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31 JULY 1963 SUPERSEDING MIL-T-5578B 25 FEBRUARY 1959 MILITARY SPECIFICATION TANK, FUEL, AIRCRAFT, SELF-SEALING

This specifications has been approved by the Department of Defense and is man- datory for use by the Departments of the Army, the Navy, and the Air Force. 1. SCOPE 2. APPLICABLE DOCUMENTS 1.1 Scope. This specification covers self- 2.1 The following documents, of the issue in sealing and partially self-sealing fuel tanks for effect on date of invitation for bids or request use on aircraft. A tank shall consist of a cell for proposal, form a part of this specification or group of cells interconnected, and the com- to the extent specified herein: ponents attached directly thereto, to form a com- SPECIFICATIONS plete tank or reservoir. 1.2 Classification. The tanks shall be of FEDERAL the following general types, classes, styles and QQ-P-416-Plating, Cadmium (Electro- protection levels to be furnished as specified by deposited) the procuring activity (see 6.2): UU-P-271-Paper, Wrapping, Water- Type I — For use with engine fuel conform- proofed Kraft ing to MIL-G-5572 (intended for use PPP-B-585-Boxes, Wood, Wirebound with reciprocating engines). PPP-B-591-Boxes, Fiberboard Wood- Cleated Type II-For use with engine fuel con- PPP-B-60l-130xq Wood Cleated-Ply- forming to MIL-G-5572 or MIL-J-5624 wood (intended for use with jet engines). PPP-B-621-Boxes, Wood Nailed and Class A—Flexible cell construction. Lock-Corner Class B—Semirigid or self-supporting cell PPP-B-636-Box, Fiberboard construction. PPP-B-640-Boxes, Fiberboard9 Corru- Style I—Nonpressurized fuel system. gated, Triple Wall Style 2-Pressurized fuel system. PPP-T-60-Tape, Pressure Sensitive Ad- Protection level (A) —Cell is completely hesive, Waterproof-for Packaging and self-sealing against .50 cal. and 20 mm. Sealing Protection level (B) —Cell is completely self-sealing against .30 cal only. MILITARY Protection level (C)—Part of cell is blad- JAN-P-100-Packaging and Packing for der construction and part is self-sealing Ovenseas Shipment-General Specifica- against .50 cal. and 20 mm. tion Protection level (D) —Part of cell is blad- MIL-P-116-Preservation, Methods of der construction and part is self-sealing MIL-B-121-Barrier Material, Grease against .30 cal. only. proofed, Waterproofed, Flexible MIL-S-3136-Standard Test Fluids, Hy- NOTE drocarbon For cells of protection levels (C) and MIL-C-5541-Chemical Films for Alumi- (D), the portions of the cells to be self- num and Aluminum Alloys sealing and non-self-sealing shall be as spe- FSC 1560 cified by the procuring activity. 698-294—63-1 1 Downloaded from http://www.everyspec.com

MIL-T-5578C

MIL-G-5572-Gasoline, Aviation: Grades Air FORCE-NAvy AERONAUTICAL 80/87, 91/96, 100/130, 115/145 MS20470— Rivet-Solid-Universal Head, MIL-F-5577-Fittings, Tank, Powerplant Aluminum and Aluminum Alloy Fluid, Removable MIL-J-5624-Jet Fuel, Grades JP-4 and PUBLICATIONS JP-5 Air FORCE-NAVY ARONAUTiCAL BULLETINS MIL-T-6396-Tanks, Fuel, Oil, Water- No. 107—Inspection Standards for Stand Alcohol, Coolant Fluid, Aircraft, Non- and Dissection Tested Self-Sealing Fuel Self-Sealing, Removable, Internal and Oil Cells MIL-C-6529-Corrosion-Preventive, Air- No. ll2-Acceptance Standards for Self- craft Engine Sealing Fuel and Oil Cells MIL-C-6800-Coating, Process for Appli- (Copies of specifications, standards, drawings, and cation of Permanent Resin to Aircraft publications required by suppliers in connection with Engine Parts specific procurement functions should be obtained MIL-S-7742-Screw Threads, Standard, from the procuring activity or as directed by the con- Optimum Selected Series: General Spe- tracting officer.) cification for 2.2 Other publications. The following MIL-P-8045-Plastic, Self-Sealing Tank document forms a put of this specification to Backing Material the extent specified herein. Unless otherwise MIL-A-8625-Anodic Coatings, for Alu- indicated, the issue in effect on date of invita- minum and Aluminum Alloys tion forbids shall apply: MIL-T-9107—Test Reports, Preparation CONSOLIDATED CLASSIFICATION COMMITTEE of Uniform Freight Classification Rules MIL-L-10547-Liners, Case, and Sheet, (Applicant for copies of the above publication should Overwrap, Water-Vaporproof or Water- be addressed to the Consolidated Classification Com- mittee, 202 Chicago Union Station, Chicago 6, Ill.) proof, Flexible 3. REQUIREMENTS STANDARDS 3.1 Preproduction. This specification FEDERAL makes provisions for preproduction testing FED. TEST METH0D STANDARD (see 4.3). NO. 601-Rubber: Sampling and Test 3.2 Components. A tank shall consist of a ing cell or group of cells interconnected, and the FED. TEST METHOD STANDARD components attached directly thereto, to form No. 791-Lubricants, Liquid Fuels, and a complete tank or reservoir. Related Products; Methods of Testing 3.3 Selection of specifications and stand- Military ards. Specifications and standards for neces- MIL-STD-129-Marking for Shipment sary commodities and services not specified and Storage herein shall be selected in accordance with MIL- MIL-STD-130-Identification Marking of STD-143. U.S. Military Property 3.4 Materials. The materials used in the MIL-STD-143-Specifications and Stand- manufacture of self-sealing fuel cells shall be ards, Order of Precedence for the Selec- suitable for the purpose and shall conform to tion of applicable Government specifications. The use MIL-STD-276-Impregnation of Porous of magnesium is prohibited. Where applicable Nonferrous Metal Castings Government specifications do not exist, contrac- MS29582-Flange, Attachment, Molded tor’s specifications may be used, provided that Tank, Recessed, Full Molded, Rectang- the contractor assumes full responsibility for ular 12.00 x 18.00 the use thereof. 2 Downloaded from http://www.everyspec.com

