For you Airliner jockeys - how many of you prefer to fly without VNAV?

 

I'm using Radar Contact and it's so much easier to respond to the controllers short temper if I stay in IAS/Level change modes.

 

Anyone else prefer not to use VNAV?

 

Those who are using VNAV - what do you do specifically when the controller gives you altitudes outside of your vertical profile? Do you just jump in the FMC and adjust (dangerous) or keep switching between VNAV and other vertical modes? Seems like a pain and extra work...

 

What situation am I going to get any value or reduced workload from VNAV, when should I use it?

I don't turn it on if I'm using FSX ATC as my airliner VNAV has mostly never met ATC flight level requirements. Not sure how it is done in the real world. Same with descent. If I use the addon ProATC-X, I have no problems entering the FL in the FMC and leaving VNAV on as ATC gives a new FL long before I reach the first level ATC provided. I have had flights though using the FSX default ATC where the controller will give a new flight level just before arriving at the first issued FL. I would go ahead and put the FL in the FMC and engage VNAV. If ATC does not provide a new altitude before reaching the first FL, then I would hit the ALT button on the panel and that will keep you at the level when you hit the ALT. When ATC gives a new FL, reengage the LNAV.

 

Best regards,

Jim

I use VNAV for my climbs and descents and if ATC wants me to climb / descend at a different rate / location I use one of the other pitchmodes, usually V/S (not a big fan of LVL CHG). But ATC very rarely requests different climbrates, as I fly online only with "real" ATC.

Not a lot of commercial airliners use vnav for climb and descents. For one, atc like you to descend or climb in blocks to control traffic. Second, it can be uncomfortable for passengers because vnav doesn't care what your vertical speed is, it will just try to get to the targets of altitude and speed. I think Southwest didn't even have vnav as an option for a while. Descending in vertical speed mode is more normal. and Climb in alt change.

Not a lot of commercial airliners use vnav for climb and descents. For one, atc like you to descend or climb in blocks to control traffic. Second, it can be uncomfortable for passengers because vnav doesn't care what your vertical speed is, it will just try to get to the targets of altitude and speed. I think Southwest didn't even have vnav as an option for a while. Descending in vertical speed mode is more normal. and Climb in alt change.

 

This is correct!

 

I generally use FLCH!It allows more flexibility and control with abiding by ATC requirements.

 

In the real world,the use of VNAV/FLCH can vary from company to company,as dictated by their SOP's.

Yeah it's these ATC requirements that I see a pre-programmed VNAV being too slow to react to our needs. It's the climb that is high workload, trying to hit those departure points and get the credit for them at the same time as doing readbacks and managing the altitude/climb. On descent radar contact does give the clearance to descend in advanced of TOD, but often RC4 has a restriction I have to meet and I have to "start down now please", if I don't start descending he gets cross. Where I know the crossing restrictions from the real world I could enter them in vnav, but I don't think RC4 would match the real world charts because it doesn't use an updatable nav database.

 

It's quite funny I have been using VNAV more in my GA planes, the RealityXP VNAV tells me the exact vertical speed I need to hit the initial approach fix at the right altitude, and using it as advisory only gives me a better feeling of control.

 

I use VNAV for my climbs and descents and if ATC wants me to climb / descend at a different rate / location I use one of the other pitchmodes, usually V/S (not a big fan of LVL CHG). But ATC very rarely requests different climbrates, as I fly online only with "real" ATC.

 

Curious why you don't like LVL CHG? Seems like the most efficient way to fly because it keeps the speed where you want it and you don't have to adjust rate of climb to keep your speed when getting high. Maybe I will use LVL CHG best on the climb, and V/S best on the descent. I'm used to using V/S from GA anyway. Glad to hear "real" ATC works well with you, I hope to do more of that. I'm sure it's better than RC4 the robotic controller is very impatient. It's more like "Communicate, Navigate, Aviate" instead of the other way around. I finally got VATSIM setup in a way that doesn't crash my FSX and tried it out last night on a short flight very impressed with having a human controller. I tried FSINN first and it crashed things.. squawkbox seems usable but that's another topic.

