1、MI L-il- 6 I I SA 29 MARCH 1951 Superseding 26 April 1950 KIIL-1-6115 MILITARY SPECIECATION INSTRUMENT SYSTEMS, PITOT TUBE AND FLUSH STATIC WRT OPERATED, INSTALLATION OF This specification was approved by the Departments of the Amy, the Navy, and the Air Force for use of. procurement services of the
2、 respective Departmnts. 1. SCOPE 1.1 This specification covers the general requirements for the installation of all types of pitot tube and flush static port-operated instniment systems for use on aircraft to provide a source for dynamic and static pressures. 2. APFKtCABLE SPECIFICATIONS, OMER PUBLI
3、CATIONS, AND DRAWINGS 2.1 The following publications, of the issue in effect on date of invitation for bids, shall form a pert of this specification to the ,extent specified herein: 2.1.1 Specifications. - Federal - W-T-787 Ribing, Aluminum-Alloy (AL-52) (Aluminum- Magnesium-chmmium); Round, Seamles
4、s Mlitaq EL-P-6889 Primer; Zinc Chmmate JBN-A- Anti-Seize Coqund; White bad Base, General Purpose (For Thmaded Fittings) Air Force-Navy Aeronautical Corrosim-Pmtectiw (For) Aluminum Alloya 2.1.2 Other Publications.- Air Force-Navy Aeronautical Bulletin NO. U3 Specifications and Standards; Use of Nav
5、al Air Experimental Station Report No. NAES-INSTR. 16-44 Dual Sighting Stand and Other Wthods of Calibrating Altimeter and Airspeed (Copies of this publication may be obtained from the Technical Infomtion Branch, Bureau of Aeronautics, Navy Department, Washington 25, D. C.) c Provided by IHSNot for
6、ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-I-b335A 66 H 7779706 0325400 T t L-I -6llrA (Ilarch 1951) National Advisory Codttee for Aeronautics Tech. Note No. 1605 Accuracy of Airspeed Measurements Calibration Procedures (Copies of this mport may be obtained from t
7、he National Advisory Cornnittee foi Aeronautics, 3.724 F Street, N, U., Washington, D. C.) 2.1.3 DrawinEs. - Air Force-Navy Aeronautical Standard Drawings AN929 AN58ll AN5812 AN5813 AN6270 AND10056 AND10375 AND10398 AND10410 Cap - Pressure Seal Flared Tube Fitting Tube - Pitot, Electrically Heated,
8、“L“ Shaped, Inverted Tube - Pitot, Electrically Heated, “LIt Shaped Tube - Pitot, Electrically Gated Hose Assembly -Detachable Swiwl Fitting, Low Pressure Fitting End - Standard Dimensions for FLared Tube Colors - Fluid Line Identification Metals - Definition of Dissimilar Pitot-Static and Pitot Tub
9、e - Wiring Diagram for Connection and Gasket Seal (Unless otherwise specified, copies of this specification and copies of other publications referenced herein or required for Govemmnt procurement, and the index of Military Aeronautical (AN or HIL) Standards, my be obtained upon application to the Co
10、nmianding General, Air Materiel Command, Wright-Patterson Air Force Base, Dayton, Ohio; or the Comnanding Officer, U. S. Naval Air Station, Johnsville, Pennsylvania.) 3. REQJ1FEMEXI“T 3.1 Materials.- Materials used in the installation of pitot tube and flush static port-operated instrunrent systems
11、in military aircraft- shall be of high quality, suitable for the purpose, and shall conform to applicable Govemment specifications. Materials confoming to contractorrs specificaticns may be used provided they are released by the Government and contain provisions for adequate tests. The we of con- tr
12、actors specifications will not constitute waiver of Govenunent inspection. port-operated instrument systems Yi military aircraft shall be suitably protected to resist corrosion during nom1 service life. 3.1.1 or if more cmvenient, some of the additional instrurnts may be connected to one tube and so
13、me to the other. airspeed switches, Mach number limit switches, or amamnt controls, shall be supplied by the copilots pitot tube if a copilots pitot tube is used. Additional pitot tubes may be required to insure reliability in very large aircraft. Other pitot pressure-operated equipment, such as 3.2
14、.3.2 Number of Instruments per Pair of Static Ports.- Not more than six instruments consisting of a combination of altimeters, airspeed indicators, and rate of climb indicators, and other instruments of similar volume shall be connected to one line leading from the ITI between the static ports. If t