MIL-T-5578C 3.5 Design. The self-sealing fuel cells shall proved manufacturing tolerances as described be suitable for use with fuels conforming to in the manufacturer’s specifications. MIL-G-5572 or MIL-J-5624, or both, as 3.6.2 Fabric ply. Fuel cells shall be so fab- specified by the procuring activity, and shall ricated that the seam on any fabric ply shall not be designed in conjunction with the containing be superimposed with parallel seams of any ad- structure to avoid concentration of loads on jacent fabric ply. splices, seams, fittings, or location of concen- 3.6.3 Sealant. The fuel cells shall use an trated flexure. The assembly consisting of the approved sealant so vulcanized as to meet the cell (s) and aircraft structure in which it is retirement of this specification. The sealant mounted shall comprise the necessary strength shall be free of foreign matter, and the thickness to provide adequately for the stresses caused shall agree with the approved construction by the following: within the established manufacturing tolerance (a) Flexing resulting from vibration as described in the manufacturer’s specifications. (b) Impact loads incident to takeoff, taxi- 3.6.4 Fittings. All fittings used in self- ing, and landing (including cata- sealing fuel cells shall conform to MIL-F-5577. pulting and arresting) Both the inside and outside flanges of the fitting (c) Hydraulic surge of fuel incident to all shall be vulcanized to the cell carcass. Every dynamic conditions of flight effort shall be made to utilize fittings in a single (d) Hydraulic surge of fuel incident to plane. Where the aircraft design is such as to gunfire necessitate the use of double plane fittings, par- (e) Pressure loads resulting from hydro- ticular care should be taken to provide adequate static head of fuel during level flight exterior flange area to insure satisfactory ad- or maneuvers, and resulting from hesive strength under all conditions of opera- neutral gases, if any, used to pressur- tion. The use of through bolts shall be avoided. ize fuel cells. 3.6.4.1 Screw threads. Screw threads shall be in accordance with MIL-S-7742. The use of 3.5.1 Dimensions. The dimensions and di- pipe threads is prohibited. mensional tolerances shall be developed by the contractor or Government procuring activity. 3.7 Performance. The cells and tanks, or The dimensional tolerance specified shall be such specified parts thereof, shall satisfy the per- that the capacity of the production tanks will be formance requirements specified herein when within 1.5 percent of the designed total capacity. subjected to the following tests, as specified in 3.5.2 Capacity. The head-versus-volume section 4: curve on production tanks shall conform within (a) Inspection ------(4.6.1) 1.5 percent to the average head-versus-volume (b) Stand ------(4.6.2) curve prepared in accordance with 4.4.2.1. (c) Dissection ------(4.6.8) 3.6 Construction. The following require- (d) Inner-layer ply—------(4.6.4) (e) Cells ------— (4.6.5) ments apply to fuel cell construction intended (f) Installation ------— ------(4.6.6) for protection levels (A) and (B) and for the (g) Capacity ----—------—- (4.6.7) self-sealing portions of fuel cell construction (h) Pressure ----———------(4.6.8) intended for protection levels (C) and (D). (i) Slosh or slosh and vibration resistance ------— (4.6.9) The non-self-sealing portions of construction (j) Aging and low temperature 1eakage (4.6.10) shall conform to MIL-T-6396, type II, class B. (k) Accelerated load resistance --—-(4.6.11) 3.6.1 Inner-layer ply. The construction (l) Gunfire resistance on tank shall be such that it will be impossible to trans- installation --—---— (4.6.12) mit fuel to the sealant. If necessary to meet 3.7.1 Operating temperature. The self-seal- this requirement, a special barrier shall be uti- ing fuel cell shall be- suitable for operation lized. The inner-layer ply shall be free of throughout the temperature range of -40° to foreign matter, and the thickness shall agree 160° F insofar as self-sealing performance is with the approved construction within the ap- concerned. For all other operating conditions,

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MIL-T-5578C the cell shall be satisfactory throughout the identification in accordance with MIL-STD- temperature range of -65° to 160°F. 130. The following special marking shall be 3.8 Weight. The weight of production cells added: shall be within 5 percent of the average weight (a) Aircraft contractor of the first 10 production cells. If, during the (b) Aircraft model(s) and cell location production of cells, the weight consistently ex- (c) Specification MIL-T-5578C ceeds the tolerance on one side of the production (d) Month and year of manufacture weight, the procuring activity shall be so in- The nameplate shall be located on the cell in formed, and all pertinent data shall be supplied such a position that when the tank is installed including a recommendation for anew produc- in the aircraft, the nameplate shall be readily tion weight, the reason for exceeding the weight accessible and visible after removal of aircraft tolerances, and a log of the cell weights for re- access panels, deck doors, etc. view and establishment of a new production weight. 3.12 Age. Cells shall be not more than 2 yearn old from date of initial cure to data of 3.9 Finish. 3.9.1 External surfaces. The external sur- installation in the aircraft or delivery to the faces of cells shall be protected against the ac- procuring activity. tion of ozone and fluid conforming to MIL-S- 3.13 Workmanship. Workmanship shall 3136, type III, by a suitable lacquer or equiva- be in accordance with manufacturing practices lent coating. covering this type of equipment. 3.9.2 Steel parts. Exposed non-corrosion- 4. QUALITY ASSURANCE PROVI- resisting steel parts shall be protected against SIONS corrosion by cadmium plating, in accordance with QQ-P-416, type II. 4.1 Responsibility for inspection. Unless 3.9.3 Aluminum-alloy parts. Aluminum al- otherwise specified in the contract or purchase loy parts, except those which are fully molded order, the supplier is responsible for the per- inserts, shall be analyzed in accordance with formance of all inspection requirements as MIL-A-8625 or treated in. accordance with specified herein. Except as otherwise specified, MIL-C-5541, and then coated with a permanent the supplier may utilize his own facilities or any resin in accordance with MIL-C-6800. If commercial laboratory acceptable to the Gov- necessary to prevent porosity, parts shall be ernment. The Government reserve the right to treated in accordance with MIL-STD-276. If perform any of the inspections set forth in the required, to provide a path across the part for specification where such inspections are deemed electrical current, the film may be removed necessary to assure supplies and services con- locally. form to prescribed requirements. 3.10 Markings 4.2 Classification of tests. The inspection 3.10.1 Access door covers. The exterior sur- and testing of fuel tanks shall be classified as face of all access door covers shall be durably follows: and legibly marked “Outside". 3.10.2 Assembly torque. The torque values (a) Preproduction tests------— ------(4.3) required to assemble the fittings and accessories (b) Quality conformance tests-----—- (4.4) to the cell shall be durably and legibly marked 4.3 Preproduction tests. The preproduc- on or adjacent to each fitting or accessory in- tion tests shall consist of phase I and phase II volved. In cases where the torque required to preproduction testing. (See 4.3.1.2 and 4.3.2,2.) assemble all fittings and accessories is the same, 4.3.1 Phase I preproduction testing. For the proper torque value need be stenciled in only the purpose of this specification, phase I tests one place provided it is visible when any access are those tests accomplished on samples of ma- door is removed. terials and construction to be used in the manu- 3.11 Identification of product. Equip- facture of self-sealing or dual construction fuel ment assemblies, and parts shall be marked for cells.

