TECHNICAL EXHIBIT 4 - ASD267C AFFS System Description.pdf

PREPARED BY

M. HUTTER

DATE 18 APR 02

AERO UNION CORPORATION

CHICO MUNICIPAL AIRPORT, CHICO, CALIFORNIA

PAGE NO.

CHECKED BY

A. Proger

DATE 21 APR 02

SUBJECT

AFFS

SYSTEM DESCRIPTION

REF. DWG. NO.

113000

REPORT NO.

ASD267C

REPORT NO. ASD267

TITLE: AFFS SYSTEM DESCRIPTION

REVISION: C

PREPARED BY: M. HUTTER 18 APR02

ASD ENGINEERING DATE

APPROVED BY: M. HUTTER 21 MAY 02

PROJECT ENGINEER DATE

APPROVED BY: J. BARTHOLOMEW 21 MAY 02

ASD MANAGER DATE

D.7 - Technical Exhibit 4

DATE 18 APR 02

AERO UNION CORPORATION

DATE 21 APR 02

SUBJECT

AFFS

SYSTEM DESCRIPTION

REF. DWG. NO.

113000

REPORT NO.

ASD267C

REVISIONS

REVISION DESCRIPTION DATE APPROVAL

NC INITIAL RELEASE 21MAY02 MH

A Updated for the production unit 11DEC03 AP

B Changed “3600+ gallons” to “3000”. 07-12-31 S. Earl Added revision to title page. Added Description of NOZZLE switch.

Updated description of controllers to Include multiple controllers. Revised Figures. Added numbering, TOC, List of Figures.

C Revised Section 4.6 to state that the 08-06-30 S. EARL system automatically disarms when E-Dump is initiated.

Deleted the last paragraph: “If the E-Dump is initiated......”

SUBJECT

Table of Content

1. INTRODUCTION

2. REFERENCES

3. ABBREVIATIONS

4. SYSTEM DESCRIPTION

4.1. General Description

4.2. Nozzle Assembly

4.3. High Pressure Air System

4.4. Control System

4.4.1. Drop Control Pendant:

4.4.2. Load Master Controls:

4.4.3. System PLC’s:

4.5. System Sensors

4.6. Emergency Dump System

List of Figures

Figure 1. C-130 Aircraft Figure 2. AFFS Configuration Figure 3. C-130 Isometric View Figure 4. C-130 Side View Figure 5. C-130 Cargo Floor Arrangements Figure 6. Electrical Cabinet Figure 7. Throttle Body and Pintle Assembly Figure 8. Drop Control Pendant Figure 9. Load Master Control Boxes

SUBJECT

1. INTRODUCTION

The purpose of this report is familiarize the reader with the Aero Union C-130 AFFS.

Figure 1. C-130 Aircraft

2. REFERENCES

ASD577 C-130 AFFS Hydraulic System Report ASD581 C-130 AFFS Electrical System Description ASD582 C-130 AFFS Air System Description ASD598 C-130 AFFS Mechanical Interface Report DWG 113000 Installation Assembly, C-130 AFFS DWG 113053 Air System Schematic DWG 113293 Hydraulic System Schematic

3. ABBREVIATIONS

AFFS Airborne Fire Fighting System (also known as MAFFS II) ASD Aero Union Corporation, Airborne System Division AUC Aero Union Corporation OBVP Overboard Vent Pipe PLC Programmable Logic Controller PSI Pounds per Square Inch

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4. SYSTEM DESCRIPTION

4.1. General Description

The Aero Union AFFS is a constant flow, 3000 gallon, roll-on/roll-off aerial fire fighting system for the C-130 aircraft. Similar to MAFFS, AFFS is a pressurized system with its own charging capability. The unit is self contained and can operate independently from any airtanker base. The AFFS has been engineered to meet or exceed the Interagency Airtanker Board Criteria for Retardant Systems.

The coverage level and volume for each drop are selected from the system’s control panel. A drop button is used to execute the selected drop. The retardant is discharged through a high velocity nozzle through the left paratroop door. The installation and operation of the AFFS requires no permanent modification of the aircraft.

