Aero Praha

[maxim08]

I have been asked to research this unusual, to me, propeller. While I am familiar with many later WW1 aviation propellers, this one appears earlier being of the Chauviere style of very broad chord.

The boss in particular is puzzling being quite small in diameter but with 8 bolts quite reminiscent of a 50 Gnome style, an engine for which I have no hub dimensions.

I will try to attach photos but I no longer have external photo hosting. I will supply as much written info as I can.

Decals, appear to be waterslide, 1 on each blade. A white circle surrounded by a blue circle surrounded by a red circle. 'AERO' and 'PRAHA' in white superimposed on the blue circle of the roundel. The roundel is bisected by the image of a light wood propeller.

Diameter, 2595mm
Pitch, unknown
Boss diameter, 175mm at the face but barrel shaped so wider at the mid-point.
6 laminations of what appear to be ash; 4 @ 18.75mm, 1 @ 15mm and 1 @ 10mm totalling 100mm thickness.
8 bolt holes with a PCD of 4-1/4" (108mm)
10mm bolt holes or, perhaps, 3/8"
Max blade width is 245mm, 875mm from boss centre
Min blade width is 105mm, 175mm from boss centre

Markings:
1071 on boss face.
AERO above CIS 1071, on one side, 12.5mm high characters (1/2")

I'm pretty adept at measuring old propellers but this one seems an odd combination of metric and imperial, particularly in regards to the hub mounting.

Any help greatly appreciated.

Regards,
John

[Dbahnson]

Can you send me photos via email? i can host them here.

[Sparrow]

This propeller was made in Czechoslovakia. I can't help much but you can ask at historicpropellers.com
They make replica propellers and they are located in Czech Republic, so they probably can tell more details about your propeller.

[maxim08]

dbahnson, images sent.

Sparrow, thank you for the reply. I should have noted in my post that 'Praha' is indeed Prague.

Regards,
John

[Dbahnson]

Here are the photos. It's an elegant propeller, but I agree it's likely a reproduction prop, perhaps of a Chauviere.

[Sparrow]

I don't know how it was in pre-war Czechoslovakia but in Poland it was popular to make copies of original foreign (mostly French or German) propellers. Maybe it is the reason that propeller resembles Chauviere.

[pmdec]

Hi,

Thank you for the decal pic. It's a new one for me!

BTW, "čís 1071" has to be "number 1071", not serial, as the word for number in Czech is číslo.

Regards,
PM

[maxim08]

Can anyone confirm the bolt pattern (PCD) and bore for a Gnome 50 engine?

Regards,
John