Propellers are a very necessary part of our airplane’s relationship with its operating medium. Obviously, a powerplant is the heart of the plane’s ability to sustain flight, but without the propeller the engine is just so much dead weight (jets notwithstanding). And picking the right prop to transfer the engine’s power to forward motion is critical.
Propeller making is as much art as science, so finding just the right combination of material, pitch, blade length and count, and, if necessary, mechanisms for adjustment and control, can take some doing. Ask any assembly of builders to name their favorite prop supplier and you’ll often get disparate responses of worshipful praise. Each one thinks his propeller maker is the best one out there, even though it may have taken two or three attempts to fine-tune his present propeller.
Certified or Non?
Selecting your propeller begins with making the choice of going with FAA-certified or non-certified installations. If you’re using a certified engine in your homebuilt, you may want to stick with a certified prop, reducing the Phase 1 test hours over the time required if using a non-certified propeller; even if your engine is a bone-stock Continental or Lycoming, using an uncertified prop requires your homebuilt to undergo extra test flying.
Determine if the propeller type you have in mind will fit on your engine. Simple fixed-pitch propellers aren’t so simple; instead, each installation has to be optimized for the intended operating parameters, and if no pitch adjustment is possible, a compromise must be struck between takeoff and climb performance or high-speed cruising flight. You can’t just bolt on a propeller you happen to find lying around and expect it to work. Such empirical experimentation will result in a lot of high-speed runs up and down the runway, and maybe some scary moments eking out enough climb to get around the airport.
To avoid this, look at propeller specs on successfully-flying airplanes that share your engine type and speed range, then use something similar on your plane. Or, you can order a custom-made propeller matched to your engine’s power output and torque curve, along with the design airspeed expected. Thrust is the objective, not just rpm. Static rpm is a starting point, but thrust equals performance.
Basic propeller design incorporates two specifications; tip-to-tip diameter and blade pitch. The propeller’s span is physically restricted by the need for ground clearance in a level takeoff or landing attitude, taking into account the worst-case tire deflation and landing gear compression scenarios. If enough rpm can be generated, a too-long propeller will begin to encounter tip speeds approaching transonic velocity, which results in both a loss of efficiency and excessive noise. Tip speeds beyond 80% of Mach 1 have little effect on thrust. A prop that’s too short, on the other hand, can’t deliver as much thrust from its smaller propeller disc.
Propeller pitch is a theoretical measurement of how far the prop can advance into air during one revolution, usually expressed in inches. A propeller shaped to provide 60-inches of pitch would screw its way into solid air and pull itself five feet forward, given perfect efficiency that’s unattainable in the real world. The best propeller designs can approach 90% efficiency, however. Because the blade’s profile shape is twisted progressively from root to tip, the specified pitch is usually measured at 75% of the blade length.
The Sensenich W72CK42 propeller decorating the wall of my man-cave has a tip-to-tip length of 72 inches and a pitch of 42 inches. Its lovely wood laminations and brass leading edge guards are beautiful examples of propeller-making artistry. While wood props aren’t quite as efficient as metal or composite models, they are cheaper and provide natural vibration damping. Aluminum is durable, but heavier and easily chipped. Composite, or composite-coated wood, propellers combine lightness with stiffness, at greater cost.
Going to a three-blade or four-blade propeller doesn’t necessarily achieve any gain in performance, other than for a bit more thrust during takeoff. In fact, extra blades are LESS efficient than a simple two-blade prop, all other things being equal. Careful design work can offset some of the inherent loss created by adding a blade, but the purpose of most three-blade installations is to reduce the blade length while preserving thrust. Three blades also change the noise signature to a less-annoying frequency and can help with smoothness. However, with higher horsepower ratings, extra blades are necessary to transfer the engine power into useful thrust.
Fortunately, there are a lot of well-established propeller suppliers out there, ready to help you get the right prop on your homebuilt. Following is the latest information we have on each company, along with a listing of contact data to put you in touch with them.
Certified Propeller Manufacturers
GT Propellers is an Italy-based supplier of EASA-certified wood and composite fixed-pitch, ground-adjustable and constant-speed propellers, started in 1969 by the Tonini brothers. Collaboration with Technam Aircraft began in the early 1990s. Over 30,000 GT propellers have been produced, with over 200 variations available. Many of GT’s models comply with EASA 21P standards.
