Working title CJ4...Need help with FLC

I’m pretty sure I’m dong something wrong but I’m having a frustrating time getting FLC mode to work reliably…If I takeoff and climb out then engage autopilot and then FLC…FLC sometimes works, sometimes it doesn’t. When it doesn’t, the CJ4 will just sit there, and not climb. Same thing if I reach an altitude, and level off. I want to climb again, so I dial in the new, higher altitude then engage FLC. Again, it will just sit there, and not climb…I’ve resorted to using VS mode to avoid fighting with FLC…

What is the correct way to engage FLC during takeoff and for climbing during cruise?

Can I, on the ground, set my altitude, turn on NAV andturn on FLC and dial in a speed but leave AP off. Takeoff then engage autopilot…Or do I not touch any of those, until after takeoff, then turn on each?

The way I do it is dial in your altitude then hit TO, when you’re ready to turn on AP it comes on as Roll/Pitch.

Pitch doesn’t work well for me so I normally go Hdg/VS clean up and let the aircraft accelerate to 240kts and then hit FLC.

If I’m changing altitude (climbing) then dial in new altitude hit FLC and increase thrust to climb, if I’m much faster than 250 then I’ll drop the speed bug down to 240/250…

Works for me anyway…

For FLC to work you must change the speed and/or thrust.
E.g. to climb you must increase thrust and/or reduce speed.

If there’s no speed/thrust change, FLC can’t climb or descend.


I usually do similar to the above post, but a little more manual flying.

From memory since I’m not in front of sim:

  1. Turn on FD and set top altitude (whether cruise altitude or whatever ATC gives).
  2. While holding short runway, single notch of flaps and trim to bottom of green indicator.
  3. Line up on runway, hit TOGA.
  4. Set throttle to TO Detent (since you are using WT mods) and takeoff.
  5. Once airborne, gear up, raise flaps at V2+20. Pull throttle back to Climb Detent as soon as flaps are raised.
  6. Once past runway, set AP to NAV/FMS mode (unless following headings from ATC, then wait on this until they set you direct to waypoint). I do not turn on AP yet.
  7. Follow FD manually, trim to TOGA pitch.
  8. Turn on FLC, set speed to 240 (will see FD decrease pitch)
  9. Retrim to match FD.
  10. Once speed is matched to 240, engage autopilot.
  11. Switch from IAS to Mach at cross over point for M0.64 (close to FL300 I believe)

The CJ4 does not have an autothrottle, so you must manually increase throttle to initiate a climb, or decrease throttle to initiate a descent. Otherwise it will continue going level, as you describe.

Nice writeup.

Actually you don’t have to, the WT CJ4 does that automatically (when mach speed matches M0.64, which happens for me usually shortly after reaching FL030)