POLL: VNAV use

[Morten]

Hi fellow simmers   This is just an unofficial poll to see how you as a group compare to real pilots using the autopilot when flying airliners with VNAV capabilities.  As you know you have several different options choosing vertical profile in automated flight, FLCH, V/S, manual etc. This poll also was given to real pilots in a study, and I'll reveal the "real" answers in a few days after you made your votes.  

Edited December 3, 2016 by Morten

[mgeiss]

3x no for me. I use FLCH or VS 99% of the time. Not because VNAV in most addon planes still needs some  refinement, I just don't like to leave everything to the FMC.

Edited December 3, 2016 by mgeiss

[Eddie]

Above transition altitude or 15,000 feet in the climb, whichever is higher, and in the descent on profile STARs.

[achutchison]

I'll use flch or v/s to initiate a descent and once i've captured the vnav path i switch to vnav. Keep a close eye on it though... its not an a320!

[Defiance_co]

Heya Morten,

Being a very latecomer to the Civil Aviation side of Flight Sims

I checked all three

I need all the help i can muster

Though that said, taking over the stick and hand flying is like a pleasure and deffo not a chore

Have Fun

Tony

[HamSammich]

I generally use it most on the descent, but not the actual approach--unless, of course, it's an LNAV/VNAV approach.

[Morten]

Ok, I guess we can see the picture already.

MYTH CONFIRMED, simmers are VNAV addicts.. 

Here is what the real pilots say

• Climb       73% 
• Descent   20%
• Approach   5%

The reasons real pilots do not use VNAV as much on descent/approach are several, here are some below... .  

So, VNAV being buggy is obviously not just a sim issue.  The interesting part though is that real pilots don't use it if they don't trust/like it, but simmers apparently insist on using it anyway... weird, maybe our VNAV is less buggy than the real one  (unlikely)

Another major issue is that ATC tends to mess up your (vertical) flightplan on arrival making it hard to keep up with the FMC.

 

Edited December 4, 2016 by Morten

[mmerelles]

@Morten

when i am flying on the sim and offline i do use vnav a lot for climbing and descending, once i perform the funny part of the takeoff and initial climb i do switch to vnav for grabbing a coke, see something on the laptop or whatever. The same for initial descend via VNAV, when the funny parts starts (approach) i do go manual mode.

 

when i am on the real life, even when practicing on PE, ATC is another thing. You are more like, authorized directo XXX, descend and maintain XXX, authorized climb to XXX. So you do not care much about VNAV either because ATC over busy airspaces rarely let you alone via the procedure.

 

Most simmers will fly offline, if online there is no near congested airspaces and circumstances that arises as on the real deal. So you find yourself via vnav/ap and doing something else 

 

just my personal opinion.

[K4bel123]

@Morten

I also use VNAV nearly all the time for climb out (on- and offline). For descent I normally use VNAV only offline because ´I can clear myself to lower altitudes´, but when descending online, Vatsim or IVAO ATC also tends to mess up my vertical flightplan just like in real life and therefore I normally don´t use it.

I think this applys to many simmers but - like mmerelles said - simmers mostly fly offline (either because they don´t like flying online or because there is no sufficient ATC coverage). I guess this kinda explains the difference.

Also, real world pilots get paid for being in the cockpit and checking their instruments, flight plan, listen to ATC, scan for traffic and so on. Sim pilots on the other hand don´t need to worry about the safety of their virtual passengers or their virtual airplane and therefore tend to do other stuff like watching someone else´s live stream of another sim flight. And in order to do so, you need the autopilot to stay on it´s preprogrammed lateral and vertical flight plan, which happens to be LNAV and VNAV  

Nevertheless I find it to be quite an interesting comparison. Thanks for sharing!

[BrianCoyote]

I never liked VNAV for descent. I would never ever use it for an approach. Climb? Absolutely, there's not much for it to do there

[HamSammich]

I'm also a prevert--I like using VNAV+FD but no AP, to climb and descend. On descent, I'll eyeball it, and if the altitude or airspeed looks funny, I'll tweak by hand, using the flight director as a flight suggester.

 

Best, Marshall

[Adolfin]

I tend to use the VNAV for the climb until I am towards the end of it or if I'm online the atc clears me higher then the VNAV wants to climb to immediately, in that case level change. Decent is usually handled by the VNAV until 10-15000 , depending how it's handling it. Approach almost always vs / level change before the it's glide slope takes it 

[Slowdive]

I think the difference between the real world and the sim is that in the real world you have two pilots, in x-plane it's usually just one pilot 99.99% of the time. So it seem logical that sim pilots would use automation as much as possible.

Flying a 737 single pilot is by definition, unrealistic. So it's unsurprising that there is an unrealistic and heavy reliance on the autopilot.

I also think most IXEG customers are also PMDG customers and accustomed to a nearly perfectly functioning autopilot. So that probably raises the bar a bit on expectations.

[Adolfin]

4 hours ago, Slowdive said:

I think the difference between the real world and the sim is that in the real world you have two pilots, in x-plane it's usually just one pilot 99.99% of the time. So it seem logical that sim pilots would use automation as much as possible.

Flying a 737 single pilot is by definition, unrealistic. So it's unsurprising that there is an unrealistic and heavy reliance on the autopilot.

I also think most IXEG customers are also PMDG customers and accustomed to a nearly perfectly functioning autopilot. So that probably raises the bar a bit on expectations.