GT Propellers are built in two to six-blade configurations, but most of its LSA and light airplane props, suitable for up 110 hp, are of two and three-blade varieties, using monolithic carbon technology with a metal leading-edge protector strip.
Hartzell Propeller, Inc.
Hartzell’s involvement with aircraft propellers dates back over 100 years, when the Hartzell and Wright families were near neighbors in Dayton, Ohio. From its beginnings with walnut fixed-pitch props, Hartzell now supplies constant-speed propellers for a myriad of installations.
Hartzell Propeller offers a wide variety of propellers for the experimental and homebuilt market. It is the leading provider of constant-speed, variable- pitch propellers to the global kit airplane community. Hartzell’s props are compatible with a wide range of engines and are available with both metal and composite blades. Continuing to innovate and bring new technology to market, Hartzell has recently added a three-blade “Raptor*” hub propeller to its lineup of E/A-B products, offering higher performance and weight savings.
The latest product introduced by Hartzell is a new three-blade composite Pathfinder propeller optimized for backcountry operation, developed in conjunction with CubCrafters and Lycoming. At only 44 pounds, it provides a lightweight three-blade alternative to the Trailblazer series.
McCauley Propeller Systems
McCauley Propellers became a wholly-owned division of Cessna Aircraft back in 1960, a relationship that continues today under the Textron Aviation umbrella. McCauley Propeller Systems is headquartered in Wichita, Kansas, but propeller production takes place in Columbus, Georgia.
McCauley has 350,000 propellers in service, with over 500 models available. In addition to its aluminum fixed-pitch and constant-speed propellers, McCauley makes composite props as large as the five-blade Black-Mac Carbon unit that will be on Cessna’s new Denali turboprop.
Based in Germany, MT’s propellers are supported in North America by a Deland, Florida, service center. MT-Propeller has long provided props for Experimental/Amateur-Built aircraft, as well as certified propellers for airplanes with up to 5000 installed horsepower.
Most of MT’s propeller blades are of “natural composite” construction, using a composite structure applied to a wood core, hydraulically controlled for constant-speed and reversing functions. Up to six blades can be fitted in MT-Propeller hub systems, and an ultra-quiet nine-blade MT propeller system has been flown on a Piper Cheyenne test bed airplane. The latest MT approvals are five-blade propellers for the Quest Kodiak and Cessna 441 aircraft.
Sensenich Propeller Co.
Sensenich propellers were born in the heart of the Great Depression in 1932, and the original company headquarters is still located near Lancaster, Pennsylvania, where the firm began. Its wood and composite propeller products now come from a Plant City, Florida, division, while Sensenich’s metal propellers are built in Lititz, PA. The company supplies propellers for both certified and Experimental-category aircraft.
Announced at AirVenture 2019, Sensenich has created a whole new line of ground-adjustable composite props, swept-tip two and three-blade units that are designed for the O-320/O-360 installations in Van’s RV airplanes. The two-blade propellers are 68-72 inches in diameter, while the three-blade props are of 64-68 inch diameter. In addition, a two-blade 74-76 inch diameter Pitts propeller is available, and a big 78-82 inch thruster for STOL airplanes (Bearhawk, Super Cub, RANS, Zenith) was introduced. In both of the latter cases, three-blade units were under development. Bonded leading edges and Sensenich’s unique pitch-setting gauge are standard.
|Company||Date Founded||Construction||Horsepower Range|
|GT Propellers||1969||Wood and composite||30 to 2500 hp|
|Via del Commercio 7, 47838 Riccione (RN) Italy | +39 0541 69 33 99|
|Hartzell Propeller, Inc.||1917||Metal and composite||Up to 2180 hp|
|One Propeller Place, Piqua, OH 45356 | 800-942-7767|
|McCauley Propeller Systems||1938||Metal and composite||100 to 1200 hp|
|10511 East Central Ave, Wichita, KS 67206 | 800-621-7767|
|MT-Propeller USA, Inc.||1981||Natural composite||Up to 5000 hp|
|1180 Airport Terminal Dr, Deland, FL 32724 | 386-736-7762|
|Sensenich Wood Propeller Co.||1932||Wood and composite||50 to 275 hp|
|2008 Wood Ct, Plant City, FL 33563 | 813-752-3711|
|Sensenich Propeller Mfg. Co. Inc.||1932||Metal||65 to 200 hp|
|14 Citation Ln, Lititz, PA 17543 | 717-569-0435|
Airmaster Propellers, Ltd.
