Plane Facts: Propellers

Leonardo da Vinci airscrew designs:c. 1480

First coaxial helicopter blade design:Mikhail Lomonosov, 1754

Year of first airborne propeller use:1784

Aircraft it was used in:a balloon

Means of power:hand-cranking

Early experimenter with metal prop blades:Sir George Cayley, c. 1790

First practical aircraft propeller design:Wright Brothers

Their discovery:the twisted airfoil design

Basis of twisted airfoil:propeller blades are more like wings than screws

Efficiency of Wrights' propellers:about 82%

Efficiency of today's propellers:around 90%

First useful metal aircraft propellers:Alberto Santos-Dumont, 1906

Number of propellers Hartzell produces each year:around 3,000

Largest production plane prop:Garuda prop, 22 ft.6 in. diameter on Linke-Hofmann R.II

One main reason for taildragger configuration:better clearance for longer blades

Largest prop on fighter plane:Vought F4U Corsair, 1939, 13 ft., three-blade

Replacement:four-blade prop with shorter blades

Fewest blades on a production propeller:1

Manufacturer:Everel Propeller Corp.

Applications:J-2 Cub (option), Taylorcraft, Cessna Airmaster

First practical controllable pitch prop:1927, electrically actuated

Advantage over hydraulics:adjustable without engine power

First production constant-speed propeller:1930, Hamilton Standard

Actuation mechanism:hydraulic (oil pressure)

Recognition for achievement:Collier Trophy

First feathering propeller: 1937, Hamilton Standard Hydromatic

First reversible pitch propeller: probably Hamilton Standard, around 1947, DC-6

Propellers on Spruce Goose (H-4):eight four-blade Hamilton Standard, 17 ft. 2 in. diameter

Most common shape of propeller tips:rounded and square

Purported benefit of square tips:greater strength

Advantage of three-blade props vs. two-blades:quieter and smoother

Reason #1 for this:shorter blades = slower tip speeds

Reason #2 for this:more but smaller pressure pulses per revolution

Most propeller blades, production airplane:Antonov SV-24, 14 blades per engine (4 engines)

Arrangement:two discs per engine, 8 blades forward, 6 in the rear

Weight of metal three-blade propeller/spinner on Cirrus SR20:80.7 lbs.

Weight of Hartzell three-blade Raptor composite prop on same plane:51.2 lbs.

Long-accepted forward aircraft speed limit for prop planes: around 500 mph

Reason for a "speed limit":shockwaves from tips going supersonic

Rationale for more than two blades:shorter blades, slower tip speeds

Negatives for multiple blades:other blades disturb the airstream

Fastest propeller-driven plane (turboprop):XF-84F Thunderscreech, Mach .83 (disputed)

Fastest piston-powered propeller plane:Rare Bear (modified Grumman F8F Bearcat), 528 mph

Fastest combat-duty propeller plane, WWII (disputed):Messerschmitt Me 209, 470 mph

Fastest propeller-driven seaplane:Macchi M.C.72, 441 mph

Popular motorglider propeller type:folding blade

Extension mechanism:centrifugal force

Retraction mechanism:airflow

Next-gen propeller applications:NASA experimental electric planes have as many as 18 engines, all with props