Reference is made to the "Master Navigation Watch Manual" Revised July 1956, Courtesy of Michael Klipp, on our Library page http://library.ihc185.com/catalogs/.

I combined all these individual pages into a single pdf document to facilitate browsing for our dear members, and I noticed the following 5 pages are missing:

Pages 3, 10, 17, 21, and 23.

Can a kind member having the original please scan these 5 pages and post them to Debbie at ihc185@roadrunner.com?

Many thanks

If you do not have these they would come in handy.


MIL -W -5492A(ASG)
12 FEBRUARY 1957
Superseding
MIL-W-5492
9 January 1950


MILITARY SPECIFICATION
WATCH, POCKET, NAVIGATION MASTER

This specification has been approved by the Department of the Air Force and by the Navy Bureau of Aeronautics.

1. SCOPE

1.1 This specification covers one type of master navigational watch.

2. APPLICABLE DOCUMENTS

2.1 The following specifications, standards, and publication, of the issue in effect on date of invitation for bids, form a part of this specification to the extent specified herein:

SPECIFICATIONS
Military
MIL-D-5028 - Drawings and Data Lists: Preparation of Manufacturers’ (for Production Aeronautical and Associated Equipment)
MIL-P-6064 - Packaging of Lightweight Aircraft Accessories

STANDARDS
MS28076 - Watch, Pocket, Navigation Master
MIL-STD-129 - Marking for Shipment and Storage
MIL-STD-130 Identification Marking of U. S. Military Property

PUBLICATIONS
Air Force-Navy Aeronautical Bulletin
No. 405 Storage Life - Aeronautical Articles

(Copies of specifications, standards, drawings, and publications required by contractors in connection with specific procurement functions should be obtained from the procuring activity or as directed by the contracting officer.)

3. REQUIREMENTS

3.1 Qualification.- The watches furnished under this specification shall be a product which has been tested and has passed the Qualification tests specified herein.

3.2 Material.- Material not specifically described herein shall be of the best quality and suitable for the purpose intended.

3.2.1 Nonmagnetic material.- Nonmagnetic materials shall be used for all parts of the watches except where magnetic materials are essential.

3.3 Design and construction.- The watches shall be so constructed that no parts will work loose in service. They shall be built to withstand the normal strain of jars, vibrations, and such other conditions as are incident to shipping, storage, and service, without failure.

3.3.1 Watch case.- The watch case shall be made of noncritical alloy. The entire outside surface of the case shall have either a polished or butler finish acceptable to the procuring activity. The case shall be the open-face type with a screw bezel and screw back, and shall be dustproof and moistureproof but need not be immersionproof. The bezel and back shall have knurled edges. Dimensions of the case shall conform to Standard MS28076.

3.3.2 Crystal.- The watch crystal shall be made of tempered glass. The glass shall be clear, free from bubbles, flaws, or other imperfections which may interfere with normal reading of the watch.

3.3.3 Watch movement.- The watch movement shall be 16 size and shall have not less than 21 jewel bearings, located at bearing points most essential t o reduce friction of train and escapement parts. Balance jewels shall be mounted in adjustable bushings and all other jewels shall be mounted either in bushings or by friction fit. All jewels shall be mounted in such manner that they will not become loose while in service. End stone jewels shall be securely mounted in readily removable caps to facilitate cleaning and oiling.

3.3.3.1 Lever regulator.- The movement shall have a micrometer-type-lever regulator for varying the rate, and the watch shall-be furnished with the lever regulator in its middle position within +/-5 percent of the range on either side. The regulator screw shall be easily accessible and may be either capstan head or provided with screwdriver slot. If a screwdriver adjustment is provided, the adjustment shall be made without having to use a screwdriver at any angle other than in perfect alignment with the screw.

3.3.3.2 Movement marking.- Bridges or mounting plates shall be stamped or engraved to show the number of jewels, the name of manufacturer, model number of the movement, number od adjustments, and that it is adjusted to temperature. The pillar or foundation plate shall be stamped or engraved with the manufacturer’s serial number.

3.3.4 Rundown.- The watch shall be constructed to run for not less than 48 hours for one complete winding of the mainspring.

3.3.5 Balance and hairspring unit.- The balance and hairspring unit shall be of the temperature-compensating type. The balance shall be fitted with not less than 12 screws, of which at least 4 shall be regulating screws.

3.3.5.2 Hairspring.- The hairspring shall be of the Breguet type.

3.3.6 Stem control.- The watch shall be of the stem wind and set type, so constructed that when the stem is pulled out for setting, a flexible spring will engage the balance wheel, stopping its movement but allowing the hour and minute hands to be set. Upon releasing the stem the watch shall again start to run.

