Reliable Systems for Small Engine

The main goal is to develop technologies for digital electronics and control software for integration with aircraft (a/c) cockpit and on-board diagnostics. The specific innovative technical solutions will be focused on affordable full-authority engine control system (Engine Electronic Control - EEC/ Full Authority Digital Engine Control - FADEC) which will be based on COTS components (Commercial-Off-The-Shelf).
The engine control will be supported by innovative sub-systems (fuel metering pump, propeller governor based on BLDC technology, MEMS power generation, etc.) and their embedded control and monitoring of engine parameters. Integration of propeller and fuel metering control systems together with EEC/FADEC can reduce engine fuel consumption by 4 – 8 % and decrease aircraft operating costs.
Activities will focus on principles of engine diagnostics and engine health monitoring.  The smart engine diagnostic and health monitoring system for small aircraft engines will enable engine on-condition maintenance. This can bring significant effects in terms of engine TBO prolongation and maintenance costs savings.
The EEC/FADEC, engine diagnostics based on on-board wireless technology lead to decreased ratio of engine and accessory weight to aircraft weight (wire weight reduction), decreased costs for maintenance, installation, and increased engine life. 


Advanced automatic control system for small engines (WP4.1)
Affordable and reliable solutions for propulsion units of small airplane and rotorcraft in regulatory category CS-23 require the adoption of new advanced technology from transportation aircraft (fly-by-wire, power-by-wire, wireless, modular integrated and distributed control concepts, etc.) with respect to reliability and safety requirements. The EEC/FADEC is an extremely price sensitive item, which has a limited usage for small aircraft so far. To meet price expectations it is necessary to investigate COTS-based HW/SW control components and components based on MEMS technology for energy harvesting and scavenging. Wireless sensors will be analyzed and validated. The ESPOSA will also deal with reusable HW/SW components (embedded reliable real time operation systems – RTOS based involves define/redefine SW artifacts in accordance with Design Assurance  Level (DAL) partitioning, FPGA for HW modification, etc.)
The work will deliver the cost effective solution for new components and systems. Aircraft producers expect the serial price of EEC/FADEC for small engines (gas turbine baseline engines BE1, BE2) to be 1/10 - 1/15th of the engine price. Nowadays, the standard price of an EEC/FADEC is around 1/5th of the engine price.
The EEC/FADEC interfaces for cockpit instruments, single power lever engine control, adaptive and model based (predictive) distributed fault tolerant control will effectively reduce pilot workload by 10-20%. An improved level of operational safety, emergency procedures and reliability are made possible by EEC/FADEC redundancy, embedded diagnostics of engine and engine subsystem (BITE), new reliable engine fault diagnostics and health monitoring and backup power supply (sustainable MEMS based generators).

Smart health monitoring system (WP4.2)
Maintenance costs account for about 20% of an aircraft’s overall expenses per flight hour. The current engine health monitoring systems are practically not used for small aircraft due to their high acquistion costs. An on-engine/on-board sensing system enables condition based maintenance. Being able to go to on-demand maintenance vs. schedule maintenance saves costs because the maintenance crews will not have to inspect all components in fixed intervals. Traditional HUMS installations with sensors, wires and boxes on-board of aircraft consume a higher percentage of the aircraft value and available payload. With the smart health monitoring system (HUMS “light”) technology the HUMS installation costs and weight will significantly come down and be comparable to the percentage of the aircraft value and available payload of intermediate to heavy aircraft.
The overwhelming motivation for going to a wireless sensor network (WSN) is to reduce the number of wires (installation cost) and wire weight on the engine/aircraft. For a mid-size helicopter a wireless sensor network is estimated to reduce the weight by 15-30 kg per aircraft and the installation time from 3-4 days to 1 day. It is also much easier to add new or temporary sensors. This is especially important for small engines since they are not equipped with the same amount of sensors as big engines and for retrofitting of existing aircraft/engines with smart health monitoring systems. Small innovative sensing combined with energy harvesting solutions is a key enabler for smart wireless health monitoring systems for their penetrating into small aircraft sector.
Such smart health monitoring system will be applicable for affordable engine health monitoring system, mainly to provide engine data for low cycle fatigue analysis for predicting rotating component structural life to extend mean time between component removals.  The innovative and affordable engine health monitoring system tailored for small aircraft may be the major contributor to the reduction of engine maintenance costs and significant prolongation of TBO intervals, contributing significantly to DOC reduction.

Affordable more electric solution for fuel and propeller control systems (WP 4.3)
The RTD work will concentrate on affordable technologies for decentralized solutions of fuel and propeller control systems with novel electric actuation systems and integrated electronics with the self diagnostics tools and back-up algorithm to decrease the overall maintenance costs. Developmental work will cover activities aimed at novel heat resistant control system of Brushless DC motors (BLDC) motors.
Modern electrical distribution (fly-by-wire concept of More Electrical Aircraft - MEA) is more practical and offers easy reconfiguration of systems (EHA, EMA). Electric actuation brings advances in efficient aircraft systems maintainability (faster aircraft turnaround and improved fault diagnosis based on built-in test (BIT)) and installation, operational and maintenance costs (fewer mechanical components and fewer spares and tools are needed). It also brings potential benefits in improved reliability (improved MTBFs) and reduced system weight. Weight reduction by 10% is estimated.