Posted on: 09 June 2015 by Mark Howells
ATR is about to begin the first phase of its flight test campaign on an ATR 72-600 prototype designed in response to standards laid out by the EU’s consortium for green aviation, ‘Clean Sky,’ which was launched in 2008.
In this first phase, ATR’s Clean Sky modification is structural. The ‘Upper crown panel Section 13’ of the prototype’s fuselage, which measures 7 m², is made of a new composite material created especially by SITEC.
The panel, which would traditionally be made of aluminium, has been fitted with approximately 130 vibro-acoustic and fibre-optic sensors to measure the noise emitted by the composite material. The result will be compared to the noise emitted by a 72-600 with an aluminium panel, which ATR confirmed completed testing in February this year. The respective aircraft will also be compared in terms of weight and fuel consumption.
The aim of the newly-installed sensors is also to undertake what ATR is referring to as Structural Health Monitoring (SHM) in a bid to improve the aircraft’s maintenance processes and increase the life-cycle of the fuselage. In this respect, they will be able to determine whether the composite panel suffers from delamination, whereby repeated impact can cause composite material to separate and lose its toughness.
During the tests, the results will be monitored by two teams, a flight test engineering station on board the aircraft as well as another team on the ground.
The second modification to the prototype, which will be carried out between the end of 2015 and the beginning of 2016, will see a move towards the all-electric aircraft. The OEM explained that there is not currently enough power available on commercial aircraft due to components like the air conditioning – which is currently a bleed system – using up 10% of power created by the engine. This is the reason the company is in the process of creating an all-electric system.
ATR went on to say that not using the engine power for its purpose, but for different tasks, is causing unnecessary pollution. This finite power resource is why it’s necessary to implement an energy management system which means aircraft parts are only using energy when they need to. The engineering team described it as being like a lightbulb, but said a similar system probably wouldn’t be installed on aircraft until 2030.
Ironically, to ensure the safety of the flight tests, ATR has to replace the two 20 kilovolt-amp (KVA) generators on board with 40 KVA generators as well as implementing a new 270 volt DC power supply. One of ATR’s engineers says in the future there is the possibility of an aircraft containing a 25 KVA generator, but no more than that.
The OEM claims it will be the first regional aircraft manufacturer to take flight with its Clean Sky programme after other companies began delaying the launch of their campaigns. However, at present, the company described it as a business case. The cost implication of using composite materials is huge, so it will be interesting to assess the benefits for regional aircraft. One engineer said it could be useful for determining new aerodynamic structures and assessing how to use carbon fibre in the next generation of new aircraft (but that will be 20 years from now…).
Stephanie Taylor, editorial assistant, Low-Fare & Regional Airlines/LARAnews.netToulouse, France