HawkDsl

Real Engine 1.4

Recommended Posts

39 minutes ago, LDP1949 said:

 I downloaded the C404 yesterday for P3DV4 and can perform some testing as it relates to FF as mentioned above. 

Can you confirm the FF figures from the POH/FSX in P3Dv4 and the, according to AndiKunzi, way too low climb rate?

Btw, glide ratio with both props feathered is also correct...at least in FSX.

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

6 hours ago, LDP1949 said:

When you say Fuel Flow is low and Drag / Sink rate is low, can you detail steps to correct .air file?  I really wish there was someone equal to Brent Stolle with the expertise to adjust FDE dynamics as exist in real-world ops. As I understand it, he is no longer in engaged in flight sim stuff. 

T/O FF is roughly 42 GPH/engine, so about 250 pph, and must be in the White arc. Cruise climb (MP and RPM end of green arcs) is done with the FF at the blue triangle at 145 pph as per book,. In reality, a bit richer to keep EGTs down.

Sink rate in landing config is in a way that you can make really steep approaches at 140 KIAS. However, I can't tell the numbers without trying it in the plane and recording that. The C421C is also a bit different, probably.

However, if you arrive at medium loadings at the fence at a Speed of 100 KIAS and pull the engines to idle, you just don't float down half the runway until you can touchdown near stall. The plane just sits down quickly.

If someone who is involved in developing the C421 would come to Stuttgart, I could do a performance recording / comparison flight (just in case this post is read by the right person). 

 

Share this post


Link to post
Share on other sites
1 hour ago, AndiKunzi said:

However, if you arrive at medium loadings at the fence at a Speed of 100 KIAS and pull the engines to idle, you just don't float down half the runway until you can touchdown near stall. The plane just sits down quickly:

For this effect you need to switch to x-plane as FSX/P3D doesn't simulate prop wash / loss of lift over the wings.

Nice side effect when using x-plane (and basically every other sim except FSX/P3D); you will get the correct sound when changing power/prop RPM.

That's a real show stopper and immersion killer IMO in FSX/P3D. 

Share this post


Link to post
Share on other sites

P3DV4 Data: 

TAKEOFF: 

During takeoff roll, FF 31 GPH/engine, well below the white arc. TOW 6548; FLAP TO/APCH

CLIMB: 

Climbing out of 5000: 

MP - 33.6

RPM - 1900

FF - 21 GPH/engine

EGT - 1455F

CHT - 148F

IAS - 130 KIAS

CRUISE:

MP - 31.0

RPM - 1700 

FF - 15.3 GPH/engine - TOTAL LB/HR - 190

EGT - 1502F

CHT - 106F

IAS - 151 KIAS

TAS - 179 

TEMP - +7C / ISA +12

C404 POH CRUISE DATA: 10000 FT / MP 31.0 /RPM 1700 / STD TEMP -5

BHP - 62.2

KTAS - 176

TOTAL LB/HR - 220 

I should have checked the aircraft.cfg fuel scaler before I began. I will do that now as most Alabeo/Carenado require some adjustment. 

Any advice on how to adjust .air file is appreciated. 

Les Parson

 

 

 

 

Share this post


Link to post
Share on other sites

Thanks for the tests, but tests should always be performed at ISA conditions.

You can't simply compare test at ISA +12 and compare them with ISA POH data. 

Confirm you were at MTOW?

At FL100, 8400lbs, 1700RPM and 31.0MP  I get:   175ktas   225pph   EGT 1022F  

 

 

Share this post


Link to post
Share on other sites

Is there a way to increase prop drag on idle? This could replace the missing prop wash effect and could enhance reality of OEI (one eng inop) behaviour. Drag remains almost same for windmilling or feathered prop, whereas in real life, a windmilling prop costs 400 fpm ROC.

Gear down is -350 fpm, flaps 15 is -200 fpm and flaps 45 is -800 fpm as per POH of the C421C, which should be very close to the figures of the C404.

