Altitude Profile Point and Identifier

[Guest chrut]

Hello,After hours of searching in the forum, I simply had no other choice but to post a new topic. Sorry in advance if this has already been discussed.As I was training on planning and executing step climbs the other day, I noticed that a "altitude profile pointand identifier" isn't created for step climbs and therefore not shown on the ND. Top of Descent (T/D) and Top of Climb (T/C) are however created and shown on the ND, but the S/C is missing. This is VERY annoying and I don't know what is wrong.Perhaps it has something to do with my setup, as I couldn't find any threads addressing this particular issue. I run the PMDG 744X on a Vista 64 machine with a Q9550 CPU and 4GB ram. The installation went smoothly and there aren't any other problems other than the one metioned that I have noticed.Cheers!

[Mats_J 2]

Sami,AFAIK the step climb programming is implemented in the PMDG model. Unfortunately I am not too familiar with the inards of the S/C programming. Maybe you could share your flight plan and somebody with the know could take a look at it?Hope it helps,

[downscc 1,327]

Most likely no steps required if you don't see any. A heavy 747 may start at FL310 and the first stelp climb may not be for 600 nm... so it depends on your weight, lenght of trip and step climb value. I change mine to 2000 from ICAO since NATS routes observe reduced verticle separation rules.

[Guest chrut]

Hey guys, thanks for chiming in!What I did was this: changing the step size from ICAO to 2000 (due to RVSM) and in the LEGS page entered a step climb (/AAAAS = /FL350S). This was confirmed and checked in VNAV CRZ, PROG and in LEGS (large font). But when I looked in MAP or PLAN view, I didn't see the "S/C" symbol at the FIX.Of course Dan you're right, I'm well aware of that step climbs are dependet of route, weight etc. and that the FMS calc. S/C automatically. But when your flying NAT routes especially, you might want to manually edit S/C to certain fixes in order to comply with ATC regulations. Anyway, I'll check again tonight....

[downscc 1,327]

I see what you are doing... the SC symbol may not show up when you enter a hard constraint at a fix. Most the time, I thought the guys just used the forecast step climbs and of course cleared it with Gander or Shannon or whoever they need to be talking to. The FMS does a lot better job of predicting the best economical point to step than I do, although I know a guy in England that can calculate it to the knat's hinny.

[Guest chrut]

I see what you are doing... the SC symbol may not show up when you enter a hard constraint at a fix. Most the time, I thought the guys just used the forecast step climbs and of course cleared it with Gander or Shannon or whoever they need to be talking to. The FMS does a lot better job of predicting the best economical point to step than I do, although I know a guy in England that can calculate it to the knat's hinny.

Ah, okay... didn't see that in the manual. So the S/C symbol only appears if the FMS calculates the step climb?Also, I fully agree that FMS calc s/c best, but as far as I know you have to request S/C when you're giving Gander etc. position report and climb when passing the NEXT fix. Therefore, planning and setting hard S/C constraint at a fix is important.

[downscc 1,327]

I assumed you didn't have to climb at the reporting fix, but you had to have clearance for the climb with an expected time and then assigned an altitude block. Have you flown the NATS?

[Guest chrut]

I assumed you didn't have to climb at the reporting fix, but you had to have clearance for the climb with an expected time and then assigned an altitude block. Have you flown the NATS?

No not yet, I've only read about it in VATSIM tutorials. Hopefully, I'll soon take my new 744X over the pond on the net (after about 2 months perhaps, more training is needed).What I've learned so far is that step climbs are requested when you're giving position reports in order to reduce chatter and for the ATC to know where the step climbs take place. So when passing point A, I give my postion report (time, MAC speed, FL, ETE next waypoint etc.) and request a S/C. If the S/C is granted, it's to be carried out when reaching point B. So this is the reason why I was training to plan (the charts are very useful) and set S/C at certain WPT.I could be wrong, as I only have limited experience regarding NATS. Anyway, it's great to have somone like you Dan that is so active here at the forum. It only leads to more knowledge for me, the beginner, which is great!Thanks!Edit: Can you just confirm this: "So the S/C symbol only appears if the FMS calculates the step climb?"

[Guest chrut]

Just an update:As I enter in step climbs via LEGS page, they are recognized in the ND panel when DATA on the EFIS is pushed (MAKEL 33000 0119Z). But the S/C symbol is not shown.Will provide picture!

