AC NO: m-59 DATE 0 a 2119168 ADVISORY . .
CIFEULAR MAINTENANCE INSPECTION NOTES FOR CONVAIR MODELS 240 AND 600/24OD; MODELS 340/440 AN-D 640/340D/440D SERIES AIRCRAFT Consolidated reprint, February 1974;
includes change 1.
DEPARTMENT OF TRANSPORTATION FEDERAL AVIATION AllMINISTRATIOW Initiated by: ~Fs-30~
AC 20-59 CH 1 8/24/72 .
AC MO: 20-5g DATE . : Z/19/68 .
ADVISORY
CIRCULAR
DEPARTMENT OF TRANSPORTATION
FEDERAL AVIATION ADMINISTRATION * SUBJECT: MAINTENANCE INSPECTION NOTES FOR CONVAIR MODELS 240 AND 600/24oD; MODELS 340/440 AND 640/340D/440D SERIES AIRCRAFT * *
1. PURPOSE. This handbook describes maintenance inspection notes which can be used for the maintenance support of certain structural parts of Convair 240 and 600/240D; Models 340/440 and 640/340D/440D series aircraft. *
2. DESCRIPTION. Maintenance on the wing, fuselage, and empennage structure is reviewed with a view toward supplementing information currently available.
3 . HOW TO GET THIS PUBLICATION.
a. Order additional copies of this publication from:
Department of Transportation Federal Aviation Administration Distribution Unit, TAD-484.3 Washington, D.C. 20590
b. Identify this publication as: Advisory Circular 20-59 - Maintenance Inspection Notes for Convair 240, 600/240D, 340/440, and 630/340D/440D Series Aircraft.
C;d qq&#* C. R, MELUGIN, JR.
Acting Director, Flight Standards Service * Initiated by: us-300
AC 2049 CH 1 a/24/72 Page i .
TABLE OF CONTENTS Page No.
1 l Iatroductlon .
2 . Description 4: 3 General Background Information 5 . Type of Cons,truction 6 7 :
General Inspecthn Tips Nondestructive Testing (NDT) APPENDIX 1 STATION CHARTS (i paged Figure A-1 Wing Station8 1 Figure A-2 Fuselage Station8 2 APPENDIX 2 FUSELAGE COMPONENTS Fu8ehge E(rjor Coaponeats Fuselage Nose Section Fu8ehge Cabin Section ' Fu8elage Tail Section Furelage'Stringer Diagram (z pages) 1 2 3 4 5 Pigurb B-1 Figure B-2 Figure B-3 Figure B-4 Figure B-5 APPENDIX 3 Figure C-l Figure C-2 Figure c-3 ‘Figure C-4 Figure C-5 *APPENDIX4 *APPENDIX 5 APPENDIX 6
WING COMPONENTS Wing Coaponeat8 Wing Leading Edge Structure Wing Inter-Spar .Structure Wing Tailing Edge Structure Wing Tip Structure MAINTENANCE INFORMATION* MODEL 240 AND 600/24OD (STC # SA 1054 WE) SERIES AIRCRAFT ~DEL3hO/bbOAND6bO/~D/bbOD (STC # AS 1096 WE) SERIES AIRCRAFT
a. . .
1 1 1 1 2 2 3 (5 pager) (9 paged 1 (5 pages) 1 (6 P4w0 1 *
AC 20-59 2/19/68 1 . INTRODUCTION, This advisory circular provides maintenance information ..- - which can be used by m$chanics, repair agencies, owners, and operators in developing maintenance programs, making improvements in existing programs, and conducting inspections and repairs on certain structural parts of Convair 240, 34W440, 24OT, and 340T airplanes. The material is based, ___ in part, upon information made available through discussions with personnel who have maintained these types of airplanes for thousands of q hours of time in service; The intent of the circular is to impart some of this knowledge to other interested person,s so that it is not lost.
2. DESCRIPTION. The circular contains guidance material for performing maintenance on wing, fuselage, and empennage structure. The information has been derived from.service experience. It does not comprise a full and complete maintenance program for the subject aircraft but should be considered as supplemental maintenance data. Included in the circular are diagramatic sketches and station identifications of the wing and fuselage, In addition, there is a listing of selected maintenance difficulties which have been reported since 1964.
3 0 BACKGROUND.
a. Aircraft Use. The agency has realized that several different types of transport aircraft are being phased out of service by some airlines because of the availability of newer equipment. Such older aircraft are being purchased by other operators who may not be familiar with ' the scope of required maintenance and'the means which have been used to keep the aircraft in a safe condition.
b . Maintenance "Know How." Since maintenance "know how.' is not transferred with the aircraft, the new operator generally goes through a learning cycle before he is able to rapidly pinpoint the important/ critical problem areas of the aircraft. In this respect, identification of known areas where structural problems have been experienced will help in the preparation of an initial maintenance,program by a new operator. - It also can serve as a guide to other operators who have not accumulated sufficient service experience to have knowledge 'of all the problem areas of the aircraft. .