The AFFS is designed to interface with the A/A32H-4A Cargo Handling System. As a palletized unit, the AFFS can be rolled on to the C-130 from its own support trailer.

Figure 2. AFFS Configuration

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The AFFS is comprised of four major assemblies. The forward, center and aft pallets, which are connected together as a single assembly; the Overboard Vent Assembly and the Paratroop Door Pressure Plug.

- The forward pallet houses the system’s air compressors and power distribution panel. It is handled as a separate pallet.

- The center pallet is made up of the primary retardant tank and truss structure and contains the system’s air control components and high pressure tanks. It is structurally connected to the aft pallet and therefore, the two pallet are handled as one.

- The aft pallet contains the cabin crew stations, the right side fill station, the foam injection system and the inboard discharge manifold, as well as the hydraulic system.

- Structurally connected to the aft pallet is the Overboard Vent Pipe Assembly, Also referred to as the Overboard Vent Pipe (OBVP). The outboard section is removed and stowed during relocation flights.

- The nozzle assembly is mounted to the aft and center pallet, and includes the actual nozzle, the two supporting braces, the left fill assembly, and the fairing. It is removed and stowed during relocation flights.

- The paratroop door pressure plug is installed instead of the actual aircraft door, and allows the aircraft to be pressurized during AFFS missions. The door is removed and stowed during relocation flights.

Figure 3. C-130 Isometric View

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Figure 4. C-130 Side View

A detailed description of the mechanical interface of the system with the aircraft is provided in ASD598 C-130 Mechanical Interface Report.

A Load Master and an observer station are integrated into the AFFS Aft Pallet. The load Master has the overall responsibility for the operation of the system. The Load Master station includes three control boxes used to control the operation of the system and set the variables of the air drops, and is described in details in section 4.3. The final command to drop is achieved by a trigger on one of the two Drop Pendant on the system. The Load Master has a Drop Pendant at his station. A Cockpit Drop Pendant is installed at the co-pilot’s flight deck station providing similar functionality to the load master’s.

The AFFS is secured to the aircraft using 12 10,000 lbs tie down devices as shown on Figure 5 below:

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Figure 5. C-130 Cargo Floor Arrangements

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Once the AFFS is installed in the aircraft, power is connected to the electrical cabinet in the form of two AC harnesses and one DC harness. Also connected are the aircraft generator monitors via a separate harness. The Electrical cabinet is located on the Forward Pallet, and is shown below.

Figure 6. Electrical Cabinet

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The AFFS provides an emergency jettison capability (E-Dump). The E-Dump event is initiated from either the Load Master station or pilot station by a switch on the Drop Pendant. The E-Dump Switch in both the Cockpit Pendants are enabled together. Either station may initiate an emergency discharge of the system. The Emergency Dump system is equipped with a backup battery, so that in case of an aircraft power failure there will be sufficient power available for opening the pintle and the two overboard vent valves.

The AFFS may be filled from either side of the aircraft. The right side is equipped with a fill station which deploys out the paratroop door. The left side fill station is built into the discharge manifold. There is a single fill station box provided with the system that can be mounted in either position. The fill station box has a visual volume indicator, as well as an electrical connector for connecting to the aircraft intercom system (ICS). During fill operations, the retardant tank is vented out the paratroop door. In the event of an overfill, overboard dump also occurs out the paratroop door vent.

When the system’s Arm Switch is momentarily selected to the ARM position, the main retardant tank is charged to operating pressure and the system’s Drop Buttons is enabled. In addition, an indicator lamp on the Cabin Control Box illuminates the Armed Segment and the Drop Pendant Armed Indicator illuminates indicating a “live” Drop Button.