The auto pilot is not perfectly good on the ixeg. The amount of times I've seen it slow down too much or not at all in time. Or decend too slow. I love the plane but it's not uncommon that I have to take the autopilot out before fully set up for an ils approach 

[Slowdive]

10 minutes ago, Adolfin said:

The auto pilot is not perfectly good on the ixeg. The amount of times I've seen it slow down too much or not at all in time. Or decend too slow. I love the plane but it's not uncommon that I have to take the autopilot out before fully set up for an ils approach 

I understand that the IXEG autopilot is not perfect, and I didn't mean to imply that it was. Rather, I was simply saying that perhaps IXEG customers are a little critical due to having experienced the PMDG 737 product which has an excellent autopilot. And while IXEG isn't perfect I think it's getting close. Perhaps with another update or two it will be up there with PMDG.

[Iain]

I use VNAV rarely on climb, sometimes in cruise, sometimes on descent and hardly ever on approach.

My current base for all flights is EGPH (Edinburgh Scotland), nearly all SIDS have a height restriction of 6000ft at some waypoint on the SID, often quite far from the departure.  There is also the 250kt rule under 10'000ft.  In really life, ATC will more than likely give a no speed and height restriction soon after takeoff.

In the PMDG, the FMC deals with all these small, on the fly rule changes without any problem, but I have issues with the IGEX version.  

If I use FL CH and climb about 10'000ft and wait until I am passed the waypoint with the height restriction of 6000ft, and I then switch to VNAV, you are not on the profile the FMC expect, the VNAV goes nuts basically, trying to slow you down from 300kts to 250kts or less,  Then to follow, it's often hard to get the autopilot to behave in any way at all, HDG select, V/S modes won't engage, or they do engage in cruise but after a few minutes they disengage.

Also I find the VNAV climb speeds and descent speeds are slow, even with a CI change, they seem to stay the same.  Changing the target speed helps, but then the speed seems to drift high from the new target speed after a few minutes.

Maybe some user error from my side in there, it' doesn't take away any enjoyment of the aircraft for me, this thing has heaps more atmosphere than any plane I have ever flown (simmer for 30 years, 1000 hrs on PMDG).  So I look forward to the future updates!

Cheers

Iain

 

[Vantskruv]

I did not answer this poll, but I think VNAV and autothrottle removes the fun of the game. In theory, you would only start up the airplane, lineup the runway, activate the autopilot. After you landed you deactive the autopilot. Of course there is more too it. I currently try to concentrate on airplanes which is not too automatic, just to have something to do when in cruise. Currently my favourite airplanes are:

* Felis Tupolev 154

and

* PMDG DC6

 

[Iain]

The beauty of simming, you are the captain and can do it what ever way you like!   Like you, I don't mind using other modes more often as it keeps you on your toes with your planning.

I know a couple of Easyjet pilots from frequent flying, they live near my house in Scotland,  was sitting in the cockpit during a long boarding the other week, chatting for 30mins about this and that, "playing" with the MCDU and various other controls, asked him about VNAV use, or autopilot use in general after takeoff, he said a lot depends on weather and how tired they are, that flight was their last for the day and VNAV goes on asap after takeoff!  He knew the 737 classic cockpit so we had a great chat about the quirks of each aircraft, he also said the A320 cockpit has more space than a 747...need to look that up sometime as seems hard to believe.

 

 

[sizziano]

On 12/4/2016 at 10:33 AM, Morten said:

Ok, I guess we can see the picture already.

MYTH CONFIRMED, simmers are VNAV addicts.. 

Here is what the real pilots say

• Climb       73% 
• Descent   20%
• Approach   5%

The reasons real pilots do not use VNAV as much on descent/approach are several, here are some below... .  

So, VNAV being buggy is obviously not just a sim issue.  The interesting part though is that real pilots don't use it if they don't trust/like it, but simmers apparently insist on using it anyway... weird, maybe our VNAV is less buggy than the real one  (unlikely)

Another major issue is that ATC tends to mess up your (vertical) flightplan on arrival making it hard to keep up with the FMC.

 

 

Pretty interesting. I'd like to see an updated poll of pilots flying modern aircraft. I would wager the use would be higher.

[Rodeo]

Looks like the survey is dated 1997? I wonder what the results would be in 2016, especially for modern airliners like Embraers and Airbusses.

[Tom Stian]

When I saw this movie I was thinking about this poll and about using VNAV.

Very interesting video about automation dependency and the levels of automation.

 

Be the "ball" and not the automation manager 

 

 

Edited February 11, 2017 by Tom Stian

[Litjan]

My favourite video on the subject...

[Dhruv]

I suspect the trends have shifted slightly since 1997, especially in the US as more and more "Optimized Profile Descent" (OPD) STARs are becoming the norm. These newer procedures have specific block altitude and speed restrictions on multiple successive fixes and can't be flown without at least some sort of advisory VNAV at minimum generating a descent path that complies with the restrictions.

[Litjan]

3 minutes ago, Dhruv said:

I suspect the trends have shifted slightly since 1997, especially in the US as more and more "Optimized Profile Descent" (OPD) STARs are becoming the norm. These newer procedures have specific block altitude and speed restrictions on multiple successive fixes and can't be flown without at least some sort of advisory VNAV at minimum generating a descent path that complies with the restrictions.

That is certainly true - we are starting to get CDO arrivals (continous descent operation) here in Germany, too. And while a seasoned pilot can certainly fly the profile in selected modes, it is more economical and safe to do so in a vertically managed mode.

Again, we are going to "fix" VNAV - its just going to take some time...

Jan

 

[hhbrbg]

19 hours ago, Tom Stian said:

When I saw this movie I was thinking about this poll and about using VNAV.

Very interesting video about automation dependency and the levels of automation.

 

Be the "ball" and not the automation manager 

 

 

Great video, thanks!

Tom

Edited February 12, 2017 by hhbrbg