機場提議強風時飛機應湊近飛
文章來源:未知 文章作者:enread 發布時間:2021-02-27 05:26 字體: [ ]  進入論壇
(單詞翻譯:雙擊或拖選)
It may seem counterintuitive, but on windy days, aircraft should fly closer together. Those are the plans at Heathrow airport anyway.
 
The problem is that Heathrow is running at full capacity1. It cannot process more than the 480,000 flights it currently2 handles per year. With flights booked throughout the day, there is no chance to make up for delays later in the morning as there is at quieter airports. And the biggest cause of these delays is wind.
 
In order to stay safe, airports leave gaps4 of several kilometres between landing5 aircraft. This is because as an aeroplane cuts through the sky it creates a vortex - a trail of churned up air - which is dangerous for other planes to fly through. For a large aircraft like the Boeing A380 the gap3 can be eleven kilometres.
 
However, planes measure their speed through the air, not over the ground. Therefore, if planes are flying into a headwind, scientists say the gap can be safely reduced. Imagine a plane is flying over the ground at 400 km per hour, but the air around the plane is moving in the opposite direction at 50 km per hour. That means the plane is actually only travelling at 350 km per hour through the air. By studying thousands of flying planes using lasers6, scientists discovered that the wind also has the effect of quickly smoothing out their vortices.
 
The wind's slowing effect means that currently on windy days, arrivals at Heathrow drop from 45 per hour to as few as 32. With the new system that should be back up to 40 landings per hour.
 
Some people may feel nervous at the idea of flying closer together. To make sure the system is totally safe it has undergone7 four years of scientific research and safety testing. Designers now hope to sell the new system to the world's 25 busiest airports.


點擊收聽單詞發音收聽單詞發音  

1 capacity ITxy7     
n.能力,力量,接受力;容量,能量,容積
參考例句:
  • She is employed by the president in an advisory capacity.她被總裁聘為顧問。
  • This carriage has a seating capacity of 120 people.這節車廂定員120人。
2 currently SvMzI2     
adv.通常地,普遍地,當前
參考例句:
  • Currently it is not possible to reconcile this conflicting evidence.當前還未有可能去解釋這一矛盾的例證。
  • Our contracts are currently under review.我們的合同正在復查。
3 gap FhkxL     
n.缺口;間隔;差距;不足,缺陷
參考例句:
  • We must see that there is no gap in our defence.我們必須確保我們的防御沒有漏洞。
  • There is a gap of five miles between towns.鎮與鎮之間相隔五英里。
4 gaps bbe42eaa7764c91d334cb43068f0cb9d     
n.缺口( gap的名詞復數 );不同;間隔;[植物學]裂
參考例句:
  • Contraction of the timbers left gaps in the fence. 木料收縮,結果圍墻露出縫來。 來自《簡明英漢詞典》
  • The record is not complete; there are several gaps in it. 這份紀錄不完整,中間有幾處間斷。 來自《簡明英漢詞典》
5 landing wpwz3N     
n.登陸;著陸;樓梯平臺
參考例句:
  • Owing to engine trouble,the plane had to make a forced landing.由于發動機出了毛病,飛機不得不進行迫降。
  • When are we landing?我們什么時候著陸?
6 lasers c2d5ea851d247ef91f8c9fab844527a0     
n.激光( laser的名詞復數 );激光器,鐳射器
參考例句:
  • One example is the use of lasers to separate isotopes. 用激光分離同位素就是一個例子。 來自英漢非文學 - 科技
  • Lasers promise to change this by making isotope separation easier, and cheaper. 激光可以改變這種局面,從而使同位素分離變得比較容易、比較廉價一些。 來自英漢非文學 - 科技
7 undergone cd7e1189f288029419c4a9e5d01f2dd5     
undergo的過去分詞
參考例句:
  • The way in which we work has undergone a complete transformation in the past decade. 在過去的十年里,我們的工作方式經歷了徹底的變革。
  • Her whole attitude had undergone a subtle change. 她的整個態度發生了微妙的變化。
TAG標簽: airports flights capacity
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