With AIN Media Group's Aviation International News and its predecessor Aviation Convention News celebrating the company's 50th year of continuous publication this year, AIN’s editorial staff is going back through the archives each month to bring readers some interesting events that were covered over the past half-century.

REWIND (May 2010): Ash from a volcano in Iceland brought disruption to European air transport last month on a scale that far exceeded the combined efforts of global terrorism and the financial crisis. Huge swaths of the continent’s airspace were closed for prolonged periods and hundreds of thousands of travelers were stranded at various points around the world for days on end.

Business aviation, though generally hailed as the traveler’s flexible friend, also was just about brought to its knees in Europe. Due to the sheer unpredictability and complexity of airspace access rules, bizjets and even pistons were able to make only limited use of opportunities to conduct VFR flights in low-level uncontrolled airspace. Helicopters found themselves constrained too but were able to conduct some flights to assist stranded travelers.

Almost a week into the emergency, a core tension emerged between the understandable caution of technical experts anxious to avoid allowing potentially unsafe flying and the seemingly more pragmatic approach of political leaders desperate to end the social and economic paralysis.

FAST-FORWARD: In a then-unprecedented situation, aircraft operators were given just a few hours' notice of the impending airspace shutdown on April 15, 2010 following the eruption of the Eyjafjallajökull volcano which ejected a massive ash cloud that led to the closure of most of the European IFR airspace until April 20. While volcano eruptions are not common occurrences, they normally only affect areas where air traffic is light and airspace is uncongested. However when Eyjafjallajökull erupted, it impacted some of the world’s most congested airspace, and International Civil Aviation Organization guidance at the time was for operators to avoid any amount of ash, regardless of concentration. Because of that, UK air traffic control announced that it would not provide clearance for flights in contaminated airspace, a measure soon adopted by other European countries. With guidance from hundreds of experts, the necessary data was amassed for the basis of the new guidelines which were put in place.

Those measures were tested the following year with the eruption of Iceland’s Grimsvotn volcano. This time, the aviation industry was better prepared. All the main players were involved in daily teleconferences and the new three-zone system was brought into play. All airline companies had to establish a safety case if they wanted to operate in areas of medium or high-density ash. The new zoning system meant operators had more freedom to operate in higher areas of ash than they had during the eruption of 2010. The Grimsvotn ash disruption lasted only a few days and its effects were much less widely felt than in the previous event.