Aircraft Systems Flight & Engine Control Systems


Flight Control has a name: Diehl Aerospace

The Centre of Excellence (CoE) for flight control has long-time experience in the field of primary and secondary flight control. Among the CoE's tasks is the development of basic technologies as well as the processing of research and technology programs up to product development of flight control computers and systems for civil and military aviation.

Flight Control Systems

Slat Flap Control Computer (SFCC)

The system for the high-lift control developed by Diehl Aerospace consists of two computers, one flaps lever and associated sensors in the wings. The so-called Slat Flap Control Computer (SFCC) controls and monitors the slats and flaps during take-off and landing of the aircraft. This is realized by activation, control and monitoring of the actuators which move the slats and flaps. The so-called Flaps Lever situated in the cockpit is the man-machine interface of the system. The position sensors in the wings detect the exact position of the flaps and report the collected data to the SFCC.

As secondary flight control, the flight control system belongs to the safety-related devices of the aircraft. These devices are based on a redundant design. Thus, even if any given component malfunctions a secure landing is in each case guaranteed. The SFCC, built up redundantly, is present twice onboard at different positions. In case one computer detects an error, the system conducts an automatic change over to the other computer without hindering the functionality of the whole system.

With the start of the A340 program in 1988 Diehl Aerospace became a system supplier for the SFCC for the A330/A340 family.  Today, A340 is equipped with second generation SFCC. Diehl Aerospace already accompanied the development phase of Airbus A380 and A350. The A320 Family came into Diehl Aerospace’s portfolio within a modernization of its system. Diehl Aerospace is today a system supplier of all civil Airbus aircraft. Thereby, the requirements for the high-lift control developed significantly. The innovations onboard of A380 were the electric motors, the continuous speed control and the AFDX data bus. The A350 XWB features new actuators and position sensors which enable the independent positioning of the various flaps segments. Diehl Aerospace’s high-lift control met the increasing technical requirements of the aircraft manufacturers only by means of continuous development.


Components for the Flight Control Electronics

Actuator Control Electronics, ACE

Since 2004 Diehl Aerospace, in cooperation with Honeywell, has developed components for the Flight Control Electronics (FCE) package for the Boeing 787 Dreamliner. The FCE package consists, among others, of Flight Control Modules (FCMs), Actuator Control Electronics (ACEs), Power Conditioning Modules (PCMs), a Mode Control Panel (MCP), and Rate, Acceleration and Pressure Sensors. The FCE package integrates fly-by-wire primary flight control, high-lift control, autoflight, and processing of air data/inertial data for use by other airplane systems. These functions are integrated into a set of airplane modules providing a high-integrity, partitioned processing environment with redundant components providing high availability and autonomous backup control. The Flight Control Module provides digital processing functionality to support the high-integrity execution of the primary flight control, high-lift control, and autoflight software. Diehl, in cooperation with Honeywell and Boeing, developed and certified the high-lift software partition which provides control of the leading-edge and trailing-edge high-lift surfaces.

A total of four Actuator Control Electronics modules (ACEs) provide actuation control and interfaces to analog inputs such as pilot controls, rate sensors and accelerometers. The ACEs provide control of the aileron, flaperon, elevator, rudder, spoiler, leading-edge and trailing-edge surfaces along with interface to the captain’s and first officer’s column, wheel, and rudder pedal sensors. Two types of ACEs are incorporated – designated ACE 1 and ACE 2. Diehl Aerospace is responsible for the development and production of the ACE 2 hardware. The ACE 2 specifically provides the generic functionality of the interface and control to the primary surfaces (elevators, ailerons, flaperons, spoilers, and rudder) and their associated flight deck controls. In addition, the ACE 2 provides partial control of the flight deck actuators (spoiler handle drive and rudder trim), the interface to the stabilizer actuator and the actuation of the High-Lift Power Distribution Units.

As the FCE package (and within it the ACE 2) controls all primary and secondary surfaces (including High Lift), it belongs to the safety critical elements of the airplane. Therefore, each ACE 2 incorporates a redundant, self-monitoring design to meet the high integrity requirements. Two ACE 2 units together with two ACE 1 units provide the availability required for the airplane.


Flight Control Computer

Flight Control Computer

The Flight Control Computer (FCC) is the core element of the Eurofighter Typhoon fly-by-wire system. The FCC receives, and handles sensor data, pilot inputs and data for information exchange from other avionics equipment. Furthermore, the FCC computes and compares the commands to control the Eurofighter Typhoon and transmits the signals to the control surface actuators. Thus the FCC stabilizes and controls the aircraft and contributes to the Eurofighter Typhoon's outstanding flight performance, such as its agility and manoeuvrability. The safety-critical flight control system of the Eurofighter Typhoon consists of a quadruple redundant, highly reliable and fault-tolerant computer system with four FCCs. Each FCC is a complex real-time system with multiprocessor architecture and its own power supply. The different FCCs communicate via optical and electrical data buses.


Stick Sensor and Interface Control Assembly

Stick Sensor and Interface Control Assembly

The Eurofighter Typhoon is steered by a central pilot stick, the so-called Stick Sensor and Interface Control Assembly (SSICA). The amplitudes of the pilot stick correspond to the electrically generated quantity of control signals. Via a complex spring/damper system, the stick is reset to its neutral position without noteworthy overshoots. For the quadruplex fly-by-wire system of the Eurofighter Typhoon, this system does not only quadruply record control inputs of the pilot and transmit them to the flight control system, but also picks up and collects other cockpit-operating information that is sent to the flight control system.


Versatile Electronic Control Box

Versatile Electronic Control Box

The abbreviation VECB denotes a universal engine control system for auxiliary power units. It controls and monitors the auxiliary power units in the aircraft of the Airbus A320 family and the A330/A340 family. The VECB is a versatile system, meaning that the same unit can control different types of single engine families without substantial modifications. Furthermore, the VECB is equipped with an overspeed protection mechanism, which protects the engine against fatal damages in case of failure. A key advantage of this system is that modifications can be made to other engines with a minimum of effort. Diehl Aerospace is system supplier for the VECB.


Digital Engine Control Unit

Digital Engine Control Unit

The DECU is the Digital Engine Control of the Tornado. The system has two redundant channels: one for basic engine control and another for afterburner control. Both channels have self-monitoring functions, meaning that only one of the two redundant channels can activate fuel metering. Should this channel fail or malfunction, the system automatically switches over to the second stand-by redundant channel. In the event of a malfunction, the afterburner channel reverts to fixed default values. Diehl Aerospace is also responsible as system supplier for the DECU.


Engine Control and Monitoring Unit

Engine Control and Monitoring Unit

The Tiger operates with two engines driving the rotor through a joint gear. Each engine is equipped with one Engine Control and Monitoring Unit (ECMU). They communicate with each other continuously and, in the event of an engine failure, switch the remaining engine over to emergency mode. The ECMU is designed as a simplex controller with manual back-up and an independent, dissimilar overspeed and shaft break detection unit which was developed by Diehl Aerospace. In this form, it is being used for turbo shaft engines for the first time. The Diehl Aerospace ECMU offers excellent electromagnetic compatibility and effective lightning protection.