NAVY MIL-I-21718-1958 INDICATOR AIRSPEED PITOT-STATIC MAXIMUM ALLOWABLE SPEED 40-400 KNOTS《最大允许速度为40至400海里每小时 全压静压飞行速度指示器》.pdf

1、66 = 9999906 OL3054Y 4 7- M I L-1-2 I 7 I 8 ( AE R 20 NOVEMBER 1958 MLITARY SPECIFICATION This specification has been approved by the Bureau of Aeronautics, Department of the Navy. 1. SCOPE 1.1 m. - This specification covers certain design requirements and ali performance require- ments for one type

2、 of pitot static, maximum allowable airspeed indicator, range 40 to 400 knots. 2.1 The following specifications, standards and publications of the issue in effect on date of invitation for bids, form a part of this specification: SPECIFICATIONS Federal QQQ-6-320 QQ-x-290 QQ-P-416 Military MIL-P-u6 M

3、IL-E-5272 MIL-A-8625 Federal FED. STD. No. 1 FED. STD. NO. 595 Military MIL-STD-13 w25333 Ens33558 chromium Plating (ELectrodeposited) Nickel Plating (Electrodeposited) Plating, Cadmium (Electrodeposited) Preservation, Methods of Environmental Testing, Aeronautical and Associated Equipment, General

4、Specification for Chemical Films for Aluminum and Alimiinum Alloys Plates, Information and Identification Screw Threads, Standard, Aeronautical Preparation for Delivery of Naval Aeronautical Anodic Coatings, for Aluminum and Aiuminum Alloys Equipment, General Specification for Standard for Laborator

5、y Atmospheric Conditions for Testing Colors Identification Marking of U. S. Military Property Indicator, Airspeed, Pitot Static; Maximum Allowable Numerals and Letters, Aircraft Instrument Dial, Speed, 40-400 Knots Standard Form of Provided by IHSNot for ResaleNo reproduction or networking permitted

6、 without license from IHS-,-,-MIL-I- 2171U(ier) MS33585 33586 Air Force - Navy Aeronautical Pointers, Dial, Standard Design of Aircraft Instrument Metals, Definition of Dissimilar Am5727 Glass, Aircraft Instrument Cover HJBLICATIONS Air Force - Navy Aeronautical Bulletin No. 143 No. 418 Differential

7、 Pressures Specifications and Standards, Use of (When requesting any of the applicable documents refer to both title and number. specification and applicable documents may be obtained upon application to the Commanding Officer, Naval Aviation Supply Depot, TOO Robbins Avenue, Philadelphia 11, Pennsy

8、lvania, Attention: Copies of this Code AD. ) has been tested and has passed the qualification tests specified herein. 3.2 Selection of Governmect- do-cumun.n Individua. - Unless otherwise specified, the indicator may be gently tapped or vibrated before a test reading is taken. 4.5.5 Vibration stanq.

9、 - Whenever a vibration stand is specified, it shall be a device which will vibrate at any desired frequency between 5 and 50 cycles per second and shall subject the indi- cator to such vibration that a point on the vibration stand shall describe, in a plane inclined 45 degrees to the horizontal pla

10、ne, a circle of the diameter specified herein. 4.5.6 Test mints and toler- . - The indicator test points and tolerances shall be as specified in Tables I, II, and III. 4.6 Test methods. - 4.6.1 Between 40 and 2oO knots Between 2111 and 400 knots Maximum allowable speed pointer -mPing: Time required

11、from full scale deflecti to 50 knots Position Error: Indicated airspeed pointer l 140 inches of water Static pressure connection; 6.0 inches of water (Test altitudes of O to 50,OOO feet) (Test airspeeds of 50 to 400 knots) Vibration Failure : Test altitude - 20,000 feet Indicated airspeed - 250 knot

12、s Seasoning Tolerances (Values in knots specified) unless otherwise Q i 9 3.5 5.0 3.0 M.5 1.0 second 2.5 3.0 1/16 inch 2.0 2.0 2.5 2.0 2.5 2.5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TABLF: II SCALE ERRORS AT ROOM TBIIPERATURF: (33DICATED AIR

13、SPEED) Speed Knots 40 50* 60* 70 80 90 loo* 110 120 130 140* 150 ia* 170 180 190 200* 210 220 230 240 250s 260 270 280 290 300* 310 320 330 340 350“ 360 370 380 390 400* Pressure inches of Water 1 045 1.634 2.354 3.207 4.192 5- 30 6.563 7.951 9.475 11.14 12.94 14.87 16.95 19 17 21.54 24.05 26.71 299

14、.51 35-56 32.47 38.84 42.27 45 85 49.59 53.50 57- 58 61.82 66.24 70 83 75-61 80.56 85 70 91.04 96.56 102.28 108.20 114.33 Allowable scale errors Knots 5.0 4.0 4.0 3.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.5 2.5 2.5 2.5 2.5 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3*0 3.0 3.0 4.0 4.0 4.0 4.0 4.0 4.0 4.0 4.0 4.0 4.0 5.0 *