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MIL-T-5578C 4.3.1.1 Phase I test samples. Phase I test (c) Class A or B: samples shall consist of the following: (1) Protection levels (C) or (D): (B) Class A (flexible construction): a. Three cells with outside dimensions (1) Protection levels (A) and (B). of 30 by 30 by 24 inches containing a. Three flexible cells to fit the metal- a fitting conforming to. Part No. container shown in figure 1 The MS29582-1, centered on the top flexible cells shall contain a fitting surface thereof. The top of the cell conforming to Part No. MS29582-1 and the top half of the sides shall centered on the top surface thereof. be of approved non-self-sealing b. Eight metal side panels in accord- construction conforming to MIL-T- ance with sheet 5 of figure 1 6396, type II. The lower half of C. Eight sheets of backing material 27 the sides and bottom shall be of self- by 30 inches and two sheets of sealing construction conforming to backing material 30 by 30 inches, requirements specified herein. conforming to MIL-P-8045. The b. Eight metal side panels in accord- weight of the backing material for ance with sheet 5 of figure 1. style 1 cells shall not exceed ½ c. Eight sheets of backing material 27 pound per square foot. by 30 inches and two sheets of back- d. Two 12- by 12-inch samples of ing material 30 by 30 inches con- composite cell construction. forming to MIL-P-8045. The e. One sample of inner-layer ply, weight of the backing material for without barrier, approximately 900 style 1 cells shall not exceed ½ square inches in area with seam. pound per square foot. f. One sample of inner-layer ply, with d. Two 12- by 12-inch samples of com- barrier, approximately 900 square posite cell construction. inches in area without seam. e. One sample of inner-layer ply, with- g. One sample 6 by 6 by 0.075 to 0.125 out barrier, approximately 900 inch inner-layer ply, without square inches in area with seam barrier. (self-sealing portion only). f. One sample of inner-layer ply, (b) Class B (semi-rigid or self-supporting with barrier, approximately 900 construction): square inches in area without seam (1) Protection levels (A) and (B): (self-sealing portion only). a. Three semi-rigid or self-supporting g. One sample 6 by 6 by 0.075 to self-sealing cells with outside dimen- 0.125 inch inner-layer ply, without sions of 30 by 30 by 24 inches con- barrier (self-sealing portion only). taining a fitting conforming to Part None of these samples shall be preplasticised No. MS29582-1 centered on the top with fluid prior to submission. Any variations surface thereof. in the basic construction will be approved by b. Two 12- by 12-inch samples of com- the procuring activity and shall be indicated by posite cell construction. a suitable dash numbering system. c. One sample of inner-layer ply, 4.3.1.2 Phase I test. Phase I preproduc- without barrier, approximately 900 tion tests shall consist of the following tests square inches in area with seam. described under 4.6: d. One sample of inner-layer ply, with (a) Inspection ------(4.6.1) barrier, approximately 900 square (b) Inner-layer ply------— ---—---- (4.6.4) inches in area without seam. (c) Cells ------—— (4.6.5) e. One sample 6 by 6 by 0.075 to 0.125 4.3.2 Phase II preproduction testing. For inch inner-layer ply, without purposes of this specification, phase II prepro- barrier. duction tests are those tests accomplished on

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MIL-T-5578C complete full-scale fuel tanks, or portions there- 4.4.1 Individual tests. Each fuel cell shall of, submit ted for approval as satisfactory tanks be subjected to the following tests as described for a particular aircraft installation. under 4.6.1: 4.3.2.1 Phase II test samples. Phase II test (a) Examination ------(4.6.1.1) samples shall consist of one or more complete (b) Workmanship ------(4.6.1.2] full-scale fuel tanks or portions thereof and the (c) Dimentions ------(4.6.1.3) supporting structure or jig, or both, equipped (d) Weight ------(4.6.1.4) with all applicable fuel-cell components. The 4.4.2 Sampling plans and tests. tank or tanks shall be of the same materials and 4.4.2.1 Capacity check samples. Each of construction as used in the cell submitted for the first 10 production cells shall be checked for phase I tests, and shall be designed to fit in a capacity in accordance with 4.6.7. An average particular location in a specific aircraft. Excep- head-versus-volume curve shall be constructed tions to the above shall comprise those cells from these tests. which, because of the particular aircraft design, 4.4.2.2 Stand test samples. Cells selected require the use of graduated wall thickness and at random from part numbers specified by the weight, and any other exceptions specifically contractor and the procuring activity, in accord- authorized by the procuring activity. ance with the following schedule, shall be sub- 4.3.2.2 Phase II tests. Phase H preproduc- jected to the stand test described in 4.6.2. In tion tests shall consist of the following tests de- the event that more than one part number is scribed under 4.6 and shall be conducted in the selected for sampling, the tests shall be con- order listed: ducted on an alternating basis. Number of samples Number of units produced (a) Inspection ------(4.6.1) 1 ------0-50. Installation ------(4.6.6) (b) 1 ------1 every 90 days or 1 out of each Capacity (4.6.7) (c) ------additional 500 cells, whichever (4.6.8) (d) Pressure ------occurs first. (e) Slosh or slosh and vibration re- sistance ------(4.6.9) The samples specified above shall be selected (f) Aging and low temperature leak age-- (4.6.10) from all cells produced at a particular plant for (g] Accelerated load resistance ------(4.6.11) a specific a aircraft and approved under the same (h) Gunfire resistance on tank installa- tion ------(4.6.12) preproduction test and identified with the man- ufacturer's same construction number. The 4.3.3 Reports of tests. random samples selected shall be representative 4.3.3.1 Phase I. of cells submitted by the manufacturer for ac- 4.3.3.1.1 Preproduction approval. Phase I ceptance with respect to quality of workman- test reports shall be in accordance with MIL-T- ship and the number and type of repairs. 9107. These reports shell be signed or approved 4.4.2.3 Dissection teat samples. Cells se- by a responsible representative of the manufac- lected at random from part numbers specified turer or the laboratory in which the tests are by the contractor and the procuring activity, conducted. in accordance with the following schedule, shall 4.3.3.1.2 Preemptive approval. (See be dissected its ShOwn in figure 2, and subjected 6.4.2.1.) to the dissection test of 4.6.3. 4.3.3.2 Phase II. Phase II test reports shall Number be prepared in accordance with MIL-T-9107. of samples Number of units produced At least 1 month prior to the initiation of phase 2------0-50. 1 ------One out of each additional 90 days' II testing, a schedule shall be supplied to the production, or one out of each ad- procuring activity indicating the anticipated ditional 50 units produced, which- start and finish dates of all tests. ever occurs latest. However, the 4.4 Quality conformance tests. Quality maximum time between tests conformance tests shall consist of: shall not exceed 180 days. (a) Individual tests------(4.4.1) The samples specified above shall be selected (b) Sampling plans and tests------(4.4.2) from rolls produced at a particular plant for a 11 Downloaded from http://www.everyspec.com

