Navigation path

Decrease textIncrease textDividerPrint versionRSSDivider

Safe automatic flight back and landing of aircraft

Tags: Air


The SOFIA project is a response to the challenge of developing concepts and techniques enabling the safe and automatic return of an aeroplane in the event of hostile actions. This is proposed as the continuation of the SAFEE works on FRF (flight reconfiguration function), a system which returns aircraft automatically to the ground. SOFIA will design architectures for integrating the FRF system into several typologies of avionics for civil transport aircraft. This requires the development of one of these architectures, the validation (following E-OCVM) of the FRF concept and of the means to integrate it in the current ATM. A safety assessment of FRF at aircraft and operational (ATC) levels (applying ESARR) is also needed.

SOFIA will produce the FRF system, which will take control of the aircraft and safely return it to ground under a security emergency (e.g. hijacking), disabling the control and command of the aircraft from the cockpit. This means creating and executing a new flight plan towards a secure airport and landing the aircraft at it. The flight plan can be generated on the ground (ATC) or in a military airplane and transmitted to the aircraft, or created autonomously at the FRF system.


The main objective of SOFIA is to develop and validate the FRF system to safely and automatically return civil transport aircraft to the ground when they come under hostile action conditions. The project will also analyse what kind of conflicts can generate FRF in the airspace and will propose some solutions to minimise the impact. The overall SOFIA objectives are as follows:

  • demonstrate that FRF can be designed and developed in a reliable and affordable manner;
  • demonstrate that an FRF equipped aircraft is safe during its normal operation;
  • demonstrate that when FRF is in command of an aircraft it can be safely and securely returned to the ground at a designated airport;
  • formulate a proposal to integrate FRF in the current and future (ADS-B, CDM, 4D Trajectory Negotiation) airspace;
  • determine the modifications needed in the ATC systems on the ground to handle FRF;
  • implement FRF and necessary modifications in ATC to perform validation trials representative of two operation modes:
    • flight plan re-planning with negotiation: flight plan generated by ATC and executed by FRF;
    • flight plan re-planning without negotiation: FRF creates and executes the flight plan.
SOFIA scope
SOFIA scope

Description of work

SOFIA is chiefly a technological project with a strong technical component to design, develop and validate the flight reconfiguration function. It also dedicates an important part to assessing the operational issues related with the integration of the FRF system into the airspace.

SOFIA will benefit from the UAV experience regarding ‘sense and avoid’, and especially automatic flight, and the commercial aviation experience regarding certification, whereby one common FRF function will be developed in compliance with international aviation rules.

SOFIA follows a stepwise approach in its development. It is formed by four interrelated main steps that are complemented by the dissemination and exploitation activities:

  1. Assessment of the issues related with the operation of the FRF in airspace

    In this task, the air and ground system environment in which the FRF will be used is defined. The necessary procedures for the operation of the FRF including all air and ground (ATC) procedures will be detailed. The regulatory and certification frameworks will be assessed, identifying possible conflicts for the FRF operation.

  2. Design of the FRF system

    Here the specification and integration of the FRF on some typical avionic architecture that are anticipated for future aircraft will be examined. The design covers the three solutions: FPL generated and sent by ATC, FPL generated autonomously by FRF and station keeping.

  3. Development of the FRF system for enabling the validation exercises

    In this task, the simulation environments that allow FRF functional validation are set-up. This includes the adaptation of already available flight simulator components and the development of appropriate new mock-up components. The station keeping solution will not be developed.

  4. Validation of the FRF system and its integration into the airspace

    This will be performed by experimental validation in three steps:

    1. Preliminary validation on virtual GAL ATENA cabin simulator linked to the DFS ATC simulator, and a preliminary flight test (IoA);
    2. Final validation on THA cabin and UAV simulators;
    3. Experimental flight tests (DAI) linked to the DFS ATC simulator.


The main expected result from the SOFIA project is the development of a system that provides the airplane with the capacity to return automatically to the ground when an onboard hostile action takes place, e.g. hostile individuals have replaced the pilots. This assumes such hazards for which the activation of FRF is the only solution to avoid any major damage, not only to the aircraft and its passengers but also to the population and infrastructures on the ground.

Furthermore, FRF development poses a great challenge for European industry, ANSP and research centres because of the difficulties in carrying out such a system and integrating it in the airspace whilst maintaining safety levels in the aircraft operation. SOFIA will allow the aeronautical European community to acquire knowledge about the required techniques and solutions. Such developments will therefore enable the European industry to assume a leadership position to implement this kind of solution worldwide.

Validation resources
Validation resources