The Air Tractor AT-802F and the Fire Retardant Dispersal System (FRDS) have grown up together. Proven to be a formidable firefighting system since its introduction in 1993, the AT-802F aircraft and the Generation II FRDS are now set to move single engine air tanker firefighting into a new era of improved control, reliability and overall effectiveness.
The original Air Tractor FRDS represented a leap forward in fire gate control technology for aerial firefighting applications. With its computerized fire gate technology, air tanker pilots could simply and quickly dial-in coverage level and drop amount. Calculations were then handled by the system’s on-board computer, making it possible for the pilot to deliver a consistent and controlled amount of fire retardant to the specified drop zone.
You can learn more about how to operate the FRDS GEN II by installing the FRDS GEN II Simulator.
HISTORY
Since its introduction, the Air Tractor FRDS fire gate has earned a reputation in wildland firefighting circles for uniform coverage and system reliability. But in the past 16 years computer technology has made exponential advances, so the Generation II FRDS fire gate has been updated to allow pilots and operators to take full advantage of those advances.
Says Leland Snow, President of Air Tractor, Inc., “The Air Tractor FRDS has been the most precise and accurate fire gate for single engine air tankers since its introduction with the AT-802F in 1993. Now it’s been improved with the latest computer technology and self-diagnostics. It’s the next logical step in the evolution of this computerized fire gate.”
IMPROVEMENTS
Improved delivery accuracy, improved door speed and new advanced leakage compensation algorithms are among the second generation FRDS enhancements. The fire gate doors — which open and close with timing that’s measured in milliseconds — are even more responsive.
Numerous reliability enhancements have been designed-in throughout the new Air Tractor FRDS system. The components of the system have been “hardened” to protect against the effects of vibration and humidity; the system also has improved waterproofing throughout. Microprocessor and electro-mechanical back-up systems have been added. A three valve redundant auto salvo system assures reliable door opening for accurate drops.
Computer processing advances make the FRDS pilot interface more user friendly. An easy-to-read display allows pilots to assess system status at a glance. Field service and maintenance has been simplified with a “black box” or cable swap-out program and self-diagnostic and alert message features that indicate possible malfunctions and help isolate problems in the system.
The hydraulic system of the FRDS also reflects numerous reliability improvements. The new dual-head hydraulic pump is 93% efficient, and powered by a heavy-duty DC motor. An inlet filter helps prevent contaminants from entering the hydraulic system and extends component life. The entire hydraulic system has been tested in a controlled environment of over 160° (F) for more than 6,000 flight hours.
The previous FRDS system’s servo valve has been replaced with three identical directional valves, providing three levels of redundancy when opening and closing fire gate doors. An independent pressure switch (electro-mechanical system) and pressure sensor control the hydraulic pump.
In total, all these improvements work together to make the Generation II FRDS easier for operators to use and even more reliable and simple to maintain. The minimal initial training that is required for system maintenance further improves the operational economics of the new system.
THE BEST DISPERSAL SYSTEM ON THE MARKET
Since its introduction, ease of use and ease of maintenance have been the hallmark of the Air Tractor FRDS-equipped AT-802A and 802AF. In 3 to 5 seconds the pilot can dial-in the coverage level, the drop amount, the ground speed and arm the system. With a press of the trigger on the control stick, the computer opens and closes the fire gate doors according to the selected parameters. For pilots, operators and fire management personnel on the ground, it’s a “point and shoot” system that proves its worth with every fire drop.
The first AT-802F aircraft equipped with the Generation II FRDS was shipped to Avialsa, based near Valencia, Spain where it joined their fleet of 22 other AT-802F and AT-802AF single engine air tankers.