 

Not a lot of commercial airliners use vnav for climb and descents. For one, atc like you to descend or climb in blocks to control traffic. Second, it can be uncomfortable for passengers because vnav doesn't care what your vertical speed is, it will just try to get to the targets of altitude and speed. I think Southwest didn't even have vnav as an option for a while. Descending in vertical speed mode is more normal. and Climb in alt change.

 

This is what I wanted to hear That I don't have to use VNAV and that real world doesn't have to use VNAV.

 

I think what I will take away from this discussion is a new standard procedure for using these modes. This is what I'm thinking:

A. Use VNAV as Advisory Only

B. Use LVL CHG / IAS during climb

C. Use V/S during descent based on VNAV advisory

 

I'm sure for any specific plane it's going to have more specific procedures, but I fly too many, this method will work for anything I have, dropping back to V/S for GA where there is no LVL CHG.

Keep in mind that VS does not have speed protection.In other words it can be unpredictable if you're not carefull.

FLCH is used a great deal more in airliners than is VS

 

 

Boeing prefers pilots to use FLCH/LVL CHG/VNAV instead of VS mode. There have been many instances of pilots using VS and getting too slow or too fast.

"Speed on elevators" modes like LVL CHG ensure that an unsafe flight condition is much less likely to develop than is the case using VS.

 

 

Hope this helps!

That's true you're right. I've had more trouble in the climb where the speed gets too low it's hard to get it back. In the descent though it's not as much trouble reducing the throttles as needed. If its not a excessive descent rate I'm not likely to overspeed.

 

The thing I like about VS in descent is that you can use the 3:1 rule to calculate descent distance at 1000fpm very quickly. IAS in descent I don't know what it's going to do especially if auto trottle is turned on.

When I jumpseated on a Maersk Air UK 737-500 back in the pre-9/11 days between Birmingham and Milan the pilots made extensive use of VS in the descent. Climbs were generally made in VNAV, with the altitude window set to the next cleared flight level. The skipper explained that FLCH for small changes can be uncomfortable for punters due to the deck angle/engine noise that controlling speed with pitch can give.

I make use of the best mode for the moment and situation. If flying off-line, usually VNAV all the way to the final approach.

When on-line sometimes VS is better, sometimes LVL CHG is better.

I like to use LVL CHG for early climbs as it gives you protection of airspeed and V/S for descents so you can control your rate although you need to watch in case of overspeed. I use V/S for high altitude climbs/cruise speeds like step climbs for the 747 where I set a rate of say 500fpm and not going to stall.

Keep in mind that VS does not have speed protection.In other words it can be unpredictable if you're not carefull.

FLCH is used a great deal more in airliners than is VS

 

 

Boeing prefers pilots to use FLCH/LVL CHG/VNAV instead of VS mode. There have been many instances of pilots using VS and getting too slow or too fast.

"Speed on elevators" modes like LVL CHG ensure that an unsafe flight condition is much less likely to develop than is the case using VS.

 

 

Hope this helps!

 

Absolutely, FL/CH is preferable.

 

There was an incident some years ago, in a Dash 8 [Climbing in VS]. The pilots were so busy chatting in the cockpit that they didn't notice their speed decaying. Subsequently they stalled. VS uis fine, but with vigilance.

 

Malmo Aviation ordered there Avro 146's without the VNAV option.

 

A retired 767 pilot told me a couple of years ago how he used VNAV in the climb occasionally, but never in the decent.

I started on my new method using lvl change in climb and it's much easier to react quickly.

 

Did a couple more flights with the Avro and hardly touched VNAV. I found it was ok to turn on once ATC cleared me to cruise alt, but then it's kind of pointless

 

LVL change I started to use in the descent but changed to VS when I didn't like the rate.

 

I like the VNAV advisory in the gps planes better than these airliners, I know it's funny but it's how it is

I use radar contact all the time and when in the NGX use VNAV pretty much down to the FAF. I can't comment on the QW146 as I haven't flown a complete flight yet but in the NG I'll activate VNAV and use Altitude and Speed intervene on the MCP to change the rate at which I descend. For "FLXXX commands in XX miles or less" I'll most probably use FL CH if the restriction doesn't meet my vertical profile.