Bf109E-3

[6S.Manu]

Originally Posted by JG52Uther

Wonder if there is a bug with the mixture...Its auto so we can't change it,but it sounds like the mix is too rich at altitude.

We can change the Mix also in the 109 (the central of the 3 levels near the throttle).

Today I tried again with my friends in multiplayer (with the "mod" finally we can fly together, but the multiplay "seems" limited to 6 players, have you ever hosted for more humans?): flying in a inflight 109 (former AI) I reached the 5 km before any shake. Maybe I had the first shake after x seconds from the airplane selection (takeoff/2,5km = 2km/5km)

I really don't know: anyway we tested some SpitIIa vs 109E4 and, I'm really sorry to say it, but the energy management seems to be AGAIN the one of IL2 version < 4.10.

It was our first real test, so probably we are still noobs with the full EM: anyway the 109 seems to lose tons of energy in a candle.

I'm still optimist (but please I can't wait AGAIN 10 years to have good FMs): for now the priorities are others I hope.

[ICDP]

The Spitfire Mk IIa is modelled quite well for a +12 lbs boost version (even thought he boost shows as +8 lbs). Unfortunately the 109 is about 30-60 kph too slow at all altitudes.

That would explain why your 109 lost so much energy, it simply has too little power.

[JZG_Con]

Originally Posted by ICDP

The Spitfire Mk IIa is modelled quite well for a +12 lbs boost version (even thought he boost shows as +8 lbs). Unfortunately the 109 is about 30-60 kph too slow at all altitudes.

That would explain why your 109 lost so much energy, it simply has too little power.

oh .no not again , well the new patched worked wonders for me , but ive def lost some speed ..energy ..bf 109.

I have rarely flown the 109 up to now but on some forums the rumor rans that the mixture ratio of the 109 is messed up and only has 0 or 100%. Could this be the reason why the performance is lacking? I could imagine that optimising the mixture also might be a factor for engine power ...

I am just guessing ...

[Hunin]

Unfortunatly I don't have time to dig my teeth into this right now but here is the relevant ingame data.

Quick first impressions:

1. Cl max seems too low for both retracted and fully extended flaps.
Should be 1.4 and 1.9 according to british testing, 1.3 and 1.62 ingame atm.

2. Turn time of 25 seconds corresponds with british testing but is significantly higher then the 18. something stated in the official Baubeschreibung.

3. 460 km/h on the deck corresponds with both german testing of Wrk.Nr. 1792
and swiss testing. The Baubeschreibung on the other hand gives 500 km/h.
Any ideas where that difference might come from Kurfy?

Anyway here are the cold hard facts:

;
; Messerschmitt Bf. 109 E-3 Flightmodel
;

;
[Aircraft]
;

Wingspan 9.867 m
Length 8.738 m

;
[Systems]
;

Propulsion Engine Daimler-Benz DB601A Propellor VDM Generic
Hydraulics Source Engine0 Pressure 100 bar Reservoir 8.5 pt
Electrics Source Engine0 Voltage 25.1 V BatteryCapacity 54 Ah GeneratorOutput 650 sW at 2000 RPM

LandingFlaps Mechanical Extends 25 sec
Undercarriage Retractable Hydraulic Extends 5.0 sec Folds Outwards OperatesThrough 320 kmh EmergencySystem PneumaticDischarge SafetyLock Nil SpringsStiffness Main 0.6 Tail 0.6 MaxDragEquivalentS 0.7 m2
WheelBrakes Hydraulic Efficiency 1.5
Fenster Mechanical Opens 0.5 sec
PitotHeater Electrical
LeadingEdgeSlats Mechanical Automatic Move 0.1 sec ResponseRange 15.0 to 15.01 deg

Hatch0 Mechanical Motion Type SwingingForward Time 2.0 sec Jettison Type Detachable Time 0.2 sec
Hatch1 Mechanical Motion Type Nil Time 0.0 sec Jettison Type Detachable Time 0.2 sec

;
[Controls]
;

Aileron Slider Threshold 340 kmh
Elevator Slider Threshold 400 kmh
Rudder Slider Threshold 400 kmh