15、here are more than 6 but not mre than I2 such instmurients installed, a CMBS however, Inspection doors may . i.2.13 Removal of Tube.- A union shall be installed in the pitot and static Ums at the point of attachment of the mounting strut to the wing or fuselage to permit the mmval and replacernt of
16、the pitot tube and flush static port. 3,2.13.1 Modification,- The pitot tube shall not be modified in form or color by the attachnisnt of any rings, sleeves, or other additions of pint or finish. 3.2.y Clearing of Lines.- The pitot aqd static Unes shall be blown clear vbth dry, high-presm air inmedi
17、ately before the pitot and static tube or tubes are connected and the instruments are installed in the system or sgsttjms. remomd, and all instrunient connections ahall be vented to the atmosphere while the air is being bown through all Unes. with heater elements shall be in accordance with Drawing
18、ANDl0410. be lowted where they can be convenientlv reset in flight. All Win plugs shall be 3.2.15 Eleotrica1Circuit.- The electrical circuit for the pitot tubes provide( Circuit breakers shall c Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-I-
19、bLL5A bb W 7777906 OL25Y09 b W MIL-1-6ll5A (March 1951) 3.3 Perfornrance.- “he installation of pitot tubes and flush static port-operated instrument systems shall satisfy the performance requiremnts as specified in Section 4 when subjected to the tests headed as follows: Electrical Wiring Compass De
20、viation Leakage Flushness and Smoothness Determination of Pitot Tube and Flush Static Port Effect of Maneuver System installation Error 4. SAMPLING, INSPECTION, AND “EST PROCEDUFES 4.1 General.- All the tests required for the testing of these installations are classified as Inspection tests, for whi
21、ch necessary sampJing techniques and methods of testing are specified in this section. The contractor shall be responsible for accom- plishing the required tests. all inspection and testing shall be under the supemision of the Government Inspector. Acceptance or approval of matetial during course of
22、 manufacture shall in no case be construed as a guaranty of the acceptance of the finished product. When inspection is conducted at the contractorls plant, 4.1.1 Individual Tests.- Each installation shall be subjected to the following tests, as described herein under “Test Methodstt: (a) Examination
23、 of installation b) Electrical Wiring (c) Compass Deviation (d) Leakage (e) Flushness and Smoothness In addition, all installatikshall be subjected to any of the other tests specifled herein which the Inspector considers necessary to determine conformance with the require- ments of this specificatio
24、n, O 4.1.2 Special Teata.- The first pitot tube and flush static port installation on an airplane model of any design airplane model design submitted for acceptance under contract, shall be subject to all tim tests described herein under “Test fabrication of the installation for the remining airplan
25、es on the order, to detemine suitabiiity of design and canpliance with performance requiremnts of this specification. Rejection and Retest.- The individual installations failing to meet their and the first installation embodying a change in the This shall be done prior to the 4.1.3 respective tests
26、shall be rejected. reworked or replaced to correct the defects and resubmitted for acceptance. subitting, full particulars concerning previous rejections ahall be furnished the Inspector. installations which have been rejected may be Before re- 4.2 Test Methoda.- 4.2.1 Examination of Inatallation.-
27、AU pitot tube and flush static port-system installaticxis shall be visually examined to determine conformance with the requirements of this specification not comred y tests. Electrical Wiring.- The electric circuit installation shall be such that with the heating elements of the tube properly connec
28、ted and operating from a conbined generator and battery source of 28.5V, the voltage as measured across the terminal of a 24V tube ehan be not less than 24V. (For 115V a-c tubes the voltage at the tube ahail be not less than nov.) 4.2.2 F c Provided by IHSNot for ResaleNo reproduction or networking
29、permitted without license from IHS-,-,-BL-I-6ll5A (March 1951) .4.2.3 Compass Deviation.- With the airplane pointed to each of the four cardinal headings, the compass reading of all compasses in the airplane shall be noted with the electrical circuit tOFFl and with the electrical circuit lON.ll on a
