IMPORTANT - GPS WAAS Shutdown; Be Sure To Find Out How This Effects Your GPS Unit

The NAAA received information on July 12th that some changes are being made to the GPS Wide Area Augmentation System (WAAS) by which many operators receive differential information to ensure the accuracy of their GPS swath marking. This could result in the loss of the WAAS signal in many of the agricultural GPS units available to the agricultural aviation industry. According to an announcement by the FAA Global Navigation Systems Group, a new satellite (PRN #138) was put into operation this week which should provide better WAAS coverage information to the entire United States. They then intend to shut off two satellites (PRN #122 and PRN #134) which are currently providing the augmentation signal. The shutdown was initially scheduled between July 16 and July 20, 2007, but through NAAA action, Ms. Deborah Lawrence, FAA WAAS Program Manager, notified the NAAA staff that the FAA would allow the two satellites to remain online until July 31, 2007 in order for upgrades to be made to ag aircraft equipment. There will be no extension beyond that date.

Again, we have learned from GPS manufacturers that this shutdown could result in the loss of the WAAS signal in many of the agricultural GPS units available to the agricultural aviation industry. The various manufacturers report that corrective action may vary anywhere between no action being required on the newer units to equipment that must be returned to the factory or dealer for updating. Some units may be updated by the use of a keyboard, a replacement chip or programming information downloaded from the internet and installed in the unit. The system must then be re-booted for the changes to take effect. If the unit requires an upgrade, the GPS companies contacted have agreed to have personnel available to ensure a quick, one-day turn-around to minimize the time that operators will be without their GPS.

Although the NAAA was able to secure extra time to upgrade equipment, the July 31 deadline has passed. The NAAA recommends that all operators immediately contact either their GPS manufacturer or dealer to verify which corrective action is required on the model they are operating.