Our Navy Aug 1, 1945   Our Coral Carriers Helped Turn the Tide of Battle By Vern A. Miller Air power has been the deciding factor in our crushing offensive against the Japs in the Pacific. Our big, ungainly, teak-topped ships have furnished the one-two punch that, time and time again, has sent the Japs reeling into a corner. And the miracle of our sustained attack from the air must have loomed as black magic to the frenzied Admirals of the Rising Sun. For in the unrelenting pressure we were able to exert, there was evidence that the American Navy was in possession of a secret that gave our roving fleets an endurance beyond anything heretofore possible in the realm of logistics. Somewhere, the Japs must have reasoned, America had stacked the deck against them. How could our carriers remain at sea month after month with no decline in hitting power? How could our planes go through strike after strike, month after month of constant flying, and still maintain top efficiency? Did our machines never wear out? Were American airmen immune to battle fatigue? The answer to this seeming mystery would have been immediately apparent to our enemy if he could have been accorded the privilege of visiting one of the islands we had so recently taken from him. Here, where only weeks before had been swamp and jungle or ridged and pot-holed coral structure, stretched the long, smooth trigonometric pattern of runways. Hangars, revetments, supply buildings, and all the other facilities for storage, repair and upkeep of planes, huddled about the bomber-length takeoff strips. These were our unsinkable carriers, our island flattops, the miracle behind our overwhelming Pacific offensive. Without these air bases at strategic points, our carriers would have been unable to range from the Kuriles to the Spice Islands, up and down and through the seas that Japan had thought were closed to enemy power. But there is more to the secret than mere air bases. Behind those air fields and the vital role they have played in Pacific warfare, is the story of two Navy outfits that came, full fledged, from our secret councils of war. They were the CASUs and the Acorns. Until recently these units were on the hush-hush list, but our mounting success has released them from the shrouding blanket of security, and their story can at last be told. To understand, fully, the importance of these units, we must go back to the beginning of Naval aviation. World War II brought swift development of military aircraft. These aircraft, and the personnel handling them, were used in an excellent manner by the formation of squadrons which were composed of both the flight crews and ground men all in one large unit. For this period the arrangement was adequate for full efficiency. The squadrons were fairly mobile, and it was seldom necessary to move an entire unit from one airfield to another swiftly. With the advent of Naval aviation, the same thing held true. In the years from 1920 to the present war, squadrons were assigned to our few aircraft carriers, complete in all details. When it was not necessary for the squadrons to remain aboard ship, they picked up, bag and baggage, spare aircraft parts and material as well as personnel, and moved ashore to some Naval Air Station. There they maintained their regular flying routine dive bombing, gunnery, tactics, and the other training procedures until they were again required aboard their ships. While on the air station, they operated as a complete unit with all the necessary technicians required to maintain the aircraft in combat readiness. When the fast paced and swiftly moving war descended upon us in December 1941, squadrons in a complete unit, proved to be too immobile it became quite evident that the old system of squadron operation would not be feasible. Whenever the squadrons embarked, or when they disembarked, there entailed shifting large groups of men and tons upon tons of material needless waste of manpower and time. This also proved to be the case whenever an aircraft carrier made port for any length of time and when it was still necessary for the pilots to continue their flying to keep themselves and airplanes in top combat condition. Men and material had to be shifted from the ship to the air station to maintain these aircraft. The squadrons were cumbersome arrangements of aircraft and men, and something had to be done about it in a hurry. And as always, the Navy came through with the answer. Compact maintenance units were formed, called Carrier Aircraft Service Units (abbreviated to CASU) and Patrol Aircraft Service Units (abbreviated to PATSU). As the names imply, the CASUs were primarily for the purpose of maintaining carrier type of aircraft; the PATSU handled the maintenance of patrol type of aircraft, usually the large PBY Catalina flying boats and the Lockheed PV Venturas. Fundamentally the two units are the same, so hereafter only the CASU will be considered. The nucleus of the CASU is made up of all the aviation ratings of the Navy: Aviation Machinist's Mates, Aviation Machinist's Mates with special jobs and designations such as Propeller, Instrument, Carburetor, and Hydraulic; Aviation Radiomen, Aviation Radarmen, Aviation Radio Technicians, Aviation Electricians, Aviation Painters, Aviation