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THE method of controlling work on the factory varies considerably. It can start from simply telling an operator the quantity required of a certain part, handing him the blueprint and telling him to get on with the job, to a complex breakdown where everything has been considered in advance, an exact line‐up prepared, and an adherence to a fixed production plan.

UNDER the heading of Statistical Control, we are faced with several terms which are still in their infancy as regards scope and definition.

A SYSTEM as applied to a general factory would come under the broad heading of Works Organization. It could be embodied to embrace every activity of the company from a canteen to the welding of a part.

IN our series of papers on Production Control in Aircraft Engineering, we have so far covered the following subjects: (1) Preproduction Planning (Dec. 1942), (2) The Production Plan (July 1944), (3) Shop‐loading (Aug. 1943), (4) Manufacturing Order Control (Jan. 1944), (5) A System of Works Control (September 1943). The British Standards Institution in their booklet 1100, Part I, Principles of Production Control, give 6 subjects as covering the entire field, (1) Scheduling, (2) Machine and Labour Utilization, (3) Stock Control, (4) Manufacturing Order Control, (5) Progressing, and (6) The Production Plan. It will therefore be seen that No. 1, Scheduling; No. 3, Stock Control; No. 5, Progressing, have not been covered. (Note: At this stage, we can assume that No. 2, Machine and Labour Utilization, was sufficiently dealt with in the Shop‐loading paper.)

PLANNING is a term that can be loosely applied to include several fields. It is quite often used in the sense of indicating the operations and tooling necessary to produce a manufactured part; though more truthfully this could be termed process planning or processing.

ONE of the first essentials in the initiation of any work is to organize it to a definite plan; which may be interpreted as follows:

FOR some time past there has been in current use in the United States, the term “Industrial Engineering”; a term which in England is used but seldom, and with many varying interpretations.

TO overcome the discomfort, nerve strain and fatigue to both passengers and crew on multi‐engined aircraft resulting from the noise and vibrations of engines running at slightly varying speeds, the need of an accurate, easily read indication of such variations is readily apparent. A direct comparison of r.p.m. indicators is ineffective because the permissible tolerance on each indicator might result in a total difference of the order of 50 r.p.m. even though the speed of the engines under comparison is the same. The development of the 3‐phase electric tachometer indicators overcame this difficulty by comparing the relative frequencies of two or more tachometer generators (not the voltages), before this has been translated into an indicated r.p.m., by means of a small synchronous motor operating a magnetic drag unit; the desired result is obtained even though the possibility of permissible errors in a yet serviceable indicator has not been obviated. These two frequencies arc used to operate what is, in reality, a beat‐frequency indicator with a pointer rotating in proportion to the difference in speed. As the difference in speed of the two engines results in a difference in the frequencies developed by the two tachometer generators, so the pointer of the synchroscope will rotate either clockwise or anti‐clockwise according to which engine is running faster. When both engines are running at the same speed the frequencies will be alike and the pointer will remain stationary. Any difference in voltage output of the two generators will not affect this final indication, but will have some bearing on the speed difference at which the pointer begins to rotate where this rate of rotation is directly proportionate to the difference in engine speed. However, as a large variation between engine speeds will not cause any pointer rotation at all, but merely be shown as a flickering of the pointer, this is of no material importance.

ALTHOUGH the Hawker Sea Fury is an individual design its structure has been developed step by step from its forebears. The Hurricane had a tubular fuselage and metal‐covered wing; on the Typhoon the rear fuselage became a monocoque; while in the Tempest the semi‐elliptical wing appeared. The wing of the ‐Fury is generally similar in construction to that of the Tempest; but differs in the important point that it is continuous beneath the fuselage instead of being bolted to the sides. With the introduction of folding wings, when development was centred on the Naval Sea Fury in 1945, further modifications were made that resulted in the present wing design.

IN this issue PROFESSOR J. V. CONNOLLY brings to a conclusion the series of articles on Production Engineering, Administration and Management which have been written at our invitation and the publication of which we started in May last year.