3.3.7 Sweep second hand,- The watch shall have a center pivoted sweep second hand. The sweep second hand shaft shall have a jewel bearing in the rear plate.

3.3.8 Watch dial.- The dial shall have a dull black finish with white markings. Style and arrangement of numerals, -graduations, and 'GCT" shall conform to figure 1. The hour hand shall be of the railroad spade type, and the minute and sweep second hands shall be straight. All markings and finishes shall be durable to withstand usage encountered in service.

3.4 Interchangeability.- All parts, except hairsprings, having the same manufacturer's part number shall be directly and completely interchangeable with each other with respect to installation and performance. Changes in manufacturer's part numbers shall be governed by the drawing number requirements of Specification MIL-D-5028, or as otherwise specified by the procuring activity.

3.5 Weight.- The weight of each watch shall not exceed 5 ounces.

3.6 Adjustment.- The watch shall be adjusted to keep mean solar time. The watch shall be furnished adjusted for isochronism, for temperature, and for at least two positions as follows: horizontal with dial up; and vertical with the pendant up.

3.7 Lubrication.- The watch shall be furnished with sufficient lubricant to provide for a least 1 year of operation. The lubricant shall be of such quality that satisfactory lubrication will be provided when the watch is run at temperatures ranging from +35 deg to -20 deg C.

3.8 Performance.- The watch shall satisfy the performance requirements specified in section 4.

3.9 Identification of product.- The back of the case shall be etched or engraved for identification in accordance with Standard MIL-STD-130.

3.9.1 Use of AN or MIL designations.- AN or MIL designations shall not be applied to a product, except for Qualification test samples, nor referred to in correspondence, until notice of approval has been received from the activity responsible for qualification.

3.10 Workmanship.- Workmanship and finish shall be in accordance with the best practice for high-quality aircraft watches.

4. QUALITY ASSURANCE PROVISIONS

4.1 Classification of tests.- The inspection and testing of watches shall be classified as follows:

(a) Qualification tests: Qualification tests are those tests performed on samples submitted for approval as qualified products .

(b) Acceptance tests: Acceptance tests are those tests performed on individual lots which have been submitted for acceptance,

4.2 Test conditions.- Except as otherwise specified herein, all tests shall be conducted at room temperature (approximately 23 deg C) and at atmospheric pressure of approximately 29.98 inches of mercury.

4.3 Qualification tests.-

4.3.1 Sampling instructions.- The Qualification test samples shall consist of two watches of each manufacturer's part number upon which qualification is desired. Samples shall be identified as required and forwarded to the activity responsible for qualification, designated i n the letter of authorization from that activity, tests of this specification as described under Acceptance tests. (See 6.4.)

4.3.2 Tests.- The Qualification tests of watches shall consist of all the tests of this specification as described under Acceptance tests.

4.4 Acceptance tests.- The Acceptance tests shall consist of Individual tests.

4.4.1 Individual tests. - Each watch submitted for acceptance under contract shall be subjected t o the following tests. Tests shall be conducted in order listed.

4.4.1.1 Examination of product.- Each watch shall be carefully examined to determine conformance with this specification with respect to material, workmanship, and construction.

4.4.1.2 Daily rate, room temperature, horizontal position.- The watch shall be run for 1 day to allow it to settle down. The daily rate of the watch shall then be determined for a period of 5 days with the watch in a horizontal position, dial up, and with daily winding. The average of the daily rate during the test period shall not exceed 5 seconds. The average variation from the average daily rate shall not exceed 2 seconds.

4.4.1.3 Daily rate, room temperature, vertical position.- The daily rate of the watch shall be determined for a period of 5 days with the watch in a vertical position, with the numeral 24 of the dial up, and with daily winding. The average of the daily rate during the test period shall not exceed 5 seconds. The average variation from the average daily rate shall not exceed 2 seconds. The difference in the average daily rate obtained in this test and in the room temperature rate test, horizontal position, specified in 4.4.1.2, shall not exceed 5 seconds.

4.4.1.4 Isochronism.- The watch shall be fully wound and the errors determined at the end of the first 12 hours and at the end of 24 hours. The difference between the error for the first 12 hours and half the error for the 24 hours of this period shall not exceed 1 second. The watch shall be tested for isochronism in the horizontal
position, dial up, and in the vertical position, with the numeral 24 of the dial up. The isochronism tests may be combined with the room temperature rate tests, horizontal and vertical positions specified in 4.4.1.2 and 4.4.1.3, respectively.

4.4.1.5 Daily rate, -20 deg C, horizontal position.- The watch shall be fully wound and then subjected to a temperature of -20 deg C for a period of 24 hours. The daily rate of the watch shall then be determined.

