British airline safety consultant John Trevett tells swissinfo that publishing lists of banned airlines will help travellers choose the right carriers.
The Swiss Federal Civil Aviation Office on Thursday published a blacklist of banned airlines in Switzerland, after similar decisions in France, Belgium and Britain.
The two companies banned in Switzerland are Egypt's Flash Airlines and Armenian carrier Air Van Airlines.
Publication of the names comes 18 months after a Flash Airlines charter jet crashed shortly after take-off from the Egyptian resort of Sharm el-Sheikh.
Switzerland's blacklist does not include airlines banned in other countries that do not touch down in Switzerland.
For carriers banned in other countries but still permitted to fly to Switzerland, targeted inspections are planned.
swissinfo: Countries like Switzerland, Britain, France and Belgium have produced blacklists of banned airlines. How credible are these lists?
John Trevett: The lists are the result of government inspections and it is the prerogative of the authorities to publish these lists. It hasn't been done until recently.
There is probably a concentration on airlines from certain countries, based on information received, but there are also many inspections that do not turn anything up. The fact that there are regular inspections should mean that any airline flying to a country knows it will be checked at some point.
swissinfo: Others countries haven't published blacklists. Is this because these nations feel it is not necessary?
J.T.: Virtually all developed countries have a blacklist of some kind. The whole debate at the moment is whether this information should be published and how. I personally think all data should be made public, be it good or bad. The United States, for example, draws up lists of countries it feels meet or don't meet international standards for airline safety. It's up to national regulators to clamp down then on their own companies.
Publishing lists is a growing trend, though. Eighteen months ago, nobody had even thought about it. The Flash Airlines crash in Egypt made publishing a blacklist an issue, although whether a company like that could survive such an accident probably makes it a moot point since travellers aren't likely to climb back on board one of their aircraft.
swissinfo: There are airlines whose aircraft have problems, but aren't blacklisted. How bad do you have to be?
J.T.: Incidents and accidents can happen to the best-managed airlines in the world. The bigger the company, the more likely there will be some incidents, although it will not be statistically significant. These incidents don't necessarily mean that there is anything wrong with a carrier.
It's only if inspectors find breaches of international safety regulations that they will consider banning a company. But ideally they need to make a number of inspections over time to get a complete picture before making a decision.
swissinfo: Given it takes multiple inspections before an airline is banned, what is the blacklist worth to a traveller?
J.T.: The chances of dying in a plane crash are already very slim, something like less than one in a million, while those of sustaining a minor injury are less than one in 100,000. But there are airlines that have worse records than that, and there are significant differences between airline accident rates.
As a consumer, I would want access to the blacklist and know who the banned airlines are. I would like to know if a company is dangerous before I get on board.
swissinfo: Should aviation authorities not consider publishing incident records for airlines?
J.T.: There are different systems for reporting incidents and they can be publicly available. The best ones are anonymous, when people in aviation feel they can put their hands up and report incidents.
There are also many countries where it is mandatory to report incidents, whether or not they result in an accident. In western countries, this type of system is well developed, but elsewhere this is not always the case.
Even if this information can be found in some cases, the public is also not aware of its availability. But they can refer to lists of airlines with permission to operate in a country.
swissinfo: So what should frequent travellers do to avoid unnecessary risks if they can't access this information?
J.T.: They need to consider the risk factors involved in flying. They should avoid unnecessary flights. They should not take trips involving too many take-offs and landings, when 90 per cent of accidents happen. And generally be aware of older aircraft. They can be safe if properly maintained. There are also risks involved in flying in difficult environments. The best option is to stick to established, tried and tested airlines.
swissinfo-interview: Scott Capper
John Trevett is a British technical and economic aviation consultant.
His subscription-based Flightsafe advisory service provides safety assessments of 900 airlines based on a specific rating system.
The scoring system is aimed mainly at business travel managers.
The two airlines banned from Switzerland are Flash Airlines (Egypt) and Air Van Airlines (Armenia).
The French blacklist contains five companies:
Air Koryo (North Korea)
Air Saint-Thomas (US)
International Air Service (Liberia)
Lineas AER of Mozambique (LAM)
Phuket Airlines (Thailand).
There are nine companies on the Belgian list:
Africa Lines (Central African Republic)
Air Memphis (Egypt)
Air Van Airlines (Armenia)
Central Air Express (Democratic Republic of Congo)
International Air Tours Limited (Nigeria)
Johnsons Air Limited (Ghana)
Silverback Cargo Freighters (Rwanda)
South Airlines (Ukraine).