Airmaster Propellers, based in New Zealand, has a broad range of electrically-controlled constant-speed propellers for experimental and ultralight-type aircraft. The company’s two and three-blade hubs hold a variety of blade styles, although Airmaster builds no blades of its own, preferring to offer complete propeller systems in collaboration with existing blade manufacturers like Warp Drive, Kiev, WhirlWind and Sensenich.
Airmaster’s unique mode selector allows the pilot to dial in preset takeoff, climb and cruise pitch settings, after which it holds the desired rpm with little interaction required. There are several U.S. resellers of Airmaster prop systems, including Custom Flight Creations, The Airplane Factory, Kitfox LLC, RANS Aircraft, Kaolin Aviation Services and Arion Aircraft.
Oklahoma-based Arrowprop is now primarily a supplier of composite propellers for ultralight and small experimental airplanes of up to 100 hp, although its former wood props are still available for special orders. The firm makes propellers up to 72 inches in diameter and has been in business since 1961.
Bolly Propellers of Virginia, South Australia, began as a premier supplier of wood and composite propellers for radio-control model airplanes, before branching out into full-size aircraft. Bolly specializes in ground-adjustable propellers of carbon-fiber blade construction. Its Optima Series props are available in five models of increasing horsepower ratings, using two, three, and four-blade hub styles.
Craig Catto began building two and three-blade fixed-pitch propellers in 1974, for a variety of non-certified applications. Catto propellers use a wood core encapsulated in a structural composite overlay. The firm has received ASTM certification to allow Light Sport category aircraft to be equipped with Catto props. A durable electro-formed nickel leading edge for the blades is available as an option.
Competition Aircraft, Inc.
Competition Aircraft of Grass Valley, California, has been building its Ultra-Prop line of ground-adjustable composite props since 1984, with some 1800 props in service. The original Ultra-Prop line is comprised of 59-inch diameter models for ultralights, trikes, gyrocopters and powered parachutes, with engines of up to 50 hp. The larger Ultra-Prop II is a carbon-fiber reinforced propeller for applications of 25 hp per blade at 2500 rpm, allowing it to be used on engines up to 100 hp; about 300 Ultra-Prop IIs had been supplied as of this writing. The two-to-four blade Ultra-Prop II’s have a diameter of 66 inches, while the five and six-blade models are 67 and 671/2 inches overall.
Culver Props, now owned by Valley Engineering in Rolla, Missouri, has been around since 1983; it was purchased from the original owners in 2000 to complement Valley Engineering’s line of ultralight and small Experimental/Amateur-Built airplanes. The company has expanded into new temporary quarters, while awaiting construction of a new “dream shop” to handle increased business.
Culver’s two-blade fixed-pitch props can be furnished for engines up to 300 hp, using laminated maple, mahogany, birch and cherry woods. Culver Props are also popular for WW-I and similar replica antique aircraft, even including period-correct scimitar shapes, and it furnishes props for wall-décor purposes.
France-based DUC Hélices opened a subsidiary, DUC Propellers USA, in Sebring, Florida, to better serve the North American market for its propeller and rotor products. DUC’s forged-carbon composite propellers are European Aviation Safety Agency (EASA) certified, suitable for ultralight and experimental aircraft up to 140 hp. Its “Swirl” propellers are designed to give a constant-speed effect for high-speed aircraft, while the “Windspoon” models are designed for slower airspeeds. At Aero Friedrichshafen 2018, DUC Hlightweight constant-speed propeller, a three-blade hydraulically-operated unit under development. Weighing only 6.2 kg (13.6 pounds), it is primarily aimed at Rotax 9-series engines.
Located in Vernon, British Columbia, Canada, GSC Systems has a 35-year history of producing wood propellers for trikes, powered parachutes and powered paragliders. The company offers fixed-pitch propellers, which are preferred for direct-drive installations, and Tech II and Tech III ground-adjustable props in two and three-blade configurations. Diameters are available from 32 to 72 inches. Only clear Eastern maple is used, laminated and CNC shaped, then coated with automotive urethane.
Hoffman Propeller, GmbH
A German manufacturer of wood composite propellers for all types of aircraft, from general aviation airplanes to dirigibles, Hoffman Propeller was founded in 1955. For airplanes, Hoffmann offers fixed-pitch, ground-adjustable and hydraulically-controlled HO-V series constant-speed models, in two- or three-blade configurations. The wood core is covered with fiber-reinforced epoxy, then coated with polyurethane lacquer. Four North American distributors, including Steen Aero Lab, are among the worldwide dealers shown at Hoffman Propeller’s website.