MIL-T-5578C specific aircraft and approved under the same 4.6 Test methods. preproduction test and identified with the manu- 4.6.1 Inspection. facturer's same construction number. The ran- 4.6.1.1 Examination. Each fuel cell shall dom samples selected shall be representative of be carefully examined to determine conform- cells submitted by the manufacturer for accept- ance with all the requirements of this specifica- ance with respect to quality of workmanship tion for which no specific tests are described and and the number and type of repairs. to determine conformance with the manufac- 4.4.2.4 Inspection standards. When one item turer’s material and fabrication specifications. selected from production fails to meet this spec- 4.6.1.2 Workmanship. The fuel cells shall ification, action shall be taken in accordance with Bulletin No. 112. be inspected to determine conformance to the 4.5 Test conditions. In addition to the test acceptable standards listed in Bulletin No. 112. conditions set forth in specific tests, the condi- 4.6.1.3 Dimensions. A check shall be made tions specified herein shall apply. on each cell to insure that all dimensions critical 4.5.1 Test fluid. Test fluid shall be in ac- to the installation are within the dimensional cordance with MIL-S-3136. tolerances established by the contractor or pro- 4.5.1.1 Type I fluid shall be MIL-S-3136, curing activity. The tolerances specified for type I this test shall not conflict with the capacity re- 4.5.1.2 Type III fluid shall be MIL-S-3136, quirements specified in 3.5.1. type III. 4.6.1.4 Weight. Each cell shall be weighed 4.5.2 Temperate tolerances. Unless other- to determine compliance with the tolerance on wise specified, the following temperature tol- weight. (See 3.8.) erances shall be maintained: . 4.6.2 Stand. Class A cells only shall be col- Specified temperature Tolerance lapsed and held strapped for 30 minutes in a Above 100° F------+ 100 F position comparable to that encountered prior Below 100° F------+ 5° F to installation in its respective aircraft cavity, 4.5.3 Tank mounting structure. The tank then released, and adequately supported. Both mounting structure shall correspond as closely class A and class B cells shall be filled with as practicable with respect to shape, dimensions, type III fluid. During the filling process the and material to the tank supporting structure in capacity test (4.6.7) shall be conducted to deter- the vehicle. The necessary stops, cushions, mine conformance with 3.5.2. Cells shall then pads, and hangers identical with those used in be tested in accordance with the following time the finished vehicle, for mounting and support- cycle: ing the tank shall be provided. The test tank (a) First cell selected ------90 days shall be mounted in the test structure in a man- (b) Second cell ------30 days ner which duplicates the actual installation. In (c) Third cell------30 days addition, all lines attached to the tank in the This time cycle shall be repent.ed for additional actual installation shall be included. The walls chosen in accordance with 4.4.2.2 for the length and configuration of these lines shall be duration of the contract. Upon completion of the same as in the actual installation, from the the test, and at the intermediate inspections, the tank to the first support. cells shall be carefully examined for any evi- 4.5.4 Tank support jig. The support jig dence of failure. After the examination, if shall be suitable for carrying the mounted sam- faulty performance is indicated, the cell shall be ple tank and designed for bolting to the vibrator dissected as shown in figure 2 and inspected for and rocker assembly. The jig framework shall evidence of failure. In the event of failure of be sufficiently rigid to prevent the possibility of this test, the procuring activity and the con- unrealistic stresses being imposed on the tractor shall be notified. Bulletin No. 107 shall mounted tank. apply.

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MIL-T-5578C 4.6.3 Dissection. The sectioned portion of tensile strength shall not be reduced more than each cell selected in 4.4.2.3 shall be examined 20 percent calculated on the basis of the original for conditions outlined in Bulletin No. 107. cross sectional area. In the event, of failure on this test, the procuring 4.6.4.3 Permeability. activity and contractor shall be notified imme- 4.6.4.3.1 Preparation of test specimens. The diately. uncured inner liner shall be applied to a 10- by 4.6.4 Inner-layer ply. Samples of the inner- 10-inch piece of corrugated fiberboard coated layer ply of constructions intended for protec- on one side with a suitable water-soluble break- tion levels (A) and (B) and of the self-sealing away agent, The exposed surface of the inner portions of constructions intended for protec- liner shall be coated with prime cement and tion levels (C) and (D) shall be subjected to barrier resin (if required) that conform to the following tests. manufacturer's specifications. The assembly 4.6.4.1 Fuel contamination. A 5-gram samp- shall then be wrapped with cellophane and le of the inner-layer ply, without barrier, shall covered with a suitable waterproof bag. The be diced into approximately l/16-inch squares assembly shall be vulcanized by the method used and placed in a flask containing 250 ml of type in regular production. After vulcanization, III fluid, and allowed to stand for 48 hours at the waterproof bag and cellophane shall be re- 77° F. The contaminated test fluid shall be moved. The inner liner shall then be removed decanted off and the gum residue determined from the fiberboard, using water if necessary. by Method 3302 of Federal Test Method Stand- The free moisture shall then be wiped from the ard No. 791, except that the time of evaporation assembly, and the assembly shall be conditioned shall be 45 minutes. After cooling, the test for 24 hours at a temperature of 77° F and a beakers shall be weighed and the gum content relative humidity of 40 percent + 5 percent. determined. The beakers shall be then placed After the conditioning, two disks 2.5 inches in in an appropriate bath and maintained at 572° diameter shall be cut from the vulcanized panel. F for 30 minutes. After cooling to room tem- One hundred milliliters of type III fluid shall perature in a closed container, the beaker shall be placed in a cup conforming to figure 3. A be weighed and the stoved gums determined. nylon solution of 10 percent of type FM6001 or The necessary correction for preformed gums FM6501 nylon in 2B alcohol, maintained at 120° in the test fluid shall be made in each case. The F, shall be applied to the face of the cup flange fluid contamination shall be not greater than 60 as specified on figure 3. When the nylon solu- milligrams per 100 millileters of contaminated tion is almost dry, the test disk shall be applied fluid and, upon stoving, shall be not greater to the cup with the barrier, if any, facing out- than 20 milligrams per 100 milliliters of con- ward. The assembly shall be completed by at- taminated fluid. taching the bolting ring shown on figure 3 and 4.6.4.2 Inner liner strength. The tensile tightening the bolts in accordance with the strength of the inner-layer ply, without barrier, following: shall be determined in accordance with Federal Bolt torque in Test Method Standard No. 601, Method 4111, Innerliner tvpe pounds-inches before and after immersion in water for 72 Gum stocks ------5 to 10 Coated fabrics------15 to 20 hours at a temperature of 135° + 3° F. The Unsupported plastic films ------20 to 25

