Need Help on Fixing Vertical Speed – Climb and Descent
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At last, I have succeeded in flying the Just Flight Bae146 from Leeds/Bradfield Airport to London City Centre Airport, utilizing the on-board Flight Management Computer, and LittleNavMap. I used the FMC to fly the SID, main route, and Star, entering the SID using the “direct-to“ command in the FMC from the runway heading in the autopilot, and landing with the GLS and ILS buttons.
Most of this I learnt from excellent tutorials by Jonathan Becket, they are truly invaluable.
However, I am having much difficulty with vertical speed control – the plane can porpoise a bit going up or down (using yoke or trim wheel) and it is difficult catching the VS button on the autopilot to capture the correct value as it goes by. I am using the SYNC control on the autopilot. But is there any way I can input the vertical speed in a more positive fashion?
I would be interested to learn how others handle this maneuver, Jonathan Becket handles it flawlessly but I don’t know how he keeps the plane stable in a climb or descent while selecting the VS.
Nigel
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@nigelgrant Do you use the AP disengage to set the angle of descent? That’s how I use VS. The other method of course is to go with IAS and power back the thrust to descend. I’ll agree though; vertical Nav is tricky with this bird.
There’s a descent mode too IIRC: DESC ?
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Cleva Treva
Thx for your response and my apologies for taking so long to respond - I have been trying out your suggestions (I think).
I bound a yoke button to the “toggle after burner” command to create the autopilot SYNC (a couple of message strings in this forum describe this process) and I suspect this is equivalent to the autopilot disengage command you refer to? It disengages the AP but retains the parameter settings except for the one I am changing, ie the VS. Then when I toggle the AP back on, it retains the original parameter settings but sets the VS at the new value I have selected. Works like a charm and it is easy to click the button as the VS gauge needle swings through the desired VS.
I could not find the descent mode IIRC: DESC you referred to?
I have been practicing my landings at LOWI which has an offset ILS, but I keep losing my autopilot and its parameters and I am unable to turn any of them back on – so I am still testing.
Regards
Nigel
Vancouver -
@nigelgrant said in Need Help on Fixing Vertical Speed – Climb and Descent:
I could not find the descent mode IIRC: DESC you referred to?
I think you mix up AP with the TMS?!
For VS setting: What happens when you bring the aircraft in a stable climbrate with the elevator trim and push the VS knob then?
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There is a pitch control toggle on the Pedestal.
If you engage VS on the MCP, it will engage the AP and maintain your current VS rate.
You can then use the Pitch control to adjust this.
Or, if stable with AP Altitude ON... change the value in the Altitude window, then hit VS on the MCP, and adjust the VS rate using the pitch control.
It will only work if you change the altitude.
I use a button box with small trim wheels / Streamdeck, which makes this easier... but I'm sure you can find the relevant commands and assign a pair of buttons/rocker switch on one of your controllers ?
(Don't forget VS should only really be used for small changes in altitude. IAS is the safest way)
The Desc mode referred to above is not really relevant... it just tells you the minimum N2 (?) required for electrical systems etc to work properly.
