civilian workmen employed in the overhaul of aircraft. Thus, the labor which was at one time performed entirely by enlisted men at no cost to "Aviation, Navy," is now being done by increasing numbers of civilians at a greater charge to this appropriation, though actually more economically with respect to the entire naval appropriation. Enlisted men are constantly being taken away from their overhaul work in order to perform the military duties which are necessarily required of them. A civilian not so obligated devotes about 10 percent more time to work that can be measured as the tangible output of an overhaul department. Furthermore, military necessity requires that enlisted men be alternated between sea and shore duty. The constant shift in duties generally prevents the average enlisted man from attaining the same state of efficiency that is reached by a civilian workman who may be employed on a particular class of work for a number of years. Of the increase asked on account of aircraft overhaul, approximately $95.200 is to defray the cost of 56 additional civilian employees, required for 1939, to handle the increased overhaul work.

The following table shows the ratio of planes overhauled to planes operated:

Past records have indicated a fairly constant ratio from which the number of overhauls can be predicated with reasonable accuracy. The desire to effect greater economies has led to a reduction in the above-mentioned ratio for the year 1939. Experience has demonstrated the feasibility of extending the operating interval between overhauls without any reduction in the safety of operations. Advantage is being taken of this fact, but with it must be accepted a slight increase in operating cost (as distinguished from overhaul cost) because of work that will now be accomplished by operating personnel. The policy herein outlined and recently put into effect will undoubtedly result in a saving. The reduction in the proportionate number of major overhauls will bring with it an increase in the number of minor overhauls performed by air stations and operating personnel combined.

An average of about 50 percent of the work performed by overhaul stations throughout the Navy is of the nature of minor overhaul. This item must be taken into consideration when comparing the various stations on the basis of major overhauls and total cost of all work performed. For convenience in comparison, the percentage of minor overhaul at each station for the fiscal years 1936, 1937, 1938, and 1939 has been taken from the detailed table of analysis of aircraft overhaul and is reproduced below, followed by an explanatory statement:

At San Diego the percentage of money spent for minor overhaul has remained fairly constant, because the nature of the work has been essentially the same. At Norfolk, however, a sharp increase in minor overhaul can be expected due to the operation of the Yorktown, Enterprise, and Wasp squadrons in that area during the fiscal year 1938 and a part of 1939. The moderate increase at Pensacola during 1938 and 1939 is caused by the increased training at that station. Part of the minor overhaul work will be accomplished by the squadron personnel, and the full effect of increased operations. will not be felt by the overhaul plant. Coco Solo and Pearl Harbor are expected to continue minor overhaul on approximately the same basis as heretofore. The sharp drop in minor overhaul at the aircraft factory has been brought about by a concentration of effort on the manufacture of airplanes and engines. The work formerly accomplished by the aircraft factory will be done by the other overhaul bases and by the squadron personnel. The marine activities will continue on much the same basis as in previous years. The allstations average minor overhaul percentage will remain about constant for the 4 years under consideration.

In developing the cost accounting system now followed by all the major overhaul bases, it was found necessary to evaluate each type of overhaul in work units. This is revised each year to keep step with the modifications in airplane and engine types. Increased difficulty in overhaul is followed by an increase in work units assigned, so that each station's output can be compared with that of the preceding year and with that of each other. Under the present system this method of evaulation has a slight lag due to the fact that the weighted averages are computed annually. The table below shows the development of the unit system. The work units are proportional to the time spent on overhaul and are equivalent to 100 man-hours of labor per unit. Thus, in 1935, a single-seater fighter airplane required approximately 1,800 hours to overhaul, or 18 units; in 1937, the latest model of the fighter (VF) type required 2,300 hours, or 23 units.

REPLACEMENT AND INCREASE IN OVERHAUL EQUIPMENT

Under this item there was appropriated $166,000 for 1938, and $250,000 is requested for 1939, an increase of $84,000.

In order to care for the additional work load at aircraft overhaul activities, due to the increased number of planes as well as the greatly increased size and complexity of aircraft in service, additional new equipment, as well as replacements, is necessary. The preliminary estimates for 1938 included $243,455 for the above purposes. The sum appropriated was $166,000. The equipment which was not provided for in 1938 has become increasingly necessary. The estimates for 1939, therefore, again include a portion of this equipment, as well as that necessary because of normal replacements and increased work load due to the increased number of airplanes in service. The individual estimates for the current fiscal year submitted by the various overhaul activities are more than double the amounts listed herein. Owing to budgetary limitations it has been necessary in preparing this estimate to eliminate therefrom more than half of the items requested for 1939 by the several air stations.

OPERATION OF TRAINING AIRCRAFT AT NAVAL AIR STATION, PENSACOLA, AND UTILITY UNITS AT OTHER AIR STATIONS

Due to the reduction in flight training at Pensacola for 1939, the amount requested under this heading for that year is $909,900 or $170,100 less than the amount appropriated for 1938, which was $1,080,000. Small additional increases for Newport, San Diego, and Seattle are requested for the reasons given below, but the total amount is less because of the reduced estimate for Pensacola.

The increase of $2,000 at Newport is due to the additional assignment of one torpedo plane and one patrol plane for experimental

purposes.

The increase of $1,500 at San Diego is due solely to the increase in cost of gasoline on the west coast.

The Seattle unit has been formed since the preparation of the 1938 estimates and consequently appears as a new item. Gasoline costs at that station are approximately the same as shown for San Diego. The amount requested ($10,500) is the minimum on which it is estimated the airplanes assigned to this station can be operated.

