Propeller database?

[elbmc1969]

Do folks have enough information to start putting together a timeline of propellers? I'm particularly interested in when two-pitch and constant speed props were introduced for various aircraft, since those make quite a difference to performance. In any case, I big database seems as though it would be really useful, even with minimal information.

Thanks!

Potez 630 with Hispano-Suiza 14 Ab-02 and -03 or -10 and -11
Hispano 31M and 32M, three-bladed metal prop, manully variable in flight. Diameter 2.35m. Hydraulic servo--licensed Hamilton design. Limits 19-29 degrees.
(Notice descriptive et d'utilisation de l'avion Potez 630-C3 moteurs Hispano-Suiza 14 AB . Approuvée par D.M. n° 2551 2/MAM. 8 du 6 mai 1939)

Potez 631 with Gnome et Rhône 14 M. 6 and 14 M. 7 engines:
Gnome et Rhône 2190 and 2191, three-bladed metal prop, variable in flight. Diameter 2.55m. Pneumatic servo, electrical control. Primary pneumatic system powered by an 8L air bottle at a pressure of 17kg/cm^2
(Notice descriptive d'utilisation, d'entretien et de réparation de l'avion "Potez 631-C3" à moteurs Gnome-Rhône, 14 M6 et 14 M7 . [Approuvé par D.M. n° 3349 2/MAM. 8 du 14 juin 193)

Potez 63.11 (63-11) with Gnome et Rhône 14 M 04 or 14 M 05 engines:
Ratier 1527 M or 1528 M, three-bladed metal prop, variable in flight. Diameter 2.55m. Electric servo-motor with Automatic and Manual settings.
(Notice de caractéristiques et de performances de l'avion Potez 63-11 à moteurs Gnome et Rhône 14 M 04 et 14 M 05 : Approuvée par D.M. n° 111 RS 2/MAM 8, du 24 février 1940)

Focke-Wulf 190D-9 solid propeller hub
VS111 Part No. 9-27011 A-4
Focke-Wulf 190D-11 hollow propeller hub
VS9 Part No. 9-27012 A-2 (?)
Focke-Wulf 190D-13 hollow propeller hub
VS9 Part No. 9-27012 C-1
(VS-9 and VS-111 propellers)

 

[Michael Hope]

In the 1930's is when the change from two position to constant speed happened. I know that some aircraft did not change right away, like the Spitfire, until during the B.o.B.
Are you interested in any particular aircraft, or from a particular country?
Do you also want to add the change on multi engine aircraft from just constant speed, to the addition of full feathering?
They are still manufacturing manual electric pitch change propellers today, that pilot decides what pitch he wants and are not constant speed.

 

[Shortround6]

Actual use was all over the place. When they became available (came on the market) is a lot easier to pinpoint. How fast various airlines or air forces adopted them is a whole different story.
You also have to be very careful in the early 30s (or with translation) as sometimes full descriptions are not given (words left out) or in the advertising "hype" things aren't well explained

You had fixed pitch props. What you saw was what you had, period, end of story.
you also had ground adjustable propellers, still made today for light aircraft.

Mechanics on the ground can adjust the fixed pitch for the intended flight/s of a particular aircraft. A little less pitch for better take-off and climb but a little worse cruise, or change things so the take-off is a bit worse but cruise speed/fuel economy is better.
Unfortunately in some 1930s magazine articles they leave out the word "ground" and just say "adjustable propeller".

Once a mechanism is introduced to change the pitch in flight you have a two pitch propeller, confusingly these were also sometimes referred to as adjustable pitch.
Sometimes the mechanism was pretty crude.

The props on the DH 88 (and some other low powered mid 30s aircraft) used an air bladder to hold the props in fine pitch and once the plane got up to a certain speed the flat discs on the front of each spinner were pushed back activating an air valve that allowed the bladder to deflate and the props to go to course pitch. There was no way to return to fine pitch while in the air. At best you would need air tanks and an air compressor. On race planes this system was light weight and the air bladders would be pumped back up on the ground.

once you got hydraulic pitch change mechanisms you could go back and forth (and these may have predated the pneumatic system) and then it didn't take much more to allow the propeller control to stop the pitch change at intermediate positions. Still an adjustable pitch prop but once this is common the either/or props became more commonly known as 2 pitch. The term "variable pitch" was also used, sometimes for these props but some times for the 2 pitch props. Electric operation came in to play.

