Lee100

Scenario 4. When at cruise in P.ALT and cleared to descend by ATC after the TOD point: 1. At the TOD point, the aircraft does not descend. This is OK 2. At the TOD point, the aircraft should automatically slow to ECON descent speed. It does not and is a bug 3. At the TOD point, the Flight Plan page LSK 1R should display a DECEL prompt. It does not and is a bug. DECEL selection should cause deceleration to Green Dot speed 4. After the TOD point, setting a lower altitude on the MCP and pulling the Alt Sel knob causes a descent in P.DES at ECON descent speed. This is OK Note: In the real world, the vertical path from the initial lower altitude constraint to the cruise altitude is built by using idle thrust and ECON descent speed. If the aircraft is not allowed to descend until after the TOD point, once in descent it will lower the nose to increase its descent rate and attempt to capture the vertical path from above, but may remain above the vertical path unless the speedbrakes are deployed manually for more drag. The simulator does the same and seems to do a good job of maintaining the vertical path once captured.

Scenario 3. Descent in P.DES at the TOD point: This scenario is for when ATC clears "Pilot's Discretion" to a lower altitude. It allows use of the optimum vertical path and is the preferred scenario if possible. When at cruise in P.ALT and ATC cleared to descend at "Pilot's Discretion" before the TOD point, setting a lower altitude on the MCP and pulling the Alt Sel knob arms the P.DES mode. The aircraft stays at the existing cruise altitude until reaching the TOD point where it automatically descends in P.DES at ECON descent speed. The simulator works exactly like the real world aircraft.

It's been a few days and no one has responded to this thread. I'll go ahead and post the results of Scenarios 2, 3, and 4 for future reference. Scenario 2. Cruise descent in P.DES before the TOD point: When at cruise in P.ALT and ATC cleared to descend immediately to an intermediate altitude before the TOD point: In the real world, there are two options. Both options cause the aircraft to descend at 1,000 fpm and ECON descent speed, but they use different speeds after reaching the lower cruise altitude: Set lower altitude on the MCP and pull the Alt Sel knob which merely arms the P.DES mode. The aircraft does not descend yet. Option 1--select IMM DES prompt in Flt Plan page LSK R1. The aircraft maintains ECON descent speed after level off. Option 2--set lower altitude in Prog page cruise altitude LSK L1. The aircraft changes to ECON cruise speed after level off. In the simulator: 1. Setting lower altitude on the MCP and pulling the Alt Sel knob merely arms the P.DES mode. This is OK 2. After setting lower altitude, the aircraft does not descend and an IMM DES prompt appears on Flt Plan page LSK R1. This is OK 3. Setting lower altitude in the Prog page cruise altitude LSK L1 has no effect. Therefore, Option 2 isn't available. This is a bug 4. Selecting IMM DES causes a 1,000 fpm descent at 290 KIAS in P.DES without needing an Alt Sel knob pull. This is OK except the knob pull is necessary in the real world 5. Upon reaching the lower altitude, the aircraft maintains ECON descent speed. This is OK

I'd like to start a discussion about how the iniBuilds' A300-600 vertical Profile mode works versus the real world aircraft IniBuilds has done a great job of replicating an extremely complex system, but there still seem to be some bugs. I propose to examine four real world scenarios in the sim and compare them to how the real world aircraft actually works based on my understanding of available resources. I'd appreciate any comments or corrections from everyone else. Throughout, I tested using the latest v1.1.6 version in MSFS 2020. The four scenarios are: 1. Cruise climb in P.CLB before the Top of Descent (TOD) point 2. Cruise descent in P.DES before the TOD point 3. Descent in P.DES at the TOD point 4. Descent in P.DES after the TOD point ----- To start the ball rolling, here is the first scenario: When at cruise in P.ALT and ATC cleared to climb before the TOD point (without a Step Climb point entered in FMS): 1. After setting a higher altitude on the Mode Control Panel (MCP), no climb occurs. This is OK 2. IMM CLB prompt appears on Flt Plan LS R1, but serves no purpose as the aircraft won't climb until the Altitude Select knob is pulled anyway. IMM CLB prompt display without a Step Climb point may be a bug. 3. After pulling the Altitude Select knob, the aircraft climbs in P.CLB without selecting IMM CLB and automatically resets the Prog Page cruise alitude to the MCP higher altitude. This is OK Note--During climb in the real world aircraft, setting a higher altitude on the MCP automatically erases any lower altitude constraints in the FMS. This is a "feature" of the aircraft, but many pilots consider it a bug as it is then possible to violate SID altitude restrictions when ATC cleared to climb via the SID. The sim does not appear to model this "feature".

Bert, I had the same issue and iniBuilds support recommended that I entirely uninstall the A-300 and reinstall it from scratch. That worked for me. If it doesn't, I recommend you contact them directly.