Most piston twins have comparable figures for OEI regarding windmilling prop and gear. Flaps on the 404 produce more drag, as stated above. That's why I changed drag in aircraft.cfg for flaps 45 to 1.4 (flaps 15: 1.1).

Regarding climb performance: I made quite a couple of more flights, got used to the weird leaning simulation and found climb data to be rather OK if leaned in the way P3D wants it. As full power per book is always full rich and cruise climb is done with FF at the blue triangle, I did that wrong in the sense of P3D and stand corrected in a way that if leaned like the simulator requires (and not a real TSIO engine), climb data is correct.

Still, I find beta_max = 60 good for high altitude cruise (simulating what we do in the C421). beta_feather = 65 improves feathering for me at all speeds. In real life, feathering is a rather quick process.

Share this post


Link to post
Share on other sites

Just compared the ROC with the POH values and full flaps reduce the ROC a lot, by 600ft/min and the extended gear another 300ft/min at 109kias

That's what i get in FSX as well.  Same goes for the GA ROC at 92kias at 850ft/min.

Feathered vs windmilling drag is too low but that might be an FSX/P3D restriction.

 

Share this post


Link to post
Share on other sites
7 hours ago, AndiKunzi said:

Is there a way to increase prop drag on idle? This could replace the missing prop wash effect and could enhance reality of OEI (one eng inop) behaviour. Drag remains almost same for windmilling or feathered prop, whereas in real life, a windmilling prop costs 400 fpm ROC.

Gear down is -350 fpm, flaps 15 is -200 fpm and flaps 45 is -800 fpm as per POH of the C421C, which should be very close to the figures of the C404.

Most piston twins have comparable figures for OEI regarding windmilling prop and gear. Flaps on the 404 produce more drag, as stated above. That's why I changed drag in aircraft.cfg for flaps 45 to 1.4 (flaps 15: 1.1).

Regarding climb performance: I made quite a couple of more flights, got used to the weird leaning simulation and found climb data to be rather OK if leaned in the way P3D wants it. As full power per book is always full rich and cruise climb is done with FF at the blue triangle, I did that wrong in the sense of P3D and stand corrected in a way that if leaned like the simulator requires (and not a real TSIO engine), climb data is correct.

Still, I find beta_max = 60 good for high altitude cruise (simulating what we do in the C421). beta_feather = 65 improves feathering for me at all speeds. In real life, feathering is a rather quick process.

Can you highlight any other aircraft.cfg or .air file modifications you might have?

I recently made CHT changes in .air file as recommended from an older post. 

Thanks / Les Parson

 

Share this post


Link to post
Share on other sites
On 10/6/2017 at 11:39 PM, J35OE said:

Thanks for the tests, but tests should always be performed at ISA conditions.

You can't simply compare test at ISA +12 and compare them with ISA POH data. 

Confirm you were at MTOW?

At FL100, 8400lbs, 1700RPM and 31.0MP  I get:   175ktas   225pph   EGT 1022F  

 

 

You're right. We did analysis this way in the airline world with real time variables in ISA and especially wind for seasonal block adjustments. This environment is of course much different. 

Share this post


Link to post
Share on other sites

Andi, 

How do these actual numbers sound (P3DV4): 

A 14000 / FL140

MP: 31

RPM: 1700

FF TOTAL/LB/HR: 220

EGT: 1396F 

CHT: 266F

KIAS: 144

TAS: 184

 

Share this post


Link to post
Share on other sites

Very good, except for EGT and CHT, which is probably due to the weird leaning mechanism in FSX / P3D.

If leaning to book values at 55 to 65 %, this will be about 50 dF ROP (rich of peak), which means about 1600 dF TIT / EGT. The GTSIO-520 run really cool, because of their excellent cooling design, even without cowl flaps. You'll see about 340 dF in cruise at about 62 % and leaning per AFM / POH.

On fuel injected engines, (almost) no adjustments have to be made with altitude changes.