4.4.1.6 Daily rate, 5 deg C, horizontal position.- The watch shall be tested as in the -20 deg C rate test specified in 4.4.1.5, except that the temperature shall be 5 deg C. The daily rate of the watch shall not differ from the daily rate obtained in the rate test at -20 deg C by more than 15 seconds.

4.4.1.7 Daily rate, 35 deg C, horizontal position.- The watch shall be tested as in the -20 deg C rate test specified in 4.4.1.5. except that the temperature shall be 35 deg C. The daily rate of the watch shall not differ from the daily rate obtained in the rate test at 5̊C by more than 10 seconds.

4.4.1.6 Rate recovery, room temperature, horizontal position.- The daily rate of the watch shall be determined for a period of 3 days with the watch in a horizontal position, dial up, and with daily winding. The average of the daily rates during the test period shall not exceed 5 seconds. The average variation from the average daily rate shall not exceed 2 seconds. The average daily rate shall not differ from the average daily rate obtained in the room temperature rate test, horizontal position, specified in 4.4.1.2, by more than 4 seconds. The room temperature for this test shall be approximately the same as the temperature in the original room temperature test.

4.4.2 Rejection and retest.- The individual watches failing to meet their respective tests shall be rejected. Watches which have been rejected may be replaced or repaired to correct the defects and resubmitted for acceptance. Before resubmitting, full particulars concerning previous rejection and the action taken to correct the defects shall be furnished to the Inspector. Units rejected after retest shall not be resubmitted without the specific approval of the procuring activity,

5. PREPARATION FOR DELIVERY

5.1 Application.- The requirements of section 5 apply only t o direct purchases by or direct shipments to the Government.

5.2 Packaging.- Unless otherwise specified, watches shall be packed in accordance with Specification MIL-P-6064, group X, type II container.

5.3 Marking of shipments.- Interior packages and exterior shipping containers shall be marked in accordance with Standard MIL-STD-129. The identification shall be composed of the following information listed in the order shown:

Stock No. or other identification number as specified in the purchase document*
WATCH, POCKET, NAVIGATION MASTER
MS28076 (proper dash number)
Manfacturer's Part No.

*Note: The contractor shall enter the Federal Stock No. specified in the purchase doucment or as furnished by the procuring activity. When the Federal Stock No. is not provided or available from the procuring activity, leave space therefor and enter the Stock No. or other identification when provided by the procuring activity.

5.3.1 Reinspection dates.- ReinspectLon marking shall be added in accordance with ANA Bulletin No. 405.

5.3.2 Precautionary marking.- The following precautionary marking shall appear on two opposite sides of each interior and exterior shipping container, whenever practicable, depending on the size of the carton:

FRAGILE
DELICATE INSI1IUMEWPS
HANDLE WITH CARE

6. NOTES

6.1 Intended use.- The watches covered by this specification are intended for use as precision timepieces in the navigation of aircraft.

6.2 Superseding data.- This specification supersedes Specification ML-W-5492 which specification incorporated the requirements of Specification AN-W-26. The Office of Standardization has authorized the revision of this specification, previously fully coordinated, as an ASG limited coordination specification in view of its primarily aeronautical application.

6.3 Ordering data.- Procurement documents should specify the following:

(a) Title, number, and date of this specification.
(b) MS Part No. of the watch required.

6.4 Provisions for qualification.- With respect t o products requiring qualification, awards will be made only for such products as have, prior to the bid opening date, been tested and 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 The attention of suppliers is called to this requirement, and manufacturers are urged t o arrange t o have the products that they propose t o offer t o the Federal Government, tested for qualification in order that they may be eligible to be awarded contracts or orders for the products covered by this specification. Requests for information pertaining to qualification of products covered by this specification should be addressed t o the Bureau of Aeronautics, Navy Department, Washington 25, D. C., the activity responsible for qualification, with a copy to the Commander, Wright Air Development Center, Wright-Patterson A i r Force Base, Ohio.

NOTICE: When Government drawings, specifications, or other data are used for any purpose other than in connection with a definitely related Government procurement operation, the United States Government thereby incurs no responsibility nor any obligation whatsoever; and the fact that the Government may have formulated, furnished, or in any way supplied the said drawings, specifications, or other data is not to be regarded by implication 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 sell any patented invention that may in any way be related thereto.

Custodians:
Navy - Bureau of Aeronautics
Air Force

Paul, I have sent you and Debbie an email with the 4 missing pages attached. Page 3 is not missing from the library version it is listed as "Case, Dial, Movement, Train, etc.".

Bob