Ivo Zdarsky escaped from communist Czechoslovakia in 1984, using an aircraft and propeller of his own making. Since then, Long Beach, CA-based Ivoprops have become widely known for their imbedded torsion rod that allows pitch adjustment, either on the ground or electrically in-flight. Ultralight, Medium and Magnum models are offered, in two or three blade styles, and there’s even a six-blade “X” system. The Medium series propellers are for engines up to 100 hp, while the Magnum props can handle up to 700 hp. Blade construction is of carbon fiber composite, finished with black gelcoat and a stainless steel leading edge.
Performance Propellers USA, LLC
Performance Propellers, based in Donnie, TX, offers two and three-blade CNC-cut laminated wood propellers for experimental and aerobatic aircraft. Takeoff and climb performance is maintained without compromising cruise performance by optimizing blade profile and flexibility. Each propeller is custom made, and the purchaser can try the prop out and send it back for tweaking after verifying initial rpm. The final finish and poured rainproof leading edge are then applied.
Primarily designed for Rotax engine installations, Utah-based Powerfin offers ground-adjustable carbon fiber propellers for a variety of light experimental aircraft. Two to five-blade hubs are available, with four different blade styles. Custom blade colors are now being offered, to match the owner’s paint design. With well over 20 years of experience, Powerfin denotes its products as “professionally designed and handcrafted.”
Prince Aircraft Co.
With over 40 years of experience building wood and carbon fiber propellers, Lonnie Prince’s company in Whitehouse, Ohio has produced over 10,000 props, primarily for airplanes in the 100- to 300-hp range. Prince’s unique droop P-tip blade design can give an effective 72-inch diameter with only 68 inches of blade length. A scimitar shaped blade allows the Prince prop to adjust its pitch over a four-inch range as airspeed changes, according to company literature. Both wood and wood-core carbon fiber construction is offered.
Edward Sterba has been carving props for 40 years, so there’s very little he doesn’t know about achieving the best performance out of a wood propeller for light experimental aircraft. Although Sterba began as a supplier of props for converted Volkswagen engines, he can make propellers for engines up to 200 hp, commonly for RV builders. His Sweptback series have a narrow noise-reducing tip, targeted primarily for VW installations, while the Race series props have a curved leading edge and narrow tip and are used on Continental and Lycoming engines in RVs, Mustang and Long EZ airplanes. Sterba uses hard maple, northern birch and cherry woods, with a urethane insert for leading edge protection.
Sterna Propellers is located in Zephyrhills, Florida, where it has been in business since 1996. It specializes in custom-design propellers, using composite blade structure in ground-adjustable hubs, primarily for light experimental aircraft. However, it also offers rotor blades and is working with electric-power aircraft applications. Horsepower per blade ranges from 30 to 75 hp, with various series of props optimized for specific engines.
Tarver Propellers, LLC
Kent Tarver of Fallon, Nevada owns the rights to the unique Koppers Aeromatic F200 propeller, designed in the 1940s. It was developed for light airplanes of the post-WWII era, giving airspeed-related automatic pitch shifting to optimize both takeoff and cruise performance. Aeromatics fell out of fashion with the introduction of hydraulic constant-speed propellers, but their wood-core and laminate blade construction and hub designs are still supported by Tarver Propellers. These propellers are sold exclusively for Experimental aircraft and installation is dependent on the engine being used.
Tennessee Propellers, Inc.
Tennessee Propellers supplies two-blade props for ultralight and experimental aircraft, using laminated hard maple finished with a two-part polyurethane coating. Leading edge protection can be either an adhesive-backed anti-abrasion tape or a “Uralite” inlaid urethane rubber leading edge. Now headquartered just across the state line in Georgia, Tennessee Propellers is still located in the Chattanooga area.
Warp Drive, Inc.
Based in Ventura, Iowa, Warp Drive propellers are ground-adjustable props with solid carbon fiber blades. Complete propellers in two- to six-blade styles are offered, and Warp Drive’s well-regarded blades are sold separately for use in some other brands of in-flight adjustable hubs. Warp Drive primarily markets its aircraft propellers for use on ultralights, trikes, gyroplanes, powered parachutes and LSA and light experimental airplanes, with engines up to 180 hp.
