SEEGER. FIRE EXTINGUISHING SYSTEM 443cl TICHlllCAL TRAINING SQUADRON 44311 MILITARY AIRLIFT W G, ING (MAC) ALTUS AIR FORCE BASE, OKLAHOMA
A FIRE E){TINGUISHING SYST~ OBJECTIVES~ When you complete this program, you should be able to: 1. State the type of fire extinguishing system used on the C-141 aircraft, 2, Locate the fire bottles and components. 3, List the purpose of the fire emergency control handles. 4. State two ways to expose the discharge buttons. 5. Identify the indication of the low pressure warning lights. 6. Identify the purpose of the "NORMAL" - "ALTERNATE" fire extinguisher bottle select switches, INTRODUCTION This book is arranged l ike an ordinary book; however, the text does not always follow the page numbers, Therefore, it will not be necessary to read each page. There will be directions on each page to guide you. Now turn to page one and begin the program, I ' 22 March 1971
B SUB-SYSTEM (LEFT WING)
1 A high rate Discharge Extinguishing System is provided using Dibromodifluoromethane (DB) as the agent, J Two identical sub-systems are installed one on each wing, (see illustration on opposite page). Each system has its own containers, emergency control handles, low pressure warning l_ights, fire extinguishing discharge buttons, and select switches. Which of the following statements best describe the engine fire extinguishing system? a. A high-rate discharge system connecting all engines. Turn to Page 2 b. A low-rate discharge system with two identical sub-systems, one on each wing. Turn to Page 3 c. A high-rate discharge system with two identical sub-systems, one on each wing. Turn to Page 4
From Pag.e 1 2 No! You must have misread the statement about the two subsystems, Go back and read page one and make another selection. "
From Page 1 3 You picked "b". Perhaps you were thinki_ng of another system, This is a HIGH-RATE DISCHARGE SYSTEM with two IDENTICAL SUB-SYSTEMS ONE ON EACH WING, Go to page 4.
From Page 3 4 You are right! It is a HIGH-RATE DISCHARGE SYSTEM with TWO IDENTICAL SUB-SYSTEMS, one located on each wing. To help understand the system it is necessary to know WHAT the systems components are and WHERE they are located. Let's talk about the containers first. FOUR spherical type FIRE BOTTLES, two located in the UPPER PORTION of each OUTBOARD PYLON, store the fire extinguishing agent. Turn to page 5.
From Page 4 5 A pressure gage located on the SIDE of each CONTAINER and accessible through an inspection door on the right side of each outboard pylon, is the """ ~ to ascertain the container is adequatel y pressurized for operation. PRESSURE GAGE The only means for checking adequate bottle pressure is a pressure gage located on the: a. Container Turn to Page 6 b. Engineers panel Turn to Page 7
From Page 5 6 Good! A pressure gage located on the side of each container and accessible through an inspection door on the right side of each outboard pylon is the only way to check the pressure. There is als.o a DUAL MANIFOLD that routes fluid to ZONE I and ZONE II of each engine. The agent from one or both bottles can be discharged to each nacelle. ~---TO ENG # 2 ZONE Zone I is the combustion-turbine (HOT) section and Zone II is the fancompressor (cold) section of the engine. Take a look at the picture, The extinguishing agent from one or both bottles can be discharged to each nacelle~ a, yes Turn to Page 8 b. no Turn to Pa2e 9
From Page 5 7 Sorry? The pressur~ gage is located on the SIDE of each CONTAINER, Go back and read Page 5. Make another selection. I PRESSURE GAGE
From Page 6 Yes! You are right, the extinguishing agent from one or both bottles 8 can be discharged to each nacelle. Turn to page 10.
From Page 6 point. You chose no l That is the wro.ng answer. You must have missed the Go back to page 6
From Page 8 10 There are FOUR fir e emergency control handles located between the engine instrument panel and the windshield. Pulling the fire emergency control handle accomplishes the following: MECHANICALLY closes the : (1) Fuel manifold shutoff valve. (2) Exposes the fire extinguisher discharge button. ELECTRI CALLY activates the : (1) Engine fuel control shutoff valve. (2) Generator line contactors. (3) Hydraulic fluid shutoff valve. (4) Bleed air shutoff valves. (5) Nacelle cooling air ducts. Pulling the fire emergency control handl e MECHANICALLY activates the : a. Manifold shutoff valve, and discharge the fire bottles. Turn to Page 11 b. Manifold shutoff valve and exposes the fire extinguisher discharge button. Turn to Page 13 c. Both a and b are correct. Turn to Page 12
From Page 10 11 No! Pulling the fire control handle MECHANICALLY closes the fuel manifold shutoff valve and EXPOSES the fire extinguisher discharge BUTI'ON. Proceed to page 13. DISCHARGE BUTTON
F'J?om Page 10 12 You selected "c" for your answer, That is not ~ight. Maybe you should go back to p_age 10.
