Aerial Fire Projects
Aircraft operators and fire-fighting authorities take for granted capabilities that up until a few years ago didn't exist. At Trotter Controls we took the early simple mechanical "pull the lever'' designs and evolved it to today's computer-controlled "drop by wire" firegate systems equipped with advanced telemetry and data gathering capability. Read more at Aerial Fire.
FRDS GEN III
The Trotter Controls team, in collaboration with Air Tractor, set about re-designing the successful FRDS GEN II system from the ground up to reduce weight. The team at Trotter Controls saw that the power available from today's ultra-efficient electric motors, customarily used for vehicle propulsion, would be more than capable of controlling the flow of fluid from the AT-802 tank. This meant the weighty hydraulic power unit, valve manifold, and accumulator as well as all associated plumbing could be removed from the legacy FRDS. These heavy, failure-prone hydraulic components were replaced by a very simple and lightweight electric motor/gearbox and DataVault based control system.
In another example of innovation, a single torque tube is used to open and close the bomb bay style doors. Compared to the dual torque tube design used industry-wide, this new simpler design minimizes the obstruction of the liquid flow path through the gate as well as reduces component count and weight.
All Electric Helimax / AST
Taking electric motor and Data Vault control technology to new limits, Trotter Controls worked with Airborne Suppression Technologies to create a ground-breaking constant-flow, carbon fiber tank for CH-47 aircraft. This system received STC's and is operating over fires worldwide.
Considerable advancements in constant-flow compensation have been made during the evolutionary development process since tank flow rates are now compensated for aircraft speed, maneuvering G's, as well as the level of fluid in the tank to maintain constant coverage of retardant on the ground. By way of comparison, a system without G's compensation would flow 41% too much liquid during a one G maneuver, thus wasting retardant and reducing the length of the covered ground line. Trotter Controls systems use retardant in the most efficient way possible.
Brainerd UH60 Blackhawk
Working with the team at Brainerd Helicopters, Trotter Controls also created an all-electric, Data Vault controlled constant-flow firegate for Brainerd's fleet of UH-60 Firehawks. The system is “all-electric” and developed as a low impact plug and play solution. The power for the system is provided via a small tank skid battery and a 15 amp charging circuit to the DC buss of the aircraft.
It is a simple, lightweight, state of the art system that provides GPS/acceleration compensated constant retardant flow and split load performance similar to VLAT airtankers. Along with the Helimax system, it received STC's and operates over fires worldwide.
10 Tanker DC-10 Tank
The highly capable DC-10 airframe has three independent tanks with a total volume above 10,000 gallons. Still, by 2015, its aging control system was no longer able to meet the extremely stringent IAB specifications for VLAT aircraft.
Trotter Controls worked with the 10 Tanker engineering team to produce a state-of-the-art constant flow system using a variant of the FRDS GEN II controller hardware to control the flow rate from each firegate. A Master Controller, together with a network of Data Vaults, determines the gate configuration needed to achieve the commanded coverage level and delivery quantity.
The retardant can be delivered either using each gate in sequence or by controlling all three gates together (ganged). The system is so accurate that it can provide a 10,000-gallon payload in 8 equal drops of 1,250 gallons each.
The upgrade has been very well received by 10 Tankers' customers and has dramatically enhanced the aircraft's performance during operations worldwide.
DataVault
In 2014, recognizing that the need for real time data would become a worldwide trend, Trotter Controls began developing a firegate telemetry system that could be used on a variety of fixed-wing and rotary aircraft. By 2016, the DataVault product was ready for deployment. Four aircraft successfully demonstrated its capability to collect and deliver aircraft firefighting data via iridium satellite to the various reporting agencies. Air Tractor FRDS GEN I/GEN II/GEN III systems as well as a host of other aircraft are supported.
Conceived as the telemetry and control equivalent of a "Swiss Army Knife," DataVault can read sensors, control valves, interact with the pilot and send satellite messages. Since the controller can communicate with peripherals via virtually any standard protocol, Data Vault is easily expanded and can deploy in a myriad of aviation applications.
Since its inception, more than 300 Data Vault telemetry systems have been installed worldwide in a variety of roles on fixed-wing and rotary aircraft of all sizes.
FRDS GEN II
By 2006, more than 150 AT-802F firebombers had been delivered with the first generation Air Tractor gate and were in service worldwide. It was time to move on, and Leland asked Trotter Controls, to apply state of the art and newly available micro-processors to the fire-fighting challenge.
The Trotter Controls team patented a new hydraulic valve control method, which allowed the new FRDS GEN II system to utilize multiple redundant cost-effective and rugged directional valves in place of a single fault-prone servo valve. Additionally, advanced self-diagnostic features were added to the system as well as enhanced flow control capability.
Since then, more than 230 FRDS GEN II systems have shipped worldwide, many being upgraded from the original GEN I systems.
Trotter Controls has provided worldwide service and support for the Air Tractor fleet since the inception of the GEN I system. Several employees involved with the first GEN I system at Spectra Technologies are now with Trotter Controls and are still building and supporting systems worldwide.
FRDS GEN I
The SEAT revolution began with Leland Snow, the legendary developer of the Air Tractor series of aircraft. In the early 1990s, he had the vision to create a low-cost 800-gallon fire-bomber based on his hugely successful AT-502 crop-duster.
He and the design team at Air Tractor began work on the much larger airframe and powerplant design that would become the equally successful AT-802. Leland was an engineer's engineer. His tools were pencil, slide rule, protractor and paper. But like all geniuses, he knew the limits of his capability and was wise enough to ask a local company, Spectra Technologies, to computerize the fire gate.
A team led by Professor Robert L Woods took on the task, and a young Victor Trotter was selected to develop the controls and hydraulics designs. A fundamental objective was to improve the efficiency of the material's delivery from the hopper, and thus the constant flow FRDS GEN I system was born. Interestingly, more than 30 years after their inception, several GEN I systems are still in service and are finally at the end of their operating life (support for GEN I systems was discontinued as of Q 1, 2020).
Our technology driven goal has always focused on maximizing the ground line (length of the pattern on the ground) that can be protected using the least amount of retardant possible. Trotter Controls is currently developing all-electric as well as hydraulically controlled constant-flow / constant-coverage firegate systems using the DataVault controls platform for various other airframes. The advances in performance, weight, and data gathering capability are serving to increase the effectiveness of the aircraft and provide real-time awareness to fire-management operations.
