Note from the author: Please upvote https://forums.flightsimulator.com/t/workaround-for-missing-propeller-drag-please/368300

This is no livery, this is a flight model mod. The idea is to make the flight behavior more realistic. The most important detail is a realistic maximum lift-drag ratio (L/D)max. This one change makes many other changes necessary. The second detail is I use gear and flaps drag to have a work around for missing propeller drag and ground effect. Now you can flare your airplane before touch-down.
See http://www.andreadrian.de/FS_2020_sailplanes/ for more of my work for MSFS 2020:
Gliders: SG-38, Aircreations 582SL
Sailplanes: DG-808S, Ka 6E, ASK23
Trainer: Tiger Moth
Seaplane: Grumman Goose G21A
Warbirds: Fokker Dr1, North American P-51D

Flight model modification version 1.14.5.0, date 2021-03-11:

I included "Uwa's lighting mods" from https://uwajimaya.github.io/FS2020/
Uwajimaya, I credit your work!
Pack version 1.13 (Feb 16, 2021)

This flight level mod sets (L/D)max to 80% of the real life value. This is part of the "missing propeller drag" workaround. For (L/D)max see https://code7700.com/aero_l_over_d_max.htm

Using the parameters drag_coef_zero_lift, htail_incidence, thrust_scalar and fuel_flow_scalar the maximum airspeed, (L/D)max and fuel consumption can be set to one operating point OP. I set the OP to full weight, no flaps, retracted landing gear, full thrust, level flight, no elevator input and altitude 10000 ft.

I use the MSFS 2020 documentation from https://docs.flightsimulator.com/html/Samples_And_Tutorials/Defining_A_Flight_Model.htm Citations are in "". Asobo has expanded the documentation, but sadly the documentation is still far away from complete. Asobo please go on!

To all critics of my work: First, I am an armchair pilot. If you only accept flight model mods from real life 4 stars pilots, don't use it. Second, if you think my mod is atrocious, don't use it. To everybody else: The mod is the best I can do with my knowledge of MSFS 2020. Stay happy and healthy!

autopilot_available = 1
See https://forums.flightsimulator.com/t/discussion-sim-update-3-1-14-5-0/375656/436

wing_incidence = 2 ; Wing incidence (DEGREES)
htail_incidence = 1 ; 0 ; Horizontal tail incidence (DEGREES)
No elevator input needed for level flight at full thrust at OP.

fuselage_length = -1 ; 20 ; Nose to tail (FEET)
Use automatic fuselage_length.

elevator_trim_neutral = 0 ; 1 ; Elevator trim max angle (absolute value) (DEGREES), for indicators only (no influence on flight model)
I want to have the green area in the middle of VSI.

drag_coef_zero_lift = 0.04460
"this value is usually of around 0.02 to 0.025 for an aircraft with a glide ratio above 15, 0.03 to 0.04 for aircraft with glide ratios of about 10, and up to 0.1 for some slow bush planes with very low glide ratios."
I use additional parasitic drag as "missing propeller drag" workaround. I use Aircraft Editor, Debug, Sim Polar VhVs to set (L/D)max (glide ratio) to a realistic value "within the limitations of the current simulation".

lift_coef_flaps = 0.4379 ; 0.87570
This is NOT the "flight dynamics bug" workaround. I sometimes use less lift_coef_flaps because it is too exaggerated.

drag_coef_flaps = 0.15 ; 0.10020
"If the aircraft has flaps you can define the lift and drag coefficients that will be added when the flaps are fully deployed"
I sometimes use additional drag_coef_flaps as "missing propeller drag" workaround, too. But not here.

drag_coef_gear = 0.00500
"gear drag is usually between 0.005 and 0.01"
I sometimes use additional drag_coef_gear as "missing propeller drag" workaround, too. But not here.

lift_coef_spoilers = 0 ; -0.10000
drag_coef_spoilers = 0 ; 0.10000
The airplane has no spoilers.

induced_drag_scalar = 1.5 ; 1
flap_induced_drag_scalar = 1.5 ; 1
"a value between 1.2 and 1.5 is usually fine. If this value is above 1.5, the plane will generate a lot of drag at slow speed, and if the value is closer to 1, it will glide very easily at slow speeds."
I use additional induced drag as "missing propeller drag" workaround, too.

