NAVAL AVIATION
COMBAT STATISTICS

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NAVAL AVIATION COMBAT STATISTICS
WORLD WAR II

CONTENTS

NOTES ON SECURITY CLASSIFICATION (this is the lost to history page iv)

GENERAL INTRODUCTION

1. General Scope of Report
2. Data not Included
3. Scope of the Data
4. Sources and Methods

DEFINITIONS

COMPLETENESS OR ACCURACY OF DATA

1. In General
2. With Respect to Specific Items

TABULAR DATA AND TEXTUAL COMMENT

A. GENERAL DATA ON FLIGHTS, ACTION SORTIES, BOMB TONNAGE DROPPED, ENEMY AIRCRAFT DESTROYED, AND OWN AIRCRAFT LOSSES

1. General Summaries of Carrier and Land-Based Operations
2. Carrier Operations, General Data
3. Land-Based Operations, General Data

B. SPECIALIZED DATA, BY SUBJECT MATTER

1. Aerial Combat Data in Detail
2. Anti-Aircraft Loss and Damage
3. Attack Data, by Geographical Area
4. Attack Data, by Type of Target Attacked
5. Ordnance Data
    (a) Expenditures, General
    (b) Bomb and Torpedo Expenditures
    (c) Rocket and Ammunition Expenditures
6. Night Air Operations
    (a) Night Attack
    (b) Night Air Combat
7. Long Range Search Plane Operations

APPENDIX: JAPANESE SHIPPING SUNK BY NAVAL AIRCRAFT

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EVALUATION SECTION
AIR BRANCH

NAVAL AVIATION COMBAT STATISTICS, WORLD WAR II.

GENERAL INTRODUCTION

1. GENERAL SCOPE OF REPORT

This report contains air combat, attack, and combat operations statistics of Naval and Marine aviation during the war. It is designed as a basic reference document, compressing into one volume the most pertinent statistical data compiled in the IBM tabulation system maintained by Air Branch, ONI, and its predecessors, Air Intelligence Group, ONI, and Air Technical Analysis Division, DCNO(Air). Certain related data from other sources, compiled on statistical bases comparable to those used in the Op-23-V tabulation system, have been added.

The 60 statistical tables herein are supplemented by an interpretive text, tied closely to the data presented. In no sense is any attempt made in this text to present a connected narrative account of the war record of Naval aviation. The essence of the report is combat statistics, and the story is told solely as the statistics themselves may be led to tell it. The story told is also limited to the overall story, a perspective of Naval aviation and its many components as a whole, and data for individual ships, squadrons or other units are not provided.

2. DATA NOT INCLUDED

Not all the story of Naval aviation, which could be told in statistical terms, is covered in this report. The reasons for the omissions arise from the history and assigned functions of the statistical unit preparing the data, and from the lack of any integrated statistical organization covering all naval air operations. Postwar personnel shortages prevented this Branch from making good these deficiencies.

Naval air anti-submarine warfare is the first exclusion. This results from the establishment, many months prior to initiation of the general air combat statistical analysis program, of a special ASW statistical analysis unit, (directly under CominCh, and later under Tenth Fleet). To avoid duplication of a field well covered elsewhere, no records of air ASW activity were kept by this Branch or its predecessors.

The second principal exclusion is complete, detailed data on flights not involving actual action with the enemy (for search, reconnaissance, defensive, or other purposes), and losses sustained on such flights. This arose from (a) the prior existence of another office (Flight Statistics, DCNO(Air)) primarily concerned with data on non-action flights, (b) the primary importance of devoting the limited manpower and facilities available to the analysis of action statistics not compiled elsewhere and (c) a lack of complete, uniform and detailed incoming reports on non-action flights. This exclusion has been partly compensated by including in some tables herein data on total flights reported monthly (for 1944-45 only) by squadrons which were engaged in action during any month, and non-action losses by such squadrons during the entire war.

These items, however, do not give a full picture of the extent of naval air defensive or reconnaissance patrol activity or losses sustained therein. It is doubtful whether data exist which would permit a full and accurate statistical presentation of this activity.

A further exclusion is data on the operations of VO-VS aircraft. These operations were not regularly reported by the units involved, in a manner permitting their tabulation by the IBM card system.

The final major exclusion is data on losses of flying personnel. Losses as reported in action reports are not final, because of subsequent rescues, or return of captured airmen. Data on these is maintained by BuPers, but is not compiled and reported on a basis comparable with the aircraft loss data herein.

3. SCOPE OF THE DATA

Despite the exclusions listed, the bulk of Naval aviation's achievements, at least in the Pacific war, are covered by the data herein. Included are full data on all reported aerial combat, and all reported attacks on enemy targets other than submarines, by all Navy and Marine carrier and land-based aircraft. The following general categories of figures are provided:

Total Flights, by squadrons reporting action against the enemy

Action Sorties

Losses and damage from enemy action

Losses from operational causes

Own planes engaging enemy aircraft

Enemy aircraft engaged

Enemy aircraft destroyed, air and ground

Planes attacking targets

Bomb and torpedo expenditures on targets

Rocket expenditures

Ammunition expenditures.

