坐飛機時會被要求將手機關機或調成飛行模式，因為在飛機上使用手機會對飛行產生干擾，尤其是起飛和降落的時候，那么這種干擾具體指的是什么呢？來看看這篇干貨吧。

We all know the routine by heart: “Please ensure your seats are in the upright position, tray tables stowed, window shades are up, laptops are stored in the overhead bins and electronic devices are set to flight mode.”

這句常規提醒我們都爛熟于心：“請確保您的座椅靠背垂直，餐桌和遮光板收起，筆記本電腦放在頭頂的行李架上，手機調成飛行模式。”

Now, the first four are reasonable, right? Window shades need to be up so we can see if there’s an emergency, such as fire. Tray tables need to be stowed and seats upright so we can get out of the row quickly. Laptops can become projectiles in an emergency, as the seat back pockets are not strong enough to contain them.

前幾個要求都很合理，不是嗎？遮光板收起，我們才能看見起火等緊急狀況。餐桌收起，座椅垂直，我們才能迅速離開座位。在發生緊急情況時筆記本電腦會變成亂飛的拋射物，因為椅背的袋子不夠牢固。

And mobile phones need to be set to flight mode so they can’t cause an emergency for the airplane, right? Well, it depends whom you ask.

還有，手機需要調成飛行模式，這樣才不會引發飛機緊急事故，對嗎？這得看你問誰了。

Aviation navigation and communication relies on radio services, which has been coordinated to minimize interference since the 1920s.

由于飛機導航和通信都依賴無線電服務，自上世紀20年代以來一直都是通過協調盡量減少無線信號干擾。

The digital technology currently in use is much more advanced than some of the older analog technologies we used even 60 years ago. Research has shown personal electronic devices can emit a signal within the same frequency band as the aircraft’s communications and navigation systems, creating what is known as electromagnetic interference.

目前應用的數字技術比60年前所用的一些老的模擬技術要先進得多。研究顯示，個人電子設備會發送與飛機通信和導航系統同一頻率范圍內的信號，從而造成所謂的電磁干擾。

But in 1992, the US Federal Aviation Authority and Boeing, in an independent study, investigated the use of electronic devices on aircraft interference and found no issues with computers or other personal electronic devices during non-critical phases of flight. (Takeoffs and landings are considered the critical phases.)

但在1992年，美國聯邦航空管理局和波音公司聯合開展的一項獨立研究調查了使用電子設備對飛行的干擾，結果發現，在飛行的非關鍵階段使用電腦或其他個人電子設備不會干擾飛行。（起飛和降落被視為飛行的關鍵階段。）

The US Federal Communications Commission also began to create reserved frequency bandwidths for different uses – such as mobile phones and aircraft navigation and communications – so they do not interfere with one another. Governments around the globe developed the same strategies and policies to prevent interference problems with aviation. In the EU, electronic devices have been allowed to stay on since 2014.

美國聯邦通信委員會也開始推出手機、飛機導航和通信等不同用途的專用頻段，這樣它們就不會互相干擾。全球各地的政府也采用了同樣的戰略和政策，防止飛行干擾問題。歐盟從2014年起開始允許在飛機上保持電子設備開機。

Why then, with these global standards in place, has the aviation industry continued to ban the use of mobile phones? One of the problems lies with something you may not expect – ground interference.

既然有了這些全球標準，為什么航空業還是繼續禁止在飛機上使用手機呢？其中一個問題可能是你想不到的，那就是地面干擾。

Wireless networks are connected by a series of towers; the networks could become overloaded if passengers flying over these ground networks are all using their phones.

無線網絡通過一系列信號塔來互聯，如果飛越地面網絡的乘客全在使用手機，網絡可能會超載。

Of course, when it comes to mobile networks, the biggest change in recent years is the move to a new standard. Current 5G wireless networks – desirable for their higher speed data transfer – have caused concern for many within the aviation industry.

當然，近年來移動網絡的最大改變就是新標準的轉換。現行的5G無線網絡（由于更高速的數據傳輸而受到歡迎）引發了許多航空業人士的擔憂。

Radio frequency bandwidth is limited, yet we are still trying to add more new devices to it. The aviation industry points out that the 5G wireless network bandwidth spectrum is remarkably close to the reserved aviation bandwidth spectrum, which may cause interference with navigation systems near airports that assist with landing the aircraft.

無線頻段是有限的，而我們仍在試圖添加更多新設備。航空業指出，5G無線網絡頻段非常接近航空專用頻段，這可能會對機場附近輔助飛機著陸的導航系統造成干擾。

Besides, It would be an inconvenience for cabin crew to wait for passengers to finish their call to ask them if they would like any drinks or something to eat.

除此以外，如果乘客在飛機上打電話，空服人員得等乘客打完電話才能詢問他們是否需要飲料或食物，這也會帶來不便。

英文來源：美國有線電視新聞網

翻譯&編輯：丹妮