15、 Test points Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TABLF: III SCALE ERRORS AT ROOM TEWFBkTURE (Maximum Allowable Speed) Altitude 1,000 Feet O 5 10 15 20 25 30 35 40 45 50 364* 334 305“ 277 251* 227 181 161* 203* - - Altitude 1,000 Feet O 5

16、10 15 20 25 30 35 b 45 To 4 4 4 4 4 4 4 4 4 - - MACE NUMBER Indicated Airspeed mots 397* 364 333“ 303 275“ 248 =3* 199 177* 157“ - 3 Allouable Scale Errors Knots 4 4 4 4 4 4 4 4 4 4 - Indicated I Allowable Airspeed Knots - - 390* 356 323s 292 262* 235 a9* 186 i65* Indicated Airspeed Knots Allowable

17、kale Errors Knots - - - - 4 4 4 4 4 4 4 Indi cat ed Airspeed Knots Allowable Scale Errors Knots - - - 1- 4 4 4 4 4 4 4 Scale Errors mots - - 4 4 4 4 4 4 4 4 4 * Test points 4.6.2.1 Case leak. - The pitot and static connections of the indicator shall be joined with a “Y“ connection and shall be conne

18、cted together to the same mercury manometer and sources of suction and pressure. connections of the indicator with the source disconnected for a period of 10 seconds, the difference between the mercury levels in the manometer shall not change by more than 0.2 inch. . A suction of 1.5 inches of mercu

19、ry shall be applied to the pitot and static pressure 4.6.2.2 D-. - With the static connection open to the atmosphere, a pressure sufficient to produce approximately full scale deflection of the indicated airspeed pointer, shall be applied to the pitot connection of the indicator at which point the c

20、onnecting tubing shall be pinched off or otherwise completely sealed. shall not change its position by more than one knot. miring a period of one minute, the indicated airspeed pointer Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-I-2373 bb 777

21、77Ob 0330555 7 MIL-I-21716(Aer) 4.6.3 Scale errors at room temQG.rsturr. - 4.6.3.1 Indicated airspeed. - The indicated airspeed pointer su be tested for Scale errors at the points Of the scale indicated by asterisks in Table 11. The test shall be made by subjecting the indicator to the pressures spe

22、cified to produce these readms, first with pressures inCressin;, then with pressures decreasing. With pressures increasin;, the pres-e shall be brought UP to, but shall not exceed the pressures specified to give the desired reading, and with pressures decreasing, the pressure shall be brought down t

23、o, but shall not fall below the pressures specified to give the esired reading. When desired by the Inspector, the indicator shall be tested for scale error at any additional point or points on the scale. The errors at these ad to an increase in altitude of approximately 3,000 feet per minute. The i

24、ndicator shall remain at the pressure corresponding to each test point for at least 1/2 minute but not more than 5 minutes before a test reading is taken. The scale errors shall not exceed the allowable scale errors specified in Table III. setting wlth the Hysteresis test. Durin; The reduction in pr

25、essure, as indicated by the barometer Shall This test shall be cambined at each Mach number 4.6.4 HvsteresQ . - Hot more than i5 minutes after the indicator has been subjected to the pressure corresponding to the highest altitude specified in Table III, the pressure shall be increased at a rate corr

26、esponding to a decrease in altitude of approximately 3,000 feet per minute until the pressure corresponding to 30,000 feet is reached. least 4 minutes, but not more than i5 minutes before the test reading is taken. After the reading has been taken, the pressure shall be further increased at the abov

27、e rate until the pressure COT- responding to 10,000 feet is reached. minute, but not more than 10 minutes, before a test reading is taken, After the reading has been taken, the pressure shall be further increased at the above rate until atmospheric pressure is reached. from the corresponding reading

28、, with decreasing pressure, by more than 2 knots. The indicator shall remin at this pressure for at The indicator shall remain at this pressure for at least One The reading of the maximum speed pointer at either of the two test points shall not differ 4.6.5 the maxi- The pointer adjustment No damage

29、 or loosening in 4.6.15 Overpressure. - 4.6.15.1 The pressure specified in Table I shall be applied to the pitot pressure connection of the indicator for a period of 10 minutes. 4.6.15.2 The pressure specified in Table I shall be applied to the static connection of the indicator for a period of 10 m

30、inutes. 4.6.15.3 Not less than 5 minutes following the application of Overpressure tests the indicator shall be tested for scale errors as specified in the Scale errors at room temperature test. The errors at the test points shall not exceed those specified in Tables II and III by more than the valu

31、es specified in Table I. 4.6.16 S-. - The indicator shall be subjected to 1,OOO applications of a differential pressure sufficient to produce approximately full scale deflection. made at a rate not greater than 6 per minute. indicator shall be tested for scale errors as specified in the Scale errors

