21-AIR CONDITIONING DESCRIPTION
REMARKS
REFERENCE
AIR CONDITIONING D/O 21-00-00
AIR CONDITIONING MAINTENANCE PRACTICES
AMM 21-00-00/201
Two tasks are supplied in this procedure. The first task is to use an external source to supply conditioned air. The second task is to use the airplane packs to supply conditioned air.
A. Smoke or fumes flow into the passenger cabin or the flight compartment through the air distribution system during flight. This problem is usually caused by contamination of the air by oil, glycol, fuel, or hydraulic fluid. In flight, contamination can be caused by leakage of these fluids in one of the engines. B. Smoke or fumes can also be caused by oil, glycol, hydraulic fluid, fuel fumes or exhaust fumes being ingested into the inlet of one of the engines. From the inlet, the contaminant can go into the pneumatic and/or the air conditioning system and vaporize at higher temperatures.
REMOVE THE SMOKE OR FUMES FROM AIR CONDITIONING SYSTEM T/S
AMM 21-00-00/101
C. The APU is a likely source of the smoke or odors. An APU failure can release oil into the air conditioning system. Oil, glycol, fuel or hydraulic fluid ingested into the inlet of the APU is another possible source of the contamination. D. Fumes can also be caused by the use of petroleum jelly during maintenance of the pneumatic ducts or air distribution ducts. E. Do not do these procedures with the passengers or the crew on the airplane since it can cause smoke or fumes in the passenger cabin. F. Related Information: (1) AMM 21-00-00/001, 21-00-00/001, Air Conditioning Simplified Diagrams.
G. Trouble shooting is provided for these faults:
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PROCEDURE 1:
Smoke or Fumes in the Passenger Cabin or Flight Compartment reported during flight. Smoke Stops with Isolation Valve Closed, Right Pack Switch Off. PROCEDURE 2: Smoke or Fumes in the Passenger Cabin or Flight Compartment reported during flight. Smoke stops with Isolation Valve Closed, Left Pack Switch Off. PROCEDURE 3: Smoke or Fumes in the Passenger Cabin or Flight Compartment, reported during flight. Smoke does not stop with Isolation Valve Closed, each of the two Pack Switches Off (In Turn). PROCEDURE 4: Smoke or Fumes in the Passenger Cabin or Fl ight Compartment - Stops with Recirculation Fan Off.
REMOVE THE SMOKE OR FUMES FROM AIR CONDITIONING SYSTEM
AIRPLANE ABILITY TO MAINTAIN CABIN PRESSURE IN FLIGHT ON SINGLE PACK OPERATION T/S
AMM 21-00-00/201
AMM 21-00-05/101
This procedure gives instructions to remove the oil contamination from the air conditioning and pneumatic systems. You must first isolate the cause of the oil contamination and repair the problem before you do this (10) Remove the check valve at the pneumatic ground connector (Ref/ 36-11-45/401). NOTE: -This -This will permit the initial bleed bleed air, which has more more oil contamination, to go out through the check check valve opening. (15) Operate the air conditioning packs: Make sure the aft outflow valve is open (Ref 21-31-00/201) or least one passenger entry door is open. (20) Examine these components for oil contamination: (a) Heat exchangers (b) Coalescer bags in the water separators Trouble shooting the airplane ability to maintain cabin pressure in flight on a single pack operation involves the air cycle system, the pneumatic supply system, the pressurization control system, and various airplane openings that could possibly be a source of leakage. leakage. An understanding of how the different components are interrelated as well as the function of each is needed to locate and correct problems in either system.
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AIRPLANE DISPATCH WITH SINGLE PACK OPERATION – CONFIDENCE CHECK
RECIRCULATION FAN T/S
AMM 21-00-05/201
AMM 21-21-22/101
Main distribution recirculation fan trouble shooting can be accomplished without operating the air conditioning packs and no special equipment is needed. B. Intermittent or cycling operation of recirculation fan indicates fan overheats or defective overheat switch. Remove and replace recirculation fan.
CONTROL CABIN CONDITIONED CONDITIONED AIR DISTRIBUTION DISTRIBUTION SYS. D/O 21-22-00
CONTROL CABIN CONDITIONED AIR DUCTREPAIRS
AMM 21-22-11/801
This procedure has two tasks to repair the polycarbonate (lexan) air ducts which have damage. One procedure uses a patch to repair the damaged air duct. (permanent) The second procedure uses a tape to repair the damaged air duct. (temporary) This procedure also has a task to repair the aluminum alloy ducts in section 53 which are installed on the left side of the forward cargo compartment. T The procedure can be used to replace a damaged duct or to repair a leak at the joint between two ducts.
