FD Takeoff Guidance
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Hi Guys,
I start from cold and dark and am wondering how to get good takeoff guidance from the flight directors, like what's set in the 'Ready for TO' state. I can arm LNAV but the only way I get decent pitch guidance is to press the AP disengage button to get GA mode - however this then overrides my armed LNAV with ROLL, so after takeoff I then need to go to IAS mode for pitch then LNAV again for roll as LNAV won't engage whilst in GA mode. It's quite alot of button pressing low to the ground. Tips welcomed! Thanks.
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Hi Guys,
I start from cold and dark and am wondering how to get good takeoff guidance from the flight directors, like what's set in the 'Ready for TO' state. I can arm LNAV but the only way I get decent pitch guidance is to press the AP disengage button to get GA mode - however this then overrides my armed LNAV with ROLL, so after takeoff I then need to go to IAS mode for pitch then LNAV again for roll as LNAV won't engage whilst in GA mode. It's quite alot of button pressing low to the ground. Tips welcomed! Thanks.
@tommchowat https://www.youtube.com/watch?v=njIB2hABlSY&ab_channel=JustFlight
146 Professional MSFS from Just Flight - Takeoff and Climb Tutorial
The best and the clearest sequence. -
Yep it's a decent video, however it seems that just before he taxis onto the runway the vertical FD is doing nothing useful at all, but when it cuts back into the cockpit when he's on the runway, it's at about a ten degree pitch up attitude. In both instances 'PITCH' is in green on the FMA, I'm just wondering where the difference is.
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The FD won’t show “anything useful” whilst taxing, it’s a flight director after all.
It will start to make sense when lined up. I’ve always used GA mode for take off just seems to be what everyone does. Right or wrong I have heading and vs selected AP on at 500 then LNAV.
That’s if I don’t hand fly it all the way to FL100, this aircraft is to nice to fly for AP. -
The FD won’t show “anything useful” whilst taxing, it’s a flight director after all.
It will start to make sense when lined up. I’ve always used GA mode for take off just seems to be what everyone does. Right or wrong I have heading and vs selected AP on at 500 then LNAV.
That’s if I don’t hand fly it all the way to FL100, this aircraft is to nice to fly for AP.@rustyrdc yeah I'm currently using GA mode for takeoff, vertical guidance is good but LNAV or HDG won't work as it's overridden by the GA 'ROLL' mode, so wings will be commanded level until you select a different vertical mode.
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@rustyrdc yeah I'm currently using GA mode for takeoff, vertical guidance is good but LNAV or HDG won't work as it's overridden by the GA 'ROLL' mode, so wings will be commanded level until you select a different vertical mode.
@tommchowat ah I really didn’t notice that tbh. As I say selecting LNAV after take off works fine for me so that’s probably why I’ve not noticed
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@tommchowat ah I really didn’t notice that tbh. As I say selecting LNAV after take off works fine for me so that’s probably why I’ve not noticed
@rustyrdc weird - if I take off in GA mode I can't actually select LNAV until I select a different vertical mode, which as I understand from the manual is the correct logic for the autopilot.
So what I'm wondering is how to get correct vertical guidance on takeoff - or does this even exist as a flight director mode on the 146? Perhaps you only get sensible vertical indications once you select your first mode after takeoff?
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@rustyrdc weird - if I take off in GA mode I can't actually select LNAV until I select a different vertical mode, which as I understand from the manual is the correct logic for the autopilot.
So what I'm wondering is how to get correct vertical guidance on takeoff - or does this even exist as a flight director mode on the 146? Perhaps you only get sensible vertical indications once you select your first mode after takeoff?
@tommchowat Before takeoff and if you have introduce your route in the FMC, press the switch RNAV to change VOR navigation to LNAV. Then press LNAV in the MCP pannel and before entering the runway press the red button on the yoke to activate GA modus. The FD rises about 10 degrees.
Proceed with the takeoff, rotate, climb and follow the NAV guidance from the FD. You can climb manually or with the AP. I like to fly manually until the aircraft is stablished in the SID. Accelerate and retract flaps. Continue accelerating and when you are about 220 Kt pres IAS mode so that the aircraft mantains the selected speed and climb to desired FL.
I usually do it manually and at this point I press the AP to take over. It always works fine for me and is a joy to fly. Hope it helps. -
@tommchowat Before takeoff and if you have introduce your route in the FMC, press the switch RNAV to change VOR navigation to LNAV. Then press LNAV in the MCP pannel and before entering the runway press the red button on the yoke to activate GA modus. The FD rises about 10 degrees.
Proceed with the takeoff, rotate, climb and follow the NAV guidance from the FD. You can climb manually or with the AP. I like to fly manually until the aircraft is stablished in the SID. Accelerate and retract flaps. Continue accelerating and when you are about 220 Kt pres IAS mode so that the aircraft mantains the selected speed and climb to desired FL.
I usually do it manually and at this point I press the AP to take over. It always works fine for me and is a joy to fly. Hope it helps.@alh that's exactly how I do it. I arm LNAV on the ground, then I press the AP switch to activate GA mode. I get correct FD indications on takeoff, but once airborne LNAV doesn't appear to do anything and the FD commands wings level because I believe the GA mode also includes a wings level command which overrides LNAV.
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Think I've cracked it.
So basically the situation was, when taking off with GA mode, I had no LNAV guidance after liftoff even though it was on the FMA as I believe GA mode also commands wings level, which overrides LNAV.
I was wondering how in the panel state 'Ready for TO', the FD pitch bar was at ten degrees up without using GA mode.
Turns out on the centre pedestal just below the AP master switch you can use the toggle switch to move the FD pitch bar. I moved it to about ten degrees nose up and armed LNAV. Bingo, I had immediate lateral guidance after liftoff and a good vertical pitch bar without using GA mode.
FMA's should be RNAV, LNAV and PITCH (with ALT armed).
How correct this is procedurally, I've no idea!
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Think I've cracked it.
So basically the situation was, when taking off with GA mode, I had no LNAV guidance after liftoff even though it was on the FMA as I believe GA mode also commands wings level, which overrides LNAV.
I was wondering how in the panel state 'Ready for TO', the FD pitch bar was at ten degrees up without using GA mode.
Turns out on the centre pedestal just below the AP master switch you can use the toggle switch to move the FD pitch bar. I moved it to about ten degrees nose up and armed LNAV. Bingo, I had immediate lateral guidance after liftoff and a good vertical pitch bar without using GA mode.
FMA's should be RNAV, LNAV and PITCH (with ALT armed).
How correct this is procedurally, I've no idea!
@tommchowat As long as it works for you and you are happy, who cares?:winking_face:
I am happy to hear that it is working for you. Nice flights!