[downscc 1,327]

Sami, I think you are seeing what is supposed to happen. The SC symbol occurs at FMS-derived step climb points but if you set a waypoint with an altitude constraint the ND displays the waypoint... I wouldn't expect the SC symbol, just as there are no SC symbols in SIDS with altitude constraints.I use the FMS-derived step climb points, and if I were using an ATC service such that I could only step at reporting points then I would still use the FMS-derived climb points but only as a reference. The plane isn't going to climb until you change the MCP ALT setting anyway. Use the information available, make a decision and then act on your decison. If the step climb is close to a reporting point then use that as the occasion to climb even it is early or late according to the FMS schedule. This is a lot easier than trying to set hard constraints at climb points that correspond to reporting points, and in the end nothing happens until you change the MCP ALT knob. Right?

[Guest chrut]

Sami, I think you are seeing what is supposed to happen. The SC symbol occurs at FMS-derived step climb points but if you set a waypoint with an altitude constraint the ND displays the waypoint... I wouldn't expect the SC symbol, just as there are no SC symbols in SIDS with altitude constraints.I use the FMS-derived step climb points, and if I were using an ATC service such that I could only step at reporting points then I would still use the FMS-derived climb points but only as a reference. The plane isn't going to climb until you change the MCP ALT setting anyway. Use the information available, make a decision and then act on your decison. If the step climb is close to a reporting point then use that as the occasion to climb even it is early or late according to the FMS schedule. This is a lot easier than trying to set hard constraints at climb points that correspond to reporting points, and in the end nothing happens until you change the MCP ALT knob. Right?

Hey again!Well, that's no SID (I'm in CRZ flight) and that is no ordinary altitude constrain (SSS/AAAA). It's a step climb (SSS/AAAAS), note the S in bold font showing in the LEGS page. I made those so the ND and FMS (with time, ETA and so on) remind me that it's time to step clim, by setting MCP alt like you say, when reaching that WPT. This is what the manual says (p. 49 in the FMS section):"Planned Step Climb: Planned step points are specified by the crew using crew entered modifications in the RTE LEGS page of the FMC. A planned step entry is made on the RTE LEGS page by entering the step altitude at a specific waypoint followed by ‘S’ to indicate a step point. The FMC will follow planned steps in the flight plan until no further planned steps are encountered. If the FMC determines that further step climbs can be made, they will be computed under the optimum step climb calculation described earlier."I made this topic to see IF this is correct airplane behaviour (can't find this in the manual): Is it normal not to see the S/C symbol when manually editing step climbs? Are S/C symbols only shown when FMS calculates them? That's what I'm trying to find out and I have no questions regarding HOW to step climb or which way is more economical. I just want to figure out if there's something wrong with my setup or is this how it should be. It should be noted that T/C and T/D symbols display just fine on the ND.Cheers!Edit: This is what the manual says about Altitude Profile Point and Identifier (p. 25 in the cockpit overivew section):"Represents the FMC calculated T/C (Top of Climb), T/D (Top of Descent), S/C (Step Climb), and E/D (End of Descent). Deceleration and predicted altitude/ETA points have no identifier."Can somone confirm that S/C symbols are only shown when FMS calculates them?

[Guest chrut]

Update:I can confirm that when FMC is calculating step climbs, the "S/C" symbols are shown. However when I "pin" the step climb to a FIX (FL310S), the S/C symbol dissapears. Even the FMC calculated S/C symbols that come after the planned step climb are gone. Is this a bug or is it suppose to happen?Here I'm about to "pin" my step climb to a FIX:Where did the S/C symbol go?After the planned step climb has been deleted, the S/C symbol appears:Here is an old picture from RL (Virgin atlantic), showing planned step climbs in a NAT route with S/C symbols - notice the FL340S and FL350S under the relevant WPTs:

[DLP084 5]

Hi, seems to be a bug here. This is what the real 747 AOM says: "Predicted step altitudes display on the RTE LEGS page. The distance and ETA tothe next step point (predicted or flight crew entered) display on the CDU CRZ andPROG pages. They also display on the ND map display with a green circle andS/C label."Jan-Paul

[Guest chrut]

Hi, seems to be a bug here. This is what the real 747 AOM says: "Predicted step altitudes display on the RTE LEGS page. The distance and ETA tothe next step point (predicted or flight crew entered) display on the CDU CRZ andPROG pages. They also display on the ND map display with a green circle andS/C label."Jan-Paul

Thank you

[Guest chrut]

Also, when comparing the RL picture above with the one included here, I see that the step climb altitude in the ND - when the EFIS DATA button is pushed - is showing 33000 and not FL330S. That might be something to look into.