BHT-ALL-SPM
STANDARD
PRACTICES
MANUAL
(Applicable to all Bell Helicopter Models)
The instructions set forth in this manual, as supplemented or modified by Alert Service Bulletins and other directions issued by Bell Helicopter Textron and Airworthiness Directives issued by the Federal Aviation Administration, must be strictly followed.
STANDARD
PRACTICES
MANUAL
(Applicable to all Bell Helicopter Models)
The instructions set forth in this manual, as supplemented or modified by Alert Service Bulletins and other directions issued by Bell Helicopter Textron and Airworthiness Directives issued by the Federal Aviation Administration, must be strictly followed.
NOTICE
COPYRIGHT NOTICE COPYRIGHT 2004 BELL ® HELICOPTER TEXTRON INC. AND BELL HELICOPTER TEXTRON CANADA LTD.
BHT-ALL-SPM
PN Rev. 1 30 JUN 2004
These data are proprietary to Bell Helicopter Textron Inc. Disclosure, reproduction, or use of these data for any purpose other than helicopter maintenance is forbidden without prior written authorization from Bell Helicopter Textron Inc.
PROPRIETARY RIGHTS NOTICE
Additional copies of this publication may be obtained by contacting: Commercial Publication Distribution Center
Bell Helicopter Textron Inc. P. O. Box 482
WARNING
THIS MANUAL APPLIES ONLY TO HELICOPTERS AND COMPONENTS MAINTAINED IN ACCORDANCE WITH BELL HELICOPTER TEXTRON (BELL) APPROVED PROCEDURES USING BELL APPROVED PARTS. ALL INSPECTION, REPAIR AND OVERHAUL PROCEDURES PUBLISHED BY BELL, INCLUDING PART RETIREMENT LIFE, ARE BASED SOLELY ON THE USE OF BELL PARTS THAT HAVE BEEN MAINTAINED USING BELL APPROVED DATA. THE DATA PUBLISHED HEREIN OR OTHERWISE SUPPLIED BY BELL IS NOT APPLICABLE TO NON-BELL PARTS OR PARTS THAT HAVE BEEN REPAIRED USING DATA AND/OR PROCESSES NOT APPROVED BY BELL.
BELL IS NOT RESPONSIBLE FOR ANY PART OTHER THAN THOSE THAT IT HAS APPROVED.
BEFORE PERFORMING ANY PROCEDURE CONTAINED IN THIS MANUAL YOU MUST INSPECT THE AFFECTED PARTS AND RECO RDS FOR EVIDENCE OF ANY MANUFACTURE, REPAIR, REWORK OR USE OF A PROCESS NOT APPROVED BY BELL.
IF YOU IDENTIFY OR SUSPECT THE USE OF PARTS NOT AUTHORIZED BY BELL, EITHER REMOVE THE AFFECTED ITEM FROM THE AIRCRAFT OR OBTAIN INSTRUCTIONS FOR CONTINUED AIRWORTHINESS FROM THE MANUFACTURER OR THE ORGANIZATION THAT APPROVED THE REPAIR.
BHT-ALL-SPM
LIST OF EFFECTIVE PAGES
On a revised page, the portion of the text and illustration affected by the latest revision is indicated by a black vertical line.
30 JUN 2004 Rev. 1 A/B
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Cover ...1 Title ...1 PN ...1 Warning...1 A/B ...1 Help...1 Customer Feedback...1 i/ii...1 Index 1 — Index 4...1 Index 5/Index6 ...1 Chapter 1-00-00 1/2 ...1 3/4 ...1 Chapter 2-00-00 1/2 ...0 3 — 20 ...0 21/22 ...0 Chapter 3-00-00 1 — 20 ...0 Chapter 4-00-00 1/2 ...0 3 — 30 ...0 Chapter 5-00-00 1/2 ...0 3 — 6 ...0 Chapter 6-00-00 1 — 20 ...1 Chapter 7-00-00 1/2 ... 0 3 — 10 ... 0 11/12 ... 0 Chapter 8-00-00 1 — 26 ... 0 Chapter 9-00-00 1 — 112 ... 0 113/114 ... 0 Chapter 10-00-00 1/2 ... 0 3 — 10 ... 0 11/12 ... 0 Chapter 11-00-00 1/2 ... 0 3 — 6 ... 0 7/8 ... 0 Chapter 12-00-00 1/2 ... 1 3/4 ...Deleted 5 — 68 ...Deleted Chapter 13-00-00 1/2 ... 0 3 — 22 ... 0 23/24 ... 0 Original... 0...1 MAR 90 Reissue ... 0... 8 SEP 92 Reissue ... 0...3 FEB 95 Reissue ... 0... 10 OCT 96 Reissue...0 ... 20 AUG 99 Reissue...0 ... 23 MAY 00 Revision...1 ... 30 JUN 04H
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BHT-ALL-SPM
CONTENTS
CHAPTER
SUBJECT
Introduction ... 1 Torque... 2Corrosion Control and Protective Coverings/Coatings ... 3
Painting ... 4
Cleaning... 5
Nondestructive Inspection... 6
Bonding... 7
Miscellaneous Practices ... 8
Bearings, Sleeves, and Bushings ... 9
Storage ... 10
Use of Solvents... 11
Nickel-Cadmium Aircraft Storage Battery ... 12
Consumable Materials ... 13 NOTE:
The contents of Chapter 12 have been deleted. Please refer to the Bell Helicopter Electrical Standard Practices Manual (BHT-ELEC-SPM) for information on Nickel-Cadmium Aircraft Batteries.
30 JUN 2004 Rev. 1 i/ii
1
ALPHABETICAL INDEX
Subject Paragraph/Table/ Figure Number Subject Paragraph/Table/ Figure Number AAcrylic windows and windshields . . . 7-7 Adhesive data . . . 13-2 Affect of applied force to rigid frame and
audible indicating torque wrenches
using nonconcentric attachments. . . F2-7 Alternates for Bell Helicopter Textron
adhesives . . . T13-2 Application of polyurethane enamel. . . 4-18
Polyurethane enamel — equipment
requirements . . . 4-19 Polyurethane enamel — general
information . . . 4-20 Polyurethane enamel — procedure
requirements . . . 4-21 Polyurethane enamel — process
control requirements . . . 4-22 Touch-up painting procedures for
polyurethane enamel . . . 4-23
B
Bearing and sleeve replacement data . . . T9-4 Bearing inspection and replacement criteria . . T9-1 Bearing replacement . . . 9-4 Bearing removal . . . 9-5 Bearing rotational torque check . . . F9-4 Bearing staking tool kit application. . . T9-3 Bearing wear limits. . . T9-2
Bearing installation — ring staking
method. . . 9-6 Black oxide. . . 3-21
Gear tooth wear pattern inspection using Fluoroglide or Permalon 327 . . . 3-22
Bonded rod end bearings, inserts, and
clevis — replacement . . . 9-14 Bonding procedure. . . 7-2 Bushings . . . 9-12 Bushing replacement . . . 9-13
C
Chemical film (chromic acid)
treatment — magnesium . . . 3-15 Aluminum alloy — chemical film
treatment (touchup) . . . 3-16 Cadmium plating . . . 3-17 Chromate conversion coating . . . 3-18 Cleaning . . . 5-1 Cleaning bearings . . . 5-6 Cleaning carpet . . . 5-3 Cleaning headliner and trim panels . . . 5-4 Cleaning hydraulic assemblies and
servicing units. . . 5-5 Cleaning metals (except titanium) . . . 5-7 Cleaning plastic and glass . . . 5-9 Cleaning titanium . . . 5-8 Cleaning upholstery . . . 5-2
Consumable material list . . . T13-1 Consumable materials . . . 1-2 Consumable materials . . . 13-1 Copper plating bath . . . T3-4 Corrosion corrective treatment . . . 3-6
BHT-ALL-SPM
ALPHABETICAL INDEX (Cont)
Subject Paragraph/Table/
Figure Number
Subject Paragraph/Table/
Figure Number
Index 2 Rev. 1 30 JUN 2004
Corrosion removal — aluminum parts . . . 3-8 Corrosion removal — elastomeric
components . . . 3-10 Corrosion removal — magnesium
parts . . . 3-9 Corrosion removal — steel parts . . . 3-7 Corrosion prevention . . . 3-2 Corrosion preventive oil . . . 3-4 Corrosion preventive treatment . . . 3-3 Corrosion protection — control bolts,
rotating and non-rotating . . . 3-5 Corrosion protection — faying surfaces . . . 3-11 Corrosion protection — exceptions . . . 3-14 Dissimilar metals . . . 3-13 Similar metals. . . 3-12
D
Definitions of similar and dissimilar metals. . . . T3-1
E
English to metric and British Imperial
units formulas . . . F8-2
Environmental conditions . . . 10-2 Epoxy adhesive, mixing ratio, pot life, and
curing schedule . . . T7-1 Epoxy enamel application. . . 4-17 Epoxy polyamide primer application. . . 4-6
Epoxy polyamide primer — equipment
requirements . . . 4-7 Epoxy/zinc coating . . . 4-24
