DC Designs Concorde not following loaded flight plan

Last year in FS 2020, with my HOTAS ONE flight stick, I was able to get Concorde smoothly up to Mach 2 at 50000 feet. I took a break for several months and since returning to the sim, I cannot repeat what I did before and don’t remember the steps I’d taken. The DC Designs Concorde Operations Manual (no info on which version, therein) and several YouTube tutorials I’ve tried all have contradictory instructions and step sequences. My latest attempt was trying to follow the September 2025 YouTube tutorial, “DC Designs Concorde take-off, climb, fuel transfer / super-cruise procedure.” That video shows Concorde taking off with its Heathrow-JFK flight plan loaded, and a smooth ascent on autopilot with no need to use physical throttle or yoke.

I emulated the video’s steps as follows:

Prep:

Flight Engineer CIVA INS MODE switch to NAV (not made exactly clear in the video)

FMC Panel: INS REMOTE switch to LOAD Flight Plan. Once FP loaded, then OFF.

FMC Panel: INS AUTOMAN switch to Auto

FMC Panel: DATA SELECTOR knob to “Distance/Time”.

Fuel transfer: Fuel set at 100%, Tank 11 transfer to 50%, total fuel now just under max

AFCS panel: Set Autothrottle to 250 knots

AFCS panel: Set Autopilot Altitude Selector knob to first objective of 10500 ft.

Centre pedestal aft: Turn on all 4 REHEAT Afterburners (manually or mapped to “X” button on my HOTAS)

Runway take off as usual: Release parking brake, throttle to full, proceed down runway. At 170 knots, pull up on yoke, lift off, raise landing gear and nose/visor. Gradual positive rate of climb. But this is where the fun starts.

Ascent:

At 250 knots, toggle off Afterburners (reduce throttle slightly). Then quickly in AFCS panel:

AUTOTHROTTLE 1 and 2 ON

IAS ACQ ON

AUTOPILOT AP1 and AP2 ON

ALT ACQ On

HDG HOLD ON

However, even when following these “Ascent” steps exactly, I can’t get Concorde to ascend without using the yoke and she either quickly diverts or dives. Typically, the passengers object, and who can blame them? Clearly there is no autopilot or flight plan having any effect here whatsoever.

At the risk of repeating the most frequent question in this forum, “What am I missing?”

Please add the msfs-2020 or msfs-2024 tag to your post, depending on which sim your post is about.

Did you start from Cold and Dark or on the runway? If the latter, I have found the autopilot does not engage, so I suggest the former.

Good question, I should have mentioned that I didn’t start Cold and Dark. When I press FLY, the sim takes me to Concorde waiting on the runway, with engines already on. It even lowers the visor, then waits for me to take it from there.

Unfortunately, in my experience at least, the auto pilot does not behave unless the aircraft is started from cold and dark. I made the following quick start guide a while back to be able to be up and running from cold and dark from within a few minutes with, most importantly, a fully functioning auto pilot. You will need to start your flight from a gate for the aircraft to load up cold and dark for this.

Resets_DCD_Concorde_Cold_Dark_Quick_Start_Guide-2.pdf (5.5 MB)

Thanks; since I posted, I’ve gathered from several sources now that a Cold and Dark start is the preferred option for autopilot to function better in Concorde. I’ve never tried it so far with this aircraft but between your guide and the onboard Checklist, I hope to get things to go more smoothly.

Update: I tried a Cold and Dark startup option with the Concorde by selecting a Heathrow/JFK flight plan but then changing the departure point from the runway to a ramp. I soon discovered that the original flight plan could not then be loaded into the FMC panel screen with the pilot’s CIVA INS REMOTE switch set to LOAD. The Flight Engineer’s CIVA INS MODE switch was inoperative as well so I couldn’t set it to NAV. No point in even taking off.

March 13 edit: I have learned elsewhere that changing the departure position from a runway to a ramp or gate for a cold and dark start in MSFS 2020 can indeed, as I suspected, cancel or overwrite the loaded flight plan, regardless of the aircraft. Well, isn’t that just great. The only workaround might be to select my departure gate or ramp last, after all other settings (aircraft, weather, fuel, cargo) are configured. With my present situation, I recognize that this is a MSFS 2020 issue—not a Concorde issue. However, the Concorde autopilot and SIM flight plan glitches are still interrelated. These represent bugs which should have been solved by now.