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MIL-T-5578C

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MIL-T-5578C 4.6.4.3.2 Conduct of test. The cups, pre- In cases where the adhesion of the seam is less pared as specified in the preceding paragraph, than the strength of the material, the adhesion shall be placed in a suitable rack and main- shall be a minimum of 6 pounds per inch. tained at a temperature of 77o F and a relative 4.6.4.5 Slit resistance. A section of the com- humidity of 40 percent + 5 percent for a l-hour posite cell construction sample shall be selected. equilibration period. The cup shall be weighed A slit of the inner layer ply, 1 inch long to the to the nearest 0.005 gram and placed in the rack depth of the sealant, shall be cut parallel to the with the face of the-cup facing upward. The calender grain, if present, or to the direction of cup shall be maintained at a temperature of minimum tear resistance. The test section shall 77° + 50 F and a relative humidity of 40 per- be 5 inches long with width sufficient to clamp cent + 5 percent for a 24-hour period. The cup in a vise, with the jaws of vise 1 inch from the shall then be weighed to check for the integrity slit when the test section is bent 180 degrees. of the seal. The bolts shall be retorqued if The slit shall be parallel to vise jaws and on the necessary. The cup shall be inverted (test disk outside of the bend. The sample shall be held down) in a rack that permits free access of air in this folded condition for 1 hour and the in- to the test disk. The cups shall be weighed at crease in length of the slit noted. The slit shall the end of the third, fifth, and eighth day after not increase more than 0.25 inch. inverting. Defective films or leaks resulting 4.6.4.6 Innerliner adhesion. The adhesion from faulty assembly will usually be found of the inner-layer ply to the sealant shall be when weighing on the third day. The diffusion tested by the strip back method, using a jaw rate calculation shall be made on the fifth to the separation rate of 2 inches per minute in accord- eighth day period and expressed as fluid ounces ance with Federal Test Method Standard No. per square foot per 24 hours. The permeability 601, Method 8011. The adhesion shall be a min- shall be less than 0.025 fluid ounce per square imum of 6 pounds per inch. foot per 24 hours. 4.6.4.7 Stress aging. Ten samples of the NOTE : inner-layer ply 4 inches square shall be double folded with the point of double fold located Diffusion expressed in fluid ounces per in the center of the sample. The material shall square foot per 24 hours equals the be held in the folded position by means of a gram loss of the test specimen per 46 spring clip, or equivalent, located 0.5 inch from hours multiplied by a factor K which the double folded edge. Folded samples shall is defined as follows: be soaked in type III fluid, for 7 days at 160° F, and air dried for 7 days at 160° F. There shall be no evidence of blistering, cracking, sep- aration, or other material failure. 4.6.5 Cells. The sample phase I cells shall Where: Sp Gr=specific gravity of test fluid 0 be subjected to the tests described in the follow- at 77 F ing paragraphs. R=inside radius of the test cup in inches 4.6.5.1 Fuel resistance of exterior surfaces. 4.6.4.4 Seam adhesion. The seam adhesion The cells shall be placed in a container suffi- of the inner layer ply to itself before and after ciently large to permit immersion of the bottom immersion in type III fluid for 72 hours at a half of the cell in type III fluid. The cells shall temperature of 135° F shall be tested within 4 be immersed for 24 hours at the ambient tem- hours along the length of the seam by the strip- perature. The cells shall then be removed and back method, using a jaw separation rate of 2 examined for swelling, separation, blisters, pin- inches per minute in accordance with Federal holes dissolution, or other evidence of deter- Test Method Standard No. 601, Method 8011. ioration. The exterior surface of the cell con-

