NLR News | Dedicated to innovation in aerospace

8 May 2013 by jcvenema

Dutch research organizations sign agreement with COMAC from China

COMAC-logo The German-Dutch Wind Tunnels (DNW), the National Aerospace Laboratory (NLR) and Delft University of Technology (TUD) signed this week a cooperation agreement with COMAC-BASTRI during the economic mission to China. BASTRI is the research branch of Chinese aircraft manufacturer COMAC (Commercial Aircraft Corporation of China). The strategic cooperation covers a period of ten years. It is a good example of cooperation between Dutch scientific, research and knowledge organizations in their efforts to jointly enter into cooperation with foreign R & D institutes. The cooperation also involves participation of Dutch industry.

The Sino-Dutch cooperation includes joint R & D in the field of materials and new wind tunnel applications. In addition, the parties agreed to join efforts in the realization of a joint EU framework programme participation. In addition, the agreement includes consultancy, where knowledge and advice on projects and goals is transferred between the organizations. Also included in the agreement is exchange and training of researchers. Another part of the agreement is that parties can use each other’s facilities. Finally, at least once a year a Joint Cooperation Meeting will be organized aiming at strengthening the relationship, formulate new goals for cooperation and to discuss the progress of the projects.

NLR - COMAC-BASTRI

2 May 2013 by jcvenema

Early planning prevents delays

Fixed Flight Speed

The punctuality and capacity of an airport can be improved and increased by giving pilots early information of their expected arrival time.

Efficiency is very important in the air transport industry, because it has both environmental and economic benefits. The greater the predictability of air traffic, the less aircraft need to manoeuver which leads to inefficiency, which often leads to delays and knock-on effects for following traffic, including increased fuel consumption. As part of the Single European Sky ATM Research (SESAR) project, NLR assessed whether predictability could be improved by providing pilots approaching Amsterdam Airport Schiphol with fixed flight speeds. Simulations completed in 2012 revealed that this would indeed result in more predictable traffic flows.

This study of smarter arrival management (AMAN) applies for all airports, but is especially relevant for Schiphol. Dutch airspace is small, which means Air Traffic Control the Netherlands (LVNL) only contacts arriving aircraft when they have already begun to make their descent over Belgium or Germany. In most instances, it is only then that the anticipated arrival time of the aircraft becomes clear. But there may also be other aircraft waiting to use the same runway at that time, which may hamper efficiency.

One possible solution would be a data link between LVNL and Eurocontrol’s Maastricht Upper Area Control Centre (MUAC) in Limburg, which controls air traffic over most of Northern Europe. Based on the characteristics of the approaching aircraft, its flight schedule and the meteorological conditions, LVNL could relay information to aircraft via MUAC, stipulating preferred speed before they enter Dutch airspace.

To make this test possible, LVNL’s next generation AMAN was tested using NLR’s NARSIM simulator. The simulation was based on scenarios of heavy air traffic that had actually occurred, with dozens of flights approaching every hour. So-called pseudo-pilots played their real alter-egos, and the roles of LVNL and MUAC staff were also simulated. The study revealed that this method offered a better means of precisely stipulating the arrival of flights at Schiphol. This broadening of the planning horizon will not only benefit Schiphol, but also other European mainports.

Also visit our ATM and Airports capability page.

17 Apr 2013 by jcvenema

An academy for UAS pilots

UAS training

NLR assessed the feasibility of a training academy for operators of unmanned aerial vehicles, which are on the brink of a major breakthrough, according to aviation analysts.

The potential applications of unmanned aerial systems (UASs) are growing exponentially, not only for military operations, but especially for civilian purposes. UASs are already being deployed by corporations and governments for the inspection of pipelines and wind turbines, for instance, but also for monitoring football matches and other major events, and for the early detection of forest fires. The key benefit of UASs is that their sensors can be flexibly deployed in poorly accessible or hazardous locations. UASs are better suited to such tasks than cranes, for instance, or manned aircraft and helicopters.

As the market for UASs has grown, there has been an increasing need for regulation, safety standards and training. NLR conducted an economic and substantive feasibility study for the proposed establishment of a training center for UAS pilots. The study, concluded in 2012, confirmed that an academy of this kind is feasible.

The project, dubbed Unmanned Aircraft Systems Training Academy (UTA), encompasses all aspects of UAS operations. These may be subdivided into two categories: the one entails flying over built-up areas, while the other covers operations over less risky terrain. The trainees must be comprehensively instructed in both the theoretical and practical aspects of working with unmanned aerial vehicles. This program will include simulator training as well as flights with real UASs.

The study was conducted in collaboration with the World Class Aviation Academy, AEC Air Support, the Midpoint Brabant regional development organization, and Gate2. The latter party was involved because the proposed location for the new academy is the town of Rijen, in the Dutch province of North Brabant. Gate2 is teaming up with businesses and knowledge institutes to establish, among other things, new aviation-related commercial and innovation projects. One example is the Rotary Wing Training Center that opened in 2011 on the Gate2 business park next to the Gilze Rijen airbase. Chinook technicians from around the world are also trained here in close cooperation with Boeing. Other innovative projects focus on new materials, digitized maintenance, simulation technology and other aviation-related developments. NLR participates in a number of these projects.

The UTA will initially focus on training for civilian UAS operations, including those in the safety domain. Training for military operators will later be included in the curriculum.

NLR is the Netherlands’ leading institute for conducting feasibility studies of the kind, having gained extensive experience in the training of police officials, for instance, but also in the technical and regulatory aspects of UAS operations. NLR’s expertise in these fields also extends beyond the national borders to markets elsewhere.

Also visit our Modelling and Simulation capability page.

