ArannAvi8tor

777 Auto Step Climb

Recommended Posts

I have done a number of flights lately and on every one the Auto Step Climb doesn't seem to be working. I start at the initial  cruise altitude and come back at the end of the flight and I am still at that altitude.

 

I program the step climbs in the legs page with an "S" after the altitude and the altitudes show throughout the legs page correctly, but no climb is made.

 

I believe everything is up to date, I am kind of at  a loss as this worked fine a while ago.

 

Joe O'Connell

Edited by ArannAvi8tor

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

Go into the pmdg options and set auto step climb. It is all explained in the manual.

Share this post


Link to post
Share on other sites
3 minutes ago, ph-cxz said:

Go into the pmdg options and set auto step climb. It is all explained in the manual.

I should have been more clear, yes auto step climb is active on all of these flights.

 

joe oconnell

Edited by ArannAvi8tor

Share this post


Link to post
Share on other sites
13 minutes ago, ArannAvi8tor said:

I program the step climbs in the legs page with an "S" after the altitude and the altitudes show throughout the legs page correctly, but no climb is made.

Why are you setting them manually?

Share this post


Link to post
Share on other sites

I set them based on the flight plan that I created. I use SimBrief and they plan the step climbs for me.

 

This hasn't been a problem in the past perhaps since the last update but I am not sure.

Share this post


Link to post
Share on other sites

The flight plan is a "plan," and when to step climb depends on many variables that the plan cannot predict with 100% accuracy.  Winds and temperatures vary, ATC may not be able to give you the higher altitude, you might be on an airway with altitude constraints, etc.  Only the FMS knows when the optimal time arrives for a step climb... and then depending on winds it might not be the most economical choice so the pilot has to make a decision. 

The auto step climb should be working with manually entered step climbs, unless there is an issue with buffet margins or other safety considerations.

Nothing changed the auto step climb feature in the last update.

Need more specifics if you want to go down this specific case any deeper.  Lots of specifics.

Share this post


Link to post
Share on other sites
13 minutes ago, ArannAvi8tor said:

I use SimBrief and they plan the step climbs for me.

The SimBrief plan isn't planning the steps for you as much as giving ATC an idea of the segments where you'll be at those altitudes. The steps in the plan serve a secondary purpose of letting you know, too, but you would already know this because you'd be following the FMC steps on the FMC profile, unless otherwise noted (NAT segments are flown at constant alt and speed, usually, so that's one example you'd follow the plan over the FMC).

So, unless you're flying a particular segment with a required altitude, don't throw the SimBrief altitudes in, and, instead, follow the OPT profile.

Either way, it should follow those, provided the altitude on the MCP matches the altitude currently on the VNAV CRZ page.

Share this post


Link to post
Share on other sites

OK, so I understand how step climbs work, but what am I missing about the auto step climb feature?

Share this post


Link to post
Share on other sites
9 minutes ago, ArannAvi8tor said:

OK, so I understand how step climbs work, but what am I missing about the auto step climb feature?

I'm confused by what you mean here.

If you're referring to my earlier post about using the FMC without the 'S' entries, over the SimBrief plan, then I disagree. Your post earlier references using manual entry climbs, which points to a misunderstanding of how they work. Because of this, I clarified.

If you're referring to knowing exactly how the auto step climb function works, then it should be working, which it isn't. Because of this, I have to assume there's a misunderstanding or a misconfiguration somewhere. So far, while you seem to be a implying a lot, you have done very little confirming. It is extremely important that you slow down a bit, and work with us. We're trying to help you. "I know how this works" doesn't help us. It seems like it would, but it doesn't. When offering support to someone, you can never take the vague assertion of "I know what I'm doing."

 

When you get to your initial cruise altitude, what is your MCP set to?

Share this post


Link to post
Share on other sites

I apologize about the confusion.

 

I started the flight like I always do. I take off and climb to FL290 and that is what is on the MCP. In the past with the Auto Step Climb on, the feature would change the MCP to 310 and climb to 310. it doesn't appear to be doing that anymore.

 

In the past it didn't matter how I setup the step climb either letting the aircraft decide when or setting them manually.

