Flight Mechanics, Flight Control and Aeroelasticity

Auto-SFS – Automatic Slat/Flap Setting

Auto-SFS is a research project that targets the design and validation of an automatic high-lift system. Auto-SFS is a work package in the scope of the German aviation research program.


Commercial aircraft high-lift systems development currently concentrates on two aspects. On the one hand, the aerodynamic performance of high-lift systems is optimised. New functions and devices as well as high-lift systems for new aircraft configurations and radically new concepts are regarded. On the other hand, intensive research is put into the system architecture and components of high-lift systems, among others the automation of such a system is of high interest. This is triggered by the development of innovative electric and hydraulic actuators, mechanic components and new sources of electric and hydraulic power. In particular, the substitution of electro-hydraulic actuators with electric actuation systems holds significant potential. In the HIT/HiLiT work packages WP2.3 and WP3.2 of the German aviation research program (Luftfahrtforschungsprogramm, LuFo) IV, research is being conducted on the automation of high-lift systems as well as on the development of new functions. TU Berlin is a contractor of Airbus Deutschland in this project.


Objective of the Auto-SFS project is the design and validation of an automatic high-lift system which holds at least a similar safety standard of todays aircraft but gives improvements in comparison to current high-lift systems by

  • reducing noise and emissions while enabling new approach procedures to be flown through reducing cockpit crew workload.
  • optimising the aerodynamic configuration to improve aircraft performance and extend the flight envelope.
  • enabling new technologies and functions, thus saving weight.

Main result of the Auto-SFS project will be a validated concept for an automatic high-lift system.

Tasks of the TU-Berlin

Development of concepts for Auto-SFS-System including operational requirements

  • Study on the dependencies between Auto-SFS and current ATC procedures
  • Concepts for new ATC procedures obtaining maximum benefit from Auto-SFS
  • Requirements to an Auto-SFS-System, derived from handling qualities as well as ATC requirements
  • Development of evaluation criteria and analysis tools
  • Selection of feasible concepts
  • Realisation of a prototype system in A330-Full-Flight-Simulator of ZFB
  • Demonstration and tuning of concepts in simulator study with test pilots and airline crews
  • Sensitivity study including weather influence

Project Phases

Phase 1Short-Term RealisationThe aircraft is operated in accordance with current procedures, the high-lift system has an automatic basic functionality which corresponds to current manual useage.
Phase 2Mid-Term RealisationThe aircraft is operated in accordance with foreseeable future procedures, the high-lift system can be operated fully automated and has an advanced functionality.
Phase 3Long-Term RealisationThe aircraft is operated in accordance with future procedures which necessitate the automatic-high-lift capability. The high-lift system is coupled to the Flight Management System, so that the high-lift configuration can be adapted to the flight mission or transport task at any given time during the flight.


The functions developed in the individual project phases were combined into an overall system, which is now being operated as a prototype solution in the SEPHIR simulator. In a simulator campaign in July 2010, several tests were conducted with airline pilots, the evaluation of which confirmed the successful development of the Automatic Slat/Flap Setting. In addition to system safety and behavior in the event of an error, the applicability to today's flight procedures and the resulting changes in fuel requirements, pilot load and safety were examined. Compared to today's approach with manually operated flaps, the Auto-SFS functions were convincing in reducing fuel consumption and crew workload and increasing flight safety.

The graphic shows the result of a fast-time simulation with automatic high-lift configuration during a Continuous Descent Approach (CDA).

Project Partners

  • Airbus Deutschland GmbH (AD)
  • Deutsche Flugsicherung GmbH (DFS)
  • TU Berlin (TUB)