Continuing on from my previous post covering technical visits to Airbus, Eurocopter, and CRNA, I will cover here some of the other visits our group made during our study abroad program in France. The program is now complete, but I will only cover here two of the four last visits so that the post is not too lengthy. Thus, here are some insights into CESNAC and Liebherr.
CESNAC
CESNAC, or the Centre d’Exploitation des Systèmes de la Navigation Aérienne Centraux, based in Mérignac, France outside of Bordeaux, is a core organization in the French air traffic control system. It is tasked with managing all traffic systems and data for France along with providing all necessary data for CRNA, the French air traffic control centers. In addition, the group collects traffic statistics, compiles flight information in order to calculate route charges, performs airspace modifications in conjunction with air operators, and updates navigational and aerodrome data every 28 days. In summary, CESNAC acts as the interface between the French national air traffic control system and Eurocontrol, the organization that oversees all intra-European air traffic.
Flight plan processing is a complex and bureaucratic process
One of the other major tasks that CESNAC handles is flight plan processing and modification. The life of the flight plan, described to us by our guides and illustrated here on the right, is a complex and seemingly bureaucratic process, but for now it does the job. In short, the air operator files their flight plan with Eurocontrol, who forwards it on CESNAC, and who forwards it to CRNA before it is returned to CESNAC. During the flight, CRNA sends updates to the flight plan to CESNAC. After the flight is complete and the flight plan is closed, the data is archived and later analyzed by the Route Charge Office, who bills the operator based on the aircraft weight and the route of flight.
How much are these route charges? It is probably more than you think. Our guides gave us a sample route charge, using an Airbus A320 flying a route between Charles De Gaulle Airport in Paris to Bordeaux. The en-route portion of the charge was 412€, while the approach segment cost 268€, coming to a total of 680€ for the 284 nautical mile flight that lasted less than 1 hour. Again, the charges are based on the aircraft weight, so a lighter aircraft would pay less. But still, it is quite a significant charge.
The large majority of flight plans are processed automatically, but roughly 5% of plans, or roughly 200 per day, must still be approved manually. These flight plans typically deal with general aviation and military traffic, which run on unpredictable schedules and lesser-flown routes when compared to the large airlines, who have very predictable traffic flows, schedules, routes, etc. Our group was granted a live demonstration of this in the control room at CESNAC. First, the controller receives the flight information at his desk from the respective CRNA center. In 3 minutes, he must consult departure, en-route, and arrival airways charts to determine the best flight path for the aircraft to take. In some cases, the controller simply allows the aircraft to fly a direct route without any additional checkpoints in between. Personally, I was surprised how trivial and manual the process was, and that it still requires human eyes to be completed.
LIEBHERR
Our next tour took us to Liebherr Aerospace Toulouse, a division of the Liebherr Group. It is a multifaceted and diverse company, but it’s aerospace business primarily deals with the manufacturing of landing gears, flight control systems and actuators, and air management systems. The overall company employs 34,000 people worldwide and earns 8.4€ billion in revenues.
This particular site in Toulouse employs 1,000 people and earned 350€ million in 2011, enjoying steady growth since 2005. The principal activity is the manufacture of air management systems for a large base of aerospace customers. These parts include heat exchangers, bleed air controls, ventilators, humidifiers, heaters, wing anti-ice systems, cabin pressure controls, chillers, and avionics/supplemental cooling systems. The parts are largely under Liebherr’s control, as the company conducts everything from design to manufacturing, integration, and aftermarket customer service and support. Additional capabilities include research and development (which receives 25% of the revenues), project management, quality control, machining, and assembly. Our guides noted that Liebherr’s large focus on R & D is driven by market forces, since high oil prices have created a demand for more environmentally and fuel-efficient products and processes. While Liebherr enjoys good business, it does admit that it sees challenges in competing more with its American counterparts, Honeywell and Hamilton Sundstrand, along with establishing a larger footprint in military and automotive markets.
A typical schematic for a bleed air system (click for larger size)
So what does an “air management system” consist of? Basically, it controls the flow of air for all devices that require air to operate, called pneumatic devices. This consists of systems like air conditioning and anti-ice systems on the flight control surfaces. This is traditionally accomplished by diverting hot and pressurized air away from the compressor section of an engine, called “bleed air”, and distributed to wherever it is needed. However, there is a growing trend towards “bleedless systems” (see the last paragraph of an earlier post here) that eliminate the need for bleed air and replace it with engine-driven motors that power air pumps. As a result, less air is diverted away from the engines, increasing their efficiency and creating a simpler system. When asked about this growing trend, however, our Liebherr guides noted that the new Boeing and Airbus narrowbody aircraft, the 737MAX and A320NEO respectively, do not incorporate bleedless systems and thus the true advantage of the systems can be called into question. Nevertheless, their official 20-year forecast sees a significant decline in bleed air components.
Lastly, our group witnessed the heat exchanger production line, where Liebherr manufactures 6000 of them per year. The general shape is formed from the raw material, and afterwards it is sent through surface and heat treatments. Next, the product undergoes an inspection program with a water test to check for leaks and an ultrasonic tests to detect any defects in the material. Additional tests are carried out in altitude chambers to simulate operations in high-altitude and cold conditions and to verify the performance of the heat exchanger. Finally, the part goes through final assembly, is installed, and sent to the customer.
The last post of this series will give a summary of my visits to Safran Herakles and ATR. Keep a look out for it soon!