In the meanwhile, I adjusted the main variables to match our C421C as closely as possible, starting with wing area. This is useful for emergency training and decission making scenarios at different loadings and for having comparable IAS to our bird at various power settings. Stall speeds and performance figures are close enough now for me to have a good simulation until Alabeo comes out with their C421. Thus, I'm not using the original C404 anymore.

Still missing the OAT gauge. Autopilot is a small little window now docked to the upper right corner.

If somebody is interested, I can post the aircraft.cfg here.

Share this post


Link to post
Share on other sites
3 hours ago, AndiKunzi said:

Very good, except for EGT and CHT, which is probably due to the weird leaning mechanism in FSX / P3D.

If leaning to book values at 55 to 65 %, this will be about 50 dF ROP (rich of peak), which means about 1600 dF TIT / EGT. The GTSIO-520 run really cool, because of their excellent cooling design, even without cowl flaps. You'll see about 340 dF in cruise at about 62 % and leaning per AFM / POH.

On fuel injected engines, (almost) no adjustments have to be made with altitude changes.

In the meanwhile, I adjusted the main variables to match our C421C as closely as possible, starting with wing area. This is useful for emergency training and decission making scenarios at different loadings and for having comparable IAS to our bird at various power settings. Stall speeds and performance figures are close enough now for me to have a good simulation until Alabeo comes out with their C421. Thus, I'm not using the original C404 anymore.

Still missing the OAT gauge. Autopilot is a small little window now docked to the upper right corner.

If somebody is interested, I can post the aircraft.cfg here.

I'm definitely interested in anything you're able to post. I'm using the C404 in anticipation of the C421C release but that could be months away. On a separate point, I did adjust the fuel scaler in aircraft.cfg to boost fuel flow, however, I realize issues are more involved and complex. Again, anything and everything you can post will be much appreciated. 

Thanks / Les Parson

 

Share this post


Link to post
Share on other sites

As for a first model of something that behaves Close to our C421C, I did the following:

aircraft.cfg:

[General]
atc_type=cessna
atc_model=C421
editable=0
performance=Maximum Speed\t\n232 kts\t 267 mph\t 430 kmh\n\nCruise Speed\t\n222 kts\t 255 mph\t 411 kmh\n\nEngine\t\nGTSIO-520-L\t375hp\n\nPropeller\t\n3 blades McCauley\n\nMaximum Range\t\n1100 NM\t1266 sm\t2037 km\n\nService Ceiling\t\n30200 ft\t\t9205 m\n\nFuel Capacity\t\n206 U.S. gal\t779 L\n\nEmpty Weight\t\n5158 lb\t2341 kg\n\nMaximum Ramp Mass\t\n7500 lb\t3405 kg\n\nUseful Load\t\n2342 lb\t1063 kg\n\nLength\t\n39,52 ft\t12,04 m\n\nWingspan\t\n41.1 ft\t12,53 m\n\nHeight\t\n11.45 ft\t3.49 m\n\nSeating\t\n8
Category = airplane

 

[weight_and_balance]
max_gross_weight =            7500
empty_weight =                5158
reference_datum_position = 0, 0, 0
empty_weight_CG_position = 1, 0, 0
empty_weight_pitch_MOI =     10000
empty_weight_roll_MOI  =     12000
empty_weight_yaw_MOI =       13000
empty_weight_coupled_MOI =       0
max_number_of_stations =        16

 

station_load.0 = 170,  2,  0, 0
station_load.1 = 170,  2,  0, 0
station_load.2 = 170,  1,  0, 0
station_load.3 = 170,  1,  0, 0
station_load.4 =   0,  0,  0, 0
station_load.5 =   0,  0,  0, 0
station_load.6 = 170, -1,  0, 0
station_load.7 = 170, -1,  0, 0
station_load.8 =   0, -2,  0, 0
station_load.9 =   0, -2,  0, 0
station_load.10=   0,  5,  0, 0
station_load.11=   0,  4,  0, 0
station_load.12=   0,  0, -3, 0
station_load.13=   0,  0,  3, 0
station_load.14=   0, -3,  0, 0
station_load.15=   0, -4,  0, 0