Control tube internal surface —
refinishing. . . 4-25 Epoxy zinc coating application . . . 4-24
F
Fabrication of bearing/sleeve removal and
installation workaid tools . . . F9-1 Fabrication of bushing removal and
installation workaid tools . . . F9-7
Fluid ounces/gallons to milliliters/liters
and British Imperial ounces . . . F8-10 Bearing inspection criteria . . . .9-1 Fluorescent magnetic particle inspection
method (ASTM E1444) . . . 6-17 Fluorescent penetrant inspection method
(ASTM E1417). . . .6-2
Flyable storage . . . .10-3 Depreservation and activation . . . .10-7 General procedures for flyable storage . . .10-4 Maintenance during flyable storage . . . .10-6 Preparation for flyable storage . . . .10-5
G
Gear wear patterns . . . .8-12 Gear wear pattern check . . . .8-13
General rules. . . .7-1
I
Inches to millimeters conversions . . . F8-3 Inch/foot-pounds torque to newton-meters
ALPHABETICAL INDEX (Cont)
Subject Paragraph/Table/ Figure Number Subject Paragraph/Table/ Figure Number Intermediate storage . . . 10-14 Depreservation and activation . . . 10-20 General inspection. . . 10-16 General storage procedures . . . 10-15 Inspection . . . 10-19 Maintenance during intermediatestorage. . . 10-18 Miscellaneous . . . 10-21 Preservation for intermediate storage . . . 10-17
Introduction . . . 1-1
K
Kydex and Royalite parts . . . 7-9
L
List of solvents commonly used . . . T11-2 Long term storage . . . 10-22
M
Maximum temperature requirements . . . T8-1 Measuring gear teeth and splines . . . 8-10 Gear teeth and spline measuring pin kit. . . 8-11 Metric and British Imperial units
conversions. . . 8-19 Microinches to microns conversions. . . F8-6 Miscellaneous practices . . . 8-1 Control tube (adjustable) — alignment. . . 8-5 Data plate bonding . . . 8-6 Electric arc etching — unauthorized
procedure . . . 8-2 Studs and inserts replacement. . . 8-7 Surface roughness . . . 8-3 Thread protection — adjustable . . . 8-4
N
Nondestructive inspection eddy current
method . . . 6-37
Nonstructural bonding with rubber base
cement . . . 7-5
BHT-ALL-SPM
ALPHABETICAL INDEX (Cont)
Subject Paragraph/Table/
Figure Number
Subject Paragraph/Table/
Figure Number
Index 4 Rev. 1 30 JUN 2004
Organic protective requirements
for metals . . . T3-2 Ounces and pounds force to newtons
conversions . . . F8-4 Ounces and pounds mass (weight) to
kilograms conversions . . . F8-5
P
Paint application . . . 4-4 Painting — exterior surfaces . . . 4-5 Painting requirements for exterior surfaces . . . T4-1 Polycarbonate parts . . . 7-3 Polycarbonate parts repair . . . 7-4 Pounds per square inch pressure to
kilopascals conversions . . . F8-7
Procedure for checking gear dimensions
and measuring pin kits . . . F8-1
R
Repair of control tube assemblies with bonded or riveted clevises, inserts or rod
end bearings . . . F9-8 Retaining compound. . . 8-16 Application of retaining compound . . . 8-17
Ring staking . . . F9-2 Pregrooved bearing installation — roll
staking method . . . .9-7 Roll or anvil staking pregrooved bearings . . . . F9-3
Bearing installation — roll staking
method . . . .9-8 Roll staking sleeves or bushings . . . F9-5
Bearing installation — segment
staking method . . . .9-9 Pregrooved bearing installation —
staking method . . . .9-10
S
Segment staking . . . F9-6 Protection of staked bearings . . . .9-11 Selection and use of torque wrench . . . .2-5 Short term storage . . . .10-8 Depreservation and activation . . . .10-13 General preparation . . . .10-9 Inspection . . . .10-12 Maintenance during short term
storage . . . .10-11 Preservation . . . .10-10 Silicone adhesives classification and
properties . . . T7-3 Silicone bonding . . . .7-6 Solid film lubricant . . . .3-19
ALPHABETICAL INDEX (Cont)
Subject Paragraph/Table/
Figure Number
Subject Paragraph/Table/
Figure Number
Solid film lubricant repair . . . 3-20 Solid film lubricant curing . . . T3-3 Solvents . . . 11-1 Solvents. . . 11-2 Spray equipment — epoxy polyamide
primer . . . T4-2 Epoxy polyamide primer — general
information . . . 4-8 Epoxy polyamide primer — procedure
requirements . . . 4-10 Epoxy polyamide primer — process
and product requirement . . . 4-9
Standard torque values . . . F2-1 Standard torque values for flareless
fittings. . . F2-4 Standard torque values for fluid
connections . . . F2-2 Standard torque values for threaded
studs. . . F2-3 Surface preparation for application
of epoxy enamel. . . T4-7 Surface preparation for application of
epoxy polyamide primer . . . T4-3 Epoxy primer (Super-Koropon
application) . . . 4-11 Surface preparation for application of
epoxy primer (Super-Koropon). . . T4-4
T
Temperature conversions. . . F8-9
Thermal fit . . . 8-8 Methods of securing dimensional
changes — thermal fit parts. . . 8-9
Torque values . . . 2-1 Special torques. . . 2-4 Recommended installation torque range . . . 2-3 Standard torque . . . 2-2 Torque wrench concentric type
attachments . . . F2-5 Torque wrench nonconcentric type
attachments . . . F2-6 Treatment of fungus . . . 5-10 Fungus growth cleaning . . . 5-12 Fungus growth inspection . . . 5-11
U
Urethane adhesives, mixing ratio, potlife,
and curing schedule . . . T7-2 Use of solvents
Metals (except titanium)
Nonmetals (plastics and glass) . . . T11-1 Paint removers — types and usage . . . 4-2 Paint stripping — parts with Teflon
bearings . . . 4-3 Titanium (model 412, 214, & 222 main
rotor flexures, 214ST hydraulic actuator valve bodies, nodal beam
retention bolts, etc.) . . . T11-1
W
BHT-ALL-SPM
CHAPTER 1 — INTRODUCTION
Paragraph Chapter Page
Number Title Number Number
CONTENTS — MAINTENANCE PROCEDURES
1-1 Introduction ... 1-00-00 3 1-2 Consumable Materials ... 1-00-00 3
1-00-00
INTRODUCTION
1-1. INTRODUCTION
This manual contains maintenance information and procedures that are common to all Bell Helicopter models. Typical information includes standard torque charts and application procedures, corrosion control, painting, cleaning, nondestructive inspection, bonding, miscellaneous practices, bearing, sleeve and bushing inspection and replacement, storage, use of solvents, and consumable materials.
WARNING
A L L R E P A I R A N D O V E R H A U L PROCEDURES LIVES PUBLISHED BY B E L L H E L I C O P T E R T E X T R O N , INCLUDING COMPONENT RETIREMENT LIFE, ARE BASED SOLELY ON THE USE O F B E L L A P P R O V E D P A R T S A N D P R O C E S S E S . I F P A R T S O R P R O C E S S E S D E V E L O P E D O R APPROVED BY PARTIES OTHER THAN BELL HELICOPTER ARE USED, THEN THE DATA PUBLISHED OR OTHERWISE SUPPLIED BY BELL HELICOPTER ARE N O T A P P L I C A B L E . T H E U S E R I S W A R N E D T O N O T R E L Y O N B E L L HELICOPTER DATA FOR PARTS AND PROCESSES NOT APPROVED BY BELL H E L I C O P T E R. A L L A P P L I C A B L E INSPECTIONS AND REPAIR METHODS M U S T B E O B T A I N E D F R O M T H E S U P P L I E R O F T H E P A R T S O R PROCESSES NOT APPROVED BY BELL HELICOPTER. BELL HELICOPTER IS
NOT RESPONSIBLE FOR PARTS OR P R O C E S SE S O T H E R T H AN T H O SE WHICH IT HAS ITSELF DEVELOPED OR APPROVED.