Prior to a drop, the Load Master will select coverage level, drop volume and foam concentration. Selection is made with the rotary Drop Selector Switch. Coverage Levels of 0.5, 1, 2, 3, 4, 6 or 8 and volumes for 1/8, 1/4. 1/2 and ALL may be selected. Foam concentration 0f 0.1%, 0.5% and 1% may be selected. The system executes the selected drop when the Drop Button is Depressed. The Drop Button must be held for the duration of the drop. At the end of the drop, the system’s controller closes the nozzle at the required volume. If the Drop Button is released before the end of the selected drop, the controller terminates the drop by shutting the nozzle. This Drop Button feature allows for the release of “any” volume amount.

The term “Riding the Button” is used when the flight crew selects the desired Coverage Level from the ALL volume. The Drop Button is then used to start and stop the flow of retardant. This allows the flight crew some flexibility in dispensing the retardant.

4.2. Nozzle Assembly

Prior to and during the drop, the main tank is kept at a constant pressure of 75 PSI by regulating high pressure air from two storage tanks. The flow of retardant is controlled by a throttle body and pintle assembly valve. The pintle is driven by a hydraulic actuator.

SUBJECT

The description of the operation of the hydraulic actuator is covered in ASD577 C-130 AFFS Hydraulic System Report.

Figure 7. Throttle Body and Pintle Assembly

The design of the Throttle Body and Pintle assembly is based on proven constant flow delivery performance. The system uses the nozzle aperture to vary flow rate. The nozzle pintle which creates the discharge aperture, rapidly closes allowing for controlled capture of any specific volume.

4.3. High Pressure Air System

The high pressure air system consists of two arming valve, two pressure regulators, two high pressure storage tanks, and two high pressure air compressors along with associated pressure sensor controls. A main vent valve is located on the main tank, as well as a secondary vent valve used to prevent fluid from spilling during takeoff.

The air compressors are electrically driven by the aircraft’s 400 Hz,115 VAC, 3 Phase power supply. With the system powered up and the Compressor Enable Switch on the Cabin Control Panel selected to the ‘ON’ position, the low pressure switch in the high pressure reservoirs starts the compressors if pressure is below 400 PSI. The compressors run until the high pressure reservoir tanks reach operational levels of 1,200 PSI. The time required to charge the reservoirs is 32 minutes at sea level.

SUBJECT

Once the system’s high pressure reservoirs are at operational levels, the compressors shut off.

When the system’s Arm Switch is momentarily selected to the ARM position, The vent valve on the tank system closes. After a short delay, the arming valves controlling the high pressure tanks open. This allows for the regulation of pressurized air into the retardant tank. With the nozzle closed, pressure builds within the main retardant tank. If the system is armed, and the retardant tank pressure is below a set level of 600 PSI, a system low pressure Indicator illuminates. The system will operate with diminished performance.

When the drop button is depressed, the Pintle is commanded open and retardant flows out of the nozzle. The system’s two pressure regulator maintain a constant pressure in the retardant tank until the last incremental volume is fully released. At a set volume prior to the empty point of the tank, the control system automatically starts a “Cleanout” sequence. During this cleanout sequence, the pintle is commanded open, and the remainder of the retardant is expelled out of the tank in an effort to remove as much of it as possible. The system then disarms automatically, closing off the high pressure reservoirs and opening the system’s vent valve, allowing the retardant tank to vent overboard through the paratroop door.

A detailed description of the Air System is covered in ASD582 C-130 AFFS Air System Description.

4.4. Control System

Two control stations on the Aero Union AFFS are located at the load master crew station in the cargo cabin and at the copilot station in the Cockpit. The AFFS loadmaster Control Station consists of a Foam Control Box, a Cabin Control Box, a Take Off Valve Control Box and a Drop Control Pendant. The cockpit station consists of a Drop Control Pendant only. Figure 9 shows the Load Master controls.

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Figure 8. Drop Control Pendant

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Figure 9. Load Master Control Boxes

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The AFFS control panels are the same type as used on other Aero Union constant flow systems. The panels have been configured to provide for both drop control and tank status monitoring. The Cabin Control Box and Foam Control Box are fully configured panels with arming, control selection, negative status indicators, and foam injection controls. The power switch selects between Air Mode (switch on, normal operation) and Ground Mode (off position) for ground servicing.