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MIL-T-5578C struction shall show no unsatisfactory swelling, maintained at -40° F for a minimum of 4 separation, blistering, dissolution, or other days. deterioration. 4.6.5.3.2.2 Normal temperature gunfire. The 4.6.5.2 Slosh resistance. The phase I cell second cell shall be filled three-quarters full of shall be tested for slosh resistance by mounting type I fluid. The temperature of the fluid at on a suitable rocker assembly and rocking the the time of the test shall be 50° to 100° F. cell through an angle of 15 degrees on each side 4.6.5.3.3 Evaluation. The following points of the level position (total 30 degrees) at a rate shall be considered in determining the accept- of l8 + 2 cycles per minute for a period of 25 able performance of the fuel cell: hours with the cell two-thirds full of type III (a) Quantity of fuel leakage. fluid. Cells that are non-self-supporting shall (b) Time required to effect a damp seal. be installed in a test structure in accordance In general, wounds shall seal within 2 with figure 1. The fluid shall be maintained minutes at ambient temperature and at a temperature of 110° F throughout the test. within 4 minutes at -40° F. The time for the temperature rise to 110° F (c) Integrity of inner layer ply, seams, and from the ambient temperature shall not exceed joints. (Cracking of the inner liner 2 hours. There shall be no evidence of leakage will be permitted under the low tem- or failure of any kind during or as a result of perature test of 4.6.5.3.2.1) this test. (d) Integrity of fittings. 4.6.5.3 Gunfire resistance on phase I cells. (e) Deformation. 4.6.5.3.1 Test setup. Class A calls shall be (f) Support for sealant throughout the installed in the metal structure shown in figure test. 1. Class B cells shall be tested without auxiliary (g) Healing, knitting, or breaching over support. The temperature shall be measured the gunfire wound. by a thermometer or thermocouple immersed (h) Resistance of non-self-sealing mate- in the fluid. Test cells for protection levels (A) rials to tearing, and integrity Of transi- and (C) shall be mounted 75 feet from the gun. tion seam (protection levels (C) and Cells for protection levels (B) and (D) shall (D)). be mounted 50 feet from the gun. All ammuni- 4.6.5.3.3.1 Shots striking as noted below, tion shall be fired into the cell space occupied shall not be considered in evaluating the tank. by the fluid. A nonmetallic yaw plate shall be (a) Slicing shots wherein a projectile slices used to impart tumbling when required by table parallel to the cell wall instead of I. piercing. 4.6.5.3.2 Firing schedule. The firing sched- (b) Striking of cell fittings by the ule as shown on table I shall be conducted at projectile. low temperature on cell No. 1 It shall then be (c) Shots where the wounds overlap or run repeated at normal temperature on cell No. 2. together. 4.6.5.3.2.1 Low tempemture gunfire. The (d) Shots which strike within 3 inches of first cell shall be conditioned for gunfire testing corners. by filling three-quarters full of type I fluid for (e) Shots where the projectile remains im- a period of 24 hours. The fluid used in the con- bedded in the construction. ditioning shall remain in the cell during the (f) Shots where metallic fingers project gunfire test. The conditioning shall be at a into wounds, and in a mechanical man- temperature of 50° to 100° F. The cell shall ner prevent the sealant from func- then be cooled, and at the time of firing, the tioning. temperature of the fluid and cell shall have been (g) Shots where coring is present.

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MIL-T-5578C

4.6.5.4 Fuel aging following gunfire resist- test (4.6.2) shall be conducted on the third test ance. After the gunfire resistance test of 4.6. cell which shall be the same cell subjected to 5.3, the cell shall be emptied and inspected, and the slosh resistance test (4.6.5.2). The test cell any wounds which failed to seal (but did not shall be adequately supported, completely filled disqualify the cell) shall be plugged and the with type III fluid and allowed to stand. The cell refilled with type III fluid. After 24 hours cell shall be carefully examined every 30 days the cell shall be emptied, and the wounds shall for any evidence of failure. After 90 days, if be carefully examined. There shall be no evi- no evidence of failure is found, the cell will be dence if deterioration of the inner-layer ply or considered as satisfactorily conforming to this sealant. test. 4.6.5.5 Stand. For this test, the aircraft, a 4.6.6 Imtallation. For this test, the aircraft section thereof, or a tank mounting structure in or a section thereof shall be used. The installa- accordance with 4.5.3 shall be used. The stand tion test shall be conducted prior to the pressure

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MIL-T-5578C test described in 4.6.8. The installation test The pressure test (4.6.8) shall be repeated. shall consist of removing and installing the tank There shall be no evidence of leakage or failure in the test structure three times. Applicable of the fuel tank or the attachment of its com- service procedure shall be followed in tank in- ponents during this test. stallation and removal. All tank fittings shall 4.6.9.1 Fighter, attack, and interceptor air- be fastened to corresponding structure fittings craft. Test of fighter, attack, and interceptor and interconnect fittings of each installation. aircraft preproduction tanks shall be conducted The tank shall be in a satisfactory condition on on a vibrator and rocker assembly of a design the completion of this test. acceptable to the procuring activity, and shall 4.6.7 Capacity. The cell shall be slowly conform to the following requirements: filled to capacity with type III fluid. The vol- (a) Class A tanks or portions thereof, ume in gallons and the head in inches shall be except those with cells containing suspension recorded at a sufficient number of points during or supporting arrangements which maybe sub- the filling to construct a head-versus-volume ject to failure due to vibration, shall be slosh curve. tested. 4.6.8 Pressure. For this test, the tank shall Test conditions: be mounted in the preproduction slosh test Time :25 hours structure. All openings in the tank shall be Rock: Total of 30°, approximately 15° sealed during the pressure test. All parts nec- on either side of the horizontal essary to effect a satisfactory seal at the open- position. ings shall be furnished by the aircraft contrac- Cycles per minute: 16 to 20. tor. Tanks shall be subjected to a pressure (b) Class A tanks or portions thereof, with equivalent to the normal head measured at the cells containing suspension or supporting ar- bottom of the tank multiplied by a factor of 1.5. rangements which may be subject to failure due Pressures shall be measured by means of a to vibration, and class B tanks shall be simulta- manometer using type III fluid and shall be neously slosh and vibration tested. applied in such a manner that the testing pres- Test conditions: sure is stabilized. NO change in pressure shall Time: 25 hours. occur in the following 15 minutes. Rock: Total of 30°, approximately 15° 4.6.9 Slosh or slosh and vibration resistance. on either side of the horizontal For this test, an actual section of the aircraft position. structure shall be used. All fitting and non- Cycles per minute: 16 to 20. self-sealing areas in the interior of each fuel cell Displacement: The throw of the two ec- compartment shall be lined with brown paper, centric weights on the vibration ma- held in place with a suitable adhesive. The test chine shall be in the same direction and shall be adjusted to produce a total dis- specimen shall be slosh or slosh and vibration placement of 0.032 inch, +0.010 inch, tested (see 4.6.9.1 and 4.6.9.2) with the tank -0.000 inch, measured at points of in- two-thirds full of type III fluid containing a herent rigidity on the tank. staining agent at a temperature of 110° F. All speed: slosh or slosh and vibration resistance tests shall Type I tanks-90 percent of normal be conducted with the tank subjected to a pres- rated crankshaft speed. sure equivalent to the maximum stabilized vapor Type II tanks-2,000 + 100 rpm. pressure encountered in any prescribed stabi- (c) Remove cell from structure and ex- lized level flight conditions. The tank shall be amine for evidence of damage or failure. mounted in such a manner as to simulate pitch- 4.6.9.2 Types of aircraft other than fighter, ing in the actual aircraft. Special fixtures, such attack, and interceptor. Tests of all types of as baffles, shall also be tested if applicable by aircraft preproduction tanks other than fighter, mounting the aircraft structure on the rocker in attack, and interceptor type, shall be conducted another position for a portion of the test time. on a vibration and rocker assembly design 19 Downloaded from http://www.everyspec.com