1-2. CONSUMABLE MATERIALS
NOTE
Handling, storage and safety precautions for consumable materials shall be in accordance with the consumable material manufacturers instructions unless otherwise specified in this manual.
A list of consumable materials is contained in Chapter 13. This comprehensive listing provides a description, specification and suggested source. Within this manual, consumable items are referred to within the maintenance tasks by "C" number. When a task states to use solvent (C-304), refer to Chapter 13 and find item C- 304 for type of solvent to use.
CAUTION
M E T R I C E Q U I VA L E N T S T O U . S . STANDARD WEIGHTS AND MEASURES ARE PROVIDED THROUGHOUT THIS M A N U A L . W H I L E P E R F O R M I N G MEASUREMENTS TO DETERMINE THE SERVICEABILITY OF A COMPONENT OR T O E S TA B L I S H A S P E C I F I E D DIMENSION, ONLY THE U.S. STANDARD VALUES SHALL BE USED.
Bell Helicopter Textron BHT-ALL-SPM
CHAPTER 2- TORQUE
CONTENTS - MAINTENANCE PROCEDURES
Paragraph Chapter/Section Page
Number Title Number Number
2-1 Torque Values ... 2-00-00 3 2-2 Standard Torque ... 2-00-00 3
2-3 Recommended Standard Torque Range... 2-00-00 4
2-4 Specified Torques ... 2-00-00 5 2-5 Self Locking Nuts ... 2-00-00 5 2-6 Selection and Use of Torque Wrench ... 2-00-00 5
FIGURES
Figure Page
Number Title Number
2-1 Torque Wrench Concentric Type Attachments ... 19 2-2 Torque Wrench Nonconcentric Type Attachments ... 20 2-3 Affect of Applied Force to Rigid Frame and Audible Indicating
Torque Wrenches Using Nonconcentric Attachments ... 21 TABLES
Table Page
Number Title Number
2-1 Torque Value Chart (Dry) for Specified Nuts on 125000 PSI
Minimum Ultimate Tensile Strength Fasteners ... 7... 7 2-2 Torque Value Chart (Dry) for Specified Nuts on 160000 PSI
Minimum Ultimate Tensile Strength Fasteners... 11 2-3 Torque Value Chart (Dry) for Specified Nuts on 180000 PSI
Minimum Ultimate Tensile Strength Fasteners... 13 2-4 Standard Torque Values for Fluid Connections... 14 2-5 Standard Torque Values (Studs) Part I ... 15 2-6 Standard Torque for Dynamic Beam Seal Nuts
(Operating Pressures to 5000 PSI, Titanium Material)... 17 2-7 Recommended Standard Torque for Flared Fitting Nuts... 18
2-00-00 Page 1/2
TORQUE
2-1. TORQUE VALUES
WARNING
1. Description.
DO NOT EXCEED THE MAXIMUM
a. Standard Torque. A general torque ALLOWABLE TORQUE VALUE.
requirement which is applied to fasteners when a OVERSTRESSING OF THE BOLT OR
specified torque is not identified. Standard torques are NUT MAY RESULT. listed in tables 2-1 through 2-5 and do not include Tare
torque. 2-2. STANDARD TORQUE
1. The Standard Torque Charts list the
b. Specified Torque. A specific torque identified recommended standard torque for various in the maintenance manual, overhaul manual, ASB orin the maintenance manual, overhaul manual, AB or combinations of bolts and nuts. The torque listed is the TB for a particular fastener(s). Specified torque does standard torque, less friction drag of the self-locking
not include Tare torque. feature (TARE). Refer to tables 2-1 through 2-3.
c. Tare Torque. Torque required to overcome resistance of self locking nuts against mating bolt,
screw or stud threads. Tare torque must be measured CAUTION
using the same fastener combination that the torque
will be applied to. Tare torque is unique to that fastener RECOMMENDED STANDARD TORQUE combination. The preferred method for measuring tare RANGE IS GIVEN. TARE TORQUE SHALL torque is to use a dial (indicator) type torque wrench, BE ADDED TO TORQUE VALUE LISTED but may be measured by approaching the value with a UNLESS OTHERWISE STATED.
"click" style torque wrench. The measured value must
be compared to the Minimum Tare Torque Value. If STANDARD TORQUE VALUE FOR FLUID measured value is less than the minimum listed, the CONNECTIONS IS GIVEN IN TABLE 2-4. lock nut must be replaced.
STANDARD TORQUE VALUE FOR d. Applied Torque. The total torque value applied THREADED STUDS IS GIVEN IN TABLE to a fastener (preferably the nut in a nut/bolt 2-5.
combination). Applied torque is the Standard Torque or
Specified Torque, plus the Tare Torque. It is unique to STANDARD TORQUE VALUE FOR that fastener combination. An adjacent fastener DYNAMIC BEAM SEALNUT IS GIVEN IN combination utilizing the same hardware may require a TABLE 2-5.
different applied torque value. It is not acceptable to
measure tare torque for one fastener combination and STANDARD TORQUE VALUE FOR
apply this tare torque value to all similar fasteners. FLARELESS FITTINGS IS GIVEN IN Variations in wear, stress, and finish will impact tare TABLE 2-6.
values of fasteners of the same size and type.
2. Standard torque value charts usage.
e. Shear Load. A dynamic force causing two a. To locate the correct standard torque for a bolt parts in contact to move in a direction parallel to their and, nut the following must be known:
point of contact.
(1) Type of bolt used (AN, MS, NAS, etc.). f. Tension Load. A static force applied 90
BHT-ALL-SPM
Bell Helicopter
(3) Thread size of bolt (10-32, 1/4 -28, 5/16 - Minimum Tare Torque Value (Cont)
24, 3/8 -24, etc.).
MINIMUM TARE
THREAD SIZE
b. When all three are known refer to figure 2-1. TORQUE (IN-LBS)
7/8-14 70.0
(1) From table 2-1 through 2-3, locate the
sheet that carries the primary bolt number 1 -12 90.0
(designation) and the number of the nut. From the
appropriate sheet, locate thread size and read across 1 -1/8-12 117.0
for torque values. 1-1/4-14 143.0
1-3/8-12 170.0
CAUTION 1-1/2-12 197.0
2-3. RECOMMENDED STANDARD TORQUE
TARE TORQUE MUST BE MEASURED RANGE
ON THE SAME FASTENER
COMBINATION THAT THE TORQUE WILL BE APPLIED TO. USING A DIAL
INDICATOR TYPE TORQUE WRENCH, CAUTION
MEASURE TARE TORQUE OF SELF LOCKING NUT TO BE INSTALLED.
ALOCKING NUT TO BE INSTALLED. MAXIMUM ALLOWABLE TORQUE SHALL
COMPARE VALUE TO MINIMUM TARE ONLY BE USED WHEN REQUIRED TO
ONLY BE USED WHEN REQUIRED TO
TORQUE VALUE LISTED BELOW. IF ALIGN CASTELLATED NUTS.
MEASURED TARE IS LESS THAN
MINIMUM LISTED, REPLACE SELF DO NOT ADD PLAIN, FLAT WASHERS TO
LOCKING FASTENER.
ANY DRIVE SYSTEM COMPONENT TO OBTAIN SPECIFIED TORQUE. THE c. Minimum TARE torque value of self-locking DRIVE SYSTEM INCLUDES ALL SHAFTS,
DRIVE SYSTEM INCLUDES ALL SHAFTS,
bolts and nuts is as follows: COUPLINGS, GEARBOXES AND
COUPLINGS, GEARBOXES AND
BEARING HANGERS USED IN THE TRANSMISSION OF ENGINE POWER TO THE MAIN AND TAIL ROTORS OR TO
Minimum Tare Torque Value ANY REMOTE MOUNTED ACCESSORY.
DRIVE SYSTEM COMPONENTS ARE
THREAD SIZE MINIMUM TARE IDENTIFIED WITH A PART NUMBER
TORQUE (IN-LBS) WHICH HAS THE SECOND SET OF
THREE DIGITS (UNIVERSAL CODE) OF -040-, -044-, -140-, -340-, -342-, -344-, -540,
1/4 - 28 3.5 -620-, -640-, -644-, AND -645-.
5/16-24 6.5 DO NOT SUBSTITUTE WASHERS OF
3/8- 24 9.5 DIFFERENT PART NUMBERS. DO NOT ADD FLAT WASHERS TO JOINTS
7/16-20 14.0 WHERE SPECIAL WASHERS
(CHAMFERED, CONCAVE, COUNTER
1/2-20 18.0 BORED, DISSIMILAR METAL, KEYED,
9/16 -18 24.0 LOCK WASHER ETC.) ARE INSTALLED.
