and reloading the flight plan. How it's almost tied with CPDLC, which in my opinion would be a proper new cool feature is beyond me.

The 2 I'd be excited about are CPDLC and Diversion, but looks like the community is lazy and prefers whatever GSX integration is, which I find pretty disappointing as a big "community feature". Historic weather is another one I'd love so that I don't get discrepancies when using the 24hrs historic live weather in 2024. I really expected more here...

Is there no way add in your own FP with your own chosen waypoints etc?

 

6 minutes ago, Sonosusto said:

Is there no way add in your own FP with your own chosen waypoints etc?

 

Just use Simbrief and put in your own waypoints. 

12 hours ago, Noel said:

I'm flying into KPDX in the Longitude.  120mi out I tell it I'm ready for descent (to 10L per its instruct).  It tells me to descend via TEMBRS3 arrival.  So I start a so-called 'idle descent'. which puts me at 12K feet 90 miles out.  What was I supposed to do?  In the past, w/o ATC (or with default ATC) I would create a descent my less steep than idle.  What *should* I be doing with that instruct?  At TIMBRS3 the altitude is 12K feet on the FMC which is why I asssumed I should descend to that altitude.

In real life, most of the time, you'd be given step-downs ("descend and maintain...") for traffic separation and flow. The intermediate altitudes you are descending to would be defined by two things: first, the floor of the airspace owned by the controller working your flight, and second, traffic around you. With lots of traffic, the altitudes can be a bit unpredictable, but with no traffic, you go to these sector floors, which are typically somewhere around FL240, and then around FL120, and then around 5000 feet (but those altitudes vary by factors like location, terrain, radar environment, flight direction, etc). At night when sectors get consolidated, you might win the lottery and get an uninterrupted descent from cruise all the way down to something ridiculously low.

In all cases, it's your responsibility to manage your energy to make the crossing restrictions. As others have said, you must cross PUBBB at exactly 5000 feet, but keep in mind you also have to cross VANTZ between 15000 and 11000. The crossing restriction at TMBRS is "at or above," so you could cross it at whatever you want, as long as you are at or below 15000 at VANTZ.

When you get a big descent, like from cruising altitude all the way to 12000 feet, you have to do the math and fly the aircraft. It's easy to (temporarily) put a hard altitude restriction into the FMC at a particular waypoint and then see if you're going to make it or not, or else look at your descent energy ring and then adjust thrust as necessary, but I don't know the aircraft you're flying so I can't tell you how to do that. (If you have a question about the 747, let me know, lol.) If the FMC blows a circuit breaker you could just do it with basic math; it's not rocket science, and every aircraft type will have rules of thumb for estimating the distance you need to descend however many 1000's of feet you need to go down. Typically 1000's of feet x 3, for example, descending from FL330 to 12000 feet would need 63 nm (33 - 12 = 21, 21 x 3 = 63).

In a more typical scenario where ATC is clearing you to a number of intermediate altitudes, the controllers are aware of typical performance factors (after all, they can do math too!) and so they give you achievable target altitudes. Pilots love to complain about being held up too high for too long, but most of the time it's no problem. The only operational disadvantage to controllers managing your altitudes is efficiency; with ATC giving you the intermediate step-downs, your descent will be shallower than it has to be and thus you will burn a little more fuel.

There are a few published profile descents out there where the expectation is that you do something like an idle descent without any intermediate level-offs, but those are rare (at least in the USA) and the TMBR3 is not one of those. 

In your case, if I was given a descent to 12000 feet, all things being equal I would aim to cross VANTZ at 13000 (right in the middle of the allowed range) and then continue the descent to reach 12000 between VANTZ and FLOWR. Note that you have to be at or below 9000 by FLOWR, so you would expect to receive further descent clearances in a timely fashion.

 

 

 

Edited April 5, 20251 yr by prolixindec

12 hours ago, prolixindec said:

In real life, most of the time, you'd be given step-downs ("descend and maintain...") for traffic separation and flow. The intermediate altitudes you are descending to would be defined by two things: first, the floor of the airspace owned by the controller working your flight, and second, traffic around you. With lots of traffic, the altitudes can be a bit unpredictable, but with no traffic, you go to these sector floors, which are typically somewhere around FL240, and then around FL120, and then around 5000 feet (but those altitudes vary by factors like location, terrain, radar environment, flight direction, etc). At night when sectors get consolidated, you might win the lottery and get an uninterrupted descent from cruise all the way down to something ridiculously low.

In all cases, it's your responsibility to manage your energy to make the crossing restrictions. As others have said, you must cross PUBBB at exactly 5000 feet, but keep in mind you also have to cross VANTZ between 15000 and 11000. The crossing restriction at TMBRS is "at or above," so you could cross it at whatever you want, as long as you are at or below 15000 at VANTZ.

When you get a big descent, like from cruising altitude all the way to 12000 feet, you have to do the math and fly the aircraft. It's easy to (temporarily) put a hard altitude restriction into the FMC at a particular waypoint and then see if you're going to make it or not, or else look at your descent energy ring and then adjust thrust as necessary, but I don't know the aircraft you're flying so I can't tell you how to do that. (If you have a question about the 747, let me know, lol.) If the FMC blows a circuit breaker you could just do it with basic math; it's not rocket science, and every aircraft type will have rules of thumb for estimating the distance you need to descend however many 1000's of feet you need to go down. Typically 1000's of feet x 3, for example, descending from FL330 to 12000 feet would need 63 nm (33 - 12 = 21, 21 x 3 = 63).

