Featured Research

from universities, journals, and other organizations

Plane Crash In Taiwan Occurs Just Months Before Windshear Alert System Is Completed

Date:
November 6, 2000
Source:
American Institute Of Physics -- Inside Science News Service
Summary:
A warning system for detecting windshear at airports might have been able to help the pilot of Singapore Airlines flight SQ006, had it been completed. A team from the National Center for Atmospheric Research is installing a Low-Level Winshear Alert System at Chiang Kai-Shek airport.

A warning system for detecting windshear at airports might have been able to help the pilot of Singapore Airlines flight SQ006, had it been completed. "If the Taiwan Low-Level Windshear Alert System (LLWAS) at Chiang Kai-Shek airport had been completed, it would have been able to provide windshear information to the pilot for the conditions that were occurring at the time of the accident," says Bill Mahoney of the National Center for Atmospheric Research (NCAR) in Boulder, Colorado.

Windshear is a rapid change of wind speed or direction over a short distance. One form of windshear that is particularly dangerous to aircraft are microbursts, which are very short-lived, intense, downdrafts of air. Windshear is also associated with frontal systems that are the result of thunderstorms, where the front marks an abrupt transition in wind speed and direction.

NCAR is working with the Taiwan Civil Aeronautics Administration to modernize the weather detection systems at three Taiwan airports. Mahoney is the program manager for installing LLWAS at Chaing Kai-Shek (CKS) airport. Mahoney says the LLWAS is scheduled to be completed by the end of this year.

LLWAS was originally developed by the FAA in the 1970's to detect large scale wind shifts (by comparing readings from a number of wind sensors), after an accident at JFK airport in New York when a plane landed during a wind shift created by the interaction of a sea breeze and thunderstorm outflows.

In the 1980's NCAR determined that microburst windshear events were very dangerous to aircraft below 1000 feet. To address the problem, NCAR developed a new LLWAS system that detected and located microburst events. "The system was designed to provide alerts specific to each runway in operation," Mahoney says.

Now in its third generation, most LLWAS systems have between 12 and 16 wind sensors, but the largest one, at Denver International Airport, has 32 sensors. Each airport site is assessed to determine the geometry needed for the sensor network.

While it is still unclear what role the weather played in the Taiwan crash, Mahoney says "the weather that was occurring at the airport could certainly have included windshear."

According to Kelvin Droegemeier, Director of the Center for Analysis and Prediction of Storms at the University of Oklahoma, the threat of windshear is greatest when airplanes are close to the ground. Microbursts occur when a downdraft of air hits the ground and spreads out radially, creating a thin layer of fast-moving air near the ground. "When the airplane descends into this layer, the flow over the wings can increase or decrease abruptly depending on the plane's direction," says Droegemeier. This can cause the plane to suddenly rise or fall, forcing the pilot to make a correction. However, as the plane crosses the other side of the microburst, the flow over the wings changes again, and, "if not recognized and corrected, the plane may not have time to recover."

In addition to LLWAS systems at airports that have reduced the danger of windshear events, Droegmeier points out that, "tremendous strides have been taken to improve pilot training and understanding of wind shear."

Third generation LLWAS systems, like the one being installed in Taiwan, already exist at 9 U.S. airports, and are being put in place in Korea, Singapore, Saudi Arabia and Kuwait. Phase-2 LLWAS systems (which have 5-6 sensors, rather than 12-16), are in place at 100 U.S. airports. Mahoney points out that, "a Phase-1 or Phase-2 LLWAS is not designed to detect microbursts per se, but if the flow is large and strong, it may alert [the airport controller]."

LLWAS is not the only system for detecting windshear. The Federal Aviation Administration also uses Terminal Doppler Weather Radar and other radar solutions to detect windshear events.


Story Source:

The above story is based on materials provided by American Institute Of Physics -- Inside Science News Service. Note: Materials may be edited for content and length.


Cite This Page:

American Institute Of Physics -- Inside Science News Service. "Plane Crash In Taiwan Occurs Just Months Before Windshear Alert System Is Completed." ScienceDaily. ScienceDaily, 6 November 2000. <www.sciencedaily.com/releases/2000/11/001102163954.htm>.
American Institute Of Physics -- Inside Science News Service. (2000, November 6). Plane Crash In Taiwan Occurs Just Months Before Windshear Alert System Is Completed. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2000/11/001102163954.htm
American Institute Of Physics -- Inside Science News Service. "Plane Crash In Taiwan Occurs Just Months Before Windshear Alert System Is Completed." ScienceDaily. www.sciencedaily.com/releases/2000/11/001102163954.htm (accessed July 22, 2014).

Share This




More Matter & Energy News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Government Approves East Coast Oil Exploration

Government Approves East Coast Oil Exploration

AP (July 18, 2014) The Obama administration approved the use of sonic cannons to discover deposits under the ocean floor by shooting sound waves 100 times louder than a jet engine through waters shared by endangered whales and turtles. (July 18) Video provided by AP
Powered by NewsLook.com
Sunken German U-Boat Clearly Visible For First Time

Sunken German U-Boat Clearly Visible For First Time

Newsy (July 18, 2014) The wreckage of the German submarine U-166 has become clearly visible for the first time since it was discovered in 2001. Video provided by Newsy
Powered by NewsLook.com
Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Reuters - US Online Video (July 17, 2014) President Barak Obama stopped by at a lunch counter in Delaware before making remarks about boosting the nation's infrastructure. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

TheStreet (July 16, 2014) Oil Futures are bouncing back after tumbling below $100 a barrel for the first time since May yesterday. Jeff Grossman is the president of BRG Brokerage and trades at the NYMEX. Grossman tells TheStreet the Middle East is always a concern for oil traders. Oil prices were pushed down in recent weeks on Libya increasing its production. Supply disruptions in Iraq fading also contributed to prices falling. News from China's economic front showing a growth for the second quarter also calmed fears on its slowdown. Jeff Grossman talks to TheStreet's Susannah Lee on this and more on the Energy Department's Energy Information Administration (EIA) report. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins