Flying became even safer this week; or at least it should have. Thirty-one years ago, the worst accident in the history of civil aviation took place at Los Rodeos airport in northern Tenerife. A bomb attack at Las Palmas, on Gran Canaria, had caused a number of aircraft to divert to Tenerife. Among them were Boeing 747s belonging to KLM and Pan Am. Fog sharply reduced visibility. The pilot of the Dutch plane was keen to get his passengers away, but a mix-up between him, the Pan Am captain and the air-traffic controller meant that he took off while the Pan Am jet was on the runway. All the KLM passengers and crew died, along with most of those on board the American aircraft; in total, 583 perished.
On Wednesday, the International Civil Aviation Organization (ICAO) brought in a new rule laying down the minimum standard of spoken English that air-traffic controllers and pilots on international flights should possess. You might be concerned to learn, though, that it is not the most demanding of standards – and nor is it as compulsory as it might be.
The sole purpose of air-traffic control is to keep aircraft safely apart from each other and from terrain that is not an airport. To do this, pilots speak to the controllers on the ground. They mainly use a version of English known as "standardised phraseology", specifically designed for communicating the essentials about height, direction, speed, other traffic and so on. But ICAO believes communication breaks down too often; misunderstandings are the biggest single cause of aircraft flying at the wrong altitude or making runway incursions. And when things don't go according to plan, due to an engine failure or a sick passenger, the standard phrases may no longer suffice.
To reduce the contribution made by "human factors" to plane crashes, ICAO says pilots and controllers must now meet a standard known as "Level 4".
As has been widely discussed, oral language tests for British schoolchildren are set to end in order to reduce stress. Luckily for future generations of UK pilots, the international language of aviation is English. But how good do non-native speakers need to be?
Reading the rule book does not instil great confidence. While it is compulsory to "use a dialect or accent which is intelligible to the aeronautical community" (thank heavens for that), errors are allowed in both pronunciation and grammar. In addition, pilots and controllers who do not meet the required level are not out of jobs; they can request an extension of three years to brush up their language.
So should you and I be worried? To find out, I talked to Andy Roberts and Henry Emery, whose new book, Aviation English, came out on the day the new rules took effect.
"What makes this kind of English a bit different to, if you like, GCSE, is that we're not looking for perfect English," Roberts says. What counts is intelligibility. "If you make all sorts of grammatical errors but you get your message across, it doesn't matter."
Will ICAO's new rule really help, or will we remain 200 nations divided by a common language? "If we did get to the situation where all the pilots and all the air-traffic controllers in the world were at Level 4, we'd be in a better position than we are now."
Among British pilots, standards of English spoken by controllers in South America and sub-Saharan Africa give cause for concern. But the country that generates nearly half the world's aviation is not exempt: US controllers often use far too much idiomatic language.
Emery gives the example of an aircraft setting out from the gate. "In phraseology, you should say, 'Taxi to position in hold.' Americans are often quoted as saying, 'Line up and wait.' Now, 'Line up and wait' and 'Taxi to position in hold' are often interpreted in the same way, but they are different phrases with different meanings."
The crucial question: has the authors' work on Aviation English made them more or less fearful of flying? "The more time you spend with the highly skilled and professional pilots and air-traffic controllers of the world, and the more you learn about procedures for air-traffic management," Emery says, "the more faith you have in the system."
British Airways pilots are among the best in the world, which meant that last Sunday morning I could forget all about safety concerns before boarding BA478 from Heathrow to Barcelona, and focus instead on feeling irritated that I was hanging around for a delayed flight that I didn't want to be on.
As you may have read last week, I booked a round trip to the Catalan capital. Then my plans changed, and I needed only the inbound leg. But when I called BA to cancel one half, I was warned that if I failed to fly outbound, the flight home would automatically be cancelled.
The only result of my appeal on this page for someone to take my place was that my seat assignment was changed by someone impersonating me. And sadly the flight was not sufficiently late for me to be allowed not to fly under EU passengers' rights legislation.
"One Way" and "return" are very different in meaning – and in price. I pointed out last week that for some long-haul one-way flights it made sense to buy a return but throw away the inward leg, saving £200 on a typical flight to the US. The airline, I insisted, would be powerless to stop you. But Niels Sampath from Oxford warns: "That may still be true with BA. However, online forums have messages from travellers, particularly Americans, who have tried this only to then be placed on frequent-flyer blacklists or charged cancellation fees. Some airlines may be less 'powerless' to stop this practice than you suggest."
Oh dear. Over and out.
'Aviation English' is published by Macmillan