4 l GENERAL INFORMATION,
a. Manufacturer's Bulletins. It must be emphasized that the manufacturer has published several service bulletins concerning the inspection, repair, and modification of Convair 240, 340/400, 24OT, and 340T aircraft. Service bulletins highlight the importance of maintaining structural integrity on aircraft with particular reference to areas known to have experienced crack and corrosion damage. Operators are urged to become conversant with the manufacturer's recommendations and make certain that responsible maintenance personnel are knowledgeable on this, subject.
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Page 2 AC 20-39 2/19/68 - b . Airworthiness Directive. It is emphasized that the material in this circular does not supersede any of the requirements of airworthiness l directives issued under P'art 39 of the Pederal.Aviation Regulations.
5 . TYPE OF CONSTRUCTION. The major structural components of the aircraft are the wing group, the fuselage group, and tail group. -.
a. The full cantilever wing group consists of a center section integral with the fuselage and two removable outer panels. The outer panels include detachable tip sections and ailerons. The two-engine nacelles are bolted and riveted to the wing center section and include support beams on the outboard sides for installation of the main landing gear.
b . The all metal semi-monocoque fuselage consists of three sections:
nose section, cabin section, and tail cone section. Construction of the fuselage consists of longerons, longitudinal stringers, transverse bulkheads, formers, and support beams. The dorsal fin of beam and rib construction is riveted to the upper aft exterior surface of the fuselage along the center line.
c. The tail group is composed of the horizontal stabilizers with hinged elevators and vertical stabilizer with hinged rudder. The vertical and horizontal stabilizers are of full cantilever design and conventional spar and rib construction.
. 6 0 GENERAL INSPECTION TIPS.
a. Visual Inspection. The primary structure of the aircraft is designed to provide resistance to variable forces imposed while in operation by dispensing the forces through a structural pattern of "force flow" to the primary structural members of the wing and fuselage. External indications of failure, such as distorted skin, tilted or sheared .
rivets, and torn, dented, cracked, or corroded skin are usually obvious. Wkinkled skin, "oi 1 cans," and tilted rivets, adjacent to the obviously failed area often indicate secondary damage caused by transmission of stress from the failed area. Misalignment of doors and panels may indicate distortion of internal structure. Internal structural damage, although not always apparent, may be found by closely examining the exterior surface. For example:
(1) Buckled sk.in between rivets at the end of a stiffener or stringer could mean that the last attaching rivet has failed, or that the stiffener or stringer is buckled in the area of the skin buckle. When a detailed inspection of the failed area is to be performed, functional parts should be actuated to determine if the failure has caused binding.
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AC 20-59 2/19/68 .
Page 3 .
(2) Deep diagonal skin buckles, located over a frame, former, or rib could mean the member is distorted. When doubt exists doncerning internal condition, the area in question should be opened and carefully inspected.
7 . NONDESTRUCTIVE TESTING (NDTL ..- Simply stated, nondestructive testing is preventive maintenance. This includes utilization of such maintenance tools as X-ray, ultrasonic, magnetic particles, eddy current, and dye penetrant.
& Maintenance Inspection. NDT permits maintenance inspections without removing components from aircraft or tearing down complex assemblies.
Defects in various aircraft systems which would escape detection through'normal visual inspection will be identified by NDT.
b l Training Required, Special NDT training is necessary to make sure that the operator is capable of operating the equipment and inter- .
preting the results. Also, many states require that an X-ray operator have an approved certificate for use of X-ray in industrial applications, This is to minimize improper use with attendant health hazard of X-ray equipment.
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Page 4 AC 20.- 59 2/19/68 . 0 ' AIRCRAFT STATION DIAGRAMS The wing, fuselage, and empennage station diagrams included in this document were developed for the CL340 aircraft and are used as a general reference only. Several models of each of these aircraft were manufactured and have different station locator numbers based on the particular configuration. Since the defect areas generally apply to all models of both aircraft, the referenced area can be compared with a similar area and locator on the appropriate station diagram for the particular model of aircraft.
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/ 523 8 WING STATIONS (IN INCHES) 169 /* 332 / /- /' /' WING STATIONS ’ 523 545 (IN INCH ES)
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, 89/61/Z sNoILviLs 33vT3SrM ‘Z-V 3?m31d
CODE STRUCTURAL FIGURE
COMPONENT REFERENCE
1. FUSELAGE NOSE ’ SECTION FIG. &2
2. FUSELAGE CABIN \ SECTION FIG. ‘B-3
3. FUSELAGE TAIL SE$XION FIG. B-4 4, FUSELAGE STRINGER DIAGRAM FIG. B-5