E-PROPS: Frequently Asked Questions

… and if you don’t find an answer, then contact us by email: helices@e-props.fr

1- Any questions before ordering an E-Props ?

✗ The right questions to ask yourself before changing your propeller
All is explained here: Why change propeller ?


✗ How do I know which propeller is the right one for my aircraft ?
On the main page of this website, go to the “Find Your Propeller” Menu (top left) and enter the name of your aircraft or its manufacturer.
More than 260 types of aircraft are in this catalog. If you can’t find your aircraft, you can go to the “Propellers by Speed” Menu and let us guide you.
For each “engine + gearbox” set (example Rotax 912S 100 hp gearbox 2.43 – a standard one), E-Props recommends a ground adjustable pitch propeller model (and sometimes, for some aircraft, an inflight variable pitch propeller model). These recommendations are based on numerous calculations and tests, as well as feedback from pilots. You can choose this propeller without fear, it will be the right one for your aircraft. If your aircraft is not in the catalog and you are unsure, fill out the QUESTIONNAIRE TO DEFINE YOUR E-PROPS and send it by email. We will answer very soon.


✗ Are E-Props propellers certified ?
The DURANDAL-3 range of 3-blade tractor propellers for Rotax 912S & iS is certified to EASA CS-22 Subpart J. They can be used on CS-VLA and ELA1 aircraft. The other E-Props meet the ASTM F2506-13 standard. Some will soon be certified to EASA CS-P.
More information here: E-PROPS Certifications
All our propellers are designed, then manufactured by the same team, in the same workshops, with the same materials, according to the same processes and with the same controls as the range certified by EASA. A serious guarantee of quality and reliability.


✗ Can I really try the E-Props for 6 months ?
YES ! 🙂     E-Props has always offered the Guarantee SATISFIED or YOUR MONEY BACK DURING 6 MONTHS.
You buy your propeller and you have 6 months to test it, at your convenience and in your usual environment. If you don’t like something, you return it and we give you your money back, no questions asked.
To offer such a contractual guarantee, the E-Props team is sure of the performance and quality of its propellers.
If E-Props were not exceptional, customers would return them, and that would not be a sustainable situation for the company.


✗ Can you send me the contact information of one of your customers ?
We cannot transmit the contact information of our customers (respect of the Data-processing law and Freedom); we can however transfer a request to them by email. Then, if they wish, they will answer directly.
If you are looking for customer feedback on E-Props: on our website, you will find 830 USERS FEEDBACK. A complete list, sorted by aircraft.


✗ Why choose a lightweight propeller ?
In aviation, any gain in weight is very important (weight is the enemy).
– Lightweight propellers allow a better operation of the drive train (excellent respect of the engine’s moment of inertia).
– A light propeller is much more reactive, for a direct piloting, without delay between the throttle and the increase of the rotation speed.
– An ultra-light propeller will increase fuel autonomy and safety.
More information here: E-Props: the world’s lightest propellers


✗ How do I know what diameter propeller I need ?
Usually, the diameter of the propeller is defined by the ground clearance. This is the distance between the ground and the tip of the blade, with the blade placed vertically downwards. E-Props recommends a minimum ground clearance of 20-22 cm. Below this, there is a risk of hitting the ground on a clump of earth or grass. For ultralights with tail wheel, this measurement should be made in the flight line.
At E-Props, when the ground clearance is higher than 20-22 cm, it is preferable to take a propeller of the largest possible diameter: it will allow the shortest possible take-off while offering an excellent speed in cruise. Contrary to popular belief (and there are many concerning propellers…), the increase in diameter is favorable to the performance, by improving the efficiency.
For most of the ultralights and airplanes referenced in the E-Props catalog, a propeller diameter is proposed. This is the most common one for each aircraft. It can be modified on request (in the comments of the order).


✗ Do E-Props blades have metal leading edge protection ?
Since 2019, all E-Props for ultralights/aircraft have CARBON blades equipped with TITANIUM leading edge protection.


✗ Is there a risk of galvanic corrosion with E-Props ?
No. The only materials used in E-Props are Carbon and Titanium, which are neutral. There is no aluminum.
No risk of galvanic corrosion on E-Props propellers.