In a more typical scenario where ATC is clearing you to a number of intermediate altitudes, the controllers are aware of typical performance factors (after all, they can do math too!) and so they give you achievable target altitudes. Pilots love to complain about being held up too high for too long, but most of the time it's no problem. The only operational disadvantage to controllers managing your altitudes is efficiency; with ATC giving you the intermediate step-downs, your descent will be shallower than it has to be and thus you will burn a little more fuel.

There are a few published profile descents out there where the expectation is that you do something like an idle descent without any intermediate level-offs, but those are rare (at least in the USA) and the TMBR3 is not one of those. 

In your case, if I was given a descent to 12000 feet, all things being equal I would aim to cross VANTZ at 13000 (right in the middle of the allowed range) and then continue the descent to reach 12000 between VANTZ and FLOWR. Note that you have to be at or below 9000 by FLOWR, so you would expect to receive further descent clearances in a timely fashion.

Awesome overview of some fundamentals thank you very much for that!  Fortunately I have been flying w/o ATC for years and understand how to get from one altitude over X miles to the next step down, but as mentioned I was expecting ATC to give me step-downs as you mention because that is what default ATC has been doing, so was just a bit stumped as to why BATC doesn't always do this.  Thanks again!

33 minutes ago, Noel said:

Awesome overview of some fundamentals thank you very much for that!  Fortunately I have been flying w/o ATC for years and understand how to get from one altitude over X miles to the next step down, but as mentioned I was expecting ATC to give me step-downs as you mention because that is what default ATC has been doing, so was just a bit stumped as to why BATC doesn't always do this.  Thanks again!

Sometimes BATC gives me "step" altitudes, other times I'm told to "descend on the STAR". It's getting better though - another large update to the experimental branch this week (can't remember if it was reported in this thread or another). 

1 minute ago, Cpt_Piett said:

Sometimes BATC gives me "step" altitudes, other times I'm told to "descend on the STAR". It's getting better though - another large update to the experimental branch this week (can't remember if it was reported in this thread or another). 

I should prob pick up the exp branch as I know I'm going to be sticking with BATC

5 minutes ago, Noel said:

I should prob pick up the exp branch as I know I'm going to be sticking with BATC

I got it a few months back as I realized I would be using BATC more and more. Sadly FSHud development seems to have come to a halt. 

Here's the changelog for 1.6.46.Experimental as an example of continued development:

Quote

Vectors - Continued tweaks to vector algorithm based on user feedback.

Vectors - Fixed bug that caused circular vector instructions in rapid succession.

Comms - Rewrote the comm state handler to prevent spinning wheel/stuck state bugs.

Fix - Fixed bug where descent would be given too early if the user's FP didn't contain a route.

Traffic - Fix issues with runway takeoff and landing distances not being properly observed.

Traffic - Add a 300nm traffic insertion range when the player is above 19000 feet, this can help increase perceived traffic volume in higher cruise alts while keep traffic volumes more manageable around departure / destination airports.

Traffic - Prevent center controllers acknowledging traffic that hasn't called in when they are being initially injected.

Runway selection - Fix issue where runways may not update to match METAR changes on certain routes, particularly short routes with direct SID -> STAR or departure vectors.

Parking selection - Remove constraints on user parking selection (this was expected in the last build but the code was not actually applied!)

 

In reality, unless otherwise necessary for traffic, your first descent clearance is usually "pilot's discretion"... Meaning start down when you like.  You can then remain in VNAV and stay on your FMC descent profile.  You'll usually get the "descend via" clearance somewhere a little farther along, once you've already started down.  

In all cases, it's good to remember that you fly the airplane, not ATC.  You have a magic word available to you any time ATC gives you a clearance you don't agree with: "unable".

I don't bother with ATC in the sim unless it's Vatsim because nuances like this just aren't handled correctly, and I'm not going to argue with AI ATC when it tells me to do something dumb.  I can self vector a lot more effectively lol.

4 hours ago, Noel said:

I should prob pick up the exp branch as I know I'm going to be sticking with BATC

I think it's worth it.

15 minutes ago, Stearmandriver said:

You have a magic word available to you any time ATC gives you a clearance you don't agree with: "unable"

Unfortunately this is not an option with BATC, as far as I know.

4 hours ago, Cpt_Piett said:

Sadly FSHud development seems to have come to a halt. 

I doubt that. The indications are that at least one of the major items on the 2025 roadmap is/are being worked on, but I agree that the silence on progress by the developer is deafening. As we're nearly a third of the way through the year I hope that we get some news or even an update soon.

53 minutes ago, Stearmandriver said:

In all cases, it's good to remember that you fly the airplane, not ATC.  You have a magic word available to you any time ATC gives you a clearance you don't agree with: "unable".

Oh those sweet words “unable” or “standby”.

Remember  an old joke? 

ATC: Citation 3BV, say speed

Citation: speed…

ATC: Citation 3BV, say altitude 

Citation: altitude…

ATC: Citation 3BV, say cancel IFR

Citation : 200 knots  , 5000 ft

 

 

 

Much has been said about BATC. I am relatively new to BATC, having used PF3 for several years. My problem is the lack of international pilot voices. English UK, USA and AUS are available . Not realistic if flying say German or Spanish airlines . The discord site has been disappointing. Anyone have any input.