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An electronic glideslope to your airport, today!An electronic glideslope to your airport, today!

An electronic glideslope to your airport, today!
AOPA's WAAS advocacy means safer approaches

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An ILS approach is the easiest and safest kind of approach. Even for a VFR pilot, following the ILS needles at night is a guarantee you won't hit anything unseen on your way down to the runway. However, only a little more than 700 airports in the United States have a traditional instrument landing system.

"But with WAAS-certified avionics, you could most likely fly an ILS-like approach into your airport today, even if it's one of the 4,400 general aviation airports without an ILS," said AOPA President Phil Boyer.

"If your airport has a straight-in GPS approach, it probably has vertical guidance built in to the WAAS database," Boyer. "You can fly this 'pseudo' glideslope just like an ILS, with advisory vertical guidance to the visual descent point or the missed approach point."

AOPA has been pushing for WAAS - the wide area augmentation system - for almost a decade. This year, AOPA successfully lobbied Congress for full funding - some $100 million - for continued WAAS development and operations. The association also obtained a congressional directive to FAA to develop more WAAS approaches to general aviation airports.

But there are already literally thousands of approaches that can be flown like an ILS right now.

The WAAS system improves the accuracy, availability, reliability, and integrity of the GPS signal. GPS-WAAS can be used as the sole means of navigation in all flight phases, including vertical guidance on most nonprecision GPS instrument approaches. Additionally, a brand-new type of approach, the LPV instrument approach, provides minimums rivaling traditional ILS systems without the $1.5 million-plus costs of an ILS installation.

The FAA certified WAAS for instrument flight in July 2003 (see " GPS-WAAS commissioned - new future for ILS-like approaches to airports everywhere").

The first receiver certified to take full advantage of the WAAS signal with vertical guidance is the Garmin GNS480 (or Apollo CNX80 with the version 2.0 upgrade). Garmin announced that milestone at AOPA Expo in October 2004, and the company expects to have WAAS upgrades for its GSN430/530 and G1000 in 2005.

Chelton Flight Systems' FlightLogic EFIS (electronic flight information system) is currently capable of flying approaches to LNAV/VNAV minimums, using baro VNAV with the corresponding very cold temperature limitations. The FreeFlight GPS used by the EFIS will be LPV-capable by summer 2005.

Honeywell has developed a WAAS "engine" and plans its first delivery of WAAS-capable equipment in the Apex EFIS next year. Other Honeywell Bendix/King products will get WAAS shortly thereafter.

Numerous handheld GPS receivers can also receive the more accurate WAAS signal, but handhelds may not be used for navigation in instrument conditions.

"I've been involved in this WAAS project for over nine years, and there were many times Congress wanted to kill it," AOPA President Phil Boyer said during a press conference at AOPA Expo. "About four years ago, AOPA brought the industry and FAA together in one room and said, 'Let's not let anybody out of here until we can go to Congress with an honest answer - will it work and how much will it cost?'"

The answer was, yes, it will work. The technical difficulties of improving the GPS signal proved greater than originally thought, particularly coupled with an FAA demand that the system be more accurate and reliable than existing VORs and ILSs. It took longer to build, and it will cost more than early estimates - a total of about $3 billion over 25 years.

"This is the culmination of phase one," Boyer said, "and the benefits for the single pilot hand-flying IFR are tremendous. There's nothing better than following two rock-solid needles like an ILS, rather than a wiggly VOR needle or an ADF.

"That also means you can fly every approach the same way, just like an ILS," said Boyer. "That's a tremendous workload reduction, not to mention the safety benefit. Because you can standardize your approach procedures, there is less likelihood of making a mistake."

And there are thousands of these approaches you can fly today with the right equipment.

For more on flying WAAS approaches, see the December 2004 AOPA Pilot magazine article " What's Up With WAAS?"
View AOPA's WAAS video from AOPA Expo.

December 23, 2004

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