FADEC

A smart computer runs plane engines.

Long ago, pilots used levers. These moved parts to control fuel. Now, a computer does the work. It watches the engine many times a second.

The computer looks at air and heat. It uses this to make the engine work well. It even helps start the engine.

This system keeps the engine safe. It stops the engine from getting too hot. It can use two computers to stay safe.

This helps the plane fly smoothly. It is a very clever way to fly.

A FADEC is a smart computer for plane engines. FADEC stands for full authority digital engine control. This system manages how an engine works.

Long ago, pilots used levers to move parts. These parts changed how much fuel the engine used. Now, a computer does this work. The computer is called an EEC. This stands for an electronic engine controller. It is a part of the FADEC system.

The EEC watches the engine many times a second. It looks at things like air density and heat. It also checks engine pressure. The computer uses this data to make changes. It can change fuel flow or air valves. This helps the engine run with the best efficiency. It can even help start the engine.

Safety is very important for planes. A FADEC can be programmed to stay safe. It will not let the engine get too hot. To prevent errors, these systems use redundancy. This means they use two or more identical computers. If one part fails, the other can still work. This helps the plane fly safely.

A FADEC is a smart system for aircraft engines. It stands for full authority digital engine control. This system uses a digital computer to manage an engine. This computer is called an electronic engine controller, or EEC. The EEC is a key part of the whole FADEC system.

The main goal is to make engines run with maximum efficiency. This means the engine uses its energy in the best way possible for any flight condition.

How does this system work? The EEC acts like a very fast brain. It receives many pieces of information many times every second. It looks at air density and engine temperatures. It also checks engine pressures and where the power lever is set. The computer analyzes this data up to 70 times per second.

Then, it makes quick changes. It can adjust fuel flow or move air valves. It even handles starting and restarting the engine.

Engine control has changed a lot over time. Long ago, pilots used simple mechanical linkages. They moved levers to physically change fuel flow and power. Later, engineers used analogue electronic control. This used electrical signals but had issues with noise. In 1968, Rolls-Royce and Elliott Automation tested a digital system.

In the 1970s, NASA and Pratt & Whitney experimented with FADEC on an F-111 plane. These tests led to many modern engines used today.

Many important engines use this technology. The first FADEC in service was for the Rolls-Royce Pegasus engine. This engine was used for the Harrier II aircraft. Pratt & Whitney made the first military engine with FADEC, the F100. They also made the PW2000 for civil use.

The PW4000 was the first commercial engine to use a "dual FADEC" setup. These systems are very complex and require special engineering to build.

Safety is the most important part of flying. Because computers control the engine, they must be very reliable. FADEC uses redundancy to stay safe. This means it uses two or more identical digital channels.

If one channel fails, the other can still do all the work. The system can also be programmed to prevent mistakes. For example, it can stop an engine from getting too hot. This helps the pilot focus on flying while the computer keeps the engine healthy.

A Full Authority Digital Engine Control, known as FADEC, is a sophisticated system used in aviation. It manages every aspect of an aircraft engine's performance. The system consists of a digital computer called an Electronic Engine Controller (EEC) or an Engine Control Unit (ECU). It also includes various related accessories. The primary goal of a FADEC is to ensure the engine operates at maximum efficiency for any given flight condition. This technology is applied to both piston engines and jet engines.

The mechanism of a FADEC is incredibly fast and precise. It works by constantly receiving multiple input variables from the aircraft. These inputs include air density, engine temperatures, and engine pressures. It also tracks the position of the power lever requested by the pilot. The EEC analyzes this incoming data up to 70 times every second. Based on this analysis, the computer computes necessary changes to operating parameters. It can adjust fuel flow, the position of stator vanes, or the position of air bleed valves. The system even manages the processes of starting and restarting the engine.

There are important distinctions between different types of engine control systems. Originally, engines used simple mechanical linkages. Pilots or engineers moved physical levers to control fuel flow and power output. Later, engineers developed analogue electronic control. This used electrical signals to communicate settings but suffered from electronic noise and reliability issues. A true FADEC is unique because it has "full authority." This means there is no manual override for the engine's operating parameters. If a system allows for manual intervention, it is simply called an EEC or an ECU. An EEC is a component of a FADEC, but it is not a FADEC on its own.

The history of this technology shows a steady move toward automation. In the 1960s, full authority analogue control was used in the Concorde's Olympus 593 engine. However, the digital era began to take shape in 1968. During that year, Rolls-Royce and Elliott Automation tested a digital system on a Rolls-Royce Olympus Mk 320. In the 1970s, NASA and Pratt & Whitney conducted experiments with a FADEC on an F-111 aircraft. These experiments led to the Pratt & Whitney F100 and the PW2000 becoming the first military and civil engines with FADEC. The first FADEC to actually enter service was for the Rolls-Royce Pegasus engine used in the Harrier II.

FADEC provides several significant advantages for modern flight. It offers automatic protection against operating outside of safe limits. For example, it can be programmed to prevent an engine from exceeding specific temperatures. This happens automatically without any pilot intervention. The system also allows for "care-free" engine handling, which guarantees specific thrust settings. It enables manufacturers to use a single engine type for many different requirements just by reprogramming the software. Additionally, the number of parameters monitored by the system increases by an order of magnitude. This reduces the workload for flight crews, as they no longer need to monitor every small detail manually.

Safety is a critical concern when automation controls an engine. To prevent a single point of failure, FADEC uses redundancy. This means the system includes two or more separate but identical digital channels. Each channel is capable of providing all engine functions without restriction. This creates a "fault tolerant" system, which can continue to operate safely even if a fault occurs. However, total failure is a serious risk. If a total FADEC failure occurs, the engine fails. In such a case, pilots have no manual controls for throttle or engine restarts. One notable incident occurred on 9 May 2015, when an Airbus A400M crashed in Seville, Spain. This crash was caused by incorrectly installed engine control software.

FADEC technology connects deeply to the field of systems engineering. Because these systems are safety-critical, they require formal engineering processes to design and test. Engineers use specialized tools like Model-Based Systems Engineering (MBSE) to develop the software. An example of such a tool is SCADE, which is used for application development. Modern research is even looking at new ways to organize these systems. NASA has analyzed a distributed FADEC architecture for helicopters. This would move away from the current centralized architecture to provide more flexibility and lower costs.