5/8-18 32.0 1. Additional plain, flat washers of the same part
number as those specified by the parts manual may be 3/4 - 16 50.0 used when required for proper nut or cotter pin
2-00-00 Page 4
installation, or to allow specified torque to be attained. b. The graduation increments of the torque Not more than a total of three washers will be used; wrench should not be greater than 10 percent of the two under the nut for grip adjustment and one under torque value being measured.
the bolt or screw head for surface protection, unless
otherwise permitted by the applicable maintenance c. The torque wrench should be calibrated in the
manual. same torque units as the specified torque for the
fastener. 2. If the maintenance or overhaul manual does not
specify the location of the washers, they shall be 2. Force Application on Torque Wrench Grip: A placed under the bolt or screw head or under the nut, smooth steady force must be applied to obtain an whichever is being rotated during tightening, except accurate torque value. Rapid or jerky force can result where one washer, under the bolt or screw head, is in error in the torque applied.
required for material protection.
3. Tightening Fastener on the Head End: When a 3. The recommended standard torque range shall fastener is tightened from the head end, some of the be used for all applications for bolts and nuts listed in torque applied is absorbed in turning the bolt in the tables 2-1 through 2-3. The following example hole. The amount of torque absorbed will vary. For this provides a guide in the use of the torque value tables. reason, torque values specified are for tightening
fasteners on the nut end.
Example:
4. If the fastener can be inserted through the hole * Type of bolt: MS9088. and started into the nut by the fingers, use the
· Type of nut: MS14145. specified torque range.
* Type of nut: MS14145.
* Thread size of bolt: 1/4-28. 5. If the fastener is inserted through a hole that increases the tightening resistance, torque to the high * Recommended shear load installation torque limit of the specified torque range.
range: 30 to 40 inch-pounds.
2-4. SPECIFIED TORQUES 6. If the fastener is inserted into a threaded hole and if the hole thread length is more than the fastener When torques are specified in procedural steps of the diameter, use the specified torque range. If the hole applicable maintenance or overhaul manual, they take thread length is less than the fastener diameter, use preference over standard torque values given in tables the lower limit of the torque range.
2-1 through 2-3. Add tare torque to all specified
torque. 7. Tightening New Fastener: Tighten the fastener to
the standard or specified torque value, as defined in
2-5. SELF LOCKING NUTS paragraph 2-1.1. Loosen the fastener by backing off one-half turn. Retighten to desired torque value. This The seating torque values are in addition to the actual aids in cleaning and smoothing the threads and results locking torque (tare torque) value of each self locking in more accurate torque.
nut. The locking torque (tare torque) value for a self locking nut is that value after all nut threads are
engaged. 8. Re-torque - To be used when it is uncertain
whether a joint has been properly torqued. If there is
2-6. SELECTION AND USE OF TORQUE some concern that a fastener has been over-torqued,
WRENCH then the fastener should be discarded (both the nut
and bolt). Re-torque should be accomplished by the
1. Selecting Torque Wrench: following:
a. The accuracy of most torque wrenches tends (1) Remove all torque from the fastener to decrease at the extremes of the torque range. The (loosening) until no preload is on the fastener.
torque value being measured should be between the
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Bell Helicopter Textron
(3) Determine the specified torque or 11. Tightening Chilled or Heated Fastener: Do not
standard torque as applicable and add the tare torque tighten a chilled or heated fastener until it has returned to this to arrive at the applied torque. to room temperature. Heated fastener may loosen when it cools. Chilled fastener may become (4) Torque the fastener to this applied torque overstressed when it warms.
value.
12. Tightening Fastener on Part with a Slow If the fastener is one in a multi-fastener pattern Permanent Set: Hold desired torque until part is requiring a torque sequence, then all the seated.
fasteners will require re-torque.
13. Tightening Fasteners in a Series: If fasteners are 9. Fastener Thread Condition: Threads should be to be torqued in a series, select a median torque value clean and free from nicks, burrs, paint, grease, and oil within the torque required range. If some fasteners are to obtain the correct torque. However, there are some tightened to the minimum value and others to the applications where lubrication or antiseize compound maximum, force is not distributed evenly. Unequal
is used on the threads. distribution of force may cause fastener failure. Do not
apply final torque during the first drawdown. After the 10. Torque Check: This should be accomplished by median torque value is applied, loosen fasteners one torquing in the tightening direction. The value applied at a time and apply final torque. Tightening in a
should be one of the following: diametrically opposite (staggered) sequence is
desirable in most cases. a. If the applied torque is known from when the
fastener was originally installed (i.e. recorded in a 14 Tightening Fasteners with Concentric logbook), then this is the applied torque for torque Attachment: The use of a concentric attachment which
check purposes. operates concentrically with the torque wrench drive square presents no particular problem. The torque value applied is the torque value indicated. Refer to b. If the original applied torque was not recorded, figure 2-1.
then the applied torque for torque check purposes would be the minimum specified torque or minimum
standard torque as applicable plus the minimum 15. Tightening Fastener with Nonconcentric
acceptable tare torque, (refer to minimum tare torque Attachment: The use of a nonconcentric attachment
value table). which does not operate concentrically with the drive
square presents a mathematical problem. This type of attachment affects the lever length. The torque value If during the application of the applied torque as applied is not the torque value indicated. It is detailed above, no motion is detected between the necessary to calculate the effect of the lever length to fasteners, then the joint is considered acceptable. determine the correct indicated torque value. Refer to
figure 2-2. Joints which are having a torque check performed as a
part of a special inspection, as required after a 16. Force application when using Nonconcentric specified number of flight hours, only need to be
Attachment: tightened. Looseness may occur until the components
"seat" themselves and the fasteners simply need to be
tightened. This is not cause for disassembly. If a a. The point of force applied on a flexible beam-specific torque sequence is to be followed, as torqued, type torque wrench pivoted grip will not affect the then this same sequence should be followed during calculated torque applied to the fastener.
the torque check. Some fasteners in the sequence
may accept additional torque while others may not; b. The point of force applied on rigid frame and
this is acceptable. audible indicating torque wrench grips will affect the
calculated torque applied to the fastener. See figure 2-Joints that have not retained torque will require 3 for proper and improper application of force and their
disassembly and inspection effect.
2-00-00 Page 6
Table 2-1. Torque Value Chart (Dry) for Specified Nuts on 125000 PSI Minimum Ultimate Tensile Strength Fasteners
PART I
SHEAR LOAD
RECOMMENDED
BOLT DIAMETER STANDARD
BOLT NUT THREAD SIZE TORQUE RANGE
AN3 thru AN20 AN316 10 - 32 12 to 15 in-lb
AN21 thru AN37 AN320
AN42 thru AN49 MS14145 1/4 -28 30 to 40 in-lb
AN173 thru AN186 NAS1022
AN502 AN503 5/16 - 24 60 to 85 in-lb AN525 MS9088 3/8 - 24 95 to 110 in-lb MS20073 thru MS20081 MS24694 7/16 - 20 270 to 300 in-lb MS27039 NAS428 NAS1297 1/2 - 20 24 to 34 ft-lb 9/16 - 18 40 to 50 ft-lb 5/8 - 18 55 to 65 ft-lb 3/4 - 16 108 to 125 ft-lb 7/8 - 14 125 to 150 ft-lb 1-12 183 to 275 ft-lb 1-1/8 - 12 250 to 350 ft-lb 1-1/4-12 450 to 500 ft-lb
NOTE: The above values apply to any combination of bolt and nut shown unless otherwise specified. Tare torque must be added to all torque values. Refer to paragraph 2-3.
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Table 2-1. Torque Value Chart (Dry) for Specified Nuts on 125000 PSI Minimum Ultimate Tensile Strength Fasteners (Cont)
PART II
TENSION LOAD
BOLT NUT BOLT DIAMETER/
BOLT NUT THREAD SIZE RECOMMENDED
STANDARD TORQUE RANGE
AN3 thru AN20 AN310 10 - 32 20 to 25 in-lb
AN21 thru AN37 AN315
AN42 thru AN49 MS14144 1/4 - 28 50 to 70 in-lb
AN173 thru AN186 MS21043
AN502 MS21044
AN503 MS21047 thru MS21049 5/16-24 100to140in-lb
AN525 MS21051 thru MS21056 MS9088 MS21058 thru MS21062 3/8 - 24 160 to 190 in-lb MS20073 thru MS20081 MS21069 thru MS21076 MS24694 MS21225 7/16 - 20 37 to 42 ft-lb MS27039 NAS509 NAS428 NAS1473 NAS1297 NAS1474~ 1/2 - 20 40 to 58 ft-lb 9/16 - 18 66 to 83 ft-lb 5/8- 18 91 to 108 ft-lb 3/4 - 16 191 to 208 ft-lb 7/8 - 14 208 to 250 ft-lb 1 - 12 308 to 458 ft-lb 1-1/8 - 12 416 to 583 ft-lb 1-1/4- 12 750 to 916 ft-lb
NOTE: The above values apply to any combination of bolt and nut shown unless otherwise specified. Tare torque must be added to all torque values. Refer to paragraph 2-3.