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PASSENGER CABIN CABIN CONDITIONED AIR AIR DISTRIBUTION SYS. D/O 21-23-00
VENT MUFFLER
AMM 21-23-17/201
This procedure has two tasks. The first task gives instructions to clean the vent muffler. The second task gives instructions to repair the vent muffler. B. The air velocity through the vent muffler can increase if the vent muffler shell has contamination or cracks. This can cause noise levels to increase.
PRESSURIZATION CONTROL
PRESSURIZATION CONTROL SYS A/T
AMM 21-31-00/501
CABIN PRESSURIZATION OUT FLOW VALVE ./REPAIR
AMM 21-31-11/801
A. This test has six tasks. The six tasks are: (1) System Test - Pressurization Control System The system test does a check of the four modes of operation of the pressurization control system. • (2) Functional Test of the Pressure Controller The second task does a check of the system components when you measure electrical values at the pressure • controller. (3) Standby Rate Check The standby rate check does a check of the rate of cabin altitude change for the standby mode. • (4) Standby Altitude Check The standby altitude check does a check of the CAB ALT control. • (5) Automatic Rate Check The automatic rate check does a check of the rate of change in the cabin altitude in the AUTO mode. • (6) Resistance Test of the Pressurization Outflow Valve. The outflow valve resistance test does a check of the AC and DC clutches and the valve feedback • potentiometers. You must must remove the aft outflow outflow valve to do this test. This repair procedure replaces the outflow valve frame seal while the outflow valve is installed on the airplane.
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SAFETY RELIEF VALVE A/T
AMM 21-32-21/501
21-30-00
1. 2.
This subject has two tasks. The first task is a functional test of the safety relief valve using a Hamilton Standard test fixture. The second task is a functional test of the safety relief valve using Boeing test equipment. The test decreases pressure at the external pressure port to the valve to give a signal of high cabin pressure.
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COOLING 21-50-00 •
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AIR CYCLE SYSTEM T/S
AMM 21-51-00/101
ACM UNIT SERVICE
AMM 21-51-11/301
HEAT EXCHANGER CLEANING
AMM 21-51-21/701
WATER SEPARATOR COALESCER (BAG). CLEANING/PAINTING
•
The heat exchangers are cleaned with a detergent that flows through the heat exchangers in the opposite direction of the ram air. Air from the APU or from a high pressure ground cart can be used to move the detergent through the heat exchangers.
AMM 21-51-41/701 •
•
•
RAM AIR SYSTEM T/S
Trouble shooting the cooling portion of the air conditioning system involves both the air cycle system and the ram air system. An understanding of how the different components are interrelated as well as the function of each is needed to locate and correct problems in either system. Grouping individual components according to function aids in locating a defective component. The water separator, 35 F control sensor, 35 F control valve and 35 F controller are functionally related. Another grouping includes the heat exchangers, air cycle machine, ram air system, the compressor discharge and turbine inlet overheat thermal switches and the pack temperature bulb.
AMM 21-52-00/101
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•
•
If a system trips off from overheat but without excess air supply, the ram air system should be suspected. Make sure that the ram air inlet and exhaust doors are open. If unwanted material such as paper or cloth are ingested into the ram air system, they could restrict air flow through the system. Inspection doors are provided in the ram air ducts forward of each heat exchanger for duct inspection. If difficulty occurred during flight while flaps were in any position other than fully retracted, do a check of the cooling system (AMM 21-51-00/501). If the system has tripped off without excessive temperature being recorded, the thermal switches may be defective and should be checked. It is recommended that 20-10-27, Maintenance Practices, be reviewed before using heating equipment on system components.
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•
TURBOFAN UNIT SERVICE
AMM 21-52-61/301
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•
RAM AIR INLET CONTROL CABLES A/T
AMM 21-52-81/501
• • •
• •
THE EFIS COOLING SYSTEM AIR CLEANER
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AMM 21-58-61/201
This procedure replaces the oil in the turbofan. The oil capacity of the turbofan is approximately 4.5 deciliters (0.96 pint). There are two tasks in this procedure: (1) Ram Air Inlet Control Cables - Adjustment (2) Ram Air Modulation System - Operational Test The adjustment procedure is applicable to the control cables on the left or right side. You can adjust the left side cables and the right side cables at the same time. The operational test makes sure that the modulation system operates correctly after the control cables have been adjusted. Two methods are given to clean the air cleaner: The first method removes most of the loose dirt and other unwanted materials. The second method cleans the air cleaner fully, but special equipment and materials are necessary. (a) A solvent can be used to remove oils or greases from the metal surfaces. (b) Alkaline cleaners are recommended for the removal of dirt or other materials that are firmly Adhered to the metal surfaces.