Share this post


Link to post
Share on other sites
7 minutes ago, ArannAvi8tor said:

I started the flight like I always do. I take off and climb to FL290 and that is what is on the MCP. In the past with the Auto Step Climb on, the feature would change the MCP to 310 and climb to 310. it doesn't appear to be doing that anymore.

We haven't changed the code on this in quite some time, which is why I keep driving at the idea that you're doing something oddly.

To be clear, your last post simply notes a climb to FL290, but the important part is that you must climb to whatever is set in the FMC as the cruise alt, and the MCP must match that altitude.

Share this post


Link to post
Share on other sites
1 hour ago, ArannAvi8tor said:

I started the flight like I always do. I take off and climb to FL290 and that is what is on the MCP. In the past with the Auto Step Climb on, the feature would change the MCP to 310 and climb to 310. it doesn't appear to be doing that anymore.

This makes sense to you but we are not looking over your shoulder, so it is not enough information to define the problem.  MCP ALT is FL290 and FMS CRZ level is FL290?  The first step to FL310 is how far from TOC and is it an FMS STEP TO or is it a manual step?  Does PROGRESS page indicate distance to step climb before you get to the step?  Is the FL290 initial altitude as recommended by PERF page during preflight?

Share this post


Link to post
Share on other sites
3 hours ago, downscc said:

This makes sense to you but we are not looking over your shoulder, so it is not enough information to define the problem.  MCP ALT is FL290 and FMS CRZ level is FL290?  The first step to FL310 is how far from TOC and is it an FMS STEP TO or is it a manual step?  Does PROGRESS page indicate distance to step climb before you get to the step?  Is the FL290 initial altitude as recommended by PERF page during preflight?

Yes to all of that, the distance was displayed on the PROGRESS page. It was a manual step and it was probably 280nm from TOC where the first step climb was to begin.  I can try the flight again tonight and I can share more detail.

 

It appears that this is not a known issue. I can try to get more information, but it isn't the end of the world or anything I just thought I would ask here in case I wasn't alone in this.

Edited by ArannAvi8tor

Share this post


Link to post
Share on other sites

I use manual step climbs on every NAT crossing, because steps while on a track are usually not available.  Auto step climb works just fine when I use it with manual or FMS based steps.  I cannot think of many reasons why it shouldn't.

Share this post


Link to post
Share on other sites

So I think figured out what the issue is, and as I expected, I changed something.

 

I was reading through the manual (FCOM2 11.40.38) and came across where you can set the step climb size to 0 to stop the automatic calculation (I had some flights where it was overriding my planned step climbs). I just did a flight where I left the Step Size set to RVSM as is default and the auto step worked as expected and climbed to 310. I then changed the step size to 0 to test it and sure enough when I reached the next step climb the auto climb skipped over the step climb. When i changed it back to RVSM the step climb started immediately.

 

So it appears that for the auto step climb to work, the step size must be something other than zero. I am not sure if that is a bug or just me not reading the manual correctly.

Share this post


Link to post
Share on other sites
20 hours ago, ArannAvi8tor said:

So it appears that for the auto step climb to work, the step size must be something other than zero. I am not sure if that is a bug or just me not reading the manual correctly.

Step size 0 is how you turn off step climbs.  There is no need to do this when setting manual steps.  From current position up to where you set a manual step all automatic steps will be inhibited, and after your manual step the automatic step feature will continue based on step size.

Share this post


Link to post
Share on other sites
22 hours ago, ArannAvi8tor said:

So it appears that for the auto step climb to work, the step size must be something other than zero. I am not sure if that is a bug or just me not reading the manual correctly.

Step size basically means that's the altitude you wish to climb when you perform a step climb. Having it at RVSM would default it to 2,000 feet between flight level 290 and 410, I believe. On the Boeing 747-400, for instance, the default step size shows as ICAO, which would have been 4,000 feet. I personally just drop it to 2,000 manually, so the FMC will plan the step climbs at 2,000 feet. By setting the step size to 0, you basically told the FMC that you don't want to perform a step climb, which is why it didn't give you one.

Share this post


Link to post
Share on other sites
2 hours ago, Captain Kevin said:

Step size basically means that's the altitude you wish to climb when you perform a step climb. Having it at RVSM would default it to 2,000 feet between flight level 290 and 410, I believe. On the Boeing 747-400, for instance, the default step size shows as ICAO, which would have been 4,000 feet. I personally just drop it to 2,000 manually, so the FMC will plan the step climbs at 2,000 feet. By setting the step size to 0, you basically told the FMC that you don't want to perform a step climb, which is why it didn't give you one.

It is interesting that you bring up the 747.

I just did a flight with the 747 and that is where I picked up this habit. My 747 will only allow manual step climbs if I set the step size to 0. With out setting the step size to 0 the calculated steps override even my initial climb altitude.

 

4 hours ago, downscc said:

Step size 0 is how you turn off step climbs.  There is no need to do this when setting manual steps.  From current position up to where you set a manual step all automatic steps will be inhibited, and after your manual step the automatic step feature will continue based on step size.

 

According to the documentation (and how the 747 operates) setting a step size of 0 does NOT turn off step climbs it simply turns off the calculated step climbs.

 

I just did a flight from FACT to EGLL with the 747-400 and I set the initial altitude to FL300 and the calculated step climbs started at FL310 and stepped to FL350 even though I wanted even Flight Levels. By setting the step size to 0, the calculated step climbs are removed and my manual step climbs worked beautifully FL300>FL320>FL340>FL360>FL380 even on auto step climb.

 

Now the auto step climb doesn't seem to work the same way 777 (I am not sure if that is a bug or not), which is fine, I just didn't realize it.

 

Also, while i understand that you all don't know me and it is easy to assume I don't know what I am talking about, this thread has never been about my lack of understanding how the 777 or 747 FMC work, I know how they work. This thread is simply about unexpected behavior of the auto step climb feature of the PMDG 777. I would kindly ask that we focus on that part of the thread.

Share this post


Link to post
Share on other sites
10 hours ago, ArannAvi8tor said:

According to the documentation (and how the 747 operates) setting a step size of 0 does NOT turn off step climbs it simply turns off the calculated step climbs.

Not sure what you mean here.

Setting Step 0 tells the FMC that you do not plan to step. Nothing in the aircraft prevents you from changing your cruise altitude when flying. That's for you and ATC to decide - not a computer. Computers are dumb. Never place your flight in the hands of the automation alone.

10 hours ago, ArannAvi8tor said:

I just did a flight from FACT to EGLL with the 747-400 and I set the initial altitude to FL300 and the calculated step climbs started at FL310 and stepped to FL350 even though I wanted even Flight Levels. By setting the step size to 0, the calculated step climbs are removed and my manual step climbs worked beautifully FL300>FL320>FL340>FL360>FL380 even on auto step climb.

Make sure you're using 2000 instead of RVSM. Sounds like you left ICAO in there. ICAO is non-RVSM (the 747-400 came out before RVSM, so instead of 2000' steps, you used 4000' steps, and cruised on alternate odds: 310, 350, 390, etc).

10 hours ago, ArannAvi8tor said:

Also, while i understand that you all don't know me and it is easy to assume I don't know what I am talking about, this thread has never been about my lack of understanding how the 777 or 747 FMC work, I know how they work. This thread is simply about unexpected behavior of the auto step climb feature of the PMDG 777. I would kindly ask that we focus on that part of the thread.

To be honest, in the land of troubleshooting, you MUST assume that everyone doesn't know anything. That sounds harsh, but to be honest, any time I've asked for support, it's usually been something dumb that I'd forgotten, or overlooked. Nobody is above simple errors, or forgetting the basics. See your post above as an example, honestly. Note how you assumed (based on prior experience) that it should've been 300 > 320 > 340 > 360, but the reality is that you left "ICAO" in the step size. Your assumption, based on the experience you're asserting makes you more knowledgeable (and understandably so), led you astray because you assumed knowledge of one plane transferred 1:1 to another. It didn't, and it caught you out.