2-00-00 Page 8
Table 2-1. Torque Value Chart (Dry) for Specified Nuts on 125000 PSI Minimum Ultimate Tensile Strength Fasteners (Cont)
PART III
SHEAR LOAD BOLT DIAMETER/
THREAD SIZE RECOMMENDED
STANDARD TORQUE RANGE
AN3 thru AN20 MS17826 10 - 32 7 to 12 in-lb
AN21 thru AN37
AN42 thru AN49 1/4 - 28 25 to 35 in-lb
AN173 thru AN186 AN502 AN503 5/16 - 24 50 to 70 in-lb AN525 MS9088 3/8 - 24 70 to 90 in-lb MS20073 thru MS20081 MS24694 7/16 - 20 110 to 150 in-lb MS27039 NAS428 NAS1 297 1/2 - 20 150 to 200 in-lb 9/16 -18 200 to 300 in-lb 5/8 - 18 300 to 420 in-lb 3/4 - 16 45 to 62 ft-lb 7/8 - 14 79 to 96 ft-lb 1 - 12 125 to 150 ft-lb 1-1/8 - 12 208 to 292 ft-lb 1-1/4-12 292 to 375 ft-lb
NOTE: The above values apply to any combination of bolt and nut shown unless otherwise specified. Tare torque must be added to all torque values. Refer to paragraph 2-3.
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Table 2-1. Torque Value Chart (Dry) for Specified Nuts on 125000 PSI Minimum Ultimate Tensile Strength Fasteners (Cont)
PART IV
TENSION LOAD
RECOMMENDED
BOLT DIAMETER/ STANDARD TORQUE
BOLT NUT THREAD SIZE RANGE
AN3 thru AN20 MS17825 10 - 32 12 to 15 in-lb
AN21 thru AN37
AN42 thru AN49 1/4 - 28 30 to 40 in-lb
AN173 thru AN186 AN502 AN503 5/16 - 24 60 to 85 in-lb AN525 MS9088 3/8 - 24 95 to 110 in-lb MS20073 thru MS20081 MS24694 7/16 - 20 270 to 300 in-lb MS27039 NAS428 NAS 297 1/2 - 20 24 to 34 in-lb 9/16 - 18 40 to 50 in-lb 5/8 - 18 55 to 65 in-lb 3/4 - 16 108 to 125 ft-lb 7/8 - 14 125 to 150 ft-lb 1 - 12 183 to 275 ft-lb 1-1/8-12 250 to 350 ft-lb 1-1/4 - 12 450 to 500 ft-lb
NOTE: The above values apply to any combination of bolt and nut shown unless otherwise specified. Tare torque must be added to all torque values. Refer to paragraph 2-3.
2-00-00 Page 10
Table 2-2. Torque Value Chart (Dry) for Specified Nuts on 160000 PSI Minimum Ultimate Tensile Strength Fasteners
PART I
SHEAR LOAD BOLT DIAMETER/
THREAD SIZE RECOMMENDED
STANDARD TORQUE RANGE
20-057 AN310 10 - 32 20 to 25 in-lb
MS16997 thru MS16998 AN315
MS20004 thru MS20024 MS14144 1/4-28 50to70 in-lb
NAS144 thru NAS158 MS21043 NAS333 thru NAS340 MS21044
NAS517 MS21047 thru MS21049 5/16 - 24 100 to 140 in-lb
NAS623 MS21051 thru MS21056
NAS1101 MS21058 thru MS21062 3/8 - 24 160 to 190 in-lb
NAS1189 MS21069 thru MS21076
NAS1190 MS21225 7/16 - 20 37 to 42 ft-lb
NAS1303 thru NAS1320 NAS509
NAS1351 NAS1473
NAS1352 NAS1474 1/2 - 20 40 to 58 ft-lb
NAS1801
NAS6203 thru NAS6220 9/16 - 18 66 to 83 ft-lb
NAS6603 thru NAS6620
NAS7500 thru NAS7516 5/8- 18 91 to 108 ft-lb
3/4 - 16 191 to 208 ft-lb 7/8 - 14 208 to 250 ft-lb
1 - 12 308 to 458 ft-lb
1-1/8-12 416 to 583 ft-lb 1-1/4-12 750 to 916 ft-lb
NOTE: The above values apply to any combination of bolt and nut shown unless otherwise specified. Tare
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Table 2-2. Torque Value Chart (Dry) for Specified Nuts on160000 PSI Minimum Ultimate Tensile Strength Fasteners (Cont)
PART II
TENSION LOAD
BOLT NUT BOLT DIAMETER/
BOLT NUT THREAD SIZE
RECOMMENDED STANDARD TORQUE RANGE
20-057 MS21042 10 - 32 30 to 40 in-lb
MS16997 thru MS16998 NAS577
MS20004 thru MS20024 NAS1291 1/4 -28 75 to 95 in-lb
NAS144 thru NAS158 NAS333 thru NAS340
NAS517 5/16 - 24 120 to 160 in-lb
NAS623
NAS1101 3/8 - 24 25 to 28 ft-lb
NAS1189
NAS1190 7/16 - 20 39 to 43 ft-lb
NAS1303 thru NAS1320 NAS1351
NAS1352 1/2 - 20 53 to 71 ft-lb
NAS1801
NAS6203 thru NAS6220 9/16 -18 83 to 100 ft-lb
NAS6603 thru NAS6620
NAS7500 thru NAS7516 5/8 - 18 116 to 133 ft-lb
3/4 - 16 200 to 216 ft-lb
7/8 -14 333 to 375 ft-lb
1 -12 433 to 583 ft-lb
1-1/8 - 12 691 to 858 ft-lb 1-1/4 - 12 1441 to 1608 ft-lb
NOTE: The above values apply to any combination of bolt and nut shown unless otherwise specified. Tare
torque must be added to all torque values. Refer to paragraph 2-3.