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32-LANDING GEAR DESCRIPTION
REMARKS
REFERENCE
MAIN GEAR
MAIN LANDING GEAR INSPECTION MAIN LANDING GEAR TORSIONAL FREE PLAY
AMM 32-11-00/601 AMM 32-11-00/601
•
ACTIVE MLG INNER CYLINDER SEAL REPLACEMENT
AMM 32-11-21/801
•
•
MAIN GEAR TORSION LINK R/I
AMM 32-11-51/401
MAIN LANDING GEAR DAMPER R/I
AMM 32-11-81/401
MAIN LANDING AXEL
AMM 32-11-85/601
This subject has two tasks. (1) The first task replaces the active inner cylinder seals with the spare seals kept on the shock strut. (2) The second task has two parts: (a) To replace the active inner cylinder seals with the spare seals kept on the shock strut (b) To install more seals on the shock strut after all the spare seals have been used. Spare seals are kept in grooves in the shock strut lower bearing. (1) In the first groove is a T-seal (dynamic), and in the other, two O-rings (static seal). (2) The spare seals permit active seals to be replaced without shock strut inner cylinder removal. (3) When you install the last spare seal, the subsequent seal replacement requires the disassembly of the shock strut. The main gear torsion links are removed after damage, or when bushings are worn beyond service limits. Removal of the upper torsion link also disconnects the bottom end of the lower drag strut. On the right gear, the upper torsion link is connected to a spoiler lockout mechanism. The main tires should be removed and the shock strut partially extended to Provide clearance for the upper torsion link pin when replacing the upper torsion link. The main gear brakes also should be removed to provide clearance for the lower torsion link pin when replacing the lower torsion link.
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THREAD AND AXEL NUT I/C MAIN LANDING GEAR WW BLADE TYPE SEAL R/I
32-12-12/401
NOSE GEAR
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NOSE LANDING LANDING GEAR I/C
ACTIVE NLG INNER CYLINDER SEAL REPLACEMENT
NOSE LANDING LANDING AXEL THREAD AND AXEL NUT I/C
AMM 32-21-00/601
AMM 32-21-11/801
•
This procedure has these tasks: (1) An inspection of the nose landing gear (2) A torsional free play inspection of the nose landing gear. For periodic inspections, refer to paragraph 2 and for special inspections, refer to Chapter 5.
A. This subject has two tasks. The first task is a replacement of the active seals for the shock strut with the spare seals. B. The second task is a replacement of the active seals and the spare seals for the shock strut. C. The spare seals are in grooves in the lower bearing of the shock strut. One T-type dynamic seal is in the bottom groove. One O-ring type static seal is in the top groove. Use the spare seals to replace the active seals without a removal of the inner cylinder of the shock strut. When you use the spare seals, you must disassemble the shock strut when the subsequent seal replacement is necessary. D. The backup rings are made of two parts. You can replace the backup rings without a removal of the inner cylinder of the shock strut.
AMM 32-21-71/601
WHEEL AND BRAKE
BLEED THE HYDRAULIC BRAKE SYS
AMM 32-41-00/201
(1) The brake hydraulic system must be bled when a hydraulic line of the brake system is opened or if a component connected to the system is replaced. When the system is bled, the air in the brake lines or a component of the brake system is transmitted to the reservoir by the return lines or released to the atmosphere. (2) The quantity of time to bleed the system will be kept to a minimum if the brakes are filled and bled on the bench. (3) There are two tests in this task: one for the Normal Brake System and one for the Alternate Brake System.
