XN000022-1992-02-26 — Page 15

WEDNESDAY, FEBRUARY 26, 1992

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EXPECTED WINDSHEAR INCIDENT AT CHEK LAP KOK WELL WITHIN

INT'L OPERATION STANDARD

*

WHILE WINDSHEAR WILL OCCUR AT СНЕК LAP кок IN CERTAIN CIRCUMSTANCES, IT'S EXPECTED INCIDENCE IS WELL WITHIN ALL ACCEPTED

STANDARDS FOR THE OPERATION OF AN INTERNATIONAL

NORMAL

AIRPORT.

THIS WAS STATED BY THE SECRETARY FOR ECONOMIC SERVICES, MRS ANSON CHAN, TODAY (WEDNESDAY) AT THE LEGISLATIVE COUNCIL.

GIVEN

"WINDSHEAR, A CHANGE IN WIND DIRECTION AND/OR WIND SPEED OVER A DISTANCE, IS AN OCCASIONAL OCCURENCE USUALLY ASSOCIATED WITH WEATHER PHENOMENA LIKE THUNDERSTORMS, MRS CHAN SAID IN A REPLY TO A WRITTEN QUESTION BY THE HON ALBERT CHAN WAI-YIP.

SHE POINTED OUT THAT WHEN THUNDERSTORMS OCCURRED AT CHEK LAP KOK WINDSHEAR WOULD OCCUR BUT ITS DURATION WAS LIKELY TO BE SHORT (A MATTER OF MINUTES) AND DISRUPTION TO AIR TRAFFIC WOULD BE ONLY MINOR.

"THE NEW AIRPORT MAY ALSO BE AFFECTED ON RARE OCCASIONS BY 'LEE WAVE' WINDSHEAR WHICH IS CAUSED BY THE TOPOGRAPHY OF CHEK LAP KOK ISLAND AND THE HIGH LAND IMMEDIATELY TO THE SOUTH OF THE AIRPORT.

"IN THE CASE OF THIS TYPE OF WINDSHEAR, DISRUPTION TO AIRPORT MOVEMENTS IS LIKELY TO LAST SLIGHTLY LONGER.

"EXTENSIVE TESTING HAS SHOWN THAT SUCH INTERRUPTIONS WILL NOT EXCEED 0.5% OF THE AIRPORT OPERATION TIME IN TOTAL, A FIGURE WELL WITHIN INTERNATIONALLY-ACCEPTED GUIDELINES, SHE SAID,

MRS CHAN SAID MOST WINDSHEAR CONDITIONS CAUSED NO THREAT TO THE OPERATION OF THE TYPE OF LARGE PASSENGER AIRCRAFT WHICH WOULD BE USING THE NEW AIRPORT.

"IN SEVERE

CONDITIONS, HOWEVER, AIRCRAFT MOVEMENTS SUBJECT TO DELAY UNTIL CONDITIONS HAD IMPROVED," SHE ADDED.

WOULD BE

MRS CHAN SAID TO ENHANCE THE SAFETY OF AIRCRAFT OPERATIONS, THE PROVISIONAL AIRPORT AUTHORITY'S MASTER PLAN CONSULTANTS HAD RECOMMENDED THAT A SYSTEN SHOULD BE INSTALLED TO DETECT WINDSHEAR CONDITIONS AND ALERT PILOTS TO THE PRESENCE OF WINDSHEAR AND ITS SEVERITY.

"PILOTS CAN THEN MAKE INFORMED DECISIONS WHETHER ΤΟ PROCEED WITH THE INTENDED OPERATION, OR TO TAKE ACTION TO AVOID THE WINDSHEAR.

"THE COST OF THE SYSTEM RECOMMENDED BY THE MASTER PLAN CONSULTANTS IS APPROXIMATELY UK$63 MILLION. THIS INCLUDES THE COST OF FURTHER INVESTIGATION AND SYSTEM DESIGN WORK AS WELL AS EQUIPMENT COST," MRS CHAN SAIP.

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