Whats the proper way to do step climbs? I know I can go into the vnav page and put in a different crz alt and the plane will climb. I was wondering why when before a flight I put fl370s next to a way point and when I get to the s/c during the flight the plane doesn't climb and the s/c disappears. Do I have to do something besides put in the new altitude on the mcp? Does the plane not start to climb to the new altitude by itself? 

In reality you need ATC approval, so normally the AP will never climb by itself. 

Rather than ask about basics/fundamentals here, its best to slowly go though the tutorial, you will learn so much more, so much better

Without the auto step climb feature turned on no it will not automatically climb.  You are right in how to program the steps though.  But for normal use those steps are programmed for fuel and time predictions.  The crew will still need to dial the new altitude into the mcp and press the altitude selector knob to activate the step.

7 minutes ago, thibodba57 said:

Without the auto step climb feature turned on no it will not automatically climb.  You are right in how to program the steps though.  But for normal use those steps are programmed for fuel and time predictions.  The crew will still need to dial the new altitude into the mcp and press the altitude selector knob to activate the step.

Thank you.

Edit: So the pilots put in the new altitude manually when they want to climb to a new altitude right?

Edited September 4, 20187 yr by Matt Piotrowski

14 minutes ago, Matt Piotrowski said:

Thank you.

Edit: So the pilots put in the new altitude manually when they want to climb to a new altitude right?

I thought Brian was pretty clear.  Presuming you are in VNAV mode, all one does is dial the new altitude on the MCP and press the ALT button which sets a new cruise altitude and then thrust will increase and up you go in VNAV SPD mode until reaching new altitude.  Fly the tutorial was also a very good recommendation.

16 minutes ago, Matt Piotrowski said:

Thank you.

Edit: So the pilots put in the new altitude manually when they want to climb to a new altitude right?

Oh yea.  It would be bad practice to put any altitude not cleared to in the MCP. So you would get to the location you want to make the step, ask ATC get cleared and dial it into the MCP at that point.

Yeah, this is a common simmerism, somewhat furthered by a misunderstanding of VNAV itself, and perhaps a little bit of MD-11 methodology (you could be in PROF mode with the MCP above your cleared altitude and it would step up automatically, technically...) that has somehow withstood the test of time.

Step climbs are a way to fly the most optimal vertical path, just as a direct routing would be the most optimal lateral path. While both are "most optimal," that doesn't mean that they fit well "into the system." In other words. If you were the only thing up in the air, ever, then sure, it would work just fine...but you're not. Since the operative concept in ATC is first-come-first-served, a crew cannot operate on the principle of "well the plane says I need to climb, so I'm entitled to the space above me." Someone already there is entitled to the space they already occupy - not you.

Just as a pilot or crew cannot simply just decide to choose some random point ahead in their route and go directly to it without clearance, a crew can't simply just decide to climb up to their next altitude without clearance. ATC cleared you on your route, at a specific altitude. You cannot deviate from either that lateral (route), or vertical (altitude) clearance without permission. Allowing VNAV to just blast around at its whim is just asking for trouble, which is why VNAV must have specific approval (input) from the crew to allow it to climb up.

If you've ever seen the pictures from pilots out on the NATS, this concept will likely be clearly driven home. It's not uncommon to see planes 1000' above and below you (same direction, because NATS), at around your same position. Imagine you're out on the NATS - ATC doesn't have radar our there, by the way - and some crew had this mythical VNAV that just climbed when it felt like it. Both pilots up front were just having a good time reading, browsing, chatting, and so on, and the plane just did its thing. Neither of them paid any attention to it because the automation was taking care of it all. The plane right above them on the same track wouldn't even see it coming...

Similarly, even not on the NATS, say you're out over the midwest United State in the summer, and there's one of those typical frontal storms passing through, so everyone is routing around it to the north and south. All of that demand is compacted (i.e. lots of airplanes in not a lot of space) into the corridors on each "end" of the storm. You're flying along, and you stumble across that S/C symbol and the plane just jumps right on up to the next altitude. Even if you don't actually hit the plane flying opposite direction, 1000' above, as they're going along their merry way, it will at the very least raise pulses, cause a few TCAS RAs, and put a bunch of people in danger...and that's assuming the practice were okay by the regs.

 

So what about those handy "M084F340" marks on my flight plan? Those should have me covered, right?

Well...no.

Those are there to let you know that the dispatcher (and/or the flight planning tool) is assuming that you will make a climb at - our near - that point in order to follow the optimal vertical profile (and therefore get the same fuel burn they're planning, since that's one of the more important parts). It's similar to someone with the exact same computer as you saying "I get 60fps in my sim" - you're going to need to know what settings they're using to get that. The "M084F340" is also there to advise ATC that this should be expected as a request at around that point. This does not mean that you are going to get cleared for it. Note that the mark includes two data points: speed (Mach 0.84), and altitude (F340). Going back to the NATS example, and first-come-first-served. You got off the ground a little late, and the person ahead of you on the same track got there right at minimum separation, and can only do M083. Your delay put you right "in the thick of it" so the tracks are packed full of planes, and the altitudes above (350) and below (330) yours are taken, too (the NATS allow for non-standard altitudes for the direction of travel because they're all single direction - everyone goes East, or everyone goes West). With that in mind, your clearance - despite having filed as entering the track system at FL340 and going across it at M0.84 - is likely going to be such that you're going to cross it at M0.83. You've gotta fit into the system. The same situation could go for altitude, too. Say you wanted to wait to climb until that S/C mark right before the NAT segment, and a plane already got cleared at the altitude you were going to cross. By the time you request it as part of your clearance, you might not be able to get it because someone is already at that altitude, and min sep on the NATS is still pretty high, laterally.

Plans are all well and good, but the entire reason we have alternate airfields, contingency fuel, extra fuel, two pilots, a bunch of life rafts, emergency exit lights, and so on is because plans are just plans. Things don't always go as planned.

 

 

TL;DR: We've provided an option to simulate a backup crew coming up to the flight deck while you step out, and climbing up to the next altitude (assuming they were cleared) in the AUTO CRUISE options. The plane itself, however, does not automatically climb unless the crew causes it to do so, primarily for issues of sticking to your clearance, and not hitting things like other airplanes at 80% of the speed of sound.

7 hours ago, scandinavian13 said:

Step climbs are a way to fly the most optimal vertical path,.......

Almost right, Kyle, but not quite if you are flying in OZ.  If you ask ATC politely they will often block the airspace vertically for you so that you can then Cruise Climb in V/S to your heart's content! 🙂

7 hours ago, scandinavian13 said:

 The plane itself, however, does not automatically climb unless the crew causes it to do so, primarily for issues of sticking to your clearance, and not hitting things like other airplanes at 80% of the speed of sound. 

Absolutely!  You still need to maintain a good lookout in a Cruise Climb even if you are reminiscing about what it was like to fly Concorde.  But I suppose you can't beat the Mk1 eyeball when it comes to spotting aircraft without a Transponder, even if it is only at 80% of the speed of sound?!