8 Apr 2013 by jcvenema

Improved flight safety small helicopters

Simulated flight into the mist

NLR conducted intensive research to assess how innovative visual concepts could improve the flight safety of small helicopters to the desired standard.

European and American aviation authorities agree that the flight safety of small helicopters is not improving quickly enough. They encounter problems with alarming regularity, especially when visibility is poor. The majority of helicopters in this class are not equipped with the avionics that ensure safe flight under such conditions, or the pilots are insufficiently experienced or trained to use such equipment effectively. NLR conducted a risk analysis in 2012 and identified a number of technical solutions that might reduce the risk.

Based on an extensive analysis of numerous cases, two types of common accidents or incidents were identified. The first type occurs when poor weather causes the pilot to lose sight of the ground and steer the helicopter incorrectly, often with fatal consequences. The second type is almost the same as the first, except that the pilot takes no corrective measures at all, with similar consequences.

NLR proposed four possible solutions, or concepts, that require only minor adjustments to the cockpit. Three of these concepts are optical, while the third one is acoustic.

NLR technicians first modified the Helicopter Pilot Station (HPS) so that this simulated cockpit environment matched that of smaller type helicopter, which was the study’s specific area of interest. Subsequently, a number of pilots who were inexperienced with instrument flying were tested in various scenarios. This included flights in swiftly changing weather or visually challenging circumstances in wintery, mountainous terrain. Without extra technical modifications, it quickly became clear how real the risks were, with some pilots suffering virtual crashes.

Peripheral horizon for small helicopters

One of the technical solutions that NLR proposed was the so-called Heads Up Display Orange Peel, whereby symbols were projected on the canopy to indicate the position of the horizon and whether the helicopter was descending or ascending. Other potential solutions were the Malcolm Horizon, which is a horizon line projected inside across the entire canopy, and the Peripheral Horizon, consisting of strips of LED lights that help to improve the pilot’s situational awareness and thus reduce accident risk.

The Helicopter Terrain Avoidance Warning System used a computer-generated voice to automatically warn the pilot when the helicopter was at risk of encountering a dangerous position in relation to the terrain.

The HPS was then modified for further test flights, during which pilots could assess which of these measures was most effective. The conclusions of this study have now been shared with the client, the European Aviation Safety Agency (EASA), which means that industry can be approached to further develop the most promising solution.

Also visit our Rotorcraft Flight Procedures capability page.

22 Mar 2013 by jcvenema

European Clean Sky Open Rotor test campaign in the DNW LLF completed

CROR model in the DNW-LLF

Late January 2013, Airbus successfully completed an extensive test campaign in the DNW-LLF wind tunnel under the European Clean Sky program.

Worldwide a large demand for more economical aircraft exists, for environmental reasons as well as the need for airlines to improve their profitability. All aircraft and engine manufacturers are investing in more economical gas turbines and improved propulsion on aircraft. The next generation of aircraft will consume less fuel, thanks to new gas turbines or a new entrant: the “Counter Rotating Open Rotor” (CROR).

As the demand for more economical aircraft will remain high in the near and distant future, research is conducted into the next generation of aircraft in two Integrated Technology Demonstrators of the European Clean Sky program. Application of a CROR will have to further reduce fuel consumption for these aircraft. A CROR has two series-mounted rotors which rotate in opposite directions.

Adjusting the CROR model

Purpose of the second rotor is to undo the rotating motion of the air originating from the first rotor. In addition, the propulsion efficiency of a CROR is high due to its high by-pass ratio. A point of attention for the CROR is rotor noise, especially during takeoff and landing. In the European Clean Sky program the step by step research conducted will possibly lead to introduction of CROR propulsion on passenger aircraft. A first step in the development is theoretical work, the second wind tunnel measurements. For measurements in the low-speed range the DNW-LLF has been selected.

The test
The test campaign was launched in April 2012 and consisted of three test programs. The first test was performed with the engine in the LLF open test section. The second (Handling Quality) test took place on the complete model (aircraft plus engine) in the closed test section. The third test was executed with the complete model in the ‘open test section’. The measurements took hundreds of hours and resulted in many terabytes of data.

CROR balance and telemetry unit

The CROR wind tunnel model
The CROR wind tunnel model is designed by Airbus in cooperation with NLR and DNW. The model is a complete aircraft scale 1:7 with two air-powered engines. For these engines, with a maximum of 8400 rpm, Airbus designed and built the air motor. NLR designed and produced the composite propellers and rotating measuring balances. Besides propeller blades for the Airbus model, also propeller blades are designed for other engine manufacturers.

Telemetry Units
NLR designed and built rotating Telemetry Units. These Telemetry Units measure and digitize the sensor signals on forces, temperatures and pressures in the blades and balances. The measured data is transferred contactless from the rotating part to the fixed part.

CROR Model Instrumentation System

Model instrumentation system
Besides the Telemetry Units, NLR developed an acoustic measurement system with components in and outside the model. Sensors in the propeller blades were also part of this acoustic measurement system. The measurement of the data of the connected pressure sensors and microphones took place with a high degree of synchronization (deviation less than 1 microsecond). The Model Instrumentation System comprised the entire chain of data acquisition, processing and registration. An Operator Station provided the test specialists with an impression of the measurement results and allowed for monitoring of critical parameters.

Epilogue
All stakeholders are proud of the fact that the test campaign was very successful. The follow-up is now in the hands of (acoustic) specialists from Airbus and the engine manufacturers. Their first challenge lies now in interpreting the many Terabytes of data.

The results are of great importance for further development of the CROR concept in Clean Sky 2.

Also visit our Avionics Development, Wind tunnel models, Wind tunnel equipment and Flight Physics capability pages.