Ordnancemen, Aviation Metalsmiths, as well as the usual General Service ratings necessary to all naval establishments such as Yeomen, Storekeepers, Machinist's Mates, Cooks, Bakers, et cetera. The officers, both Regular Navy and Naval Reserve, are specialists in aviation. The Commanding Officer is usually a designated Naval Aviator. In the case of the CASU, when it is set up on an air station or an island air strip and functioning, whenever an aircraft carrier's airplanes fly in for a few days operations, it is quite unnecessary for them to bring maintenance personnel with them the CASU handles all this. These compact units are able to be moved to outlying bases usually landing on the South Pacific islands shortly after the Japs have been driven off. Scuttlebutt has it that in one case they even went in with the Marines and it is easy to believe. To further streamline this phase of naval aircraft operations, the aircraft carriers themselves set up an air department sufficient in size to maintain the aircraft when they are onboard. This air department operates not unlike the manner in which the CASU operates ashore. The type of work performed by the various CASUs vary in a number as great as the number of CASUs themselves, each performing duties cognizant with the area in which they are operating. However, duties of the CASUs can be divided into three complete main groups the supply and maintenance of active combat squadrons, the supply and maintenance and training of squadrons heading overseas, and the setting up of an aircraft pool in the forward area from which actively operating combat squadrons and aircraft carriers may draw replacement aircraft to replace their losses in combat. For the first group, when they are set up and operating, the squadrons land on the field with only flight personnel. It is then up to the CASU to maintain the squadrons' aircraft in a complete flyable condition, performing regular periodic inspections called "checks" that are outlined for all Naval Aircraft by the Bureau of Aeronautics. This calls for a periodic check on all parts of the aircraft, including the structural members and all their component operating parts as well as the engine and all of its accessories such as its magneto, starter, generator, fuel and hydraulic pumps, spark plugs, and carburetor. Further, the accessories of the aircraft itself must have a thorough going over, and CASU personnel check radio and radar gear, guns, turrets, and ammunition. It takes many competent specialists to keep an aircraft in the air, and the CASUs have all types. The second group performs all the work of the first in keeping the squadrons' planes in the air, but in addition they also help the squadrons to form, and literally speaking, set them off on the right foot. When the squadron is formed on the CASUs field, the squadron complement is made up of both flight crews and ground crews. The CASU trains the groundmen in how to work together to keep the planes in good operating condition, and then sets the squadron loose to carry itself through the necessary training prior to its shipment overseas to the combat area. Then the CASU is again free to organize more squadrons. For the sake of clarity, it must be pointed out that when the squadron is formed it is made up of both flight crews and groundmen. When the squadron embarks onboard its aircraft carrier, the groundmen depart from the squadron and become integral with the ship's company, going into the air department of the ship. Thus the squadron is completely streamlined, possessing only its aircraft, pilots and aircrewmen. Now for the third group. Basically, it is the same as all the other CASUs. However, its primary function differs in that it maintains all types of the Navy's aircraft in large aircraft pools to use for replacements. Once in a great while they must maintain operating squadrons in addition to their primary duty, but still their main job is furnishing aircraft completely combat ready to the fleet. These aircraft are brought to the CASU's field, usually in or very near the forward combat area, by the smaller, or Jeep, aircraft carriers. The airplanes are completely "pickled," or preserved, in the United States or Pearl Harbor prior to their shipment. They are unloaded from the aircraft carriers onto large pontoon barges and ferried to the air strip, where the CASU takes over. Immediately the planes are sprayed and the preservative compound removed from all parts of the planes' engines and structures. Then the technicians take over. They check the aircraft from the propeller hub to the tail wheel, making repairs and replacements they find necessary. Ordnancemen check all guns, turrets, bomb racks and mechanism, and boresight the guns to the designated pattern. When these men are through, the test pilot takes over and runs the plane through a comprehensive test flight. Upon his return, a trouble-shooter crew immediately corrects any discrepancies noted by the pilot in flight and the ship is then turned into the pool, ready for issue to the next squadron or aircraft carrier that arrives needing that type of airplane. Once the airplanes are put in the "ready for issue" pool, a comprehensive system of operation is set up in order to maintain