30、ny heading with the electrical circuit W?FII and with the electrical circuit I1ONIt shall be not more than 1 degree. The difference in readings 4.2.4 balcage.- 4.2.4.1 Pitot Pressure Line.- The drain holes of the pitot tube shall be sealed With the instmnts properly connected to the pitottpressure l
31、ine, the for this test. pitot pressure opening of the pitot tube shall be suitably connected to a source of pres- sure. the lowest range airspeed indicator connected to the pitot Une shall be applied and the pressure cut off. than 5 knots. A pressure sufficient to produce approxinately 3/4 of full-s
32、cale deflection on Afier 1 minute, the indicated airspeed shall have decreased not more NOTE: DO NOT APPLY VACUUM TO PITOT LINES. 4.2.4.2 Static Pressure kine.- With the instnurents properly connected to the static pressure Une, and the static pmssure openings of the flush static port sealed off, th
33、e test fitting shall be suitably connected to a source of vacum. A vmm shall be drawn on the system (at a rate within the range of the rate of cUmb indicator) suf- ficent to cause the standard altimeter to indicate 10,000 feet, and the source of vacuum cut off. 7,000 feet. After 1 minute the indicat
34、ed altitude on the altimeter shall not fall below NOTE: DO NOT APPLY PRESSURE TO STATIC PRESSURE LINES. 4.2.4.3 The static port as a whole shall be tested for leakage between the inner fitting and the static port holes. evacuating device and to a calibrated standard altimeter or a mercury manometer,
35、 and the static port holes shall be sealed in such a mer that the seal will not extend into the port holes more than the thickness of the skin of the airplane. shall then be operated until the standard altimeter indicates 10,000 feet increase in altitude or the manometer indicates 9.10 inch Hg diffe
36、rential pressure. device shall then be cut off. shall have fallen riot more than 200 feet or the differential pressure shall have changed not more than 0.2 inch Hg. of the static port shall be measured with a suitable device in which the contacting elemnt has a spherical shape with a maximum radius
37、of 1/32 inch. of the static port within a 3-hch radius of the port shall be smooth within +0.005 inch of the mold Une. 4.2.6 The inner fitting shall be connected to an The evacuating device The evacuating After 1 minute, the indicated altitude on the altimeter 4.2.5 Flushness and Smoothness.- The fl
38、ushness of rivets and the smoothness The exterior surface Determination of Pitot Tube and Flush Static Port System Installation Error. - 4.2.6.1 The inatallation error shall be determined by any one or a combination of the folloiving methods. Note 1605, and Bureau of Aeronautics Report No. NAES INST
39、R. 16-44. They are described mors completely in the NACA Technical (a) The speed course method in which the time to comr a given distance is measured. The suspended head or trailing tube iiiethod in which the readings of the system under calibration are referEd to thme of a suspended pitot-atatic he
40、ad which is either free from error or has known errors. (b) c Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-I-61LSA 66 7797906 OL254Ll 4 I (c) The altimeter method, which provides a calibration of the static system only, in which the error is d
41、etermined by comparing the altimeter reading (comated for acale error) with the known fight level pressure altitude. (d) Pacer airpane,method in which the airplane with the installations to be calibrated is flow in formation wlth one which has an airspeed installation amady calibrated by method (a),
42、 (b), or (c). An outline of ,he method an instmimentation to be used shall be 8ubPnitted to the Procuring Service and approval o and the fact that the Gowninrent may have fonnulated, furnished, or In any way supplied the said drawings, specifications, or. other data, is not to be regarded by implica
43、tion or otherwise as in any manner licensing the holder or any other person or corporation, or conveying any rights or permission to manufacture, use, or seu anypatented invention that may in any way be related thereto. When Goveniment drawings, specifications, or other data Custodian: Air Force other interest: Navy - Wer 15 I- C Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