Now at some point some bright boy figured out how to put a governor into the system and get the propeller to adjust pitch on it's own so as to keep the engine turning at a preset rpm. The propeller would adjust to load (climb or level flight) automatically. We now have the constant speed prop. Which was also sometimes called a variable pitch prop. depends on good the magazine/book writer was or how good the translation for one language to another is.

Finally they extended the pitch range (not all props covered the same range) to a point where the blades were flat/perpendicular to the air flow (or nearly so) and would not rotate a dead engine. These are feathering or fully feathering props.

All of this happened in a relatively short period of time, from about 1932 to 1939 (about 20 airlines were using fully feathering propellers at the end of 1938). Confusion as to terminology is understandable.

 

[MiTasol]

A quick resource or two showing some history and dates
https://babel.hathitrust.org/cgi/pt?id=mdp.39015006056645;view=1up;seq=242 has a section on the British Hele-Shaw Beacham propeller as entering testing by the RAF. The patent for the Hele-Shaw Beacham full feathering hydraulic propellor was 1924 and first flight was 1925. It also notes that a full description of its operation was published in the July 1929 Journal of the Royal Aeronautical Society. That article and a subsequent one are on line at The Constant Speed Variable Pitch Airscrew | The Aeronautical Journal | Cambridge Core and The Constant Speed Variable Pitch Airscrew | The Aeronautical Journal | Cambridge Core
A search of the Royal Aero web site may have similar information on the dH/HamStd and Rotol time lines

 

[Tom Fey]

"Reinventing the Propeller" by Jeremy R. Kinney, curator of propulsion at the Smithsonian National Air and Space Museum.\, USA.
Amazon product ASIN 1107142865

 

[MiTasol]

"Reinventing the Propeller" by Jeremy R. Kinney, curator of propulsion at the Smithsonian National Air and Space Museum. USA.

Sounds perfect but at AU$140 plus postage it is too rich for me
Note that the Amazon link you posted did not show except during reply

 

[elbmc1969]

Sounds perfect but at AU$140 plus postage it is too rich for me
Note that the Amazon link you posted did not show except during reply

Fortunately, there are copies in the State Library of Victoria, the University of Queensland library, the
Queensland University of Technology Kelvin Grove Campus Library, and Wesley College Melbourne. Also one in NZ.

 

[MiTasol]

Fortunately, there are copies in the State Library of Victoria, the University of Queensland library, the
Queensland University of Technology Kelvin Grove Campus Library, and Wesley College Melbourne. Also one in NZ.

Thank you
I am a member of SLQ so I have put my ILL request in.

 

[elbmc1969]

Are you interested in any particular aircraft, or from a particular country?
Do you also want to add the change on multi engine aircraft from just constant speed, to the addition of full feathering?

Ideally, I'd like to create a list of all propellers 1936-1945, with year of introduction, basic dimensions, weight (if possible), construction, pitch control (type and mechanism), and use (aircraft).

A big project, but folks have put together very large databases of other information.

 

[elbmc1969]

Are you interested in any particular aircraft, or from a particular country?

Bf109 up through the E and contemporary Bf110s would be interesting. I'm sure I could find it somewhere, but turning it over to the Internet Hive Mind seems so much more efficient!

 

[Zipper730]

You know, the idea of a propeller database on this forum would be a pretty smart idea...

 

[MiTasol]

You know, the idea of a propeller database on this forum would be a pretty smart idea...

It could start with this and look for other editions of this manual.

 

[Zipper730]

I assume the P-38 from the XP-38 all the way to the last P-38 variants all had propellers that were 11'6" in diameter?

 

[Zipper730]

It could start with this and look for other editions of this manual.

Not sure where I'd find other editions, but I have found discrepancies in the P-36's propeller diameter. 10'0" is cited in the manual, and a source listed 10'1-1/2", the database lists 10'0". Not much, but I was actually in the process of computing performance, and among other things, tip-speed.

It's surprising how fast some of those props reach when they're moving: The Spitfire at top-speed had numbers like 0.92 or something. At that point you're beating the air into sumission.