 

[flight_tuning]
cruise_lift_scalar  =1.0
pitch_stability   =1.0
roll_stability   =1.0
yaw_stability   =1.0
parasite_drag_scalar  =0.79
induced_drag_scalar  =1.15
elevator_effectiveness         =1.0
aileron_effectiveness  =1.0
rudder_effectiveness  =1.0
elevator_trim_effectiveness =1.0
aileron_trim_effectiveness =1.0
rudder_trim_effectiveness =1.0
hi_alpha_on_yaw          = 1.0  
p_factor_on_yaw          = 0.5     
torque_on_roll           = 0.5        
gyro_precession_on_yaw   = 0.5         
gyro_precession_on_pitch = 0.5    
gyro_precession_on_roll  = 0.5 

 

[GeneralEngineData]
engine_type =         0
fuel_flow_scalar =  1.0   
engine.0 =     7, -7, 0
engine.1 =     7,  7, 0
min_throttle_limit=   0

 

[piston_engine]
power_scalar =               1                  //Piston power scalar
cylinder_displacement=      90                  //Cubic inches per cylinder
compression_ratio=         7.5                  //Compression ratio
number_of_cylinders=         6                  //Number of cylinders
max_rated_rpm=            2235                  //Max rated RPM
max_rated_hp=              375                  //Max rated HP
fuel_metering_type=          0                  //0=Fuel Injected, 1=Gravity Carburetor, 2=Aerobatic Carburetor
cooling_type=                0                  //0=Cooling type Air, 1=Cooling type Liquid
normalized_starter_torque=  0.2                 //Starter torque factor
turbocharged=                1                  //Is it turbocharged? 0=FALSE, 1=TRUE
max_design_mp=              39                  //Max design manifold pressure, (inHg)
min_design_mp=               1                  //Min design manifold pressure, (inHg)
critical_altitude=       25000                  //Altitude to which the turbocharger will provide max design manifold pressure (feet)
emergency_boost_type=        0                  //0=None, 1=Water Injection, 2=Methanol/Water injection, 3=War Emergency Power
emergency_boost_mp_offset=   0                  //Additional manifold pressure supplied by emergency boost
emergency_boost_gain_offset= 0                  //Multiplier on manifold pressure due to emergency boost
fuel_air_auto_mixture=       0                  //Automixture available? 0=FALSE, 1=TRUE
auto_ignition=               0                  //Auto-Ignition available? 0=FALSE, 1=TRUE
max_rpm_mechanical_efficiency_scalar=  1        //Scalar on maximum RPM mechanical efficiency
idle_rpm_mechanical_efficiency_scalar= 1        //Scalar on idle RPM mechanical efficiency
max_rpm_friction_scalar=     1                  //Scalar on maximum RPM friction
idle_rpm_friction_scalar=    1                  //Scalar on idle RPM friction

 

[propeller]
thrust_scalar           =    1                  //Propeller thrust scalar
propeller_type          =    0                  //0=Constant Speed, 1=Fixed Pitch
propeller_diameter      =  6.7                 
propeller_blades        =    3                  //Number of propeller blades
propeller_moi           =   15                 //Propeller moment of inertia 
beta_max                =   60                  //Maximum blade pitch angle for constant speed prop, (degrees)
beta_min                =    5                  //Minimum blade pitch angle for constant speed prop, (degrees)
min_gov_rpm             = 1100                  //Miminum governed RPM
prop_tc                 = 0.03                  //Prop time-constant 0.004
gear_reduction_ratio    =  1.0                  //Propeller gear reduction ratio  17.4
fixed_pitch_beta        =    0                  //Fixed pitch angle of fixed pitch prop, (degrees)
low_speed_theory_limit  =   80                  //Speed at which low speed theory becomes blended in (feet/second)
prop_sync_available     =    1                  //Prop synchronization available? 0=FALSE, 1=TRUE
prop_deice_available    =    1                  //Prop de-icing available? 0=FALSE, 1=TRUE
prop_feathering_available=   1                  //Prop feathering available?  0=FALSE, 1=TRUE
prop_auto_feathering_available= 0               //Prop auto-feathering available?  0=FALSE, 1=TRUE
min_rpm_for_feather     =  500                  //Minimum RPM for prop feathering
beta_feather            =   65                  //Feathering pitch angle (degrees)
power_absorbed_cf       =    0                  //Coefficient of friction for power absorbed by propeller
defeathering_accumulators_available= 0          //Defeathering accumulators available? 0=FALSE, 1=TRUE
prop_reverse_available  =    0                  //Prop reverse available?  0=FALSE, 1=TRUE
minimum_on_ground_beta  =    0                  //Miminum pitch angle on ground, (degrees) 12
minimum_reverse_beta    =    0                  //Minimum pitch angle in reverse, (degrees) -10 C90