cruise_speed = 130 ; Knots True (KTAS)
[PROPELLER]
thrust_scalar = 1.45 ; 1.2 ; Propeller thrust scalar
Change in drag_coef_zero_lift needs change in thrust_scalar for the same cruise_speed.

ui_autonomy = 5 ; max duration the aircraft can fly between take-off and landing in (Hrs)
fuel_flow_scalar = 0.52 ; 0.82 ; Fuel flow scalar
Change in thrust_scalar needs change in fuel_flow_scalar for the same ui_autonomy. I use 80% LVR on ground to set fuel_flow_scalar.

toe_brakes_scale = 1 ; 0.66 ; Brake scalar
Maximum value is 1 in my experience. But still not strong enough to hold airplane at full thrust ground test.

pitch_stability = 0.04 ; 0.1
roll_stability = 0.04 ; 0.1
yaw_stability = 0.04 ; 0.1
"You need to enter a value that is higher than zero for backwards compatibility with the legacy flight model, and you can enter 0.01 - for example - if you want only the minimum friction. If the plane has more inertia, you can enter higher values."

flaps-position.0 = 0, -1, 0 ; 0, -1, 1, 0, 0, 0, 0
flaps-position.1 = 15, -1, 1 ; 15, -1, 0.33, 0, 0, 0, 0
flaps-position.2 = 37, -1, 1 ; 37, -1, 0.66, 0, 0, 0, 0
flaps-position.3 = 55, -1, 1, 0, 0, 0, 0
flaps-position drag depends on flaps angle. Therefore drag multiplier of 1 is good enough.

Summary: "If Asobo only knew what Asobo knows". Some Asobo engineers write documentation and tell everybody what to do and why. Other Asobo engineers write cfg files. As you can see above, these two groups don't talk to each other. Specially not about induced_drag_scalar and stability parameters.
Nowhere Asobo writes about the importance of (L/D)max (glide ratio) and how to set a proper (L/D)max. For me is a bad (L/D)max value the single most important reason for poor quality of (Asobo) flight models. Let's see what Asobo will do in the next software release!

Note from the author: Please upvote https://forums.flightsimulator.com/t/workaround-for-missing-propeller-drag-please/368300

Flight model modification version 1.14.5.0, date 2021-03-11:

I included "Uwa's lighting mods" from https://uwajimaya.github.io/FS2020/
Uwajimaya, I credit your work!
Pack version 1.13 (Feb 16, 2021)

This flight level mod sets (L/D)max to 80% of the real life value. This is part of the "missing propeller drag" workaround. For (L/D)max see https://code7700.com/aero_l_over_d_max.htm

autopilot_available = 1
Enable auto pilot.
See https://forums.flightsimulator.com/t/discussion-sim-update-3-1-14-5-0/375656/436

max_gross_weight = 15000 ; 16500 ; Empty weight, (LBS)
empty_weight = 9785 ; 9955 ; Empty weight, (LBS)
cruise_speed = 312 ; 244 ; Knots True (KTAS)
Use Beechcraft King Air 350i brochure year 2019 data.

empty_weight_pitch_MOI = 40224 ; 35351 ; Empty pitch moment of inertia, Jxx (SLUG SQ FEET)
empty_weight_roll_MOI = 18746 ; Empty roll moment of inertia, Jzz (SLUG SQ FEET)
empty_weight_yaw_MOI = 55909 ; 51570 ; Empty yaw moment of inertia, Jyy (SLUG SQ FEET)
"we have developed a tool that computes the MOIs based on the dimensions and geometric shape of the aircraft, now that you have defined everything. You can find the results of these MOI calculations in the Weight [Aircraft Editor] Debug Window"

point.0 = 1, 14.5, 0, -5.38, 750, 0, 0.596, 45, 0.461, 2, 0.952, 4.8, 4.8, 0, 184, 184, 2 ; 1, 14.5, 0, -5.38, 750, 0, 0.596, 30, 0.461, 2, 0.952, 4.8, 4.8, 0, 184, 184, 2
Smaller taxiing curve radius.