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Table 2-3. Torque Value Chart (Dry) for Specified Nuts on 180000 PSI Minimum Ultimate Tensile Strength Fasteners
SHEAR LOAD BOLT DIAMETER/
NUT BOLT
THREAD SIZE RECOMMENDED
STANDARD TORQUE RANGE
20-065 MS21042 10 - 32 22 to 28 in-lb
20-069 NAS577
MS21250 NAS1291 1/4 -28 65 to 79 in-lb
NAS624 thru NAS644
5/16 - 24 112 to 158 in-lb 3/8 - 24 180 to 214 in-lb 7/16- 20 42 to 47 ft-lb 1/2 - 20 45 to 54 ft-lb 9/16 - 18 74 to 93 ft-lb 5/8 - 18 102 to 122 ft-lb 3/4 - 16 215 to 234 ft-lb 7/8 - 14 234 to 281 ft-lb 1 - 12 346 to 515 ft-lb 1-1/8 - 12 468 to 656 ft-lb 1-1/4 - 12 844 to 1030 ft-lb
NOTE: The above values apply to any combination of bolt and nut shown unless otherwise specified. Tare
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Table 2-4. Standard Torque Values for Fluid Connections
HOSE END NAS591 THRU NAS596
TUBE FLARE STEEL TUBING FITTINGS AND
FLARE HOSE ASSY
SIZE (MS33583 ORE HOSE ASSY DASH
(MS33583 OR (MS33584) (MS28740 AND STEEL TUBING AL. TUBING
MS33584) NO.M28759)
MS28759)
3/16 30 to 45 in-lb 90 to 100 in-lb 70 to 100 in-lb
1/4 40 to 65 in-lb 135 to 150 in-lb 70 to 120 in-lb 4 60 to 96 in-lb 48 to 96 in-lb 5/16 60 to 80 in-lb 180 to 200 in-lb 85 to 180 in-lb 5 66 to 108 in-lb 60 to 108 in-lb
3/8 75 to 125 in-lb 270 to 300 kn-lb 100 to 250 in-lb 6 72 to 120 in-lb 72 to 120 in-lb 1/2 150 to 250 in-lb 450 to 500 in-lb 210 to 420 in-lb 8 144 to 232 in-lb 120 to 216 in-lb 5/8 200 to 350 in-lb 54 to 58 in-lb 300 to 480 in-lb 10 204 to 360 in-lb 144 to 360 in-lb 3/4 300 to 500 in-lb 75 to 83 ft-lb 41 to 70 ft-lb 12 300 to 540 in-lb 216 to 540 in-lb 1 41 to 58 ft-lb 100 to 116 ft-lb 58 to 95 ft-lb 16 42 to 58 ft-lb 480 to 696 in-lb 1-1/4 50 to 75 ft-lb 20 50 to 75 ft-lb 50 to 75 ft-lb 1-1/2 50 to 75 ft-lb 24 50 to 75 ft-lb 50 to 75 ft-lb 1-3/4 38 60 to 90 ft-lb 62 to 90 ft-lb 2 32 75 to 110 ft-lb 75 to 100 ft-lb 2-1/2 40 150 to 175 ft-lb 110 to 150 ft-lb 3 48 150 to 175 ft-lb 4 64 200 to 225 ft-lb
NOTE: Flareless tubing connections shall be tightened as follows:
Tighten the MS21921 nut 1/6 to 1/3 turn (1 to 2 flats) past point of sharp torque rise on all sizes and materials. The 1/6 to 1/3 turn (performed after the presetting operation) is the final installation torque
2-00-00 Page 14
Table 2-5. Standard Torque Values (Studs) Part I
TORQUE RANGE
THREAD SIZE
NUT END STUD END TYPE "A" TYPE "B"
10 -32 10 -24 30 to 40 in-lb 10 -32 1/4 - 20 30 to 40 in-lb 30 to 40 in-lb 1/4 - 28 1/4 - 20 50 to 95 in-lb 50 to 70 in-lb 1/4 - 28 5/16 -18 50 to 110 in-lb 50 to 80 in-lb 5/16 - 24 5/16 - 18 100 to 225 in-lb 10 to 130 in-lb 5/16 - 24 3/8 -16 100 to 240 in-lb 100 to 160 in-lb 3/8 - 24 3/8 -16 175 to 375 in-lb 175 to 250 in-lb 3/8 - 24 7/16 - 14 175 to 475 in-lb 175 to 325 in-lb 7/16 - 20 7/16 -14 20 to 54 ft-lb 250 to 400 in-lb 7/16 - 20 1/2 -13 20 to 60 ft-lb 250 to 525 in-lb 1/2 - 20 1/2 -13 33 to 83 ft-lb 33 to 58 ft-lb 1/2 - 20 9/16 -12 33 to 95 ft-lb 33 to 70 ft-lb 9/16 - 18 9/16 -12 50 to 120 ft-lb 41 to 87 ft-lb 9/16 - 18 5/8 - 11 50 to 137 ft-lb 50 to 95 ft-lb 5/8 -18 5/8 -11 75 to 166 ft-lb 58 to 116 ft-lb 5/8 - 18 11/16 -11 75 to 200 ft-lb 75 to 141 ft-lb
* For nut torque, refer to applicable chart for type of nut used. NOTE: Threaded Stud
Type A: The grip portion of the stud is approximately the same diameter as the pitch diameter of the nut end thread.
Type B: The grip portion of the stud is less than the minor diameter of the nut end thread.
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Table 2-5. Standard Torque Values (Studs) Part II (Cont) SHEAR PIN 100-076 100-085 100-090 NUT MS21042 H541L NAS1291 Thread Recommended size Inch-pounds Newton-meters 8-32 15 - 25 1.7 - 2.8 10 - 32 25 - 35 2.9 - 3.9 1/4 - 28 60- 80 6.8 - 9.0 5/16-24 130- 160 15-18 3/8 - 24 200 - 240 23 - 27 7/16 - 20 270 - 330 31 - 37 1/2 - 20 370 - 430 42 - 48
NOTE: The above values apply to any combination of pin and nut shown.
TENSION PIN 100-047 100-048 100-049 100-059 NUT MS21042 H541L NAS1291 Thread Recommended size Inch-pounds Newton-meters 8-32 30 - 40 3.4 - 4.5 10 - 32 40 - 50 4.6 - 5.6 1/4 - 28 115 - 130 13-14 5/16 - 24 200 - 250 23 - 28 3/8 - 24 360 - 420 41 - 47 Foot-pounds Newton-meters 7/16 - 20 44 - 56 60 - 75 1/2 - 20 61 - 83 83 - 112
NOTE: The above values apply to any combination of pin and nut shown.
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Table 2-6. Standard Torque for Dynamic Beam Seal Nuts (Operating Pressures to 5000 PSI, Titanium Material)
TORQUE RANGE TORQUE MAXIMUM
COUPLING NUTS JAM NUTS
FITTING SIZE FT-LBS FT-LBS -04 10-14 12 -06 15 - 25 20 -08 30 - 40 35 -10 60 - 70 48 -12 70 - 80 60 -16 135-155 82
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Table 2-7. Recommended Standard Torque for Flared Fitting Nuts
TORQUE RANGE
TUBING ALUM ALLOY HOSE FITTINGS STEEL
NOMINAL TUBING STEEL TUBING & ASSEMBLIES NAS591 THR FITTINGS
OUTSIDE MS33583/ MS33584 MS28740/ NAS591 THRU
DIAMETER MS33584 MS28759 NAS594
3/16 30 to 45 in-lb 90 to 100 in-lb 70 to 100 in-lb
1/4 40 to 65 in-lb 135 to 150 in-lb 70 to 120 in-lb 48 to 96 in-lb 60 to 96 in-lb 5/16 60 to 80 in-lb 180 to 200 in-lb 85 to 180 in-lb 60 to 108 in-lb 66 to 108 in-lb
3/8 75 to 125 in-lb 270 to 300 in-lb 100 to 250 in-lb 72 to 120 in-lb 72 to 120 in-lb 1/2 150 to 250 in-lb 450 to 500 in-lb 210 to 420 in-lb 120 to 216 in-lb 144 to 232 in-lb 5/8 200 to 350 in-lb 54 to 58 ft-lb 300 to 480 in-lb 144 to 360 in-lb 204 to 360 in-lb 3/4 300 to 500 in-lb 75 to 83 ft-lb 41 to 70 ft-lb 216 to 540 in-lb 300 to 540 in-lb
1 41 to 58 ft-lb 100 to 116 ft-lb 58 to 95 ft-lb 40 to 58 ft-lb 42 to 58 ft-lb 1-1/4 50 to 75 ft-lb 50-74 ft-lb 50 to 75 ft-lb 1-1/2 50 to 75 ft-lb 50 to 75 ft-lb 50 to 75 ft-lb 1-3/4 62 to 90 ft-lb 60 to 90 ft-lb 2 75 to 110 ft-lb 75 to 110 ft-lb 2-1/2 110-150 ft-lb 150-175 ft-lb 3 150 to 175 ft-lb 4 200 to 225 ft-lbs 2-00-00 Page 18
NOTE: APPLIED AND INDICATED TORQUE VALUES ARE THE SAME.
SPM-00020-00010-001-C00
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2 IN. 12 IN.
FORMULA TO OBTAIN CORRECT INDICATED TORQUE VALUE WHEN USING
NONCONCENTRIC ATTACHMENT
200 IN-LB TW = (TA) X (L)
(L) ± (A) TA TW
TW = INDICATED TORQUE VALUE ON TORQUE WRENCH
TA = ACTUAL TORQUE VALUE APPLIED
200 X12 2400
TO FASTENER TW= 200X12 = 24 = 171.4 IN-LB
L = LEVEL LENGTH
A = ATTACHMENT LENGTH RESULTS: FASTENER TORQUED 200 IN-LB WHEN WRENCH INDICATES FORMULA 171.4 IN-LB EXAMPLE 1 12 IN. 200 IN-LB 2 IN. 120o INLB ATA TWA 200 X 12 2400 200 X 12 2400
