Air China is the flag carrier and one of the major airlines of the People's Republic of China. Based in Beijing it is one of the world’s largest airlines in terms of fleet size but ranks behind its main competitors, China Southern Airlines and China Eastern Airlines, in terms of passenger traffic.
Air China pilot prepares for take-off by cleaning windscreen at Chek Lap Kok
Passengers watch as captain on Air China flight prepares for take-off by cleaning windscreen
As drivers, it's something we've all done. You're about to set off when you suddenly notice a nasty, large smudge on your windscreen - so you lean out of your window and wipe it off with your handkerchief.
The manoeuvre is a somewhat more complicated and eye-catching, however, when your vehicle is an Airbus A321 and you're about to set off on a flight from Hong Kong to Beijing with 180 passengers on board.
The captain of an Air China flight leaving Chek Lap Kok last Wednesday afternoon decided to pull out his hankie and give the windscreen a quick once-over as passengers filed onto the plane.
He seemed untroubled by the long drop to the tarmac below as he worked his way across the windscreen, wiping it all the way to its central pillar.
Bemused passengers looked on as they filed onto the flight.
"At least we know he's going to be able to see where he's going," said one.
A former senior Cathay Pacific pilot was not surprised by the pilot's actions.
"Most windscreen cleaning is done by engineers when the aircraft has sufficient downtime on overnights or on turnarounds, but that isn't always possible," he said. "I've actually done what that pilot did myself. If you ask the ground staff engineers to do it, they have to get out a cherry picker [a hydraulic platform], which takes 20 to 30 minutes to arrive.
"It then takes time for them to wash the windscreen and it's an expensive option too. In the interests of on-time departure, some pilots sensibly elect to do it themselves. It could be dangerous and I don't suppose that it is strictly official practice."
Asked what kind of mess pilots would want cleaned from their windscreens, the pilot said: "Mosquitoes can start to obscure the windscreen when you're operating in the tropics. I've also had birds hit it and leave a large bloody mess.
"Mainly, though, it's insects. And they can accumulate over a few flights to make it frustrating to visibility, just like it is in a car."
Pilots and first officers always have opening cockpit windows with an escape rope for evacuation purposes in case the cockpit door is jammed after a crash.
Air China's Hong Kong office did not return calls and e-mails asking for comment. The Civil Aviation Department said: "It appears that the pilot of the subject flight noted some minor dirt onthe windows and believed he could reach that spot and clean it. Since the aircraft was still on ground, the window could be open or closed freely and would have no safety implications."