The 777, for example, will auto-set your GEN source to the APU when you power that up after landing. You don't have to worry about the power source when you shut the engines down. Look back at the posts after the original 747 release and you'll see TONS of posts from our users who were absolutely baffled by the fact that the aircraft was dropping power, even though the APU was on. Simple thing: the 747 doesn't automatically transfer the source, people were used to the 777's automagic, and got bitten.

Share this post


Link to post
Share on other sites
10 hours ago, ArannAvi8tor said:

Also, while i understand that you all don't know me and it is easy to assume I don't know what I am talking about, this thread has never been about my lack of understanding how the 777 or 747 FMC work, I know how they work. This thread is simply about unexpected behavior of the auto step climb feature of the PMDG 777. I would kindly ask that we focus on that part of the thread.

But, it seems that you don’t know how it works.

If you set the step size to zero, you are telling the FMC to not calculate any step climbs down-route, so obviously the automatic step climb function (which does not exist in the real aircraft) will not work under those conditions.

Manual step climbs are not an FMC function. As pilot in command, you can initiate a climb to a higher level anywhere and any time you want, no matter what the step size may be - whether RVSM, ICAO or zero. The FMC will not prevent you from doing so, though you may bet a warning message if you command a climb to a higher altitude than the current calculated maximum altitude for your current weight.

Share this post


Link to post
Share on other sites
16 hours ago, ArannAvi8tor said:

I just did a flight with the 747 and that is where I picked up this habit. My 747 will only allow manual step climbs if I set the step size to 0. With out setting the step size to 0 the calculated steps override even my initial climb altitude.

You can initiate a step climb anytime you'd like, regardless of step size. Step size only affects the FMC calculation.

16 hours ago, ArannAvi8tor said:

According to the documentation (and how the 747 operates) setting a step size of 0 does NOT turn off step climbs it simply turns off the calculated step climbs.

Yes, that's what it's supposed to do. The only way to "turn off" the actual step climb itself is by not initiating one in the first place (I'm leaving auto-step climb out of the equation here).

16 hours ago, ArannAvi8tor said:

Also, while i understand that you all don't know me and it is easy to assume I don't know what I am talking about, this thread has never been about my lack of understanding how the 777 or 747 FMC work, I know how they work. This thread is simply about unexpected behavior of the auto step climb feature of the PMDG 777. I would kindly ask that we focus on that part of the thread.

You're right, we don't know you. That's why we can't assume what you know. In any event, based on previous responded, as Kyle and Jim have both stated, it appears that there was, in fact, a lack of understanding in how it works with regards to the step size and step climbs.

Share this post


Link to post
Share on other sites
10 hours ago, scandinavian13 said:

To be honest, in the land of troubleshooting, you MUST assume that everyone doesn't know anything.

A bit off topic, but IT support in companies usually does very well assume you don't know anything about computers when you call them for any issue even when you explain them what is the problem and that you just don't have the admin rights to fix it! 🤣

Share this post


Link to post
Share on other sites
13 hours ago, scandinavian13 said:

Not sure what you mean here.

Setting Step 0 tells the FMC that you do not plan to step. Nothing in the aircraft prevents you from changing your cruise altitude when flying. That's for you and ATC to decide - not a computer. Computers are dumb. Never place your flight in the hands of the automation alone.

So I don't know how else to say it, I encourage you to read the manual. Setting the step size of 0 simply removes the calculated step climbs, it does not prevent the Auto Step Climb feature from executing manually entered step climbs.

 

13 hours ago, scandinavian13 said:

Make sure you're using 2000 instead of RVSM. Sounds like you left ICAO in there. ICAO is non-RVSM (the 747-400 came out before RVSM, so instead of 2000' steps, you used 4000' steps, and cruised on alternate odds: 310, 350, 390, etc).

I don't want calculated step climbs, I use manually entered step climbs. This has worked for every flight I have done with the 747 there are no issues with that. What was unexpected behavior with the step size of ICAO was that when I entered a cruise altitude of FL300, I got calculated step climbs of FL310 > FL350 > FL390. By setting the step size to 0 and entering manual step climbs I was able to complete the flight with the steps FL300 > FL320 > FL340 > FL360. This is getting off topic though as this thread is about the Auto step climb feature of the 777.

