Terminology of propellers

[Matt Piatkowski]

Hello,
Pusher Prop? Puller Prop?Tractor prop? CW rotating prop? CCW rotating prop?

These names are all in use but are we going to standardize this terminology?

Thank you for your opinions and suggestions.
Matt

[Tim Wescott]

Hello,
Pusher Prop? Puller Prop?Tractor prop? CW rotating prop? CCW rotating prop?

These names are all in use but are we going to standardize this terminology?

Based on the number of efforts I've seen to do so attempted, and then die quiet deaths, probably not.  I suspect that even trying to get people to agree on whether CW should be as viewed from behind the engine or from the front would fail.  "Pusher" and "Tractor" are probably the most widely understood and likely to get you the correct mail-order prop.

The full-scale aviation industry no doubt has a standard for terminology; if you're going to push one thing or another it would be to adopt that.

[Brett Buck]

Hello,
Pusher Prop? Puller Prop?Tractor prop? CW rotating prop? CCW rotating prop?

These names are all in use but are we going to standardize this terminology?

   The short answer is almost certainly "no", we aren't and we will keep having pedantic arguments over it for the foreseeable future.

   A slighty longer answer is that we can't even have a consistent definition over what is the "front" or "back" of the prop blade, and many people have some training from somewhere that decrees a particular answer (although there is not much basis for it), so the chance of us ever coming to agreement on a wide array of similar terminology is smaller than any arbitrarily-chosen epsilon.

     Brett

[Matt Piatkowski]

Brett, Tim...I feel your opinions are shared by majority therefore the issue is closed.

Matt

[Dan McEntee]

  I have learned that when ever referring to one side of a vehicle, (ANY vehicle, car, plane boat bicycle) you relate to it as if you are sitting ion the operators seat looking in the direction of travel. I think a true pusher prop is made different than a tractor prop that rotates counter clockwise.
  Type at you later,
  Dan McEntee

[Mike Haverly]

Here we go again.  Seems pretty simple to me, pops in front are tractors and in the back are pushers.  My boat has two props in back that counter rotate and by definition are "pushing" the boat.  One is RH and the other is LH, and both are pushers.  Seems pretty moot and tiresome to keep discussing (arguing about) it.

[Ted Fancher]

Brett, Tim...I feel your opinions are shared by majority therefore the issue is closed.

Matt

I'm not sure we're empowered to do that.

[Tim Wescott]

Brett, Tim...I feel your opinions are shared by majority therefore the issue is closed.

Heh heh.  Once it's out there, it has a life of its own.

[Steve Helmick]

During WWII, Spitfires and Bf-109's used LH propellers, while Mustangs used RH propellers. It's very simple, as viewed from the pilot's position. Both are on the front, so neither is a "pusher".    Steve

[Chris Wilson]

Would not the front or the back of a propellor always be determined by the direction of travel?

As is eveything else actually if you factor the centre of mass also.

[Perry Rose]

Air screw.

[Dennis Adamisin]

As someone who has worked with several prop manufacturers and flyers on the subject I know that:

* If I ask for or sell a "Tractor" it will invariably mean a CCW, RH Rotation, or "normal" prop.

* If I call for a "Pusher", or "Reverse Rotation", those involved universally understand EXACTLY what I am talking about.

Thus, the distinction between Tractor & Pusher is pragmatically crystal clear.

* If I call for a CW rotation then the natural follow-up is which is a confirmation of which rotation is normal (CW or CCW)

* If I talk about a "righty" versus a "lefty" prop - then I better clarify whether it from is the pilot's (looking out through his painted on canopy) or mechanic's perspective. 

* The "true" statement that all props mounted in front are tractors provides no useful information. (I can hear brains exploding over that one)


The only place I have ever dealt with that needed clarification was Tru-Turn Spinners.  If you ask for a spinner with the blade holes pre-cut for a pusher prop they will cut it so it fits over a the back of the prop mounted on the back of the airplane.  In that case you MUST specify that the spinner will be in front on a reverse rotation or CW prop.  Indeed, even if you DID want a rear mounted spinner then you better clarify which direction the prop is rotating, otherwise there is no guarantee you will get what you are looking for.

[dave siegler]

995 of glow engines turn counterclockwise, so a right hand became tractor by default.  Not by design. 

It is easy for me to say right hand tractor?  when asking for a prop, if they say pusher, 99% of the time it is prop that when mounted on a right hand turning engine, will be a pusher application.


this discussion is  kind of moot. 

Over specify when you ask.  Assume a right hand engine if you get nothing, 

[John Rist]

Tower Hobbies uses the term Pusher Propeller for a reverse rotation prop.  So is this the standard?      APC also uses the term Pusher.  Typical PN is LP05030EP .  This is for a 5 X 3 electric pusher prop.  The kicker is that drone props point UP not fore or aft.  A 4 prop bird has two CW and two CCW props and the APC PN is E or EP.   

[Matt Piatkowski]

Guys,
I agree with Tim: (my original message) has a life of its own.
Please enjoy the exchange of opinions until you all get bored.
No name calling, though.
Thanks,
Matt
 

[billbyles]

Just for the heck of it, as a long-time A&P/IA who has dealt with propellers on all types of different airplanes from WWII airplanes to Pitts Specials to Rutan Long EZs, the FAA convention for nomenclature on propellers only deals with which side of the blade is called what.  The cambered side vs. the "flat" side of the blade are not called what I originally thought when I was a kid dealing with model airplane props.  The cambered side of the blade is called the "back" side of the blade, and the flat side of the blade is called the "face" of the blade.

There are light full-scale tractor twins such as the Piper Seneca that have the left-hand propeller turning in the clockwise (as seen from the cockpit) direction and the right-hand prop turning in the counter-clockwise direction.  So, at least on full-scale airplanes the direction of rotation does not always relate to "tractor" & "pusher".

[Alan Resinger]

Some years ago I was tempted to start a prop carving business for the home built crowd.  There was a gent locally who had a great reputation for his props and he had quite a a following in the Pacific Northwest and in Western Canada.  I spent some time with him as he was winding down his business and tried to gain as much of his knowledge as possible.  I also began studying all the information that I could obtain.  Engineering  texts  and papers were obtained and added to my library.   One, that was used in university aeronautical engineering classes was especially useful.  Written in the 30's when a lot of propeller theory was being fine tuned was "Àircraft Propeller Design" by Fred E. Weick, B.S. Aeronautical Engineer, Langley Aeronautical Laboratory. 
Here are some definitions from this text.
As Bill Byles stated, the flat side of the propeller is the face, while the  cambered side is the back.
If the prop works in front of the body or the motor it is a tractor prop. If it placed behind the body or engine it is a pusher prop.  Tractor props can be either right or left hand rotation.  Pusher props can also be right or left handed.
From the pilots point of view, a prop that rotates in a clockwise directon it is a right hand propeller.  If it rotates in counter clockwise direction, is is a left hand propeller.
I actually made a pusher prop for a fellow that was real project.  This was a 6 foot monster that was made from laminated maple that had a wide chord with square tips.  Final weight was close to 20 lbs.  A real beast.  It was for an airboat.

[Chris Wilson]

Mid engine aircraft must be Protractors then.