 


[Flaps.0]
type          = 1
span-outboard  = 0.6
extending-time  = 15
system_type  = 0
flaps-position.0 = 0
flaps-position.1 = 25
flaps-position.2 = 35
damaging-speed  = 190
blowout-speed  = 199
lift_scalar   = 0.7                
drag_scalar   = 1.15
pitch_scalar  = 0

[Flaps.1]
type          = 1
span-outboard  = 0.6
extending-time  = 1
system_type  = 0
flaps-position.0 = 0
flaps-position.1 = 0
flaps-position.2 = 35
damaging-speed  = 190
blowout-speed  = 199
lift_scalar   = 0.0                
drag_scalar   = 1.7
pitch_scalar  = 0

 

[vacuum_system]
max_pressure=5.0
vacuum_type=1
electric_backup_pressure=4.5
engine_map=1,1,0,0

 

[airplane_geometry]
wing_area =              214
wing_span =               41
wing_root_chord =          7
wing_dihedral =            4
wing_incidence =           2
wing_twist =               3
oswald_efficiency_factor = 1
wing_winglets_flag =       0
wing_sweep =               0
wing_pos_apex_lon  =       1
wing_pos_apex_vert =      -1
htail_area =              32
htail_span =              19
htail_pos_lon =          -24
htail_pos_vert =           1
htail_incidence =          0
htail_sweep =              0
vtail_area =              22
vtail_span =               9
vtail_sweep =             40
vtail_pos_lon =          -21
vtail_pos_vert =           5
elevator_area =           18
aileron_area =            12
rudder_area =             18
elevator_up_limit =       25
elevator_down_limit =     14
aileron_up_limit =        25
aileron_down_limit =      15   
rudder_limit =            32
elevator_trim_limit = 30
spoiler_limit =            0
aileron_to_spoileron_gain = 0
min_ailerons_for_spoilerons = 0
min_flaps_for_spoilerons = 0
spoilerons_available =     0
auto_spoiler_available=    0
spoiler_extension_time=    0

positive_g_limit_flaps_up=    5.4
positive_g_limit_flaps_down=  3.0
negative_g_limit_flaps_up=   -1.5
negative_g_limit_flaps_down= -1.5


[Reference Speeds]
flaps_up_stall_speed=   86
full_flaps_stall_speed= 77
cruise_speed=          151
max_indicated_speed=   255

 

Panel.cfg:

[Window00]
Background_color=0,0,0
size_mm=573,286
window_size_ratio=1.000
position=0
visible=1
ident=0
window_size= 0.060, 0.053
window_pos= 0.940, 0.005

gauge00=PAC404AP!Autopilot,  0, 0,573,286

That gives me a nice Little A/P in the right upper Corner of my 58 inches 4k Screen.

 

Additionally, I set the Buttons under my 2 mixture Control Levers at my Saitek Quadrant to engine 1 off and engine 2 off.

Elev Trim on A1 / A2, Rudder Trim for OEI on C1 / C2.

 

 

Share this post


Link to post
Share on other sites

Hello guys,

 I am crazy about finding the Titan C404 POH, but I was not able to find anywhere on the Internet. Can any of you send it to me?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now