4.4.1. Drop Control Pendant:

Drop Control Pendant are provided at both the Load Master’s station and the Copilot’s station. These Pendants provide for local control indication, primary drop button and the emergency drop button. An extension cord is necessary to connect the Copilot’s Pendant, but can also be used on the Load Master Pendant.

E-dump Switch: Used to initiate a Emergency Dump. This system has battery backup in the event of aircraft power failure.

Drop Button: Used to command a drop sequence.

4.4.2. Load Master Controls:

The Load Master’s seat is equipped with a pedestal arm which contains mounting provisions for both the Cabin Control Box (Master) and the Foam Control Box. One additional box, the Takeoff Vent Valve Box provides controls for the operation of the Takeoff Vent Valve. The valve is manually commanded shut during the takeoff and climb phases of the AFFS mission. The foam controls are incorporated into a separate box to allow for their removal with the modular foam system.

The following switches are a part of the Load Master Control Boxes:

Cabin Control Box:

POWER SWITCH: Located on the Cabin Control Box, it is used to supply power to the various parts of the system needed for normal operation inside of the aircraft. In the ON position, the system operates in “Air” mode. In the OFF position (Ground Mode) power is still available for running compressor #1 via a ground power cart. When the controller boots up, the system fail indicator is turned off as the system power indicator is turned on.

COMPRESSOR ENABLE SWITCH: Located on the Cabin Control Box, it is used to enable the automatic compressor controls.

SUBJECT

ARMING SWITCH: When pushed momentarily in the ARM direction, arms the system.

The controller then closes the tank’s vent valve, opens the arming valves, and enables the drop button. When pushed momentarily in the DISARM direction, disarms the system. The controller then disables the drop button, closes the arming valves, and opens the vent valve.

DROP SELECTOR: A rotary switch which allows the crew to select the drop which they wish to make. Twenty six selections are made from Coverage Levels (0.5, 1, 2, 3, 4, 6, 8 gpc) and Volumes (1/8, 1/4, 1/2, and ALL).

AFFS Drop Selector Switch

Switch Drop Selection E,H,J Target Flow Rate

Position Coverage Level Volume Gallons Gal/Sec 1 0.5 1/8 375 50 2 1 1/8 375 100 3 2 1/8 375 150 4 3 1/8 375 225 5 4 1/8 375 300 6 0.5 1/4 750 50 7 1 1/4 750 100 8 2 1/4 750 150 9 3 1/4 750 225 10 4 1/4 750 300 11 6 1/4 750 450 12 8 1/4 750 600 13 0.5 1/2 1500 50 14 1 1/2 1500 100 15 2 1/2 1500 150

SUBJECT

Switch Drop Selection E,H,J Target Flow Rate Position Coverage Level Volume Gallons Gal/Sec

16 3 1/2 1500 225 17 4 1/2 1500 300 18 6 1/2 1500 450 19 8 1/2 1500 600

20 0.5 ALL 3000 50

21 1 ALL 3000 100

22 2 ALL 3000 150

23 3 ALL 3000 225

24 4 ALL 3000 300

25 6 ALL 3000 450

26 8 ALL 3000 600

FLOAT SELECTION: Used to select between the “Primary” float and “Spare” Float. Used when a failed float is suspected.

TEST LAMPS: Used to test the illumination function of the panel indicator lamps.

NOZZLE: Used to manually open and close the nozzle for servicing. This switch only works when the system is disarmed.

Foam Control Box:

FOAM MIX SELECTION SWITCH: Used to select the level of foam concentration to be injected into the drop discharge. Percent concentrations of 0.1%, 0.5% or 1.0% can be selected.

FOAM SWITCH: Used to enable the injection of foam into the drop discharge. Once selected the system’s controller will monitor the coverage level and mix ratio selected.

The appropriate amount of foam is then injected into the discharge manifold during the drop.

The foam switch provides 28 VDC to the two solenoids and the flow control valve in the foam system.

