P3 Orion props

Member for

7 years 10 months

Posts: 299

I am sure somebody on here will know the answer. I am no expert on engines but just wondering why the Electra has square tips on the props and the Orion has rounded tips. Just noticed this now, after all these years, with the amount of TV footage of the P3s in Perth.
Original post
Profile picture for user Freehand

Member for

7 years 5 months

Posts: 980

I believe the rounded tips help reduce vibrations and make the P-3 quieter than its square-tipped counterparts.

Member for

7 years 10 months

Posts: 299

Thanks for that, I knew somebody would have the answer !
Profile picture for user SpudmanWP

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10 years 9 months

Posts: 5,196

http://www.pprune.org/tech-log/100428-prop-shapes.html
Squared off tips are less efficient, but allow higher solidity and therefore more power can be delivered to the airflow by a propeller of given diameter. C130 - short field takeoff is a primary performance requirement, so high power output is necessary. P-3 - oceanic endurance is a primary performance requirement, so efficiency becomes the overriding concern. All the above is just off the top of my head, so I await correction.

Member for

7 years 10 months

Posts: 299

Interesting reading, I am glad that I wasn't the only one that didn't know why !
Profile picture for user Freehand

Member for

7 years 5 months

Posts: 980

I used to round the tips of my RC aircraft propellors. That would quiet them down a little bit.