AileronTrim Nil Default 0.017
ElevatorTrim Slider Range -0.5 to 0.5 Default 0.25
RudderTrim Nil Default 0.06

EngineThrottle Slider
EnginePitch Slider
EngineMagneto Switch M0 M1 M2 M12
EngineRadiator Rocker
EngineOilRadiator Slider
EngineMix Toggle
EngineWEP PushButton
EngineMix Toggle

LandingFlaps Rocker
Undercarriage Switch Up Neutral Down
UndercarriageEmergency ExpendableSwitch Close Open
WheelBrakes Slider
Fenster Toggle
AltimeterPinion Rocker Range 795 to 1040 Default 1000 mbar
Puppet0PriPitLight Slider
Puppet0SightLight Slider
NavSecFrequency Rocker
Timer0 CyclicSwitch
AcemakerSight Dimmer Toggle
TankSelector0 Toggle Off On Parked 0 Cruise 1 Selection 0 Flow FuelTank 1 to FuelTank 0 at 1 kg per second Selection 1 Flow FuelTank 1 to FuelTank 0 at 1 kg per second + FuelTank 0 to Engine 0
HydraulicsHandPump PushButton
PitotHeater Toggle
Timer0 CyclicSwitch

Puppet0Hatch Toggle Close Open Selection 0 Closes Hatch 0 Selection 1 Opens Hatch 0
Puppet0Jettison ExpendableSwitch Off On Selection 1 Sheds Hatch 0 Hatch 1

;
[Instruments]
;

EngineFuelPress Hydraulic Range 0 to 2 kgcm2
EngineOilPress Hydraulic Range 0 to 10 kgcm2
EngineOilTemp Electrical Range 0 to 120 C
EngineWaterTemp Electrical Range 0 to 120 C
EngineManifoldPress Mechanical Range 0.6 to 1.8 bar
EngineRPM Electrical Range 600 to 3600 RPM
EnginePropPitch Mechanical Range 0 to 12 hour
Speedometer Mechanical Range 0 to 800 kmh Pitot Kollsman
Altimeter Mechanical Dimension m
MagneticCompass Mechanical JamAngle 90.0 deg
SlipIndicator Mechanical Amplitude 12.0 deg
TurnIndicator Mechanical Source Primary NominalTurnTime 2 min
FuelReserve Electrical Range 0 to 400 litre
ArtificialHorizon Mechanical Source Primary Pitch Range -45 to 45 deg Roll Range -181 to 181 deg

GyroFeed Primary Electrical Secondary Nil

;
[Mass]
;

Empty 2060 kg
TakeOff 2600 kg
Fuel 300 kg
FuelTanks Aluminum 100 kg Aluminum 200 kg
FuelFillingOrder Tank 0 Tank 1

;
[Squares]
;

Wing 16.4 m2
Aileron 1.1 m2
Flap 2.0 m2
Stabilizer 1.90 m2
Elevator 1.20 m2
Keel 1.00 m2
Rudder 1.10 m2

;
[Arm]
;

Aileron 2.03 m
Flap 2.04 m
Stabilizer 5.15 m
Keel 5.18 m
Elevator 5.35 m
Rudder 5.45 m
Wing_In 1.25 m
Wing_Mid 2.50 m
Wing_Out 4.10 m
GCenter 0.05 m
GCenterZ 0.00 m
GC_AOA_Shift 0.45 m
GC_Flaps_Shift 0.20 m
GC_Gear_Shift 0.05 m
Wing_V 1.5

;
[Params]
;

SpinCxLoss 0.06
SpinCyLoss 0.03

Vmin 170.0 kmh
Vmax 470.0 kmh
VmaxAllowed 750.0 kmh
VmaxH 560.0 kmh at 4500.0 m
VminFLAPS 130.0 kmh
VmaxFLAPS 250.0 kmh
Vz_climb 20.0 ms
V_climb 270.0 kmh
T_turn 25.0 sec
V_turn 340.0 kmh
K_max 13.0
FlapsMult 1.0
FlapsAngSh 10.0

