Hi. I'd like to know how to enable what I think is called "VERT SPD" in the 767. I would like the autopilot to adjust pitch to fly the plane at a specified airspeed. I saw references to VERT SPD in the manual, but I did not see instructions on how to activate it.Thanks,Rudy

Hi,By saying 'I would like the autopilot to adjust pitch to fly the plane at a specified airspeed' I think you are referring to VNAV SPD. This mode for example used during climb will hold the selected speed by adjusting the pitch required to climb.VERT SPD is a mode whereby you select the v/s (on the mcp) e.g. a number of feet per minute and then you also have to select the airspeed you want the autopilot to hold. More info is in the 767 PIC FMC.pdf manual, page 63.Carl

Hi,The function you are looking for is FL CH or flight level change, this function allows you to select a speed and the aircraft will maintain this speed by the use of controlling pitch, the higher the nose the lower the airspeed and vv, ignoring the climb/descend patch calculated by the FMC. VNAV is used to climb/descend at a calculated climb/descend path paying no attention to speed.V/S is used to select a fixed rate of climb/descend by selecting a fixed ft/min V/S.Hope this helps,Marco

During the climb, if you engage VNAV, it goes to VNAV SPEED and most certainly maintains the climb speed specified by the FMS, which can be changed if desired. VNAV PATH is used during cruise and descent.However, I also agree that FL CH is the closest autopilot function ro "VERT SPD."

Hi.FL CH is not what I'm looking for because FL CH aims the plane toward a specific altitude. I believe it also adjusts the throttle.I thought there was a mode that did not touch the throttle (auto throttle off) but let you put a speed into the MCP. The pitch of the plane will be adjusted to maintain the MCP airspeed. For example, if I put the throttles to idle and put 300 kts in the MCP, the autopilot will dive to increase to 300 kts. If I changed MCP airspeed to 150 kts, the plane would climb until IAS 300 kts.Rudy

You are describing FL CHG! YOu can use it with A/T on or off. If A/T on and you select a higher altitude, it will go to the current FMC-calculated maximum N1. If you select a lower altitude, it will put the throttles at flight idle. Or, leave the A/T off and select your own throttle setting.Yes, you do have to set your MCP altitude, but you have to do that for all the modes.Lee Hetherington (KBED)

Hi Lee,Thanks for your help. The autopilot "mode" I'm trying to describe would allow someone to fly away from the MCP selected altitude. Can use FL CH to fly away from the MCP altitude? The bottom of page 46 in 767_Pilot_in_Command-Panel_Operation_and_Systems.pdf says "The FL CH mode will fly you TO a selected altitude, while VERT SPD allows the pilot to fly AWAY from the selected altitude."Here is some "source code" that explains the behavior I'm looking for. (This was modeled in the Hawker airplane in Fly!)while( above_target_speed ){ pitch_up()}while( below_target_speed ){ pitch_down()}

I don't believe the mode you're describing exists on the 767. I'm not aware of any autopilot system that is designed to fly 'away' from an altitude constraint. FL CH invokes constant thrust (either managed by the A/T or by the pilot) and uses pitch to control airspeed in the same manner you describe. But it's all in the context of a target altitude.JPS. Any managed vertical speed mode is performed in the context of an altitude constraint on the '67.

> I'm not aware of any autopilot system that is designed to fly 'away' from an altitude constraint. I think we had a similar question to this on the forum recently, Jase, but I don't think it was answered properly. My notes seem to indicate otherwise, but I wasn't able to confirm that this was the case in real life.My notes on the 747-400, for example, say that when V/S is selected on the MCP, the V/S window unblanks and synchronizes to the present airplane V/S. "It will synchronize to 000 if the previous mode was:-ALT (altitude hold).-Takeoff or go-around and the vertical speed is negative."If the aircraft is in ALT HOLD mode, you select V/S (unblanking the window) and then dial in a non-zero V/S, I can't see how the aircraft can disobey this command... and fly away from the (current) MCP altitude. Note here that G/S mode will normally allow the plane to fly away from an MCP altitude.I was hoping that a 767 pilot could confirm that the 767 behaves similarly. Neither PIC nor PS1 will allow you to go from ALT HOLD to V/S.Cheers.Ian.

