ILS problem 3

25.10.2004

Submission:

Although it is true the condition of the ground plane on the image type GP system is the most common cause of undesirable guidance information on an approach, it is not true that nothing can be done about it. Since 1979 there has been non-image type ILS glide path system in use in the USA that has been the solution to provide ILS service at sites where tremendous amounts of money must be spent to smooth the earth to rid the approach path of these undesirable guidance indications. The antenna systems have a proven frangible construction permitting installation closer to the runway, and do not require smooth earth to form quality guidance signals. These antenna systems can provide Category I or II quality guidance signals at sites where an accepted approach procedure might be the limiting factor.

This "End-fire" system is becoming more common internationally as more difficult sites are requesting precision approach capability to Category I minimums. Systems are now commissioned in Venezuela, Korea, Norway, India and the United States. Many more countries are reviewing the capabilities of the system to meet their specific needs at sites where it was previously thought unlikely to ever achieve unrestricted ILS minimums. For more information and contact go to www.wattsantenna.com

John H. Johnson Sr., President, Watts Antenna Company, USA