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[CWMV]

So I'm starting to get into HSFX on my trusty 109E.
Now in DBW the prop acts like I would expect and have read-set pitch clock to desired setting (say 1130) to achieve desired RPM at given ata.
This doesn't seem to work in HSFX, cause the damn prop pitch changes with throttle setting.
Am I the only one seeing this?

EDIT lots of other quirky behavior too;
Prop pitch runs for 1230 when ata drops below 1.0ata-regardless of actual setting.
Cannot achieve minimum pitch of 0600
certain other foibles.

[arcturus]

Hi!

How do I learn how to read the prop pitch "clock" in the 109?

Mad respects for knowing how, my friend!

Respects

A

[CWMV]

Oh the prop pitch clock is the best way to instantly tell what the pitch is set at! Seriously its simple and effective.

Prop Pitch Clock Position
0% 6:00
5% 6:19
10% 6:39
15% 6:58
20% 7:18
25% 7:37
30% 7:57
35% 8:16
40% 8:36
45% 8:55
50% 9:15
55% 9:34
60% 9:54
65% 10:13
70% 10:33
75% 10:52
80% 11:12
85% 11:31
90% 11:51
95% 12:10
100% 12:30

Problem is that in HSFX its modeled as constant speed prop-which the 109E-1 wasn't.

[karo]

CWMV what is your HSFX? 5 or 6?

I put to the test: E-3, E-4 and E-7.
All of them have a constant speed propeller as a default setting (so it is improper), but it could be switched to a manual mode for propeller pitch (and it works perfect).   

My HSFX is 5.

Tomorrow, or the day after, I will put them to the test in HSFX6.

Ps. By the way
If you have got a clean version of HSFX6 (without any add-ons) you can try to fly Fw-190A-2 or A-3 using only the manual mode for propeller pitch. You will be surprised.   

[ddr]

[...] it could be switched to a manual mode for propeller pitch [...]

how to do?
EDIT: ...SHIFT+0 to toggle manual/auto prop pitch, excuse me for stupid question
thanks and bye!

[mikey117us]

I thought the 109 had a two pitch prop 'course" and "fine" and that was it. And starting in the Fritz of course Automatic Pitch.

[aaken]

From E4 onwards, the prop pitch is automatic with possibility to switch to manual setting. Manual setting works as intended, i.e. sets pitch independently of rpms (as Karo confirms). E1 and E3 should have had only this manual setting. Unfortunately, if my memory serves me right, when we did this (some 3 years ago) the AI did not adjust their prop pitch at all. As back-up measure a manual prop pitch with constant rpm was implemented for these 2 versions (E1 and E3) and never got changed.
Aaken

[Herra Tohtori]

I'm... not sure I'm convinced by what's said here.

Constant speed propeller is a device that adjusts the propeller angle, trying to maintain a desired RPM which is what you're actually changing with the "prop pitch" controls - it's an RPM control. If you set your desired RPM to 2400 at 44 inHg manifold pressure, and then increase the throttle setting to 55 inHg manifold pressure, a constant speed prop will initially slighly increase the RPM but then settle back to the desired setting.

On a Bf-109 (excluding early variants), the automatic propeller pitch was tied to manifold pressure so that when the automatic pitch system was engaged, the pilot could adjust engine power settings with just one lever - the throttle. The same system was used in FW-190 but with a more sophisticated mechanical computer, if I recall right.

With constant speed propeller, the "prop pitch" sets the desired RPM and throttle lever is used to set the desired manifold pressure.

With Bf-109, however, the throttle lever sets the desired manifold pressure AND engine RPM when automatic prop pitch is enabled. You can notice this easily by moving the throttle - as the manifold pressure drops, so does the engine RPM. It's generally set so that at full manifold pressure (depends on engine model), the engine is working at its full power, which is usually about 2500 RPM for DB-601 and 2800 RPM for DB-605.

Reducing the throttle lowers BOTH manifold pressure AND engine RPM. If it were a constant speed propeller, then reducing throttle would lower manifold pressure but the constant speed propeller would attempt to keep the RPM at whatever setting it was at.

With the manual prop pitch, on the other hand, you can set the Messerschmitt's propeller to work like a fixed propeller. The blades will be at required angle regardless of engine manifold pressure and RPM. So, I don't think the 109 propeller is simulated as a "constant speed propeller". It's something else.

[aaken]

What you say is correct from E4 variant onward. On these variants, using the manual mode will set the pitch of the propeller. In automatic mode the pitch will be regulated "fixing" a dependency between propeller pitch, propeller rpms and manifold pressure.
Earlier variants did not have this mode though. The lever normally found in a central position on main instrument panel sets directly the pitch. Due to problems reported above, E1 and E3 were simulated with constant rpm prop pitch device (if I remember correctly). Note that, even with constant rpm prop pitch device, the rpms will not remain constant over the entire range of throttle settings due to finest and coarsest pitch settings. When these are exceeded the prop assumes its maximum (or minimum) prop pitch position and will work as a fixed pitch device. This applies also to flight speed.
Aaken