Is the flight ban really needed? David Bentley argues no and Chris Yates argues yes

WE FEEL that the lock-down is a massive overreaction to the situation by super-cautious politicians and bureaucrats who are far more concerned about their own liability. We feel they could have approached this in a different way and possibly worked on keeping some the aircraft in the skies.

We believe that, at the moment, it's a big story, a natural incident the likes of which we've never seen here. So if it lasts a day, then although it is a massive inconvenience, most travellers will get on with it; but if it drags on, people will start looking at it in a different way. Just look at BA, with the problems it has had. It is expected to lose 800 million in the financial year that's just ended as it is, and it has just had the strikes and now its planes are grounded.

BA is not alone in being an airline that could be badly affected by this if it drags on, and Icelandic volcanos have a habit of doing that. So we feel we have to put the question about what will happen if airlines have to shut down for three or four days.

The problem is that the authorities have set a benchmark by grounding everybody. If we look at the Vatnajokull eruption in Iceland in the 1990s – a similar event under a much bigger glacier – it was handled in a different way, resulting in minimal disruption. It certainly did not lead to region-wide closures of airspace.

Such has the paranoia around safety and security grown since 9/11. Airline management will be hoping the ash – and the attendant paranoia –settles quickly.

David Bentley is a European associate of the Centre for Asia Pacific Aviation.

ONE analyst, David Bentley, yesterday queried whether the aviation lockdown was an overreaction by paranoid politicians. Here, he argues his case with a fellow expert who says the ban is vital for safety:

WE can't take risks with the safety of people in the aviation world and the decision to ground flights has come from an abundance of caution borne out of hard-won experience. This is a significantly large ash cloud of sufficient density to give rise to safety concerns and it is prudent that much of the UK remains closed to the world.

While we know where these clouds are moving, we don't necessarily know what the clouds contain. However, the evidence suggests that they do contain rock and glass particles and so on, which, when they are ingested into engines in significant amounts, will shut them down.

I accept that the financial impact on airlines is already hard – if we take a terrorist incident as an example of the cost to the aviation industry, the conservative estimate for the price of one day's partial grounding, such as happened with the liquid bomber in 2006, was a collective loss for the airlines of between 400m and 500m.

But even with that in mind, aviation safety has to be paramount. The industry, for very good reasons, is risk-averse and in the face of what we are currently experiencing, it would be incredibly stupid to put a plane in the sky with passengers on board it.

At a recent air safety conference, we were discussing the concept of "acceptable risk", but this idea only goes so far and the bottom line is that history looks unfavourably on people who are forewarned but not forearmed – and the insurance market looks similarly on such instances.

Chris Yates is an aviation security analyst with Jane's Information Group.