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Tighten the bleed valve screw to 40 +/- 10 pound-inches. Tighten the brake mounting bolts as follow: • Tighten the bolts to the first torque of 60-70 pound-feet in a criss-cross pattern. bolts, not the nuts. • NOTE: Tighten the bolts, • Tighten the bolts to the last torque of 125-135 pound-feet in a circular pattern. Tighten the bolts OF BRAKE DISCONNECT DISCONNECT VALVE to a torque of 72 - 82 inch-pounds. • Install the three bolts, P/N BACB30NM4HK3, and 3 washers, P/N BACW10BP4ACU. • Main gear brake leakage check with the wheel installed With the brake pedals not applied, do a check of the brakes for fluid leaks in these locaions: • (a) Brake pistons (b) brake housing ports (c) inlet and drain ports (d) bleed ports Wear check of brake with the wheel installed • • Set the parking brake and do a check for a worn brake unit. • •
MAIN GEAR BRAKE R/I
AMM 32-41-41/401
MAIN GEAR BRAKE I/C
AMM 32-41-41/601
WHEEL AND TIRES
SERVICING PROCEDURE TO INFLATE THE TIRE
TIRES AND WHEELS I/C
AMM 12-15-51/301
AMM 32-45-00/601
MAIN GEAR AND TIRE R/I
AMM 32-45-11/401
NOSE GEAR AND TIRE TIRE
AMM 32-45-21/401
You must deflate the tire before you remove the wheel and tire assembly from the airplane, but, if you remove the wheel and tire for brake maintenance only, you do not have to deflate the tire if you have the conditions that follow: (a) The tires are not worn too much (AMM 32-45-00/601) (b) The tires are not hot. (c) There is no evidence of wheel damage, including cracked missing tie bolts or tie nuts, or cracks in the wheel. This section gives procedures for the inspection and the check of the landing gear tires and the wheels while installed on the airplane. The inspection procedures with the wheel removed are given in the applicable wheel vendor manual. (9) Lubricate the threads with grease and install the axle n ut. (a) While you turn the wheel, tighten the axle nut to 300 pound-feet lube torque. (b) Loosen the nut to zero torque. (c) While you turn the wheel, tighten axle nut to 150 pound-feet in one continuous turn of the axle nut. When you replace a nose wheel and tire assembly, you can replace the wheel and tire assembly on the other side.
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Differences Differences in the diameter between the new and worn tires can contribute vibration to the nose landing gear. You can decrease this if you install the tires th at have equal pressure, nearly the same inflated diameters, and matching supplier part numbers. You can not use a 737-200 wheel and tire assembly on a 737-500 airplanes. (13) Do the steps that follow to install the axle nut: (a) While you turn the wheel, tighten the axle nut to 80-100 pound-feet. (b) Stop the wheel. (c) Loosen the nut to zero t orque. (d) While you turn the wheel again, do the steps that follow: 1) Tighten the axle nut to 30 pound-feet 2) Continue tightening axle nut until two lockbolt holes in the axle nut align with threaded holes in the washer for the outer bearing.
R/I
NOSE WHEEL STEERING SYSTEM
NOSE WHEEL STEERING STEERING SYS. A/T
AMM 32-51-00/501
This procedure contains two tasks: (1) The adjustment of the steering system on the nose wheel. (2) The test of the steering system on the nose wheel. Adjust the steering cables wheel steering system consists of rigging the nose wheel steering cables. You can adjust the steering system to operate the steering metering valve by the steering wheel or the rudder pedal steering. In general, it is necessary to adjust the cables when the tension values deviate from the values given in Table I more than +15/-5 pounds. You must let the cable cable temperatures to become become stable at least 1 hour before you try to adjust and/or and/or check the cable tension. (11) If you install new NWSA and NWSB cables, stretch the new cables as follows: (a) Remove the locking clips. 1) Adjust the tension of all the segments of cables NWSA and NWSB to 85 |5 pounds at 70 F ambient temperature. 2) Make sure that all the rigging pins are loose. (b) Remove all the rigging pins. (c) Remove the apex bolt of the torsion link. (d) Turn the upper torsion link horizontally and operate the steering system of the nose wheel manually through 25 cycle (center-full left-full right-center).
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LANDING GEAR POSITION INDICATING AND AND WARNING SYSTEM 32-60-00
L/G MECHANICAL DOWNLOCK INDICATION CLEANING/ PANTING
AMM 32-61-00/701
36-PNEUMATIC SYSTEM DESCRIPTION
PRESSURIZE DEPRESSURIZE PNEUMATIC SYSTEM DEACTIVATION PROCEDURE FOR T/R FOR GND MAINTENANCE PNEUMATIC SYSTEM DUCT LEAKAGE TEST BLEED AIR
REMARKS
REFERENCE
AMM 36-05-00/201
This procedure contains four tasks. 1. Uses a ground air source to pressurize the pneumatic system. 2. Uses the auxiliary power unit (APU) to pressurize the pneumatic system. 3. Uses the engines to pressurize the pneumatic system. 4. Removes the pressure from the pneumatic system.
AMM 78-31-00/201
AMM 36-11-05-705-016 •
This procedure contains these tasks: 1. The inspection of the engine bleed air precooler for allowable crack location.
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DISTRIBUTION SYSTEM AND PRECOOLER BLEED AIR
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AMM 36-12-25/501 •
2. A test to find if the level of leakage from the engine bleed air distribution system is within acceptable limits. 3. A check for leakage from the pneumatic duct sections and valves. A precooler with internal crack locations and leakage levels that are within acceptable limits is permitted for continued operation. A precooler with external crack locations that are within acceptable limits is permitted for limited operation.
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