WhirlWind Propellers Corporation
Based in El Cajon, California, WhirlWind Propellers has been supplying ground-adjustable propellers for experimental aircraft since 1995. Two and three-blade styles are offered, and a separate division, Whirl Wind Aviation, was started in 2005 to supply constant-speed propellers. WhirlWind also supplies replacement blades for the Vperod propellers used on the Vedeneyev M14P engine. Initially using wood-core blades, patented carbon fiber designs became the material of choice for WhirlWind in 2000. Today, using the latest CAD solid modeling, FEA simulation, CNC machining, and a proprietary composite molding process, WhirlWind Propellers are widely known and the company can supply blades for many other brands of ground-adjustable props.
The art of propeller making remains a vital link in the process of taking to the air. Whether spun by electric motors, piston engines or turboprop powerplants, we are always going to need the right prop to convert energy into thrust.
|Company||Date Founded||Construction||Horsepower Range|
|Airmaster Propellers, Ltd.||1999||Metal/composite||80 to 200 hp|
|20 Haszard Rd, Massey, Aukland 0614, New Zealand | +64 9 833 1794|
|Arrowprop Company, Inc.||1960||Wood and composite||Up to 100 hp|
|P.O. Box 610, Meeker, OK 74855 | 405-279-2377|
|Bolly Aviation||1978||Composite||15 to 180 hp|
|Hangar 1 Calvin Grove Airfield, Virginia, South Australia 5120 | +61 8 8380 8396|
|Catto Proellers||1974||Composite||65 to 300 hp|
|Jackson Westover Airport, 12370 Airport Rd, Hangar 156, Jackson, CA 95642 | 209-754-3553|
|Competition Aircraft, Inc.||1984||Composite||Up to 100 hp|
|10925 Shire Ct, Grass Valley, CA 95949 | 888-634-9839|
|Culver Props||1983||Wood||Up to 300 hp|
|15685 Co. Rd 7100, Rolla, MO 65401 | 573-364-6311|
|DUC Hélices||1997||Composite||100 to 160 hp|
|Sebring Regional Airport, 442 Hendricks Field Way, Sebring, FL 33870 | 863-991-0113|
|GSC Systems, Inc.||1984||Wood||35 to 115 hp|
|#8 – 2440B 14th Ave, Vernon, BC, Canada V1T 8C1 | 250-549-3772|
|Ivoprop Corporation||1986||Composite||Up to 700 hp|
|2615 East 67th Street, Unit E, Long Beach, CA 90805 | 562-602-1451|
|Performance Propellers USA, LLC||2009||Wood||50 to 300 hp|
|466 Pr 5832, Donie, TX 75838 | 713-417-2519|
|Powerfin Propellers||2008||Composite||Up to 160 hp|
|705 S. 5300 W., Suite 4-5, Hurricane, UT 84737 | 435-627-0942|
|Prince Aircraft Company||1979||Wood and composite||100 to 300 hp|
|6774 Providence St, P.O. Box 2669, Whitehouse, OH 43571 | 419-877-5557|
|Props, Inc.||1984||Wood||Up to 260 hp|
|354 S.E. 2nd St, Newport, OR 97365 | 541-265-3032|
|Edward Sterba Propeller Company||1980||Wood||30 to 200 hp|
|9660 Southeast 72nd Ave, Ocala, FL 34472 | 941-778-3103|
|Sterna Propellers||1996||Composite||60 to 225 hp|
|39442 South Ave, Zephyrhills, FL 33542 | 909-979-4535|
|Tarver Propellers||2003||Wood/composite||Up to 170 hp|
|1500 Rio Vista Dr, Hangar C-4, Fallon, NV 89406 | 775-423-0378|
|Tennessee Propellers, Inc.||1981||Wood||28 to 100 hp|
|7031 Highway 157, Rising Fawn, GA 30738 | 706-398-0651|
|see Competition Aircraft|
|Warp Drive, Inc.||1989||Composite||Up to 180 hp|
|1207 Highway 18 East, Ventura, IA 50482 | 641-357-6000|
|WhirlWind Propellers Corp.||1973||Composite||80 to 400 hp|
|1860 Joe Crosson Dr, Suite C, El Cajon, CA 92020 | 619-562-3725|
Photos: LeRoy Cook, Paul Dye and courtesy of the manufacturers.