✗ What is the best: a 2-blade or a 3-blade ?
The optimal number of blades depends on:
– the aircraft considered: tractive or propulsive configuration / high or low wings / type of engine cowling
– its engine (power)
– its gearbox (rotation speed at propeller)
– and the possible diameter of the propeller (ground clearance)
With this information, E-Props will recommend a propeller model, defined by the profile (shape) and chord (width) of the blades, the diameter and of course the ideal number of blades. This propeller will give the best performance on the considered aircraft.
Example: in the E-Props range, the best propeller for a Savannah S engine Rotax 912S 100 hp gearbox 1:2.43 is a 3-blade diameter 175 cm / chord C4 / weight 2 kg.
It is the LmPTR software, developed by Jérémie Buiatti (designer of E-Props propellers), which allows an efficient design process, able to obtain the optimum propeller for each configuration. This software analyses in detail the aerodynamic flows and the mechanical behavior of the propeller. To date, it contains more than 100,000 lines of advanced language code.
More information here: E-PROPS LmPTR Software


✗ How to define the length of the spacer and the diameter of the spinner ?
To move the propeller away from the engine hood (if necessary), a spacer is mounted. At E-Props, this spacer is called the ESU and it is made of carbon. The E-Props spinners are also made of carbon.
To define the length of the spacer and the diameter of the spinner, it is very easy by following our indications:
– Lenght of the carbon spacer: 38 available lengths
– Diameter of the carbon spinner: 15 available diameters
This video can help you: Tutorial to measure propeller spacer & spinner


✗ Can I mount another spinner than an E-Props spinner ?
Yes, it is possible, if your spinner is mounted on the E-Props spinner mounting plate.
It exists in 15 different diameters. See diagram on this page: Spinner plates
Then you will have to drill the plate with your spinner to be able to fix it.


✗ Can I paint my spinner ?
You can paint the spinner if you want. All you have to do is to sand the surface, very lightly (600 grain sandpaper). The recommended paint is a bi-component polyurethane. A well sanded primer is necessary for a beautiful finish. Be careful to the balancing.


✗ What are the most important options to choose ?
E-Props propellers are delivered complete: blades, hub, spacer (if applicable), spinner.
As an option, E-Props recommends taking a Digital Pitch Adjustment Tool , in order to fine adjust the blade pitch.
Neoprene blade covers are very popular.


✗ I’ve heard about the ESR effect. What is the ESR effect ?
At E-PROPS, we use the term “ESR effect” to refer to a fixed-pitch (or ground-adjustable pitch) propeller whose behavior very closely approximates that of an inflight variable-pitch propeller, i.e., strong traction at all engine speeds.
More information here: ESR EFFECT


✗ How can I place an order ?
You can order on line on the present store, by choosing the desired propeller, with payment by CB, PAYPAL, bank wire. You can also send us a message with all information to helices@e-props.fr or sales@e-props.fr
Indicate us your details and information requested in the QUESTIONNAIRE TO DEFINE YOUR E-PROPS. The payment is done by the same means.


✗ After I place my order, how soon will I receive my propeller ?
Due to the large number of possible configurations (diameters, number of blades, spacer lengths, spinners diameters…), E-Props propellers are made to order.
A propeller for ultralights / airplanes is usually finished by the E-Props team within 10 days.
Then, the transport time depends on the delivery address. For France, it is 48h. For foreign countries, it\’s the DHL Express delivery time.


✗ Can you ship a propeller to a foreign country ?
We deliver propellers to 83 different countries. We use the services of DHL Express, FEDEX and UPS.

2- A question about your E-Props ?

✗ To mount a V20 propeller, do you have to remove the Rotax 912 drive lugs ?
YES, absolutely. The interface part between the propeller and the gearbox of the Rotax 912, called ESU, includes the drive lugs molded in carbon. The Rotax pins are therefore no longer necessary. You just have to remove them and the ESU will be perfectly positioned in the holes of the gearbox. The weight gain is 125 g.
If these Rotax pins are difficult to remove (rusted), a tool is proposed here: Drive Lugs Changer. A video explains how to use it.


✗ How do I assemble my E-Props propellers ?
Click here to see the Manuals & Technical Documentations
Some videos allow you to visualize the assembly and the adjustments of the E-Props propellers.


✗ Where is the recommended pitch (ground adjustable pitch propeller) ?
On the Propeller Identification Sheet, document accompanying the propeller (Documentation envelope).
If you can’t find it, you can ask us for it, rather by email please.


✗ What is the TBO of my propeller ?
The DURANDAL and EXCALIBUR models have a TBO (Time between Overhaul) of 2000 hours.
For the more recent GLORIEUSE models, 2000 hours is the target.