From Page 10 & 11 Yes! Pulling the fire emergency control handle will CLOSE the fuel 13 manifold shutoff valve MECHANICALLY and expose the fire extinguisher discharge BUTTON. Pulling the fire control handle will ELECTRICALLY isolate the engine from FUEL, AIR and IGNITION to help prevent the fire from spreading. All systems are cut-off except the ENGINE OIL, which is necessary to LUBRICATE the windmilling engine. To prevent the fire from spread~ng we need to isolate the engine from: a. b. c. Fuel, air and combustion. Air, fuel and exhaust. Fuel, air and ignition. Turn to Page 14 Turn to Page 15 Turn to Page 16
From Page 13 14 You chose "a". Not hardly. COMBUSTION is the end result when all ~ngredients are available. Return to p_age 13.
From :rag~ 13 15 Yoµ ~r~ partly right. Fuel, air and.ignition are the i.ngredients, b~t exhaust is the result of combustion. Tµrn to page 16.
From Page 13 & 15 16 a fire. You are 100% correct. Fuel, air and ignition are necessary to start Four discharge buttons located under the TOP PART of the fire CONTROL HANDLE, are normally exposed by pulling the control handle, but a plastic cover may be PUNCHED out, and the fire agent discharged at any time the electrical power is on. Power to discharge all agents is supplied by the MAIN DC BUS NO, 2 through 4 engine fire extinguisher circuit breakers on #4 panel, and from the ISOLATED DC bus through 4 fire extinguisher circuit breakers on the NO. 3 CIRCUIT BREAKER PANEL. The way to expose the discharge button is: a. Pull or turn the control handle. Turn to Page 17 b. Pull control handle or punch out plastic cover. Turn to Page 18
From Page 16 17 No! Pulling the fire control handle is right, but the handle does not turn. You must pull the handle out exposing the discharge button or push out the plastic plug covering the button. Turn to page 18. DISCHARGE BUTTON LASTIC PLUG
From Page 16 18 Yes, when the fire control handle is pulled, it will expos e the discharge button, and when the plastic plug is pulled out it will expose the discharge button also. Two "NORMAL-ALTERNATE" bottle select switches located between the engine fire emergency control handles, provide the capability of discharging one or both of the containers to a single nacelle. This provides maximum t reliability for discharging the fire extinguishing agent. BOTTLE SELECT SWITCHES The two fire extinguisher bot tle sel ect switches pr ovide the capab,ility of selecting: (a) (b) (c) All four bottles to one engine. Bottles one and two, to one engine. Bottles one and f our, to one engine. Turn to Page 19 Turn to Page 21 Turn to Page 20
From Page 18 19 No! Remember the SUB-SYSTEMS are independent of each other, One system on each wing. Turn back and choose another answer. Turn back to page 18,
From Page 18 20 No! Betties. No. 1 and 4 are on opposite wi~gs. There are two bottles located in each outboard pylon. Go to page 21.
From Page 18 & 20 21 You are right! The bottle select switches provide the capability of sel ecting bottles No. 1 and No. 2 to one engine. Four l ow pressure warning lights marked fire bottle 1, 2, 3 and 4 are located on the pilots annunciator panel. These lights illuminate when the pressure drops to 225 PSI warning t he µilot of low cont ainer pressure. The low pressure warning lights come on at a: a. Low pressure of 350 PSI. Turn to Page 22 b. Low pressure of 225 PSI. Turn to Page 23
From Page 21 22 225 PSI. 350 P~I. N9! The pressure switch i.s.. set to turn on the l.ight at i Turn ~o pag~ 23.
From Page 21 & 22 23 Good! You have passed the course. When the container pressure drops to 225 PSI, the low pressure light will come on warning the pilot. ] NOTE: There is one OVERBOARD DISCHARGE INDICATOR on each outboard plyon. It is connected to the pressure relief discharge outlets. A temp of 96 to 104 C will cause a pressure build-up and blow out a red indicator disc. If the disc is missing during a walk-around inspection, check bottle _gress~e.
REVIEW 24 As a short review of the fire extinguisher system fill in the blank spaces. Then check your answers by checking key on opposite page, and make corrections as necessary. 1, The fire extinguishing system is a HIGH RATE discharge system with two identical 2, There are two spherical type containers located in each ------- pylon. 3. The fire emergency control handles when pulled will MECHANICALLY and ------- ------- system. isolate the affect~d engine from all systems except the 4. The low pressure warni.ng lights are located on the ---------- panel and will illuminate when the pressure drops to ------- 5, The four discharge buttons are exposed by pulling the ~~------ or punching out the protector --------------------- --~~--- in the fire control handle. PSI, 6, The two fire extinguisher bottle select switches provide the capability of releasing or containers to a single ~----------- ----------- '
KEY 1. Sub-systems. L:J 2. Outboard. 3. Electrically, Engine oil, 4. Annunciator panel, 225 PSI. s. Fire, Control, Handle, Plug. 6 One, both, nacelle, Air Force OC, 25 May 71-2M