先说。。side stick为什么要动来动去@@
satanjames 发表于 19-4-2012 10:08 AM
satanjames,你要表达的是为什么机师要在 approach 的时候一直将 side stick 摇来摇去来控制飞机降落飞行吧。Side stick 是不会自己动的。
如果是 wind calm condition,机师在 approach 的时候根本不需要去动 side stick,只需要在 flare 的时候将 side stick 稍微的 pull back 来 flare up 就可以了。影片里飞机的镜片是有雨水的,加上机师不断的移动 side stick,能够推断当时的 approach 时 wind condition 是相当 turbulent。就像汽车在笔直的 high way 上行驶时,司机也是会稍微的转动 steering wheel 来保持汽车行驶在 highway 的中间。
谢谢遨翔,其实没有。查了一些资料,Airbus比较没有Stick Shaker。如果飞机进入Stall的话,比较的是Alpha Floor来协助。Computer会Takeover整个System,让飞机不会Stall。关于Side Stick在Autopilot Mode,我想老何可以解释一下。呵呵老何,帮助我们一下
michyiki 发表于 20-4-2012 07:17 AM
Stall 和 Alpha floor 虽然有密切的关系,但是,stall warning 出现时未必会 Alpha floor。更正确来说 Alpha Floor 是 auto thrust 对 air speed recovery 的回应。飞机会 stall 最大的原因是 pitch angle (high angle attack) 和 steep bank angle。
先从速度说起,Airbus 的 Vls (Speed tape 上的黄色空格) 是相等于 Boeing 的 minimum maneuvering speed。低于 Vls 速度的时候,protection system 会有发出 "Speed!!! Speed !!! Speed!!!" 的警告声。在低于 Barber pole (红黑线条)的时候就是 V alpha prot (Alpha floor 会在这时候出现),再底的速度是 V alpha max (实心红色线条)。
在airbus 的 normal law 情况下即使是在 V alpha prot 速度以下 trigger 了 alpha floor 机师还将 side stick 往后拉来 pull up,飞机还是能在 V alpha max 的速度继续飞行。因为 normal law 还有 high angle of attack protection 来避免飞机超出 stall pitch angle。
Airbus 在 heavy gross weight 的 straight and level flight 时还可以在 speed tape 上看见黄色空格的 Vls 和黑红线条的 barber pole。飞机在转弯时 stall speed 会提高。在 speed tape 上的 barber pole 会随着 bank angle 的角度而提高。这时候一旦 bank 太多时就会不小心 trigger stall warning,不过 auto thrust 并不会因此而进入 alpha floor。只要减少 bank angle 就可以马上避开 stall warning。
MAS Routes Cut Affects Passenger Numbers At Local Airports
April 26, 2012 20:00 PM E-mail this news to a friend Printable version of this news
SEPANG, April 26 (Bernama) -- The decision by Malaysia Airlines (MAS) to cut some of its long-haul routes has impacted the number of passenger using local airports, Malaysia Airport Holdings Bhd (MAHB) said.
Its Chief Financial Officer Faizal Mansor said without the cut, the number of passengers using local airports, could have reached double-digit growth in the first quarter ended March 31, 2012.
"The appetite for travel is still there but without the desired flights, passengers will use alternative airports in the region," he told reporters after announcing MAHB's first quarter financial results here Thursday.
He said in the quarter, the number of passenger using local airports grew by 6.5 per cent to 16 million people from the 15.1 million recorded in the same period last year.
"The higher number of passengers was contributed by an increase in airline operators using local airports as well as the usage of bigger aircraft by them," he added.
Last year, MAS had announced route cuts to at least ten international destinations, as part of efforts to rationalise its network and return to profitability.
Among the destinations dropped by the national airline from Kuala Lumpur, were Rome, Dubai, Bandung, Cape Town, Buenos Aires and Johannesburg.
Meanwhile, on MAHB's financial results, Faizal said the company recorded a pre-tax profit of RM147 million in the first quarter, an increase of 10 per cent from the RM133.6 million in the same period last year.
Revenue rose to RM657.8 million from RM617.8 million previously and attributed to the higher number of passengers using MAHB's 39 airports in Malaysia.
Faizal said revenue generated from the airport operations segment improved by 13.1 per cent to RM478.2 million, while aeronautical revenue improved by 18.1 per cent to RM241.659 million on the back of stronger passenger numbers and implementation of new rates.
Effective Nov 15 last year, the government, has allowed MAHB to implement new passenger services charges and aircraft landing and parking charges.
Asked about the Low Cost Carrier Terminal (LCCT), he said MAHB will continue with its plan to use it as a cargo hub, upon completion of the KLIA 2.
Full flaps approach 的 attitude 是 2.5 ~ 3.0 degree。
Wide body 开始在 40~30 ft 的时候开始 flare (Narrow body 是 20 ft)。20~10 ft 就开始 close throttle。从 flare 到 touch down 的时间大概是 8~10 seconds。超过 runway 的 1/3 长度或 30秒的 flaring 就是 long flare。