On May 27, 2010 the Federal Aviation Administration (FAA) issued its final rule pertaining to Automatic Dependent Surveillance - Broadcast, also known as ADS-B. Considered by the FAA to be a critical building block for the NextGen air traffic management system, implementation will cost general aviation operators between $ 1.2 billion and $ 4.5 billion. Needless to say that come January 1, 2020 when ADS-B Out will be required for operations in Class A, B and C airspace, as well as withing a 30-nm radius of a major commercial airport - in other words, anywhere conventional encoding altimeters are required today. Needless to say, the airlines will benefit the most from the new system, and they also have the loudest voice regarding the implementation plans put forth by Air National Service Providers around the world. For general aviation aircraft, the least expensive panel mounted 1090ES Mode S transponders are the Garmin GTX-330 and the Honeywell KT-73, ranging in price from $ 5000 to $ 7,000. For larger aircraft remote mounted 1090ES Mode S transponders will cost anywhere from $ 30,000 to $ 50,000 plus installation and antennas. The least expensive way of complying with the ADS-B Out rule is to fit the aircraft with a WAAS GPS receiver which start at about $ 9,000. A remotely located WAAS GPS receive will be considerably more expensive. For those airplanes which will not fly above FL180 a 978 MHz Universal Access Transceiver (UAT) instead of the Mode S 1090ES transponders could be used at a cost of about $ 8,000. To make things even more interesting consider this: "Today's ADS-B Out rule creates a foundation for ADS-B In," Rockwell Collins' Heinrich said. "We know we're going to touch the system again. This involves a bit of 'learn as you go' as we gain experience with the system." "This is the 'final rule' for today, but I doubt it's the final, final ADS-B rule," said Bill Stone, Garmin's avionics products manager. That overtone concerns operators. As many as 150,000 aircraft will have to be fitted with ADS-B Out equipment. Operators are not anxious to upgrade avionics for ADS-B Out in the near future, only to face a separate mandate for ADS-B In at a later date. Today more than 3/4ths of the U.S. general aviation fleet now uses GPS for navigation, and of those only a small portion are WAAS boxes that meet the ADS-B Out accuracy and integrity requirements. Whatever comes next will not be cheap, and if you plan to operate your aircraft after 2020 you should start planning now on how you will comply with these new rules. Until next time keep your wings straight and level Hersch! JetAviator7 s: Don't forget to sign up for our newsletter "All Things Aviation" here!