✗ How do I adjust my ground adjustable pitch propeller ?
For E-PROPS propellers, the static traction measurement is not a significant data point, because they are designed to reach their full traction during rolling, not static. In static, the blades of E-Props are slightly stalled.
The E-Props method of adjustment is available:
– on the Propeller Identification Sheet, a document accompanying the propeller (Documentation envelope)
– on the User’s Manual, available here: Manuals & Technical Documentation
– on the menu of the website: E-PROPS propeller adjustment


✗ The aircraft goes backwards when it should go forwards !
The position of the blades is inverted compared to the good position.
See the explanatory diagrams here: E-PROPS Adjustment


✗ My spinner does not fit !
1/ Adjust the correct pitch of the blades (see the Identification Sheet of the propeller)
2/ Then only mount the spinner, otherwise in some cases the unadjusted blades may touch the edge of the spinner
Please note: the spinner has been assembled and balanced with the propeller at the E-Props workshop. The verification is systematically done by the E-Props technicians. A spinner is not delivered if it does not fit.


✗ I did not receive my invoice.
The invoice is issued when we send the propeller, as it includes all the serial numbers of the components. It is not possible to indicate these numbers before the propeller is ready. Invoices are not sent in the propeller package. They are only sent by email, as an attachment to the propeller’s shipping message. Check your spam folder.
If you did not receive anything, you can of course ask us for it (by email, thank you).


✗ My E-Props propeller is damaged, what should I do ?
First of all, contact our team to identify if the problem is serious or not.
If the propeller must be sent back for expertise and/or repair, before any return, contact our administrative and commercial department.
Our team will give you a Parcel Receipt Number, to be indicated on and/or in your package.
It is not possible to make a quote on photos; we must see the parts before to give a technical report.

3- A question about our company ?

✗ Is the company E-Props or Electravia ?
It’s all the same! When it was founded in 2008, ELECTRAVIA designed and manufactured electric motorization systems for recreational aviation. In 6 years, the team has developed more than 70 electrically-powered aircraft that have achieved major world firsts.
At the same time, the team was developing E-PROPS propellers, first in wood and then in carbon, which have met with increasing success. In 2014, ELECTRAVIA’s management decided to suspend the electric motorization activities to focus on propellers.
The company’s trade name is now ELECTRAVIA – HELICES E-PROPS.
The propellers are called E-PROPS for ELECTRAVIA – PROPELLERS.


✗ How many employees work at E-Props ?
The team includes 48 aeronautical engineers and technicians, who work in a 7200 square meters workshop based in Provence (Sisteron airfield), France.
The current production is 45000 propeller blades / year.
E-PROPS is the world leader in propellers for paramotors and exports 87% of its production in 84 different countries.


✗ E-Props is building a new factory ?
In 2021, Electravia has begun to build a 4200 square meters smart and eco-responsible building including CNC machining centers, robots and additive manufacturing machines.
All the E-Props workshops on the industrial zone have a total surface of 7200 square meters.


✗ Are you hiring at E-Props ?
Yes. It\’s all on the page JOB OFFERS

4- An other subject ?

✗ What are the names of the E-Props: Durandal, Excalibur, Glorieuse… ?
At the beginning of the manufacturing of the blades, long and thin carbon parts, the associates simulated sword fights for fun. Sword names were then used for the E-Props range.
DURANDAL: the sword of the knight Roland, stuck in the rock of Notre-Dame de Rocamadour
        Range of propellers with ground adjustable pitch for reduced engines from 65 to 150 hp, CW rotation
EXCALIBUR: the sword of King Arthur
        Range of propellers with ground adjustable pitch for reduced engines from 65 to 150 hp, CCW rotation
GLORIEUSE: the Celestial Sword of Archangel Michael
        Range of propellers with inflight variable pitch for reduced engines from 100 to 150 hp, CW rotation
It\’s still nicer than a reference based on letters and numbers, isn’t it?   🙂


✗ Where can I see the E-Props news ?
On the E-PROPS BLOG
On the E-PROPS PAGE on FACEBOOK


✗ Do you repair other propeller brands ?
No. The materials used and the manufacturing processes of each propeller manufacturer are different. We would not want to make a bad repair, which could have serious consequences.
It is always best to contact the manufacturer of the propeller in question.
Also, do not entrust the repair of an E-Props propeller to a company or person not authorized by E-Props.


✗ When will E-Props for direct drive engines be available ?
E-PROPS is working on a wide range of propellers for direct drive engines (without gearbox).
Release date: once the extension of our new factory is operational.