RangeAbility 480 km

SensYaw 0.6
SensPitch 0.7
SensRoll 0.32

;
[Polares]
;

lineCyCoeff 0.091
AOAMinCx_Shift 0.2
Cy0_0 0.15
AOACritH_0 18.0
AOACritL_0 -15.0
CyCritH_0 1.3
CyCritL_0 -0.64417434
CxMin_0 0.0275
parabCxCoeff_0 6.2E-4
Cy0_1 0.55
AOACritH_1 17.0
AOACritL_1 -19.0
CyCritH_1 1.62
CyCritL_1 -0.7
CxMin_1 0.11
parabCxCoeff_1 8.7E-4

slatAOACritHInc 3.0
slatCyCritHInc 1.3
slatParabCxCoeffInc 0.8E-4

parabAngle 5.0
Decline 0.010
maxDistAng 35.0

; ------------------------------------------------------------------------------
[DB601A]
; ------------------------------------------------------------------------------


General MaximalPower 1020 sPS DryWeight 590 kg Displacement 33.9 litre Cylinders 12 Bore 150 mm Stroke 160 mm Compression 6.9
Reliability Lifetime 100 h FailureProbability 0.0

RPM Minimal 500 Nominal 2200 Maximal 2326 Saturated 9999 Continuous 2326 Limiting 3000 Direction Right
Intake Ramming 0.5
Exhaust PlainBackpipe
Supercharger SingleStageHydroCoupling Efficiency 0.23 LimiterInput Manifold NominalPressure 1.35 bar ContinuousPressure 1.2 bar WEPPressure 1.45 bar NominalAltitude 4500 m
Valvetrain Generic SlowRunningEfficiency 0.1
FuelPump Pushrod NominalPressure 3 bar at 500 RPM
Carburettor GenericDirectInjection OrificeSlowFast 0.05 sec Dresser ThrottleDriven Input 0.75 to 1.0 Output 1.0 to 1.2
Starter Mechanical
Ignition DualMagneto FrontEfficiency 0.57

Throttle Slider Translation Linear Bore 7.9 cm IdleOpening 0.05 WEPType ClockworkWEPModeToggle OperatingTime 1 min CooldownTime 10 sec
Pitch Slider Angle Min 82 deg Max 26 deg WEP 40 deg Feathering Nil
Mix Slider Multiplier Range 0.7 to 1.0

CylinderHead Material CastIron Temperatures Min 120 C Nominal 140 C Max 160 C
AirRadiator Tunnel Louvre Nil FlowControl Nil
Water Material Glycol Reserve 75 kg Temperatures Min 40 C Nominal 94 C Max 115 C
WaterRadiator ThermostatedTunnel Pressurized Louvre Mechanical OpensAt 80 C FlowControl Manual ContinuousAt 0.25 MinimalDragAt 0.25 MaxDragEquivalentS 100 cm2
Oil Material Oil Reserve 8.5 gal Pressure 70 lbsqin at 600 RPM Temperatures Min 30 C Nominal 75 C Max 105 C
OilRadiator ThermostatedTunnel Louvre Mechanical OpensAt 20 C FlowControl Manual ContinuousAt 0.25 MinimalDragAt 0.25 MaxDragEquivalentS 100 cm2

Propellor Reductor 0.64516129 Governor VariablePitch BladeAngleSpeed 1 degsec

SoundName motor.merlin

;
[Generic]
;

Construction VisualModel VDM Diameter 3100 mm Blades 3 BladeBreadthK 0.8 Mass 140 kg AngleRange 26 deg to 82 deg
DeIcing Nil

lineCyCoeff 0.07
AOAMinCx_Shift 0.0
Cy0_0 0.0
AOACritH_0 24.0
AOACritL_0 -22.0
CyCritH_0 1.3
CyCritL_0 -0.8
CxMin_0 0.02
parabCxCoeff_0 3.8E-4

parabAngle 7.0
Decline 0.002
maxDistAng 40.0

;

[unreasonable]

If this data is from the game files it shows V climb as 270kmh. (I assume this is supposed to be Vy - speed for best rate of climb). Kurfurst's test used a start speed of 250kmh. This might explain why the slope is "wrong".

Retest? (I am nowhere near a good enough pilot to do it myself I am afraid).

[609_Huetz]

That still will leave us at the problem that the mixture is not working correctly on either side - red or blue.

My concern, the higher you get, the more your data will be off due to this.

[Kurfürst]

Originally Posted by Hunin

Quick first impressions:

1. Cl max seems too low for both retracted and fully extended flaps.
Should be 1.4 and 1.9 according to british testing, 1.3 and 1.62 ingame atm.

Possibly, I'd have to check the Kurvenwendigkeit der Me typen doc, perhaps I can some data for that..

What is behind it that they did a couple of stall speed trials with the Spit earlier, and from the stall speed they deducted Clmax (which in itself lends some room for error, recall those lenghty discussions about what 'stall speed' really is'?). Based on the date, they calculated a doghouse turn chart for the Spi.

When the 109E-3 was handed over by the French for testing, the British wanted a similiar graphical comparison made. They made a similiar test procedure to establish 109E stall speeds, based on that, the Clmax.

at http://www.kurfurst.org/Tactical_tri...ls/Morgan.html

Originally Posted by Hunin

2. Turn time of 25 seconds corresponds with british testing but is significantly higher then the 18. something stated in the official Baubeschreibung.

As noted above, there was no actual measurement of the 109E turn times by British; or if there were, the 25 seconds value was not derived from testing. The Kurwenwendigkeit der Me typen part I. report by Messerschmitt AG calculates the turn time with 990PS on the deck, using proper propellor effiency curves etc.

It gives the turn time for 109E as 18.92 secs on the deck, a fairly believable number IMHO. What complicates things that appearantly we have (ca. 50HP higher) DB 601Aa ratings present, not DB 601A the report assumes. Well say 18-18.5 secs in this case. Actually it should be possible to calculate it precisly using the report.

3. 460 km/h on the deck corresponds with both german testing of Wrk.Nr. 1792
and swiss testing. The Baubeschreibung on the other hand gives 500 km/h.
Any ideas where that difference might come from Kurfy?

I am not sure, but I and others have a very strong suspicion the 460-470ish values are either for the 30-min rating, or due for using the high altitude (2nd speed, FS gear etc.) blower at low level too.

The conditions of the Wrk.Nr. 1792 test are not known for certain, as the report aimed for relative speeds w. and w/o MG FF barrels in the wing, and not absolute figures. Even boost is uncertain, a the report mentions that the figures are not corrected for nominal engine output etc.

The Baubescreibung is the official performance specs for the 109E, which the manufacturer guaranteed to be met withon +/- 5% tolerenace. Those Emils that could not satisfy the specs were not accepted by BAL, the LW's quality control organisation. Even at the war's end!

Moreover the 500/570 specifications laid down in the Bbschr. 109E paper were confirmed with the detailed report of the Emil prototype:

http://www.kurfurst.org/Performance_...w_109V15a.html



and by French testing of Bf 109E-3 WNr. 1340 (same aircraft as tested by the Brits later) also seem to confirm that the level speed figures laid down in the in German specs can be confirmed:
http://www.kurfurst.org/Performance_...formanceT.html
(beware of the bewildering combination of open/closed raditors, RPMs and manifold pressures used.. its a bit of a pity that the French used Hgmm for boost instead of ata. Confusing..)

Besides if one uses simple common sense, its quite easy to see. If you look at the Spitfire and Bf 109E speeds and powers at rated altitude, you'll find that that both do around 570 km/h, but the Spit has actually quite a bit of more power at this altitude (as opposed to popular knowledge, the Merlin III was pretty good at alt). It follows that it has more drag. Now, at SL the Spit does, iirc some 282 mph at +6 1/4 boost, which is 890 HP. And the 109 there has 990 (601A-1) to 1050 HP (601Aa). It follows that should be a good deal faster than 282 mph (454 kph), with 150 HP extra in less draggy airframe..

Just as a side note: 5% of 500 kmh = 25 kmh, so a 475 kmh fast Emil would still have been accepted

Just wait and take a look again when mixture ratio is fixed. This might in fact lead to more nominal values when finally this parameter can be optimized.

