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Reference material - https://www.smartcockpit.com/docs/CL605-FUEL_SYSTEM.pdf Page: 16 Fuel tanks are expected to be within 400 lbs / 181 kgs of each other on taxi / takeoff / landing OR 800 lbs / 362 kgs during flight, to avoid Fuel Imbalance EICAS message. First, orient yourself on the overhead panel, we'll be working in the 2nd row (or middle row) of the FUEL panel area. (Fuel.PNG) All three of these buttons should be extinguished under normal operations. Gravity XFLOW Press to begin the process, there's a 1 second delay after pushing the button for it to illuminate OPEN. This will allow fuel to flow freely between both main (wing-based) tanks. There is no EICAS notification that this is open/occurring. (gravity.png) To observe what's happening in the sim. You can go to the Challenger 650 menu -> Study -> Engines -> Fuel System... You'll notice that whatever Main Tank (either Left or Right) has more fuel that this will continue to consume, whereas the side with less fuel will not. Thus balancing the tanks. L (R) to AUX XFLOW Press the appropriate button to begin the process, there's a 1 second delay after pushing the button for it to illuminate ON. This will remove fuel from whatever side is select and transfer it to the auxiliary tank. Determine which tank has more weight in fuel Left side? Choose L to AUX (L to AUX.png) Right side? Choose R to AUX (R to AUX.png) There is a lock out mechanism that does not allow you to press the opposite button when one is already selected. Pressing L to AUX, for example, then pressing R to AUX, will no longer illuminate the L to AUX button. Pressing the R to AUX button again will resume the L to AUX transfer and the button will illuminate ON again. Once you're done balancing the tank, make sure to deselect the previously selected L (R) to AUX button. The aircraft will now suspend fuel consumption from the two main tanks and pull from the AUX tank until depleted. *Edit* Thanks! @airforce2 As long as a main tank is below 93% full, the aux tank feeds the main tank to maintain the level at 93%. Once a main drops to 93%, the main quantity will remain constant and the aux level will drop. It will appear that the engines are burning from the aux tank, but in reality the engines are burning from the mains and that fuel is being simultaneously replaced in the main tank from the aux tank ejector xfer pumps. To observe what's happening in the sim. You can go to the Challenger 650 menu -> Study -> Engines -> Fuel System... Note: The plane will display an EICAS warning message: FUEL XFLOW SOV OPEN if either button is ON for more than 50 seconds and the tanks are balanced within 100 lbs.

On the DCP, select MENU, and it’s the top selection alongside FPV.

Yes I absolutely am shooting for the practices that are used IRL, and appreciate the level of detail that you have provided - Thank You. I will adjust my approach accordingly. Also sounds like there is a "saved state" issue that is the root cause of the weird disconnect I'm seeing (not the one related to exceeding N1 limit). So I'll count today as a double step forward. Will be interested to understand if the Hot Start team believes the state-issue can be resolved. For my live-ATC flying, I'll just use the discipline of starting from cold-dark status, which is good practice.

Kirk, In regards to the IRL engagement/use of the ATS, I've never heard of any technique or SOP whereupon TOGA is selected on the runway as the throttles are manually advanced through 25%. Would need more context to better understand. Typical SOP dictates we wait until taking the runway to select TOGA / N1 TO to avoid an unintended engagement of the ATS during taxi/ (although TOGA / N1 TO is often selected during taxi to the runway despite SOP) We can save that 'normalization of deviation' discussion for another day. 2 methods to engage ATS for TO that are commonly known or used IRL: (prerequisite = the ATS MSD indicates N1 TO) Slowly advance the power levels manually until ATS engagement (75% N1) - and thence let the ATS set TO thrust - with the PM checking that TO thrust has indeed been achieved by 80 knots. (most common). Press the ATS engagement button when on the runway and cleared for takeoff - and let the ATS take them all the way from idle up to TO thrust. (rare) My observation from your video is that you are advancing the thrust levers manually and quite aggressively compared to IRL. We do not advance the thrust levers that quickly. We also do not 'firewall' the throttles and rely on the ATS to trim or set power - that technique would probably trigger exceedances similar to your video. Reference this video from the 2 minute mark. I'd say this is very representative of a typical CL60 ATS takeoff IRL: From initial advancement of thrust levers to ATS engagement is about 7 seconds. (green lights illuminate either side ATS engagement button) Total time from initial advance of thrust levers to takeoff thrust is about 11 seconds. (vs about 4 seconds in your video) Time to 80 knots is about 14 seconds give or take. The point I'm moving towards is that ATS on this airframe was an afterthought/option that is not fully integrated. I think of the ATS as a 'helper' that has to be managed. The ATS IRL does some odd stuff - and we have to keep an eye on it. It often will overshoot the thrust targets, it won't keep up during approaches on gusty days, it won't keep up with speed changes, especially on the mach to IAS transition during descent. Then there's the airframe specific 'oddities' - such as ours where the throttles will split at low power settings triggering an occasional ATS disconnect. We have to help it / manage it quite a bit. The ATS limitations on the CL60 illustrate it's helper status. We can't use them for GA, CAT II, APR, steep approaches, or touch and goes. (to name a few, the list has 16 or so bullets) As such - relying on the ATS to trim thrust or prevent an exceedance on takeoff by firewalling the throttles - you're seeing what would probably happen IRL. I see you've troubleshot the ATS disengagement down to a saved state root cause - but if your goal is to emulate IRL technique - I hope this information will be helpful.

On business jets, you will typically climb and descend at a specific speed schedule. Example, 250/300/M0.78 means you start your climb at constant 250 KIAS until reaching 10000 ft (speed limited to 250 KIAS below 10000 ft), then pitch nose down to accelerate to 300 KIAS, then hold 300 KIAS until you reach the crossover altitude where 300 KIAS matches Mach 0.78 (high 20s, low 30s altitude, depending on the speed pair). At that point, you toggle to Mach hold and climb a constant Mach to your cruise altitude. You can achieve this by using the FLCH (Flight Level Change), which should hold you selected speed using pitch at whatever thrust setting you have set (typically you would set CL (Climb) thrust. Descent is the same, but in reverse (0.78/300/250)