Takeoff Vent Valve Box:

VENT VALVE CLOSED/OPEN: Used to manually control the position of the Takeoff Vent Valve. The valve is closed during takeoff and climb.

SUBJECT

LAMP TEST: Push to test button to check the VENT VALVE CLOSED and VENT VALVE OPEN lights.

The following indicators are a part of the Load Master Control Panels:

Cabin Control Box:

TANK QUANTITY: A lighted panel meter which indicates the quantity of fluid within the main tank. The signal for this display is a calibrated float signal from the system’s controller. Color: Green

POWER: Illuminates when the system controller comes on line. Indicates that the system indicators and switches are enabled. Color: Green

ARMED: Illuminates when the system is armed. Color: Green

COMPRESSOR ARMED (COMPRS ARMED): Illuminates when the air compressor system is enabled.

Color: Green

SYSTEM FAIL : Illuminates when the system controller detects a failed system mode or the controller is off line. The lamp is turned off by the system controller. Color: Amber

RESER PRESS (RESERVOIR PRESSURE LOW): Illuminates when the system’s high pressure reservoir pressure drops below 400 PSI. The lamp is controlled from an output from the Solutions Cubed PLC, which compares float voltage to a pressure transducer voltage. Main system release capability can not be verified if this indicator is illuminated.

Color: Amber

TANK PRESS (TANK PRESSURE LOW): The lamp is operated from two pressure switches (PS3 and PS4) located in the retardant tank’s low pressure inlet manifold When the system is armed, illuminates when the retardant tank’s pressure drops below 70 PSI.

The indicator is enabled when the Arm Switch is selected.. Proper flow control can not be assured if system pressure falls below this level.

In addition, when the system is disarmed, illuminates when more than 5 psi exists in the main tank (PS3). This indicates a failure of the tank to vent. Color: Amber

E-DUMP ELEC (E-DUMP ELECTRICAL FAILURE): Illuminates when battery power is not present at the Emergency Dump Switch. Indicates that the emergency backup batter is not connected. Color: Amber

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HYDRA PRESS (LOW HYDRAULIC PRESSURE): Illuminates when the nozzle’s hydraulic system is below operating requirements. Opening of the nozzle may not be possible. Color: Amber

NOZZLE OPEN: Illuminates whenever the nozzle is not in it’s fully closed position ( open more .125 inches) . Color: Amber

COMPRESSOR PRESS OIL LOW (OIL): Illuminates when the compressor oil pressure drops below operating requirements. The lamp is controlled by a pressure switch in the compressor block. This signal feeds back to the Entertron PLC and causes a shut down of the compressor. Note: the oil pressure light will be illuminated when the compressors are not running and approximately one second after the compressors startup. Color:

Amber

COMPRESSOR OVER HEAT (HOT): Illuminates when the compressor head or compressor motor is overheated. The lamp is controlled by a temperature switch in the block of the compressor. This signal feeds back to the Entertron PLC and causes a shut down of the compressor. Color: Amber

TEST LAMPS: Momentary push button that illuminates panel indicators when the switch is depressed. The switch is used to verify the functionality of the other tank system indicators. Color: White

Foam Control Box:

FOAM ARMED (ARMED): Illuminates when the foam system has been armed and the minimum operational pressure exist in the foam tank. Color: Green

INJECTING FOAM (INJECT): Illuminates when power is supplied to the foam tank isolation valve. Color: Green

FOAM TANK QUANTITY: A lighted panel meter which indicates the quantity of fluid within the foam tank. The signal for this display is a calibrated float signal from the system’s controller. Color: Green

Takeoff Vent Valve:

VENT VALVE CLOSED: Illuminates when the Takeoff Vent Valve is closed: Color:

Green

VENT VALVE OPEN: Illuminates when the Takeoff Vent Valve is open. Color: Amber

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4.4.3. System PLC’s:

Four Programmable Logic Controllers (PLC) make up the control system of the AFFS.

