We’ve increasingly been approached about whether there is an alternative propulsion unit for the Rotax 505 engines used in the DG-400 and DG-800A, given the well-known spare parts issues.
As part of the ongoing trend toward electrification, we’re pleased to offer you the opportunity to retrofit your DG-400 or DG-800A equipped with a Rotax 505 with a RES system (“REStrofit”).
The RES system, developed by Solo, will be integrated into the DG-400 and DG-800A in a configuration similar to that used in the JS3 RES, where the system has already proven itself:
- Motor: Emrax 208
- Pylon: Likely the same as used in the JS3
- Batteries: 2 Emectric BM384 (including charger)
- DC/DC converter
Additionally, the retrofit will include further optimizations in the DG-400 and DG-800A:
- More powerful propeller from the JS2
- Conversion to two-piece engine bay doors
- New spindle drive
- Removal of 4x 6V lead-acid batteries in the fuselage nose, replaced with a 12V LiFePo avionics battery
- Removal of the old fuel tank to make room for control electronics
- Tool-free battery installation/removal thanks to an innovative spring-loaded locking mechanism
- Optional onboard charger for charging at an EV charging station
- Replacement of the DEI unit in the instrument panel with a 57mm round instrument, allowing for larger flight computers to be installed
DG-400 Retrofit – Inside view
With these upgrades and components, we expect performance data similar to the JS3 RES—and possibly even better performance due to the new propeller:
Current JS3 RES Performance data:
- Peak power: 40kW (up to 4m/s climb rate) at 4350 rpm
- With self-launch capability:
- Climb altitude with fully charged batteries: 1700 m
- Max range: 120 km
- Without self-launch:
- Climb altitude with fully charged batteries: 2000 m
- Max range: 157 km
Benefits of the new propeller:
- Same thrust at significantly lower RPM → reduced noise and improved climb performance
The total system weight (including batteries) is comparable to the Rotax 505 system with a full fuel tank, meaning no reduction in payload capacity compared to the current setup is expected.
To safeguard the financial investment required for development and tooling, we’re initially offering this retrofit as an option for DG-400 and DG-800A owners.
Once we receive five confirmed options, we’ll begin development and conversion, with the goal of completing the first REStrofit aircraft within the next two years.
Target price for the retrofit is €67,226.89 net (€80,000.00 gross).
The retrofit includes the entire RES system (valued at approx. €50,000), complete removal of the combustion engine, full RES system installation, and test flight certification. All removed components (engine, spindle drive, DEI, etc.) remain your property and may be sold.
Retrofit-Mockup DG-400
No more driving to the gas station, no more 2-stroke fuel mixing, no more exhaust fumes!
Simply plug it in after landing, or remove the batteries without tools through the large engine doors and take them home! The next day, just roll out your glider and fly!
Easy motor operation—no choke, no flooding, no manual propeller brake!
Also, maintenance and service costs for the RES system are significantly lower compared to combustion engines.
With this retrofit, you’ll turn your DG-400 or DG-800A into an efficient, eco-friendly, and user-friendly state-of-the-art self-launch glider.
Reserve your REStrofit option now!
For any questions, the DG team is happy to assist.
Looking Beyond – A Quick Outlook:
- A retrofit with neo-winglets for the DG-400 is unfortunately not feasible due to wing structure constraints. For the DG-800, this is currently under review.
- Next phase: REStrofit will also become available for the DG-800B and DG-808C.
- For the DG-600M, a general retrofit is not planned at this time, but we’re happy to provide a custom offer upon request.
- In parallel, the new DG-1001 RES is in the final development stages. The first flight is expected by late 2025.
For further info and delivery slots, Jonas Kühn is your point of contact.
After successful flight testing, we will consider offering REStrofit options for other two-seater models as well.