The threats posed by terrorists mean that aviation security can never be taken lightly. But measures that are poorly thought out, implemented selectively or not adequately explained will only harm credibility, trust and the willingness of people to fly. That has in part been the result of a ban by the United States and Britain on passengers taking electronic devices such as laptop computers into aircraft cabins on flights to and from six nations in the Middle East and North Africa. The questions raised are reason enough for American officials to think twice about pushing for the measure globally.

Implementation of the ban in March was made with little notice and consultation with airlines and airports, causing confusion and frustration. The decision has still to be adequately explained; no specific threat has been mentioned, although reference has been made to a laptop exploding on board a Somali jet in February 2016 that killed one person. Evidence that concealment of explosives in electronic devices is a legitimate concern was shown in 2010, when British police found material disguised as an inkjet cartridge on board a cargo plane. The exacting dimensions of items prohibited from hand luggage – no bigger than 16cm by 9.3cm by 1.5cm – seems to link the measure to an earlier limit on the amount of liquid that can be taken into the cabin.

There is less uncertainty about the consequences, though. Business travellers wanting to do work during flights are the most affected, while those wanting to relax have to be content with on-board entertainment systems. Experts at the recent annual meeting of the International Air Transport Association put the potential cost of a global ban at US$3.3 billion, calculated from flight delays, booking cancellations and reduced productivity.