13 hours ago, scandinavian13 said:

To be honest, in the land of troubleshooting, you MUST assume that everyone doesn't know anything. That sounds harsh, but to be honest, any time I've asked for support, it's usually been something dumb that I'd forgotten, or overlooked. Nobody is above simple errors, or forgetting the basics. See your post above as an example, honestly. Note how you assumed (based on prior experience) that it should've been 300 > 320 > 340 > 360, but the reality is that you left "ICAO" in the step size. Your assumption, based on the experience you're asserting makes you more knowledgeable (and understandably so), led you astray because you assumed knowledge of one plane transferred 1:1 to another. It didn't, and it caught you out.

I completely understand that mentality and even exhibit it myself, however my assumption was not that the step climb proceedure was the same, but that the auto step climb feature worked the same. My mistake. As this was a feature added by PMDG not boeing, it really isn't that unreasonable to assume that PMDG built them similarly.

 

12 hours ago, JRBarrett said:

But, it seems that you don’t know how it works.

If you set the step size to zero, you are telling the FMC to not calculate any step climbs down-route, so obviously the automatic step climb function (which does not exist in the real aircraft) will not work under those conditions.

Manual step climbs are not an FMC function. As pilot in command, you can initiate a climb to a higher level anywhere and any time you want, no matter what the step size may be - whether RVSM, ICAO or zero. The FMC will not prevent you from doing so, though you may bet a warning message if you command a climb to a higher altitude than the current calculated maximum altitude for your current weight.

Actually I do know what I am talking about as that is how the plane functions. When I say manual step climbs I am referring to entering an altitude in the legs page (e.g. FL360S). The step size is for the calculated step climbs that are calculated based on weight. I personally prefer to use the step climbs entered on the legs page instead of the calculated step climbs. The auto step climb, a feature added by PMDG, will initiate either type of step climb automatically. I am aware that I can change the altitude at any time as well, but this thread is related to the Auto Step Climb feature not actually executing step climbs.

 

7 hours ago, Captain Kevin said:

You can initiate a step climb anytime you'd like, regardless of step size. Step size only affects the FMC calculation.

Thank you for repeating what I was trying to explain.

 

7 hours ago, Captain Kevin said:

Yes, that's what it's supposed to do. The only way to "turn off" the actual step climb itself is by not initiating one in the first place (I'm leaving auto-step climb out of the equation here).

Once again exactly what I was saying. I think we are finally on the same page.

 

7 hours ago, Captain Kevin said:

You're right, we don't know you. That's why we can't assume what you know. In any event, based on previous responded, as Kyle and Jim have both stated, it appears that there was, in fact, a lack of understanding in how it works with regards to the step size and step climbs

And I lost you. I know how step size works, I don't know how else to explain it. There have been a lot of assumptions about my knowledge, but re-reading the post, I don't see where it comes from.

 

 

 

 

Share this post


Link to post
Share on other sites

I will try to explain this one more time.

 

In both the 777 and 747 documentation they refer to predicted step climbs on the PERF INIT page. To quote the documentation:

  • "0" to inhibit predicted step climbs, or
  • altitudes from 1000 to 9900 in 100 foot increments, or
  • "I" for ICAO, or
  • "R" for RVSM (Only on the 777)

As I prefer to use my own planned step climbs, I enter a "0" into the step size entry on the PERF INIT page. I then head over to the LEGS page and enter my planned step climbs by entering an altitude with an "S" after it (per the manual for planned step climbs).

When I reach my cruising altitude, I set the auto step climb feature in the AUTO CRUISE page from the FS ACTIONS area of the FMS.

Per the manual, the aircraft should begin a step climb at the planned fix of the flight plan. The 747 does this perfectly. The 777 does not. I know they are different planes, so this isn't entirely unexpected. The 777 does not initiate a step climb automatically unless the step size is set to something other than "0". Like I said, I don't know if this is a bug or a feature, just the behavior of my sim.


Now that I am aware of this diversion from the manual I can adjust my settings and continue enjoying these wonderful products.

 

Kyle, please feel free to close this topic if you feel that the situation has been resolved.

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now