China's RX4E: First Four-Seat Electric Plane Certified

China Certifies Ruixiang's RX4E, the First Four-Seat Electric Aircraft

On January 2, 2025, the Civil Aviation Administration of China (CAAC) announced the certification of the RX4E, the first four-seat electric aircraft in the CCAR-23 category. This achievement aims to highlight China's edge in the aviation industry compared to the West, though many questions remain unanswered.

Challenges for Certification in Europe and the USA
The Chinese CCAR-23 standard is described by Chinese authorities as “equivalent” to the American PART-23 and European CS-23 standards for light aviation. However, no Western authority has recognized this equivalence, making it difficult to ascertain whether the aircraft meets the same requirements expected in this category.

This situation recalls the much-hyped 2023 certification of the eVTOL eHang EH216. It was revealed later that the certification only allowed the aircraft to operate under visually supervised conditions, akin to a fairground ride, rather than as the flying taxi it was initially promoted to be. Furthermore, its 16 propellers, located in the cabin evacuation path, posed significant challenges under Western certification criteria.

RX4E: Technical Details
The RX4E is a four-seat high-wing electric aircraft developed by Ruixiang General Aircraft Co. It was first unveiled in 2019 and features the following specifications:

Maximum speed: 289 km/h
Cruising speed: 220 km/h
Stall speed: 100 km/h
Takeoff distance: 380 m
Landing distance: 400 m
Maximum power: 140 kW
Range: 1.5 hours
Battery capacity: 50 kWh
Maximum takeoff weight: 1,260 kg
Empty weight: 952 kg
Price: €530,000
Battery Limitations
A notable detail is the claimed battery capacity of 70 kWh, supposedly offering 1.5 hours of autonomy. However, it remains unclear whether this figure represents total capacity or usable capacity. To preserve battery lifespan, charge levels are typically not allowed to drop below 15–20%.

If 70 kWh represents the total capacity, the usable capacity might only be 55–60 kWh. In the most efficient cruising scenario (65% of the engine’s 140 kW power output), the aircraft would consume at least 90 kWh per hour. This suggests that the battery could only support 46 minutes of flight, minus reserves required for safety and regulatory compliance. If the usable capacity is closer to 55 kWh, the range drops to 36 minutes—far from the advertised 1.5 hours.

Broader Context of Electric Aviation in the CS-23 Category
The announcement provides an opportunity to contextualize the current state of electric aviation projects within the CS-23 certification framework. This category represents a step up from the CS-LSA-certified Pipistrel Velis Electro (a two-seat aircraft), which faces limitations in the U.S. due to its uncertified status and restricted operating conditions.

The progression from two-seat to four-seat electric aircraft in the CS-23 category faces significant challenges. Safety standards are stricter, requiring fewer than one catastrophic failure per 10 million flight hours (compared to one per million hours for CS-LSA aircraft). Achieving this tenfold increase in reliability has proven difficult.

Notable Developments:
Swiss company H55 announced its certified propulsion system for the Bristell Energic, a two-seater targeting CS-23 certification.
France's Aura Aero conducted the first flight of its Integral E prototype in December 2024, also aiming for CS-23 certification but as a two-seater.
Austria’s Diamond Aircraft flew the eDA40 prototype (an electric version of its four-seat DA40, now reduced to two/three seats) in July 2023.
In the U.S., Bye Aerospace’s eFlyer 2, a two-seat electric aircraft, has faced repeated delays in its Part-23 certification process. Its four-seat variant, the eFlyer 4, remains in the conceptual phase.
Conclusion
Certifying an electric aircraft under CS/Part-23 is a formidable challenge due to the mass limitations of current batteries. While China’s RX4E announcement briefly raised hopes, the battery limitations make the claimed 1.5-hour range unrealistic. For now, significant advancements in battery energy density will be essential to make four-seat electric aircraft with meaningful range a reality.