Two Entertron Elite 2000 PLC’s control the operation of the compressors and hydraulic pump. Controller #1 controls the hydraulic pump and compressor #1. Controller #2 controls compressor #2. A Solutions Cubed PLC (Main) controls the operation of the nozzle. A second Solutions Cubed PLC (Foam) controls the operation of the foam system. The PLC’s monitors the systems switches and sensors. They also sets the status of the systems indicators. The volume calibration, reservoir pressure calibration, drop selection and nozzle position look up tables are stored in the controllers’ programs.

When the Drop Button is depressed one of the controllers executes the selected drop.

The controllers are programmable units. They are powered from 28 VDC aircraft supplied power.

When powered up, the system’s main controller will extinguish the System Fail Indicator and illuminate the Power indicator.

The controller will continuously receive and convert the tank’s float voltage (0-10 VDC) signal into a Volume Feedback Signal used to drive the system’s volume indicators.

The controller will continuously receive and compare the high pressure reservoir pressure voltage (0-10 VDC) signal to the tank’s float voltage (0-10 VDC) signal and illuminate the Reservoir Pressure Lamp as required.

The controller will monitor the system’s Drop Button and Drop Selector Switch. The drop selector switch provides two voltage signals, a volume signal (0-10 VDC) and a coverage level signal (0-10 VDC). The volume signal equates to the amount of retardant to be released (ALL, 1/2 , 1/4 , 1/8). The coverage level equates to a discharge nozzle position.

When the drop button is depressed, the controller will power the appropriate hydraulic valves (28 VDC) and open the discharge nozzle to a predetermined position to establish a desired flow rate. The controller will start an internal timing loop once the pintel is in position and terminate the drop at the end of that time base. The controller will also monitor the drop button during the discharge and will close the discharge nozzle if the button is released before the selected volume is discharged. The controller will also provide for a cleanout routine based a given float signal level.

The foam controller will monitor the Foam Arming Switch and the Foam Mix Ratio Selection Switch. When the foam system is armed, the controller will compare the coverage level signal from the Drop Selection Switch (Seven levels, 0-10 VDC) to the mix ratio signal from the Foam Mix Ratio Selection Switch (Three levels, 0-10VDC).

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4.5. System Sensors

Level Sensors:

The AFFS is equipped with three fluid level sensors or floats. The signal from these floats are calibrated to volume. The main tank has two floats. The primary float performs this function and the secondary float is an installed spare. A selection switch on the cabin control panel allows for the selection of either float. The foam tank also has one float.

Pressure Switches and Transducers:

Pressure switches and transducers are used to control the air compressor and the pressure status indicator lamps. Pressure gauges are used to give visual reference to the actual pressure within the storage reservoirs and the retardant tank.

Linear Potentiometer:

A linear potentiometer is used to track the position of the nozzle pintle.

The electrical system is described in detail in ASD581 C-130 AFFS Electrical System Description.

4.6. Emergency Dump System

The Emergency Dump system provides an alternate electrical source to jettison the load of retardant. Both Drop Control Pendants are equipped with a guarded switch on top of the grip pendant. Both emergency buttons are enabled once the system’s Power Switch is selected. Either control station can initiate an emergency dump by lifting the guard and depressing the Emergency Dump Switch.

The activation of the Emergency Dump switch opens the pintle to a full open position using the hydraulic pressure in the E-Dump accumulator and the E-Dump pressure supply line. The opening of the hydraulic isolation valves is controlled by a time delay relay. This guarantees that the E-Dump event cannot be interrupted. The duration of the E-Dump event is approximately 90 seconds. During that time, no motion of the pintle is possible.

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If the system is disarmed, the Load Master verifies that the takeoff vent valve is open before initiating the E-Dump event. On pintle opening, the retardant flows out of the tank under the force of gravity.

If the system is armed, the Load Master needs to verify that the takeoff vent valve is open, before initiating the E-Dump event. The system automatically disarms when E- Dump is initiated. The vent valves will open slightly before the pintle, allowing air pressure to drop rapidly, and therefore reducing the bulk of the thrust from the retardant.

The remainder of the retardant flows under the force of gravity.