them in the very top operating condition. As all good mechanics know, an engine must be exercised to keep it in good condition. To do this, a system is usually set up in the CASUs where all engines are pulled through several revolutions at least once a day and are turned up, or run up, every other day. In the same train of thought, an aircraft itself, as with any other mechanical object, must also be exercised to maintain its top condition. To this end, the CASUs as well as any other Naval Aviation organization, fly their aircraft at least once a week. The CASUs have test pilots to do this and to run the preliminary test flight after the de-preserving process. When originally organized, the CASU was set up to handle carrier type of aircraft only, hence the name Carrier Aircraft Service Unit. However, in the forward areas the CASUs found themselves working on all types of aircraft, even working on some of the Army's fighters and bombers. Recently, the CASUs of the forward areas had their designations changed to Combat Aircraft Service Unit (F), the "F" standing for Forward. In the same shift, some of the PATSUs had their designations changed to CASU(F). In speaking of Naval Aviation, no mention of a CASU can ever be made without mentioning the CASU's big brother the Acorn. When first conceived, the CASU was a complete unit in itself in that it had all the men and material to completely set up an operating air station on some island in the forward combat area. This system proved itself very well, but many headaches arose in the execution of the duties of maintaining an airfield, setting up and maintaining living quarters and messing facilities, keeping all trucks, jeeps, and other rolling stock in operation. All this in addition to the upkeep and maintenance of aircraft on the air strip. Further, while the CASU's mobility proved itself to be far greater than the old squadron system, when it came to island hopping the CASU offered many of the old headaches encountered under the squadron system. The war had hardly more than gotten underway, when the idea of an Acorn was brought forward. Immediately Acorns were formed. They undertook the responsibility of setting up and maintaining the airfields on the scattered Pacific islands almost as fast as they were wrested from the hands of the Japanese. Further, they handle the supply-packaging, loading, and unloading of all the gear necessary for operation of the air strip as well as the aircraft parts necessary to repair the planes that will be based on the air strip. Thus the CASU was streamlined down to the point where the squadrons found themselves when their groundmen were taken away. Composed only of personnel Officers and men and hampered only by the carrying of their personal effects, the CASU found itself to be highly mobile, just what the Navy wanted when it started out. Island hopping proved to be very easy they could be on their way to a new station as fast as they could drop their tools. In the original forming in the United States, the CASU and the Acorn are formed together and train together. While the Acorn personnel are learning how to disembark and unload from ships and how to set up an advance base, the CASU is already operating from an air strip, letting the officers and men get the feel of working together before they are called upon to operate on an air strip under the very nose of the Japanese Navy. In addition, all personnel are given hand to hand combat training. There is no telling when such training will come in more than handy at their new base overseas. The men that come to the new CASUs come from all over the Navy. Some are drawn from the fleet, others are recent graduates of the Navy's many technical schools on specialized aviation subjects, while others are boots fresh from the training stations. Many, both officers and men, are well seasoned in the work in Naval Aviation enough of them to guarantee that each CASU will be a smooth running organization when it leaves the States. When the final day comes, the CASU and the Acorn are loaded usually on the same ship the Acorn with all the necessary gear or equipment to set up operation sand they head for their new base, which possibly at that very moment is being methodically taken away from the Japs. Upon arrival at their destination, the Sea Bees set to work building the air strip and setting up living quarters. A great many times the Sea Bees have already arrived and have the strip well underway or practically completed. In any case, the Acorn disembarks and proceeds to set up operations. Usually the CASU goes along to help in order to speed up the work because they will have no aircraft to work on until the air strip is completed. With their facilities set up and the field ready for aircraft, the first planes come in. Whether they come in as operating squadrons, or whether carriers come in and unload preserved aircraft depends of course upon what the primary function of that particular air strip and CASU may be. Sometimes the details in setting up operations on an air strip prove to be rough. Of course, none of the personnel expect to find a bed of roses at the end of their jaunt overseas, but sometimes they find more than they expected. To cite one particular