View Full Version : HB gauge in Bf-109

02-03-2005, 11:34 AM
Does anyone know what this means, and how to read it? I believe in the Friedrich it's to the right of the tachometer. Just curious.

02-03-2005, 11:36 AM
I guess you mean the clock-like propellor pitch indicator. German planes expressed blade angle this time like fashin, ie. 11:30.

No idea why though, how it related to the angle...

02-03-2005, 11:45 AM
Yes that would be it. Prop pitch, eh? Interesting... I suppose since pitch is normally automatic I don't really need to know how to read it. But it sure would be nice...

02-03-2005, 12:05 PM
In later models it's left of the Engine temp. indicator and right of the RPM indicator.Yes it's prop pitch. You only need it when you decide to manage the engine yourself.

02-03-2005, 12:07 PM
The very earliest 109s had manually set prop pitch, the 109E was the first to my knowladge introducing auto pitch.

Still on later models, it could be disengage or go wrong.. pilots were insrtructed to take off, at say, 12:30 setting, the set to manual. Also for economic cruise etc. Not all that useless.

A mix of archaic and ultra modern... typical for 109!

I still wonder though, the connection to clock display... ?

02-03-2005, 02:13 PM
Oh I've played with the pitch setting on the 109. In fact, the first time I tried, I had forgotten I had set both an axis and a couple of buttons to adjust the pitch. When I turned auto off, it read my axis setting, which was full fine. Needless to say my engine didn't last much longer. I admit however, that the vast majority of the time I leave it on auto.

But now that I know what the gauge is for I'll have to revisit the manual pitch control, and try to figure out how to read the gauge.

02-04-2005, 11:52 AM
The gauge should be read like a clock. The clock position indicates the prop pitch. 6:00 corresponds to 0% prop pitch and 12:30 corresponds to 100% prop pitch. It seems to change linearly. That means:

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

Hope this helps.