MIL-T-5578C acceptable to the procuring activity and shall with brown paper held in place with a suitable conform to the following requirements: adhesive. The tank with fittings assembled (a) Class A tanks or portions thereof, shall be subjected to a 7-day soak with type III except those with cells containing suspension fluid, at a fluid temperature of 135° F. Follow- or supporting arrangements which may be sub- ing the hot fuel soak, the tank shall be emptied ject to failure due to vibration shall be slosh and air dried for a period of 7 days at a tem- tested. perature of 160° F. On completion of the 7- Test conditions: day period of air drying, the tank shall be Time :40 hours. filled with type I fluid, containing a staining Rock: Total of 30°, approximately 15° agent, and placed in a cold box for a period of 3 on either side of the horizontal days. The cold box shall be maintained at a position. temperature of – 65° F for the 3-day period. Cycles per minute: 10 to 16. At the end of this 3-day period, the tank shall (b) Class A tanks or portions thereof, with be removed from the cold box, drained, and ex- cells containing supporting or suspension ar- amined for any indications of leakage. The rangements which may be subject to failure due tank shall then be filled with type III fluid, to vibration, and Class B tanks shall be slosh containing a staining agent and allowed to and vibration tested. stand at ambient temperature for a period of Test conditions: 80 days, at which time the fluid shall be drained, Time: 25 hours simultaneous slosh and and the tank examined for any unsatisfactory vibration and 15 hours additional slosh. condition or indication of fuel leakage as shown Rock: Total of 30°, approximately 15° by any indication of stain on the brown paper on either side of the horizontal or activation of the tank sealant. Sealant acti- position. vation or any leakage of the tank, or at the Cycles per minute: 10 to 16. attachment of its component(s), shall be con- Displacement: The throw of the two ec- sidered as a tank failure. In the event of fail- centric weights on the vibration ma- ure at the attachment of the component, chine shall be in the same direction retesting for this condition may be simulated in and shall be adjusted to produce a total other than a full scale tank. displacement of 0.032 inch, +0.010 4.6.10.1 Dissection. After completion of the inch, -0.000 inch measured at point of above test, the cell shall be dissected as shown inherent rigidity on the tank. in figure 2. The sectioned portion of each cell Speed: shall be examined for conditions outlined in Type I tanks-90 percent of normal Bulletin No. 107. rated crankshaft speed. 4.6.11 Accelerated kind. The tank assembly Type II tanks-2,000 + 100 rpm. shall be mounted in a test jig that provides sup- (c) Remove cell from structure and ex- port equivalent to the aircraft structure for amine for evidence of damage or failure. which it is designed and subjected to a load test 4.6.9.2.1 Alternate vibration frequency and as mutually agreed upon between the contractor displacement. Where the above frequencies and and the procuring activity to determine the displacements are not applicable, the tank shall suitability of the tank installation under air- be vibrated at a frequency and displacement craft design accelerations, including the appro- agreed upon by the contractor and the procur- priate dynamic magnification factors. Tanks ing activity, of pressurized systems shall be subjected to 4.6.10 Aging and low temperature leakage. normal operating pressures during this test, ex- For this test, the tank shall be mounted in a cept where unpressurized conditions are con- structure for which it is designed, or a simu- sidered to be more critical. There shall be no lated test sample incorporating identical tank structural failure of any components of the fitting installations. The interior of the test tank during these tests. Deflection of the tank structure around fitting areas shall be lined shall be measured and shall be such that there 20 Downloaded from http://www.everyspec.com

MIL-T-5578C will be no interference with the functional op- The same conditions that are cause for rejection eration of the aircraft components. All tanks of the phase I test cell shall apply to this test. shall be tested dynamically. 5. PREPARATION FOR DELIVERY 4.6.11.1 Carrier-based aircraft. Tanks shall 5.1 Preservation and packaging. Preser- be tested in the directions of dynamic loadings vation and packaging shall be level A or level associated with catapult, flight, and arrested C, as specified (see 6.2). landing conditions to a total acceleration in 5.1.1 Level A. gravitational units equal to the maximum ap- 5.1.1.1 Presentation. Unless otherwise plied acceleration for which the aircraft is de- specified, tapped holes on fuel cell fittings or signed. The suitability of the tank installation attachments shall be protected from corrosion shall be tested for catapult and arrested land- by the application of a corrosion-preventive ings with various fuel loads from full down to compound conforming to MIL-C-6529, type II. the minimum fuel load specified for a safe land- Care shall be taken to prevent an excessive ing. For these tests, the tank shall be oriented amount of compound from being applied to the in the normal position for catapult or arrested fuel cell proper. Paper conforming to MIL-B- landings, as applicable. 121, grade A, shall be placed over all exposed 4.6.12 Gunfire resistance on tank installa- tapped holes and sealed with a moisture-resist- tion. For this test, the tank shall be mounted in ant tape conforming to PPP-T-60, type I, class an actual section of the aircraft structure con- 1. In those instances where cover plates are taining the backing board that will be used in bolted into their positions, it will not be neces- the specific application. The tank for this test sary to use type or grade A paper. need not include accessories. Purging capabil- 5.1.1.2 Packaging. Unless, otherwise speci- ities shall be provided to help prevent fires fied, all openings, fittings, etc., shall be covered during gunfire test. The tank shall be filled with waterproof paper conforming to UU-P- two-thirds full with type I fluid. All gunfire 271, class C-l, and sealed with a moisture- testing shall be conducted with the tank sub- resistant tape conforming to PPP-T-60, type jected to an internal pressure equivalent to the I, class 1. The cells shall be closed in such a maximum stabilized vapor pressure encountered manner as to prevent dust or other foreign mate- during any prescribed stabilized level fright rial from entering the cells. One vent hole may conditions. The tank shall be subjected to the be left open, at the option of the manufacturer, gunfire test in accordance with the capacity of but protected to prevent dust or other foreign each tank: The number of rounds of .50 caliber material from collecting in the cells. AP or .30 caliber AP ammunition to be fired 5.1.2 Level C. Cells shall be preserved and shall be determined on the basis of one round for packaged in accordance with the manufacturer’s each 15 gallons of tank capacity up to a maxi- commercial practice. mum of 10 rounds. For cells intended for pro- 5.2 Packing. Packing shall be level A, tection levels (C) and (D), at least two rounds level B, or level C, as specified (see 6.2). of .50 or .30 caliber, as applicable, shall be fired 5.2.1 Level A. cells preserved and pack- into the nonself-sealing portion of the cell. For aged to meet 5.1.1.1 and 5.1.1.2 shall be packed protection levels (A) and (C), in addition to the in overseas-type exterior shipping containers .50 caliber gunfire, one round of 20-millimeter PA ammunition shall be fired. For protection meeting PPP-B-591, PPP-B-636, PPP-B-585, level (C), this round of 20-millimeter PA am- PPP-B-621, or PPP-B-601. As far as prac- unition shall be placed in the self-sealing por- ticable, exterior shipping containers shall be of tion of the cell. All shots shall be so placed as uniform shape and size, be of minimum cube to be compatible with the aircraft installation and tare consistent with the protection required, and the combat utility of the aircraft. Tumbled and contain identical quantities. the gross .50 caliber AP rounds shall be utilized to simu- weight of each pack shall be limited to 200 late shrapnel. No bursts, shall be fired, and the pounds. Containers shall be closed and test shall be conducted at ambient temperature. strapped in accordance with the applicable con- 21 Downloaded from http://www.everyspec.com

