Prop Talk..

[breadneck]

Just wondering..

 

Were propellers type specific or engine specific or both? I would like to learn more about propellers, lol...

 

I am sure some of you guys out there know more than i do 😉 

Edited August 29, 2025 by breadneck

[breadneck]

Just now, breadneck said:

 

 

Edited August 29, 2025 by breadneck

[dylan]

this is a vague question that has caused me to retype my answer a few times. I keep over complicating my response and getting too technical.

 

the prop had to be matched to the airframe, and the engine. but. in many cases a different version of an engine would be used on several types of aircraft. each different airframe would have their own version of a propeller to go on them.
a hellcat , corsair, and a P-47 all had the pratt and whitney R2800 ( and many others) and all had a different prop. in many cases they were the same model number but with a different dash number. in theory you could take a prop off a P-47 and it should just bolt on to a hellcat if you wanted to.  the prop shaft on the 2800 is the same. it most likely wouldn't work very well, but you get my point

I hope this is the answer you were looking for.

[breadneck]

5 hours ago, dylan said:

this is a vague question that has caused me to retype my answer a few times. I keep over complicating my response and getting too technical.

 

the prop had to be matched to the airframe, and the engine. but. in many cases a different version of an engine would be used on several types of aircraft. each different airframe would have their own version of a propeller to go on them.
a hellcat , corsair, and a P-47 all had the pratt and whitney R2800 ( and many others) and all had a different prop. in many cases they were the same model number but with a different dash number. in theory you could take a prop off a P-47 and it should just bolt on to a hellcat if you wanted to.  the prop shaft on the 2800 is the same. it most likely wouldn't work very well, but you get my point

I hope this is the answer you were looking for.

 

No this is not the answer i am looking for, you will have to rewrite your reply in full  The above comparison is an interesting observation. So many share an interest in aviation, but how much do they actually know about the actual airscrews and their technical abilities? Was there a push from the industry to market certain brands that would be "superior" to other brands? From the top of my head i have heard of Hamilton, Rotol, De Havilland, Curtiss, but i feel i know too little about them.

 

I suppose variable pitch is the industry standard these days? Not exactly sure what a constant speed one is though. Found this online.

https://en.wikipedia.org/wiki/List_of_aircraft_propeller_manufacturers

 

 

 

[dylan]

well I guess I will type slower this time 😉

in the industry EVERY manufacturer will tell you that their product is vastly superior to every other product on the market. in fact if you don't buy an airplane (or engine,prop,windshield  wiper) from them you will surely die in a horrible crash. and of course they all have a reputation in the industry based on operator experience. for example Pratt and whitney makes fantastic turboprop engines. but their big turbofans are not that great. and GE makes really nice big turbofans and not so stellar turboprop engines.

 

as for constant speed, or variable pitch props. buckle up.

 

I am most familiar with the Hartzell 14sf propeller mounted on the Beech 1900D. I worked on them for 11 years. and it is probably the simplest and most reliable type of prop out there.

when we talk about a constant speed prop it refers to the fact that the propeller RPM will not change even when more throttle is applied. the propeller will increase its pitch in order to keep itself "on speed". on the 14sf this is accomplished through the prop governor. the governor is a fairly simple component that uses flyweights a speeder spring an oil booster pump  and a pilot valve.

the propeller is manufactured with counterweights on the blades that will make a spinning propeller try to rotate the blades to course pitch. the prop governor is mounted to the prop gearbox and is driven by a shaft geared to the prop shaft. so they are both turning at the same speed. engine oil is ported into the prop hub where it behaves as a hydraulic fluid, this pushes on an actuator ( known as the dome) in the hub that drives the blades to a finer pitch.

the input shaft to control the prop speed is mounted on the top of the governor and  will rotate through about 100 degrees from the aft to full forward stops. as it rotates the shaft has a helical spline that pushes down on the spring or releases it to port oil from the pump or drains it back to the gear case.

 

in operation it works like this, during take off the prop levers are set to full forward. this will rotate the shaft with the helical spline pushing down on the spring, the flyweights and the pilot valve. this ports oil to the dome and pushes the prop blades to the full fine pitch. at ldle the blades will be spinning at around 800 RPM. (i'm not sure of that exact number)  when the pilot throttles up the props will accelerate to the max RPM of 1700. then the prop governor goes into an overspeed condition ( briefly) and the flyweights due to centrifugal force pull up on the pilot valve porting oil out of the dome. this causes the pitch to increase and create more thrust. at full chooch the beech 1900 makes @1300 hp per engine. after take off the pilots will set climb power, reducing the prop RPM to 1500 and the torque to whatever the power chart says. in cruise the prop RPM will usually stay at 1500.

 

there should be plenty to chew on for tonight. I had a busy day with 2 broken 767's and i'm off to bed

cheers