Cessna Citation Longitude Flight Dynamics Modification Project

I see, very confusing but thanks for the awesome work!

Hello guys, I am currently not using the mod but I had a question about the longitude.

Despite saying this:

Fixed ITT alarm is ringing and caution message is displayed on PFD while ITT graph and numbers are green on PFD

in my experience the longitude is exactly like before the update, the ITT alarm starts if the itt temp goes over 850 despite it being green on PFD, did anyone manage to see any improvements after the update?

For me, once I get to 44,000 feet the thrust starts to rapidly oscilate between 100% and 30% and speed drops to a stall. Keep it below 44,000 and all is in order. It worked fine prior to SU7 but it might be just me though.

No, it’s a known issue with SU7: temperature spikes above FL440. Not just you :slight_smile:

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I don’t understand how they don’t catch this type of stuff prior to update release, this is a past issue reoccurring once again. I prefer they take their time on releasing updates and actually do some Quality control.

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Hello I just saw your project this little Longitude quote do you have a Discord it seems the most logical to me on the progress of this project

Is this the same issue your talking about with tempeture spikes?

It looks to me like my engines are turning off and on above 44,0000 feet.
I made a little video so you can see what it look like … I thought i didn’t have de-iceing on or something.

Yes, same thing.

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Hi There, I got same issues and more. On an ILS approach I started getting warning lights flashing and just before hitting the GS the aircraft started to descent rapidly even with speed up at about 180kt. Flew below glide slope. Had to manually land. This as never an issue until SU7

so, the FLTCH sometimes freaks out, when it does, the V/S wheel becomes the speed bug selector… real head scratcher, seen it a few times. also, it seams to happen with auto throttle problems, it will say CLIMB power but suddenly put throttle to idle. Another strange one. The reverse throttle toggle button thing. Also, the power of the reverse thrusters is extremely weak at high speed. when landing a biz jet with clam shells. that power slows you down quick! then you bring in the breaks, don’t want to over heat them :wink:

did a 1h flight at FL430 with a RNAV app and everything went fine :man_shrugging:

Trying to understand basics of using the autothrottle for takeoff and landing. Can someone set me straight on the current state of affairs given any bugs etc. that may have been introduced w/ SU7? I’m unsure what is me doing things wrong vs. a possible bug such as behavior @KingBelowMe is referencing.

Some specific questions:

  1. What is the procedure for setting/arming my autothrottle, TOGA button, and SPD FMS/Man settings for takeoff? I arm TOGA, line up, move throttle to 50% and hit autothrottle. Do I need to manually set my speedbug first? If so, to what? I thought TOGA just shot you up at a fixed speed and attitude?

  2. What is the procedure for setting or disabling my autothrottle and SPED FMS/Man settings for approach and then landing (assuming precision approach like an ILS or LPV/RNP)

  3. I have my Virpil CM3 set so the rear detent is idle, and past that down to 0 is reverse throttle via spad.next. I verify that when I move the throttle past idle it moves into the reverse range, I see the clamshells open, etc. However I’m struggling to get it to slow down to 115-120kts when I’m crossing the threshold as it seems like it is hovering a hair over idle. Am I using my autopilot incorrectly here? Or did I mess something up with my spad.next config? See #2 for trying to isolate the issue.

  4. Lastly, are there any good video tutorials that cover Takeoff and Landing in this Longitude mod that are current and walk through the proper procedures, speeds, etc.?

There are probably some better people here than me to answer this, but here’s what I do that seems to work well:

  1. The auto-throttle is not modeled accurately, so IRL procedure will not produce IRL outcomes. In the real bird, my understanding, is you press TOGA (which sets the FD angle), arm auto-throttle, set FMS speed, advance the thrust levers to a set point where the servos grab it and move them forward automatically to takeoff power, rotate, flaps up, FLCH, and then acceleration and climb speeds are managed by the FMS. When I’m flying this mod, I set speed mode to MAN, bug 220 KIAS for takeoff, activate TOGA, advance thrust levers to 40% N1, slight pause, advance thrust levers full forward, arm auto-throttle at 80 KIAS during takeoff roll, rotate, flaps up, select FLCH, increase speed bug to 250 KIAS thru 10,000 feet, increase speed to 300 KIAS above 10,000 feet. Seems to work well for me, aside from the rocket ship climb rate FLCH can sometimes produce, but hey, the sooner I get to cruise the sooner I can enjoy my beverage.

  2. Again, IRL probably not applicable, as my understanding is the IRL auto-throttle will automatically retard thrust levers close to touchdown (50 ft RA?), which isn’t modeled here. When I’m flying this mod, I usually fly the approach at 180 KIAS flaps 1 until glide path intercept, bug Vapp right before glide path intercept, gear down, full flaps, intercept the glide, reduce to 5 KIAS above Vref at 500 feet callout, deactivate auto-throttle and manually retard thrust levers at 50 feet callout to hit Vref at touchdown, land, reverse thrust, add moderate braking at 60 KIAS.

This seems to work for me, I’m sure others will have better advice, sorry I can’t really help with 3 and 4 as I don’t use that hardware and haven’t really seen any good tutorial videos out there.


On approach, our test Pliots Final approach speed is 140kts in the Longitude, the Sim seems to like a 125kt approach.

Before takeoff, the pilots push the A/T button to arm the autothrottle system but the throttle levers will not move until the pilot manually moves the throttles levers more than the preset throttle lever angle (TLA). This is to make sure that the airplane is in the takeoff configuration. The autothrottle system will then engage the hold mode and remove the electrical power from the throttle lever servos until the airplane goes more than 400 feet (121.9 m) above ground level (AGL). After 400 feet (121.9 m) AGL, the autothrottle system will disengage the hold mode and continue takeoff thrust until the landing gear and the flaps are up and a vertical mode is set. Then, the autothrottle system will control the throttle levers.

During the approach phase, the radar altimeter is used to start the retard mode at approximately 50 feet (15.2 m) AGL. The retard mode moves the throttle levers to the IDLE position for landing. If the radar altimeter becomes out-of-range or does not operate, an amber AT RETARD FAIL crew alerting system (CAS) message will show and the retard mode will not operate. Approximately five seconds after landing, the autothrottle system becomes disengaged. During the approach if a pilot pushes the TO/GA button on one of the throttle levers, the autothrottle system will move the throttle levers to the TO position and a green TO will show on the left side of the flight mode annunciations (FMA)


Dan is the AT RETARD modeled in the sim jet?

I don’t think it is.

When should the SPD knobs FMS vs. Man mode be used in the sim jet then?

FMS mode is not modeled in the sim, so it really shouldn’t be used if you are using automation.

I had to reset my Sim and in doing so , it cleaned out my Community folder. I had to redownload approx 94GB. Will not do that again … Soon
A few months back you had sent me instructions and link to you Longitude Lights mod . Is it still applicable with the Dakfly’s 1.90a and WT 7.6a? I ask because at some time in the past there was some discussion of your mod being included with Dakfly’s.
If not , could you please resend instructions and link to download the Lights mod?
Thanks and best regards

Quick report. Changes are pending my next update, but I haven’t had a chance to test properly in SU7. Other priorities have kept me away from Longitude for a while. Hopefully in the next week or two I’ll come back to this and make my next update.