2015-08-21
438
1. Plumes of volcanic ash near active volcanoes present a risk especially for night flights.
2. Prior to the European air travel disruption of April 2010, aircraft engine manufacturers had not defined specific particle levels above which engines were considered to be at risk.
3. The April 2010 eruptions of Eyjafjallajökull didn't cause sufficient economic difficulties that aircraft manufacturers were forced to define specific limits on how much ash is considered acceptable for a jet engine to ingest without damage.
4. From noon 18 May 2010, the CAA revised the safe limit downwards to 3 mg per cubic metre of air space.
5. Volcanic ash in the immediate vicinity of the eruption plume is of an entirely different particle size range and density to that found in downwind dispersal clouds which contain only the finest grade of ash.
Exercise 4. Finish the sentences.
1. The ash is hard and abrasive and can quickly cause significant wear on...
2. In 1991 the aviation industry decided to set up Volcanic Ash Advisory Centers (VAACs), one for each of 9 regions of the world, acting as liaisons between...
3. From noon 18 May 2010, the CAA revised the safe limit upwards to...
4. In order to minimise the level of further disruption that this and other volcanic eruptions could cause, the CAA announced the creation of a new category of restricted airspace called...
5. Any airspace in which the ash density exceeds 4 mg per cubic metre is categorised as...
6. It is important to make a distinction between flight through (or in immediate vicinity of) the eruption plume and flight through so-called...