RESULTS: FASTENER TORQUED 200 IN-LB RESULTS: FASTENER TORQUED 200 IN-LB WHEN WRENCH INDICATES WHEN WRENCH INDICATES
240 IN-LB 174.5 IN-LB
EXAMPLE 3 EXAMPLE 2
SPM-00020-00020-001-COO
Figure 2-2. Torque Wrench Nonconcentric Type Attachments
2-00-00
4 IN. FORMULA TO OBTAIN CORRECT INDICATED 2 IN. 12 IN.
TORQUE VALUE WHEN USING A
NONCONCENTRIC ATTACHMENT
(TA) X (L) 200
(L) + (A) IN-LB
TW = INDICATED TORQUE VALUE ON TA, TORQUE WRENCH
TA = ACTUAL TORQUE VALUE APPLIED TO FASTENER
200 X 12 2400
L= LEVEL LENGTH TW= 200X2 240 = 171.41N-LB
A = ATTACHMENT LENGTH 122
FORMULA RESULTS: FASTENER TORQUED 200 IN-LB WHEN WRENCH INDICATES
171.4 IN-LB
PROPER APPLICATION OF FORCE EXAMPLE 1 2 IN. 12 IN. -21N. =10 2 IN. IN.+21 N. =14 A- L A L 200 200 IN-LB TA TW -200X(12+2)_ 2800 = 175 IN-LB (12-2)2 - 12
RESULTS: FASTENER TORUED 200 IN-LB RESULTS: FASTENER TORQUED 200 IN-LB WHEN WRENCH INDICATES
WHEN WRENCH INDICATES 166.6 IN-LB
175 IN-LB
IMPROPER APPLICATION OF FORCE
IMPROPER APPLICATION OF FORCE EXAMPLE 3
EXAMPLE 2
SPM-00020-00030-001 -COO
Figure 2-3. Affect of Applied Force to Rigid Frame and Audible Indicating Torque Wrenches Using Nonconcentric Attachments
Bell Helicopter Textron BHT-ALL-SPM
CHAPTER 3
-
CORROSION CONTROL AND PROTECTIVE COVERINGS/COATINGS
CONTENTS - MAINTENANCE PROCEDURES
Paragraph Chapter/Section Page
Number Title Number Number
3-1 G eneral ... 3-00-00 3 3-2 Corrosion Prevention ... 3-00-00 4 3-3 Corrosion Preventive Treatment... 3-00-00 4 3-4 Corrosion Preventive Oil... 3-00-00 4 3-5 Corrosion Protection - Control Bolts, Rotating,
and Non-Rotating ... 3-00-00 4 3-6 Corrosion Corrective Treatment ... 3-00-00 4 3-7 Corrosion Removal - Steel Parts ... 3-00-00 5 3-8 Corrosion Removal- Aluminum Parts ... 3-00-00 5 3-9 Corrosion Removal - Magnesium Parts ... 3-00-00 5
3-10 Corrosion Removal - Elastomeric Components ... 3-00-00 6
3-11 Corrosion Protection - Faying Surfaces ... 3-00-00 6 3-12 Similar Metals... 3-00-00 8 3-13 Dissimilar Metals ... 3-00-00 8 3-14 Corrosion Protection - Exceptions ... 3-00-00 8 3-15 Chemical Film (Chromic Acid) Treatment
-Magnesium ... 3-00-00 9 3-16 Aluminum Alloy - Chemical Film Treatment
(Touchup) ... 3-00-00 10 3-17 Cadmium Plating... 3-00-00 11 3-18 Chromate Conversion Coating... 3-00-00 12 3-19 Solid Film Lubricant ... 3-00-00 12 3-20 Solid Film Lubricant Repair... 3-00-00 12 3-21 Black Oxide ... 3-00-00 13 3-22 Gear Tooth Wear Pattern Inspection Using Dry
Film Lubricant... 3-00-00 13 3-23 Copper Plating ... 3-00-00 14 3-24 Plastic Media Blasting. ... 3-00-00 15 3-25 Plastic Media Blasting Equipment - Description ... 3-00-00 16 3-26 Plastic Media Blasting Operator Training ... 3-00-00 17 3-27 Media Particles Method 1 ... 3-00-00 17 3-28 Media Particles Method 2... 3-00-00 17 3-31 PMB Method 2 (Open Booth) Procedures ... 3-00-00 18 3-32 Preparation of the Helicopter for PMB ... 3-00-00 19 3-33 PMB Mapping Procedure ... 3-00-00 19 3-34 Organic Coat Removal Procedure ... 3-00-00 19 3-35 PMB Clean-up Operation ... 3-00-00 20
3-00-00 Page
TABLES
Table Page
Number Title Number
3-1 Definitions of Similar and Dissimilar Metals... 7 3-2 Organic Protective Requirements for Metals ... 7 3-3 Solid Film Lubricant Curing ... 13 3-4 Copper Plating Bath ... 15 3-5 PMB Method 2 Parameters - Description... 18
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CORROSION CONTROL AND PROTECTIVE COVERINGS/COATINGS
3-1. GENERAL the alloy structure caused by heat treating procedures
or localized overheating such as from fire damage, There are many various forms of corrosion which may result in intergranular corrosion. This corrosion attack metal and metallic materials causing early part may exist without visible evidence on exterior surfaces failure. Several types of corrosion most common in and serious structural weakening may occur without aircraft are listed below. Routine and preventive detection.
maintenance and inspections are designed to help
prevent corrosion caused component failure. 5. Exfoliation. This is a type of corrosion which
most often occurs in aluminum parts made from plate, 1. Surface Corrosion. The direct surface attack bar, tube and extrusions which have long, thin grains. form of corrosion is generally the least serious of the Exfoliation corrosion is recognizable by the long, thin various forms of corrosion. It is the result of direct leafs of material which delaminate from the surface of reaction of metal surfaces with oxygen in air and a part. This type of corrosion often appears as a blister occurs more readily when metal surfaces are exposed on the surface of a part. This is due to corrosion to salt spray or salt-bearing air. Sulphur and chlorine products between the grains forcing the grains apart, compounds which may be present in smoke stack causing a bulge on the surface. Exfoliation corrosion is gases and engine exhaust gases also cause direct a form of intergranular corrosion.
surface attack. Etching may be noticed on the surface
when corrosion deposits are removed. If the metal is 6. Stress Corrosion. Stress affects metals that are
aluminum alloy with a coating of pure aluminum too highly stressed under corrosive conditions. Shrink (ALCLAD), the affect on strength of ductility of metal is fit parts and parts subjected to cold working conditions negligible; however, corrosion of a similar degree on are susceptible to stress corrosion cracking. Stressed non-clad metals may be considered serious. (Refer to metal tends to become anodic when in contact with applicable Component Repair and Overhaul Manual). stress-free metal. Galvanic corrosion occurs along the The pits may become sites for crack development in lines of stress and rapid failure of the part results. parts which are critical in fatigue.
7. Fatigue Corrosion. This is closely related to
2. Galvanic Corrosion. This is caused by dissimilar stress corrosion and appears in metals under cyclic metal contact in the presence of a liquid such as salt stress in a corrosive surrounding. A jet engine turbine spray or condensate, forming a true chemical cell. This blade is an example of a part subject to fatigue causes electrons to flow and the most easily oxidized corrosion. The corrosion causes sharp deep pits surface becomes the anode and corrodes. The which, in turn, become the origin of cracks that may emitting surface becomes the cathode of the cell. ultimately result in failure of the part. It is difficult to detect this type of attack in advance except as
3. Pitting Attack. This is a special kind of galvanic cracking develops. reaction and is usually localized. It occurs at a point of
weakness and is caused by a lack of homogeneity in 8. Fretting Corrosion. This type corrosion the alloy surface. Pitting originates from mechanical develops when two heavily loaded surfaces contact contact, faulty heat treatment, or localized each other and are subject to slight vibratory motion. contamination that breaks down surface protection. The rubbing contact removes small particles of virgin These areas become anodic characteristics of the pit metal from each surface. These particles will usually area. A deep penetrating attack develops rather than oxidize to form abrasive materials. The attack is general surface attack. compounded by the continued motion which prevents formation of any protective oxide film, creating a prime 4. Intergranular Corrosion. This is a selective type area for further corrosion to occur. Fretting is evident of corrosion and attacks along the grain boundaries of at an early stage by surface discoloration and the metal alloys. Aluminum alloys which contain presence of corrosion particles in any lubricant appreciable amounts of copper and zinc and some present. Continued fretting will ruin bearing surfaces, stainless steels are vulnerable to intergranular destroy critical dimensions, and may be serious corrosion. Piano hinges are an example of aluminum enough to eventually cause cracking and fatigue extrusions which are vulnerable. Lack of uniformity in failure. Fretting may be controlled by preventing
3-00-00 Page 3
slippage of the two surfaces or by lubricating the 3-4. CORROSION PREVENTIVE OIL
surfaces.
