Single-aisle turboelectric aircraft with rear boundary layer propulsion (STARC-ABL) • 100 KNOTS

NASA is studying advanced EAP (Electrified Aircraft Propulsion) technology to dramatically reduce fuel burn and pollution levels for single-aisle commercial aircraft carrying approximately 150 passengers in this new era of electric flight. In order to improve vehicle performance through innovative aerodynamic designs and technologies, the Single-aisle turboelectric aircraft with Rear boundary layer propulsion (STARC-ABL) idea was created.

To maximize aerodynamic benefits in flight, STARC-ABL uses an innovative electric tail thruster powered by twin underwing turbofans while maintaining a traditional turbine and airframe design.


This aircraft idea could potentially reduce fuel consumption by 7-12% while operating with the same range, speed and airport infrastructure as existing regional jets. It would also highlight the fundamental benefits of partially turboelectric propulsion systems for next-generation aircraft.

Optimized performance and aerodynamic efficiency

A crucial first step in reducing drag, which slows a vehicle and increases fuel consumption, is controlling the airflow around it. Innovative Boundary Layer Ingestion (BLI) technology, which is a feature of STARC-ABL, helps control the boundary layer – a region of slower-moving air – near the aircraft’s surface.

NASA’s NEAT (Electric Aircraft Testbed) facility where STARC-ABL will be tested is shown in an artist view | Nasa

A BLI fan mounted on the vehicle’s tail, which is integrated with the aircraft’s propulsion system, helps ingest the slower and often more turbulent layer of air. Then, to create thrust, this air is re-accelerated from the boundary layer to the aircraft’s surface.

STARC-ABL relies on propulsion-airframe integration, or the efficient integration of the propulsion system with the airflow surrounding the airframe, to achieve maximum performance (PAI). The aircraft’s turbofans are equipped with generators that produce electricity and power the rear engine.

The STARC, ABL design which features two wing-mounted turbofans and a rear engine is visualized | Nasa

Smaller wing-mounted engines can be used with the innovative addition of an aft engine which provides additional thrust, helping to reduce drag and fuel burn while reducing overall aircraft weight. Turbofans can produce megawatts of electricity in addition to thrust, which can be used to power aircraft electrical systems, including cabin conditioning and on-board instruments.

The High Efficiency Megawatt Motor (HEMM) is the generator used by STARC-ABL, which requires an advanced 2-3 MW power system. The HEMM, a 1.4 MW electric machine, reduces drag and fuel consumption for STARC-AB and offers three times less heat and weight loss than contemporary aircraft engines and generators.

Image of artist-created high-efficiency megawatt motor (HEMM) | Nasa

During the development of the concept aircraft, STARC-ABL will undergo extensive testing at the Electric Aircraft Test Bed (NEAT) at NASA’s Glenn Research Center.

Future airliners will be able to successfully transition from conventional jet engines to a more sustainable future for aviation thanks to the technology revealed by this proposal.

STARC-ABL, which is expected to join the commercial fleet around 2035, will play a crucial role in demonstrating the capabilities of turboelectric systems and parts for more environmentally friendly air transport.



Comments are closed.