First, let me clarify my earlier statement which was far too broad. I am not aware of any "managed" speed/thrust mode which operates independently of MCP altitude. There may be some aircract which have this capability, but I'm certain it is not to be found on a Boeing aircraft.Second, I decided to take up your suggestion and go straight to the horse's mouth (namely Eric) on the quirky V/S behavior you describe. As you well suspected, Ian...the PIC logic is faulty in this regard. With the sole exception of ALT CAP, you can always break out of any ALT HLD at any time and manually assume control of the aircraft using V/S. What I found is that PIC gets it right 50% of the time. If you explicitly place the aircraft in ALT HLD mode, you can switch to V/S mode without a problem. At that point you are free to direct the aircraft up or down - towards or away from the MCP Altitude as you see fit. However, if you reach ALT HLD by way of ALT CAP, then you are "stuck" in this mode unless you first dial in a lower or higher MCP altitude (what you set it to doesn't matter). This is in error and *not* a constraint that the real 767 has - according to Eric, anyway.Cheers,J

Jase,Thanks for that little piece of information. I have wondered about the V/S mode behavior myself, as sometimes it has seemed to work and sometimes not (without changing the MCP alt). Well, now I know the limitations and also something MORE about the workings of PIC and the real bird.I have to admit that SOMETIMES it would be nice if the V/S could be set independently of the manner of how ALT HOLD was achieved, but this is a MINOR discrepancy altogether... However, it would be nice to know (from Eric) why this little glitch was left in the panel. PIC offers so much realism that I no longer expect anything less than ALMOST perfection from it. This little thing classifies PIC as being ALMOST perfect, as before, so nothing's changed! You gotta love it!Best regards,Tero

>However, it would be nice to know (from Eric) why this >little glitch was left in the panel. Likely it was never tested. One must admit that arbitrarily flying "away" from the MCP altitude is not the first thing that comes to mind when making a decision to adjust altitude. For me, it's always a 3 step process (if I'm not using VNAV, that is):1. Do I need to climb or descend?2. What is my target altitude; set it...3. How fast do I want to get there; set it...Rarely, except in a case of great urgency, would one ask #3 and not bother asking #2. Generally if UP or DOWN without concern for altitude is all I care about, then I'm probably reaching for the disconnect bar and taking matters into my own hands! ;-)

"With the sole exception of ALT CAP, you can always break out of any ALT HLD at any time and manually assume control of the aircraft using V/S."I'm still a little confused, Jase...As I understand it, the above statement refers to the real aircraft (?). If so... and the (real) 767 is descending towards an MCP altitude, in which descent modes (V/S, VNAV PTH or FLCH) will the A/P transition from the current descent mode to ALT HOLD without going through ALT CAPT? Any? All? (My notes show at least V/S and FLCH transition thru ALT CAPT to get to ALT HOLD. Does this mean I can't reselect V/S to get away from the captured MCP altitude after using V/S and FLCH in descent?).Thanks.Cheers.Ian.

Ian,How about this:3000 in the MCP ALT, no AP selected mode on.Manually climb to 3000 ft and switch on the AP. There you have ALT HOLD without ALT CAPT. I assume this is the situation where one could fly away with V/S, without setting the MCP ALT again first.regards,Tero

Ian/Tero,You can press ALT HLD at any time during your climb (or descent) and the aircraft will exit your current climb/descent mode and level off wherever you happen to be. You will NOT transition through ALT CAP in this case. You only transition to ALT CAP inside of 1000' (typically) of your MCP target altitude. So try this:1. Set MCP altitude 18000'2. Take off from your favorite airport...3. Climb to 5000' by whatever means toots your horn: VNAV, V/S, FL CH...4. Press ALT HLD; the aircraft exits whatever climb mode you were in and immediately enters ALT HLD mode (NO ALT CAP here)5. Select V/S; ALT HLD light is extinguished, and 0000 is displayed in the V/S window. Dial in -1000. You are now moving away from your MCP altitude of 18000'. (the real 767 allows this too)6. Press ALT HLD again7. Select V/S; ALT HLD light is extinguished, and 0000 is displayed in the V/S window. Dial in +2000. You are now climbing towards your MCP altitude of 18000'. (the real 767 allows this too)8. Allow the A/P to capture the MCP ALT. After passing 17K, you will transition to ALT CAP and then to ALT HLD.9. Once in ALT HLD, try pressing V/S - you can't. (the real 767 allows this just as before; PIC, however, does not and is in error)10. Dial in 24000' on the MCP (this step is not necessary in the real 767 according to Eric and is an artifact of faulty gauge programming - when in doubt, blame Wade ;-)11. Select V/S; ALT HLD light is extinguished, and 0000 is displayed in the V/S window. Dial in -1000. You are again moving away from your MCP altitude.Cheers,JPS. The upshot: Ian, your original statement about the aircraft always obeying a pilot's directive to follow the specified V/S (regardless of MCP ALT) is correct, according to Eric. The real 767 behaves as you would expect; PIC does not (at least not consistently).