I’m so confused about this I don’t even know what it’s called. Put simply, I want to plug in altitudes as part of my flight plan. I’m using LNM with G1000 panels, CJ4 and Longitude. I think perhaps this is something that is done when plugging in the flight plan in the plane. I see that there are altitude settings, but I’m not clear as to whether they can be automated and I cant even work out how to add the altitudes in. Even a basic explanation of the concepts would be welcome. I’ve tried to find a video about it but they don’t really ever explain what I am trying to find out. I’ve only recently worked out what LNAV, VNAV (kind of), RNAV, VOR, NDB and ILS are. So, I’m pretty new.
1 Like
Maybe this will help (if I understand your question).
To cruise at 3000 feet.
CJ4 On runway:
Set you altitude with the Altitude knob, 3000 feet.
Click VS, Vertical climb speed, 2000 feet per min.
Click AP, Auto Pilot.
Brake off.
Throttle to max.
CJ4 will lift off and climb to 3000 feet and then maintain
that altitude.
Thanks for your response! I’ve got that worked out, and also FLC. I mean assigning altitudes to waypoints in the FPL. There is a field for entering an altitude, but I can’t get anything to stick. I am beginning to think it isn’t possible….but it seems like it really should be!
Usually when you load procedures, like arrivals (STAR) or approaches the altitudes are populated automatically. Are you seeing this?
Maybe focus on learning one set of avionics at a time. I found the CJ4 easy to learn but if you rather have something slower start with the G1000.
Basics:
You can also manually enter altitude constraints. There are three types:
- at: VNAV will target this exact altitude at the waypoint
- below: VNAV will calculate a path that will keep you at or below this altitude at the waypoint
- above: you get the idea.
What VNAV does is calculate a path from your current altitude down to the last restriction in your flight plan while meeting all restrictions along the way. Based on your current altitude it will calculate when you should start the descent, marked as top of descent (TOD).
Assuming your autopilot supports this, you can engage VNAV. This usually arms VNAV PATH mode. This will automatically start your descent and adjust your rate to meet all restrictions. However, it will only descend if you lower your altitude selector. Note that VNAV will never go lower than what you manually select, even it would violate a restriction. It’s up to you (and ATC) to make sure you’re cleared to the correct altitudes.
So, once you got your restrictions loaded, look at the last restriction and set your altitude to the same value. Then engage VNAV. Once reaching TOD, you should see the plane starting to descend.
As I said, you should pick a plane and a flight plan and we can walk through it and I can help you to get it to work for a specific case. There’s lots more, especially when it comes to RNAV approaches.
4 Likes
As usual, a specific flight plan with a specific example of what you’re trying to do will reveal the answer to why it’s not working as you expect.
Thank you so much for your response, this is very helpful. I think I will start with the G1000 as it is in so many aircraft. I do like the CJ4 as well. I will jump in the cockpit and see what I come up against and report back. Thanks again.
1 Like
I primarily fly the CJ4. If you are saying you want to input waypoint altitudes that are not part of the pre-set SIDS/STARs, then I haven’t seen that ability in the FMS. I wonder if you can build a flight plan in the world map with waypoints with custom altitudes, but it’s not something I’ve personally tried. Typically pilots just want to ascend, cruise, descend to land. Having custom altitudes along a route (aside from a SID or STAR) would be pretty unusual and wouldn’t surprise me if not possible.
1 Like
You can totally do that. Under flight plan you can enter altitude restrictions and paste it on the right side onto a waypoint. Similarly, on the direct-to page you can enter an altitude and go direct laterally and vertically, basically.
You should check out the CJ4 operating manual. It’s described in there: https://flightsimulator.azureedge.net/wp-content/uploads/2023/02/Cessna-Citation-CJ4-User-Guide-v1.pdf
1 Like
It’s actually not uncommon. ATC may give you different altitudes etc. Sometimes you see on STAR charts “expect”, which means most of the time ATC will give you that particular altitude but sometimes they don’t. Being able to change it in the FMS is essential, happens all the time.
1 Like
What made me think of it was that I was flying the Grand Caravan over a mountain range in Finland (it was pretty dicey) and I wanted to drop back down once I’d passed it but I wanted to stay in AP as I had a 45 kt head wind (!!) I mean, VS would have done it I guess. Anyway, it was really just something I was wondering about. Just gonna jump in the Caravan now and have a play with it. Back to you soon.
Note that VNAV doesn’t guarantee any terrain clearance. It usually aims for a 3 degree path down. This may or may not intercept terrain. That is unless you’re on a STAR or course. They’re designed to keep you safe.
I would have just set the new altitude and used FLC, but then again it’s not something that happens in the sim. At least not that I’ve ever seen. I either use the default VNAV altitudes, or ignore them and follow ATC assignments all the way. Never had them change a SID/STAR.
I have tried reading the manual before, but it’s way too complicated for casual fliers like me. One of my big complaints with the AAU1 update was how they changed the CJ4 into a near study level plane, ruining the experience of those that want to casually fly. We were basically scoffed at for daring to not want a 100% to the letter rule following sim experience and didn’t provide any guidance to help us get up to speed. So yeah, that manual doesn’t exist as far as I’m concerned, because I don’t feel like going to an IRL ground school just to understand it.
1 Like
Yeh okay, gotcha. I actually just managed to add in the altitude for some way points! I didn’t realise you could do it, it was so easy in the end! So my question is whether it will go to those altitudes in AP. You may already have answered this…or do I need to engage VNAV? I think the aim is def to maintain that 3 degree descent and ascent (?) Another question - what do the altitudes that are crossed out with an X mean? Is that something to do with the go around?
That sounds cool. I always thought the CJ4 was a bit too basic.
It would be cool if they had different models - one for casual flyers and one for the study levellers.
Yes, you need to engage VNAV. It will arm VNAV path. You then lower your altitude and the AP should start the descent once you pass TOD. Once you get close, your relationship to the path is shown on magenta where you’d usually see the glideslope on an ILS approach.
The crossed-out altitude means it can’t make the restriction. It either conflicts with something else or the angle would be too steep.
Note that you can always catch up to the path with vertical speed mode. For example, if you’re too high to intercept the path you can come down with an higher V/S until you’re back on path.
Google G1000 NXi VNAV tutorial. There are plenty resources that explain the details.
Hmm I can understand the frustration. However, I don’t think it got more complicated? I think you can still ignore a lot of the complexity and fly it the way you flew before, just with less bugs 