When talking about drag one has to be a bit cautious when saying which airframe is less draggy when talking about flight operations as drag is composed of friction drag and induced drag. The former is due to friction over the skin and therefore mainly dependent on speed and altitude, the latter foremost dependent on angle of attack. So it might be (might be, I don't say that it should be but yet could be) that the spit just had to fly at an angle of attack at high altitude that went along with higher induced drag while it had to use less angle of attack at lower altitudes and therefore had less drag. Actually it is quite reasonable to assume that this is indeed the case. When the air density decreases the plane has to increase angle of attack for level flight but then can reduce angle of attack with tanks more empty. The behaviour could be very much different for the 109 and the Spit. I cannot tell in which ways.

[Kurfürst]

Originally Posted by Hunin

;
[Params]
;

SpinCxLoss 0.06
SpinCyLoss 0.03

Vmin 170.0 kmh
Vmax 470.0 kmh
VmaxAllowed 750.0 kmh
VmaxH 560.0 kmh at 4500.0 m
VminFLAPS 130.0 kmh
VmaxFLAPS 250.0 kmh
Vz_climb 20.0 ms
V_climb 270.0 kmh
T_turn 25.0 sec
V_turn 340.0 kmh
K_max 13.0
FlapsMult 1.0
FlapsAngSh 10.0

RangeAbility 480 km
;

I took a look at the figures above and compared it to my documentation. See the suggested values below:

?? means I have no idea what the figure is for..
Changes are marked with bold, with source given.

SpinCxLoss 0.06 ??
SpinCyLoss 0.03 ??

Vmin 170.0 kmh - should be 153.0 kmh -
[i] this is for a throttled down (~power off) engine as the UK Morgan report posted above. It needs to be found out what 'Vmin' means in the sim, since in real life, the stall speeds are about 10 mph lower when the engine is opened up (propeller helps the wings, relative airflow speed is higher than airspeed would indicate -> more lift). So if the other planes are using Power ON stall speeds, this should be not be used but a lower stall speed value.[i]

Vmax 470.0 kmh - Should be 520. Now a bit of a comment would be needed here.

Vmax for the 109E-3 with DB 601Aa should be 500 kph (see Baubeschreibung 109E graph posted above). This was achiavable with the 1,35ata rating 5-min (1045PS at SL) and guaranteed within 5%.

However I believe this figure (the 470 kph one) is to be achieved only by using all out boost in the sim, and that is what the testing shows: 470 can only be approached by using the 1-min WEP (W button), ie. 1,45ata. This latter translates to 1175 PS at SL...

If this is the case, the Vmax. should bet 500+, at around 515-520 kph (deducted as power requirements increase with the cube), achiavable in the sim w. the 1-min boost, and so that the proper max. speed (500) could be achieved with the 5-min 1,35ata/2400 rating.


VmaxAllowed 750.0 kmh - correct. Appearantly Il-2COD does not differentiate for dive limit changes with altitude.
VmaxH 560.0 kmh at 4500.0 m - should be 570 kph at 5000m, as per Baubescreibung curves
VminFLAPS 130.0 kmh - this matches the UK Morgan/RAE report for 109E with flaps fully down
VmaxFLAPS 250.0 kmh - note: this is for fully deployed flaps, for example 20 degrees flaps were allowed up 500 km/h
Vz_climb 20.0 ms - its unclear what this is for, presumably initial climb rate. If so, probably correct if it's understood with 1-minute WEP; if meant for 5 minute rating, too high IMHO. This is based on analysis of German, French and British measurements, and the 109E Baubescreibung.
V_climb 270.0 kmh - should be 250 km/h, as per the Emil 1939 short manual.
This might be significant as it will result in steeper climbs, a working tactic described by UK evaluations for the 109E.
T_turn 25.0 sec - should be around 18-18.92 sec for SL, as discussed above.
V_turn 340.0 kmh - this needs to be re-calculated I think due to the previous change.
K_max 13.0 - ?? No idea what these last three are for..
FlapsMult 1.0
FlapsAngSh 10.0

RangeAbility 480 km - Should be 665 km?

This is probably for range, but its entirely unclear to what altitude and engine setting this should be true. Developer would be needed to comment on this.. In any case, German range tables give economic cruising range at 650 - 665 km for the Emil, pretty irrespective of altitude (different engine setups were, however, required, ie. pitch, rpm, boost etc.).