MATERIALS REQUIRED 9. Hygroscopic Material Corrosion. This is
Refer to chapter 13 for specification and source.
caused by such materials as sponge rubber, felt, cork, Refer to chapter 13 for specification and source. etc., absorbing water and holding it in contact with the NUMBER NOMENCLATURE
part. As a result, surface or galvanic corrosion may
develop. C-125 Preservative Oil
3-2. CORROSION PREVENTION Use preservative oil (C-125) as a general light corrosion preventive for bonded, exposed, and painted metals.
3-3. CORROSION PREVENTIVE TREATMENT
3-5. CORROSION PROTECTION - CONTROL
MATERIALS REQUIRED BOLTS, ROTATING, AND NON-ROTATING
Refer to chapter 13 for specification and source. MATERIALS REQUIRED
NUMBER NOMENCLATURE Refer to chapter 13 for specification and source.
C-105 Corrosion Preventive NUMBER NOMENCLATURE
C-304 Solvent C-101 Corrosion Preventive
Compound
After parts are cleaned, control and precautionary C-104 Corrosion Preventive
measures shall be exercised at all times to prevent Compound
corrosion. Fingerprint residue, reactive with moisture in the air, will cause accelerated corrosion in the
Prior to assembly, coat all rotating and non-rotating
affected areas. In order to avoid these difficulties, the preventive
control bolt shanks with corrosion preventive
following procedures shall be applied to ferrous metal compound (C-104) unless otherwise specified. After parts after cleaning and inspection. assembly, coat boltheads and exposed threads with
corrosion preventive compound (C-101). 1. Wash all ferrous parts in a clean rinse of solvent
(C-304) then drain the parts. 3-6. CORROSION CORRECTIVE
TREAT-MENT
2. Gently agitate parts in fingerprint remover MATERIALS REQUIRED
corrosion preventive (C-105) and allow to drain.
Refer to chapter 13 for specification and source.
NOTE NUMBER NOMENCLATURE
Normally, parts treated with the above
compounds may be left covered in indoor-304 Solvent
storage for approximately six days without C-500 Crocus Cloth being affected.
Corrosion corrective treatment can be applied to all 3. Immediately prior to reassembly, clean parts with metal parts of the assemblies in varying degrees solvent (C-304) and coat with approved oil. Do not (unless otherwise specified in the text). The following handle or assemble unoiled parts. method shall be applied to remove corrosion using the
Bell Helicopter Textron BHT-ALL-SPM
applicable information as a criteria to determine 4. Surfaces shall be dried using an oven 150°F
serviceability of the part. (65°C) maximum, clean dry rags, or using
compressed air which has been filtered to render it oil 1. Wash part in solvent (C-304) to remove loose and moisture free.
foreign matter.
5. Treat for corrosion prevention (paragraph 3-2). 2. Dry the part.
3-8. CORROSION REMOVAL - ALUMINUM
PARTS
3. Use crocus cloth (C-500) or hand buffing wheel
with jewelers rouge to remove corrosion from affected MATERIALS REQUIRED
area by polishing. Do not use any abrasive coarser than specified.
Refer to chapter 13 for specification and source. 4. Clean parts to remove all traces of corrosion and NUMBER NOMENCLATURE
polishing agents.
C-204 Primer
C-423 Abrasive Cloth or Paper
NOTE
No polishing is acceptable on bearing 1. Remove corrosion using 400 grit abrasive cloth or
surfaces. paper (C-423).
3-7. CORROSION REMOVAL - STEEL PARTS
NOTE
MATERIALS REQUIRED
MATERIALS REQUIRED Depth of repair shall be twice the depth of corrosion not to exceed repair limits. Refer Refer to chapter 13 for specification and source. to applicable maintenance or CR&O
manual for limits.
NUMBER NOMENCLATURE
2. Apply two coats of epoxy polyamide primer
(C-C-344 Cleaner 204) to repaired area.
1. Thoroughly mix one volume of cleaner (C-344) 3-9. CORROSION REMOVAL - MAGNESIUM
and three volumes of water. PARTS
MATERIALS REQUIRED
2. Prepared surfaces which are to receive cleaner shall be free of oil, grease, shop soil, and paint.
Recleaning shall be accomplished, as required, by any Refer to chapter 13 for specification and source. acceptable method.
NUMBER NOMENCLATURE
3. Apply cleaner to metal surface by brushing or C-116 Chromic Acid swabbing. The cleaner shall remain in contact with
metal surface for one to three minutes and shall be C-117 Hydroflouric Acid
followed by a thorough rinse. C-304 Solvent
C-305 Aliphatic Naphtha
NOTE C-309 Methyl-Ethyl-Ketone
Step 3 may be repeated, as required, to (MEK)
remove light rust. Apply cleaner to corroded area
only, then rinse. C-348 Alkaline Steel Cleaner
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c. Immerse AZ31 B alloy parts for 30 seconds to
NOTE one minute. Immerse all other alloys for four to five
A chromic acid bath is used to remove minutes. corrosion from magnesium parts.
d. Thoroughly rinse parts in fresh water to 1. Wipe parts clean before immersing in acid bath d. Torouly rie
using solvent (C-304), MEK (C-309), or aliphatic remove all traces of fluode. naphtha (C-305).
8. Immediately after corrosion removal, apply chemical film treatment (paragraph 3-15).
3-10.
CORROSION REMOVAL
-ELASTOMERIC
COMPONENTS
CORROSION REMOVAL PROCESS SHALL BE MONITORED TO ENSURE
MACHINED DIMENSIONS ARE
MAINTAINED, CORROSION LIMITS
SPECIFIED FOR THE INDIVIDUAL PART Refer to chapter 13 for specification and source. ARE NOT EXCEEDED, AND CADMIUM
PLATING IS NOT REMOVED FROM NUMBER NOMENCLATURE
STUDS.
C-305 Aliphatic Naphtha
2. Mix a solution of 20 to 24 ounces of chromic acid C-355 Detergent (C-116) with one gallon of water.
NOTE NOTE
The mixture can be used at room Many elastomeric components on
temperature to 200°F (93°C). Preferred helicopter will be severely damaged, if they temperature range being from 160°F to are allowed to remain in contact with oil. Oil
180°F (710C to 820C). contaminants should be removed on
regular basis, using mild detergent (C-355) 3. Immerse corroded part in mixture until corrosion and warm water.
has been removed.
1. Scrub elastomeric components used in main 4. Thoroughly rinse part in fresh water until all 1 crub elastomeric components used in main corrosion removing products are removed. rotor, swashplate pylon support, and airframe. Use mild detergent (C-355) and water. Rinse with water
and dry with clean cloths. 5. Remove remaining contaminants from parts
using alkaline cleaner (C-348). Follow manufacturer's
instructions for use of cleaner on magnesium parts. 2. Rinse both metal and rubber elastomeric component surfaces with aliphatic naphtha (C-305). 6. Rinse parts in fresh water until all cleaner is Wipe dry with clean cloths.
removed.
7. Acid pickle parts as follows: 3-11. CORROSION PROTECTION - FAYING
7. Acid pickle parts as follows:
SURFACES a. Prepare a 15 to 20 percent (by weight)
hydrofluoric acid solution (C-117). Refer to tables 3-1 and 3-2 for definitions of similar and dissimilar metals and organic protective b. Allow solution to reach room temperature. requirements.
Bell Helicopter Textrin I BHT-ALL-SPM
Table 3-1. Definitions of Similar and Dissimilar Metals
GROUP I GROUP II GROUP III GROUP IV
1. Magnesium and its alloys. 1. Cadmium and its alloys 1. Iron 1. Copper 2. Aluminum Alloys of 5052, 2. Zinc and its alloys 2. Lead 2. Chromium 5056, 5356, 6061, and 6063
3. Aluminum and its alloys 3. Tin 3. Nickel (Including the Aluminum
Alloys in Group I)
4. Titanium 5. Cobalt
6. Stainless Steel
NOTES:
1. Metals classified in the same group are considered similar. 2. Metals classified in different groups are considered dissimilar.
3. For the purpose of this table, the metal referred to is the metal on the surfaces of the part.
Table 3-2. Organic Protective Requirements for Metals
METAL INTERIOR EXTERIOR
Magnesium 0.4 mil (min) - epoxy polyamide 0.4 mil (min) epoxy polyamide
primer primer, then applicable finish
Aluminum 0.4 mil (min) - epoxy polyamide One coat of epoxy polyamide
primer primer, then applicable finish
Copper alloys 400 series steel and low alloy steels (see NOTE)
200 and 300 series stainless No protective finish required steels
Titanium
NOTE
When 400 series steels are used in high heat application, omit the organic finish.
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