instance, we'll line up with a CASU going overseas to a new base. While the number of this CASU cannot be given, it will have to be called just CASU "X". Completing its hand to hand combat indoctrination training period with flying colors, CASU "X" was embarked for overseas duty looking more like the Army's Commandos than a group of aviation technicians. Their period of training together on aircraft work had been cut short in the States, so they had been assured that they would learn all about a CASU in operation on an air strip at a base in a rear area, called a staging area. However, when this staging area was reached, they found that there was no room for them to operate there. Moving on up the line, they were deposited in the Admiralty Islands, which at that time was considered a forward area. Leaving the ship and coming on the beach, they discovered an island that had been so recently occupied by the enemy that it seemed to have a Japanese atmosphere. Trucks loaded with coral kept running back and forth the Sea Bees had already arrived and had the coral landing strip well underway. When shown the area in which they were to live, they made the grave discovery that the area was barren of anything but coconut trees and coral sand. Undaunted,, the CASU obtained tents from the Acorn and proceeded to set up camp. When all the shelters were up and the men had their gear stowed, it was very close to chow time. When the call of "When do we eat" made the rounds, the Supply Officer himself piped chow-down with a truck load of "K" rations. There was no mess hall or even a sign of one growing up among the palm trees. With their first "square" meal in the Admiralties over square, as in a box the CASU turned to with the Acorn in unloading supplies from the ships, and in the setting up of a more sturdy camp. Other men of the unit went to work with the Sea Bees in building the air strip. This was the choice job among the CASU personnel the Sea Bees had chow, real chow, and it wasn't dried up and in a box. With the air strip completed, the first aircraft arrived. The various departments had trouble lining up enough tools and equipment, but this they did quickly and the work began. First they handled a squadron of planes that a PATSU would have handled if a PATSU had been around Lockheed PV Ventures. It was new work for carrier plane trained boys but they came through very well. Then the aircraft descended upon the air strip by the hundreds. Fighters, bombers, torpedo planes they were all there. They came in with ferry pilots and they came in on Jeep carriers. De-preservation work began and the check crews became more than busy. The men finally got away from their stevedoring and construction work and back to the work that they liked best aircraft. Sometimes CASU "X" received rush orders for aircraft to be delivered to a certain aircraft carrier or squadron when only on that very day it had received the planes, all preserved, from a transport carrier. Then came long hours and fast work. They forgot what an eight, ten, or twelve hour work day was and found that work can be performed for twenty-four hours before another work day began. They had their job to do. and not only one time or two time did they do it by overwork, but many times. While CASH "X" was in full operation, its peak triumph was issuing completely combat ready two hundred airplanes in ten days. This operation included unloading the airplanes from the transport carrier, de-preserving, checking the plane, engine, and all accessories, cleaning and bore sighting all guns, making any repairs or replacement of damaged parts, test flying and correcting discrepancies after the flight, and then barging them out to the transport carrier for delivery to the fighting fleet. While this may not be a record, the people who performed the work feel that it comes very close to being one. Did someone mention flight orders? Yes, the CASU gets them too, for many times mechanics, radiomen, and ordinancemen must go along in flight. The Aircrewmen are nearly always flying, so they get theirs steady, every month. For the groundmen, the CASUs are allowed ten percent of their personnel to fly on technical jobs or as gunners. For those readers who don't know, flight orders are orders given to a man to fly by his commanding officer. This entitles him to fifty percent of his base pay extra in pay. While CASU "X" has been cited here as an individual unit and it is a very much alive unit its workings and accomplishments can easily be those of dozens of the CASUs in the forward areas. No doubt someone will come up with the charge that all of the details of the CASU in action have not been covered, and maybe he will be right but let us point out once more that the functions of the various Carrier Aircraft Service Units or Combat Aircraft Service Units, whichever the case may be, are as many as there are number of CASUs. In any case, every CASU that has gone overseas has proved to be a hard hitting, well organized outfit that knows what it is doing, how to do it and when. Above all, the Navy has come forth with a fast moving mobile. unit that can get things done and done fast. And that ability has been one of the most important factors in our victorious march across the Pacific.