MIL-T-5578C tainer specification or appendix thereto. Con- TANK, FUEL, AIRCRAFT, SELF- tainers shall be provided with a case liner SEALING conforming to MIL-L-10547 and shall be sealed TYPE —, CLASS —, STYLE in accordance with the appendix thereto. The case liner will not be required when the unit, PROTECTION LEVEL — intermediate, or exterior container” conforms to Model of aircraft for which cell is intended class 2 of PPP-B-636 and is sealed at all joints and location in the aircraft. and seams, including the manufacturer’s joint, Construction number of the cell. with tape conforming to PPP-T-60. 6. NOTES 5.2.2 Level B. Coils preserved and pack- 6.1 Intended use. Self-sealing fuel tanks aged to meet 5.1.1.1 and 5.1.1.2 shall be packed manufactured under this specification are in- in domestic-type exterior shipping containers tended for use in aircraft as a means for carry- meeting PPP-B-591, PPP-B-601, PPP-B-585, ing aircraft fuel including aromatic constit- PPP-B-621, PPP-B-636, or PPP-B-640. Ex- uents under all prescribed operating conditions terior shipping containers shall be of minimum and as a means of preventing, under the gunfire cube and tare consistent with the protection re- conditions specified herein, an excessive loss of quired. As far as practicable, exterior shipping fuel. containers shall be of uniform shape and size 6.2 Ordering data. Procurement docu- and contain identical quantities. The gross ments should specify the following: weight of each pack shall be limited to 500 (a) Title, number, and date of this pounds. Containers shall be closed and strapped specification. in accordance with the applicable container (b] Model designation of the aircraft. specification or appendix thereto. When fiber- (c) Name of the cell manufacturer. board containers are used, the fiberboard shall (d) Part number, type, class, style, and meet the special requirements table of PPP-B- protection level of cell desired. (See 636, as applicable. 1.2.) 5.2.3 Level C. Packages which require (e) Selection of applicable levels of preser- overpacking for acceptance by the carrier shall vation and packaging and packing. be packed in exterior-type shipping containers (See sec. 5.) in a manner that will insure safe transporta- (f) Fuel suitability. (See 3.5.) tion at the lowest rate to the point of delivery. 6.3 Definitions. Containers shall meet Uniform Freight Classi- 6.3.1 Manufacturer. For purposes of this fication Rules or regulations of other common specification, the term manufacturer refers to carriers as applicable to the mode of trans- the manufacturer of the tank. portation. 6.3.2 Contractor. The term contractor re- 5.3 Physical protection. Cushioning, fers to the prime contractor or airframe manuf- blocking, bracing, and bolting, as required, shall acturer. be in accordance with JAN-P-100, except that 6.3.3 Supplier. The term supplier as used for domestic shipments, waterproofing require- in 2.1 herein, refers to both the manufacturer ments for cushioning materials and containers and the contractor. shall be waived. Drop tests of JAN-P-100 will 6.4 Preproduction testing. be waived when preservation, packaging, and 6.4.1 Notification of approval or disap- packing of the item is for immediate use or proval. when drop tests of MIL-P-116 are applicable. 6.4.1.1 Phase I preproduction tests. In the 5.4 Marking of shipments. Each shipping case of phase I preproduction tests, written no- container shall be marked to indicate presence tification of approval or disapproval will be of preservation and method of packing. The given by the applicable procuring activity to container shall be marked in accordance with the fuel cell manufacturer. MIL-STD-129. The following additional in- 6.4.1.2 Phase II preproduction test. In the formation shall be applied to the container: case of phase II preproduction tests, notification 22 Downloaded from http://www.everyspec.com

MIL-T-5578C of approval or disapproval will be given by the 6.5 Service life. Based on past experience, applicable procuring activity to the aircraft it is considered that the normal service life of manufacturer. A copy of such notification will fuel cells covered by this specification is equiva- be supplied to the fuel cell manufacturer. lent to that of the aircraft in which they are 6.4.2 Request for information pertaining to installed. the phase I or phase II preproduction tests 6.6 Gunfire. The procuring activity may should be addressed to Commander, Aeronauti- have one round of 40-millimeter high explosive cal Systems Division, Wright-Patterson Air Force Base, Ohio, Attention: ASNPFP; to the statically detonated 24 inches from the outside Bureau of Naval Weapons, Navy Department, of the tank. The results of this round will not Washington 25, D.C.; or to the Contracting be utilized in appraising and formulating tank Officer, U.S. Army Aviation and Surface Mate- approval decision, but will aid in the develop- riel Command, P.O. Box 209, Main Office, St ment of a possible cell construction that the Louis, MO, with copies to the other Services. Services are desirous of obtaining. 6.4.2.1 Preemptive approval. Preemptive 6.7 Special environment. When the test approval is herein defined as approval for phase methods specified herein do not represent the I tests, conducted without contractual coverage. tank environment, for example, temperatures Reports of tests, in accordance with MIL-T- resulting from aerodynamic heating in excess 9107 should be furnished in duplicate to the ad- of 160° F, the test method should be modified dressees as shown in 6.4.2. These reports should as agreed upon by the contractor and the pro- be signed or approved by a responsible repre- sentative of the manufacturer or the laboratory curing activity to simulate operational comdi- in which the tests are conducted. Preemptive tions. approvals may be accepted at the option of the Custodians: Preparing activity: contractor in lieu of the phase I preproduction Army-MO Air Force-ASD Navy-Weps Project No., 1560-0014 approval specified in 4.3.3.1.1. Air Force-ASD

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