This was published 9 years ago
Planes landing in high winds video: Is it dangerous?
By Lizzie Porter
Footage of planes landing in gale force winds this week – swaying left and right and appearing to approach the runway sideways – are unlikely to fortify the courage of nervous fliers. But what are the risks posed by high winds?
First things first. Those wonky touchdowns shouldn't alarm anyone. In fact, pilots are trained to perform exactly this type of landing in the event of strong crosswinds.
Patrick Smith, a US pilot and author of Cockpit Confidential, a book on "everything you need to know about air travel", explains that the correct landing technique is "a slightly skewed alignment, with one set of tyres hitting the ground before the other."
But it takes a bit of practice. British Airways trains its pilots to land in high winds every six months. Captain Dave Thomas, head of flight technical and training at the airline, says that the difficulty of landing in high winds depends on both wind speed and direction.
In an ideal world, the pilot wants to land into the wind and in the centre of the runway. If there's a tricky cross wind, he says, they will approach with the nose of the plane facing the wind. Just as the pilot performs the "flare" – designed to slow the descent rate – he or she will bring the aeroplane's nose in line with the runway.
It this manoeuvre is performed too early, "the aeroplane won't land in the centre of the runway – or on the runway at all," says Captain Thomas. If the pilot isn't happy with their first effort, he or she will abort the landing, and try again. In what is known as a "baulked landing", the plane might even touch the runway.
In the windiest conditions "wingstrike" may occur – when, you've guessed it, a wing hits the runway. It doesn't happen often, although one notable incident took place in 2008, when a Lufthansa A320 tried to land at Hamburg Airport amid gusts of up to 47 knots (54mph). The footage on YouTube is excruciating, but no one was hurt and the plane eventually touched down on another runway.
The phenomenon known as "wind shear" also poses a risk. This is a sudden change in wind speed and/or direction, causing turbulence or a rapid increase or decrease in velocity. A tricky scenario might see a pilot attempting to land into a head wind that sudden turns into a tail wind. The result? Landing late and fast, and potentially overshooting the runway.
Airbus says wind shear is the main cause of four per cent of "approach and landing" accidents, such as the crash of the Delta Flight 191 in 1985. A loss of 54 knots of air speed in a matter of seconds saw the plane hit the ground about a mile short of the runway. This was one of several incidents that led the Federal Aviation Administration, the US equivalent of the Civil Aviation Authority (CAA), to rule that all commercial planes must be fitted with a wind shear detection and alert system. The CAA does not currently make the same demands of UK operators.
Captain Thomas says that wind shear may cause a pilot to break off a landing at around 3000 feet (914.4 metres): "It's the right thing to do – put the power on and get up and out of there."
Pilots always have a plan B in mind if the intended approach is not safe or if the airport closes because of high winds. For landing in Washington DC, for example, the BA pilot knows he could divert to Baltimore or Boston. Updates on wind and weather conditions are communicated to crew throughout a journey to help with decision making.
To curtail the dangers posed by strong winds, manufacturers issue limits for maximum ground speeds, air speeds and cross speeds in which a plane can operate, based on "analytical computations and simulations". For example, the Airbus A380 was designed to cope with crosswinds of 35 knots at take-off and 40 knots when landing.
According to the CAA, however, the pilot decides whether a landing is safe – based on experience, not algorithms.
The CAA does enforce detailed weather reporting regulations for UK airports, however – set out in a 119-page document that makes for gripping reading – and airports must also provide half-hourly reports describing conditions along the runway.
Some airports are more susceptible to strong winds. Those flying into Leeds Bradford, the highest airport in Britain at 681 feet (208 metres), have seen their fair share of wobbly approaches – including this week. Last month, a BA flight diverted to Manchester because of conditions there.
Flights in northern Scotland are also more likely to be cancelled: this week around 20 were cancelled between Aberdeen and Shetland as gusts reached 70mph. Captain Thomas says that Keflavik Airport in Iceland is notorious for its high winds, and often hosts trainee pilots for landing practice.
He adds that pilots will usually tell the cabin if a landing is likely to be bumpy: "It's better to let people know – you've normally got at least one nervous flyer on board."
High winds can make a flight uncomfortable, but are extremely unlikely to be fatal – they might even mean your holiday starts sooner. Strong tailwinds – and jet streams – can shave hours off a flight time. A BA flight nearly went supersonic this week thanks to just that – flying from New York to London in just five hours and 16 minutes when the usual journey time is nearly seven hours. That's one reason to hope for buffeting gales next time you're waiting in the departure lounge.
The Telegraph, London
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