32、 at room temperature test. The errors at the test points shall not exceed those specified in Table II by more than the tolerance specified in Table I. These applications shall be Hot less than 48 hours following this test, the 4.6.17 Altitude. - The indicator properly connected with no power applied

33、 shall be tested in accordance with Procedure II of Specification MIL-E-5272 except that the chamber shall be reduced to 3.42 inches of mercury (50,oOO feet) for a period of one hour. one hour period power shall be applied to the indicator. At the end of the one hour period and with the temperature

34、and pressure maintained as specified the indicator shall be subjected to and shall meet the requirements specified in the InaividuaL tests. Ixiring the last i5 minutes of the 4.6.18 Low temperature . - The indicator shall be tested in accordance with Procedure II of Specification MIL-E-5272. At the

35、end of the exposure period and while still at the -54C (-65F) temperature, the indicator shall be tested for saie errors as specified in the Scale errors at room temperature test (omitting that part of this test pertaining to Hysteresis), except that the test Provided by IHSNot for ResaleNo reproduc

36、tion or networking permitted without license from IHS-,-,-MIL-I-2l718(Aer) points shrdmum speed pointer stop adjustment shall operate properly. 4.6.a Acceleration. - The indicator shall be tested in accordance with Procedure II of Speci- fication MIL-E-5272. in each of the follo?dng positioas: The i

37、ndicator shaIl be subjected to an acceleration of x) gs with the indicator (a) Xormal operating position with the rear of the case toward the center of rotation. (b) (c) Rotated 90 degrees In azimuth with respect to the originL position. Dial horizontal, with the zero graduation toward the center of

38、 rotation, At the end of the acceleration test the indicator shall meet the requirements specified in the Individual tests. 4.6.U Vibration failure. - The indicator shall be tested in accordance with Procedure V of Specification MIL-E-5272. This test shall be conducted using the test settings specif

39、ied in Table I. The instrument indication at the test settings specified shall be determined with pressures increas- ing. At the end of the vibration period, the indicator shall be subjected to the pressure specified to produce the test readings (with pressure increasing). indication shall not excee

40、d the tolerance specified in Table I. The change in airspeed and/or Mach number 4.6.22 Humidity. - The indicator shall be tested in accordance with Procedure I of Specifi- cation MIL-E-5272. Precaution shall be taken to prevent dripping on the indicator. 4.6.23 Fungus resistance. - The indicator sha

41、ll be tested in accordance with Procedure I of Specification MIL-E-5272, excest that the test period shall be i4 days. ing agency, tests of component prts of the item may be accepted in lieu of, or in addition to, tests of the assembled instrument. At the option of the qualify- 4.6.24 Salt sway. - T

42、he indicator shall be tested in accordance with Procedure I of Specifi- The indicator shall be subjected to and shall meet the requirements speci- cation MIL-E-5272. conditions (see 6.2.2). fied in the Individual tests. External connections shall be made to the indicator to simulate installed 4.6.25

43、 Mounting lugs. - The indicator case shall be mounted face downward on the movable head of a suitable testing machine with the face of the case in a horizontal plane so that the mounting lugs receive no added support. lug and attached to a pull strap in the stationary head of the machine. applied fo

44、r one minute to each lug in a direction toward the front ofthe case. The lugs shallwith- stand the applied load without fracture and there shall be no damage to any part of the indicator. A suitable pin shall be inserted thrmgh the hole in the mounting A load of 1-75 pounds shall be 4.6.26 u. - The

45、indicator shall be retained for a period of not less than 30 days after having been subjected to the Seasoning test, and then tested for Scale errors at room temperature. The scale errors in this test shall not differ from those obtained 48 hours after the 1,000 ampli- fications of differential pres

46、sure specified in the Seasoning test by more than the value specified in Table I. r _I_- 15 -_ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I_- MIL-I-237L 66 = 9999906 0330559 b = MIL-I- 2WlS(Aer) 5. PREPARATION FOR DELIVERY 5.1 * 5.1.1 Level A. -

47、 The indicator shall be packaged in accordance with Specifleation MIIL-P-7936. The method of preservation shall. be in accordance with Specification MIL-P-116, Metho2 II us- metal reusable containers. 5.1.2 Level C. - When this level 1s required packaging shall be in accordance -With stanaarcl comer

48、cial practice. 5.2.1 Levels A and B. - The indicator shall be packed in accordance with Specification The level or levels required shall be as specified in the invitation for bid or MIL-P-7936. contract. 5.2.2 rid packing to be furnished. 6.4 QuBLification2 - With respect to products requiring quali

49、fication, awards will be made only for such products as have, prior to the bid opening date, been testedand approved for inclusion in the applicable Qualified Products List whether or not such products have actually been so listed by that date. 6.4.1 me attention of suppliers is caed to this requirement, and manufacturers are urged to arrange to have the products that they propose to offer to the Federal Government, teste