MAINTENANCE OF NAVAL AIR STATIONS AND THE NAVAL AIRCRAFT FACTORY

There was appropriated $3,500,000 under this item for 1938 and $3.606,900 is requested for 1939, an increase of $106,900.

The annual cost of maintenance of naval air stations and fleet air bases is dependent upon the number of airplanes to be operated under the approved operating force plan and the naval aeronautic organization, the size of the plant, the amount of deterioration of buildings and other shore facilities at these stations, and the cost of labor and materials. For purposes of economy in operation, fleet aircraft squadrons are temporarily based at air stations and air bases for considerable portions of each year while engaged in gunnery practices and other squadron exercises. Both during the time that the squadrons are operating from carriers and tenders in the vicinity of air stations and bases, and while temporarily operating directly from the stations and bases, all station facilities are fully occupied in servicing the squadrons and repairing their airplanes. Therefore, any increase in the number of airplanes operated by the aircraft squadrons places an additional burden on the stations concerned as far as maintenance of shore facilities is concerned.

The operating force plan for the fiscal year 1938 provides for operation of 1,303 airplanes during this year. For 1939, a total of 1.415 airplanes will be operated, which is an increase over 1938 of 112 airplanes, or an increase of 8.6 percent. The value of the aeronautical shore establishment has increased from approximately $50,000,000 is 1933 to about $70,000,000 in 1937, or 40 percent, or an average of 10 percent per year. The estimate for maintenance of air stations for 1939 is $3,606,900, which is an increase of $106,900 over 1938, or only 3.1 percent. Also, this increase includes a new item of $69,800 for maintenance of old Bolling Field, now maintained by the Army and a comparatively new item for the temporary base at Sitka, Alaska, where there is an increase of $20,000. These items are not dependent on the number of operating airplanes. Exclusive of these items, the increase in the estimate for 1939 is $17,100, or only one-half of 1 percent as compared with the increase of 8.6 percent in operating planes and an estimated 10 percent increase in size of plant. This represents only a very modest increase and will be barely adequate for efficient operation of our air stations and air bases during 1939, with provision for the most necessary routine repairs to plant facilities, and at the same time rendering necessary service in maintenance and repair of the aircraft of the fleet.

All air stations and bases have been required to prepare careful maintenance estimates for the fiscal year 1939 and were strictly enjoined that the estimates must be held to the lowest possible figure. The estimates submitted to the Bureau by the stations totaled $4,353,483. After very careful review, and in consideration of the requirements for rigid economy, the Navy Department has reduced these estimates to $3,606,900, which is a reduction of $746,583, or 17.1 percent. This reduced figure is believed to be the least amount on which our air stations and bases can be efficiently maintained under the approved operating force plan for the fiscal year 1939.

EXPLANATION OF INCREASES UNDER THIS ITEM

Charlotte Amalie (St. Thomas), Coco Solo, Lakehurst, naval aircraft factory, and Quantico.-No additional airplanes are being based at these stations for 1939. Therefore, no increases are being requested in maintenance funds for these stations.

Anacostia. The increase of $69.800 requested for Anacostia is required solely for upkeep of old Bolling Field, which is now maintained by the Army, but which it is expected will be turned over to the Navy during 1938. The present joint flying field at Anacostia will then have to be maintained entirely by the Navy, with consequent material increase in cost. The same is true of the additional buildings to be acquired and which are now maintained by the Army. These consist of hangars, shops, etc., and also 11 sets of officers' quarters of wooden construction, which require a large amount of repairs. A considerable increase in heat, light, and power will also be required. Altogether, the increased sum of $69,800 seems a very reasonable figure for maintenance of the whole of old Bolling Field. No increase is requested for the present naval facilities at Anacostia for 1939.

Norfolk. The increase of $11,630, or 0.6 percent, will be made necessary partly by the expected demands incident to servicing of fleet aircraft which will be based at Norfolk during a portion of the year and, in addition, by the maintenance of increasingly old structures. About 90 percent of the buildings at Norfolk are of a temporary wartime type of construction, which due to their age and deterioration, are expensive to maintain. This is particularly true in the case of the barracks and mess hall buildings which are of wooden-frame construction. The hangars are also old and require extensive repairs and improvements. The Bureau has recently received a request for an allotment of $65,000 for repairs to the doors of one hangar which are in an unsafe operating condition. Due to lack of funds, only $35,000 could be allotted to care for the most urgent part of the work.

Pearl Harbor.-For 1939 there will be an increase of 9.5 percent in the airplanes to be based on Pearl Harbor for maintenance and repair. These new airplanes are nearly all of the large patrol type. which places an extra burden on the shore-station facilities to service and repair them. Also a number of new buildings consisting of barracks and mess hall, hangars, 16 sets of officers' quarters, 36 sets of chief petty officers' quarters, boathouse and oilhouse have recently been completed. The assignment of these additional operating aircraft, with the accompanying increase in personnel to maintain these units; and the expansion of the station by the above new buildings with attendant additional heat, light, and general upkeep, will all require greater maintenance cost for 1939. The increase requested for 1939 over 1938 of $19,700, or 6.4 percent, appears very reasonable in comparison with the expansion of the station and aircraft squadrons for 1939. As at all other stations, the increase requested has been reduced to the lowest practicable figure for reasons of economy. Pensacola.-The reduction at Pensacola is due to the decreased number of students that are scheduled for training during 1939.

San Diego. The burden of increased station maintenance will fall more heavily upon San Diego in 1939 than upon any other air station.