And, with respect to each of the above items, one or more of the following cross-classifications of data are provided;

Carrier-based vs. land-based
Type of carrier
Navy vs. Marine
Theater of operation
Year, month
Carrier raid or campaign
Type or model of own aircraft
Type or model of enemy aircraft
Mission of own aircraft
Location of action, by general areas
Type of target attacked
Type of ordnance used
Night operations.

4. SOURCES AND METHODS

The method used in compiling these data deserves brief description. The basic source material for most actions was the squadron ACA-1 report for each mission, or the individual squadron or mission action report for actions prior to adoption of the ACA-1 form. Where no action reports were available, carrier battle narratives or squadron monthly war diaries were used. A check list of all carriers and squadrons in combat areas was maintained, and the war diaries of all such squadrons, and battle narratives of all such ships, were checked for possible actions in the event that no action reports had been received from any of these units.

The statistical items from these primary and secondary sources were then punched on IBM cards. The mechanical unit, for card-punching purposes, was the action of one squadron on one mission. From the file of these cards, numbering some 48,300 in all, have come most of the tabulations and cross-tabulations in this report. Additional supplementary files of summary cards, some 5,500 in number, prepared from the main card file, have also been used in preparing some of the tables.

Statistical tabulation was begun in early 1944, starting with the air operations of January 1944 and following with those of subsequent months in order. For 1944 operations a card system was used which required filling out not only one card covering each squadron on each mission, but also supplementary cards covering each separate engagement with enemy aircraft, and each separate attack on a major type of target, in addition to the primary engagement or attack participated in by the squadron.

This system was eventually found unwieldy for handling the large-scale operations of late 1944, and beginning with the operations of January 1945 a simplified card system was used in which all engagements and attacks by one squadron on one mission were covered on one card. The change of card coding systems resulted in some lack of comparability between 1944 and 1945 statistics (discussed in connection with individual items under appropriate headings hereafter), and in an inability to secure certain breakdowns of data for one year or the other. This will explain the limitation of some tables to 1944 only, or 1945 only.

Because of time and personnel limitations, 1942-43 actions were not placed on machine cards until after the end of the war, and the simplified 1945 coding system was therefore used for these years.

Of the data appearing in the tables, all were taken from the IBM cards except the following, whose origin is described briefly:

(a) Aircraft on hand, and total flights, for squadrons in action:

These figures, on a monthly basis, were obtained from Flight Statistics Section, DCNO(Air), from the monthly report of each squadron which reported engaging in action against the enemy (other than ASW) during the month. Data were not obtained for squadrons which reported no action during a given month, even if they were in action during the preceding or following month and were known to have been in an active area. Thus these figures are not complete records of plane strength, patrols or other flights in war areas, but are, as the name implies, figures for squadrons in action, directly comparable with the action data on a squadron basis. Where number of flights was not reported, or was obviously incorrect as reported, an estimate was made, based on the performance of comparable units, and the squadron’s combat activity. Where number of planes reported on hand differed excessively from normal strength and was also out of line with the number of flights and action sorties reported, normal complement was substituted. These figures are given for 1944-45 only, as they were not available on a monthly basis for earlier years.

(b) Losses on other (non-action) flights, and losses on ship or ground:

These figures were obtained from Aircraft Records Section, DCNO(Air), and also cover, on a monthly basis, only squadrons reporting action during the month of the loss. Thus they would not cover losses on negative patrols by units flying no action sorties, nor even losses on the ground or ship to enemy action if the planes were not assigned to a squadron reporting action during the month.

(c) Number of Carriers in Action; Carrier Complement:

The number of carriers in action was taken from action reports. Carrier complement is based on the apparent normal number of planes carried at the beginning of the month’s operations by carriers of each class.

(d) Enemy Aircraft Destroyed on Ground:

In the case of planes destroyed on ground by carrier-based aircraft, the final evaluations of the carrier task force commanders were used in lieu of the claims advanced in squadron action reports. Squadron claims have been used, however, for grounded planes destroyed by our land-based aircraft, in view of the small numbers involved, and the general lack of final evaluations. (Squadron claims have been used consistently for enemy aircraft destroyed in air combat, since in few instances have higher commands reduced these claims).

All statistical data, except the types listed in (a) to (d) above, have come from the basic sources previously listed.

DEFINITIONS

NUMBER OF PLANES ON HAND Number of aircraft reported assigned to a unit during a month in which that unit reported having action against the enemy (other than ASW). Data have been checked for erroneous reporting and adjustments made on basis of normal complement and volume of operations. Not presented for months prior to January 1944.

CARRIER COMPLEMENT Number of aircraft normally carried by carrier of the class at beginning of the operations in question.

NUMBER OF CARRIERS IN ACTION Total number whose aircraft engaged in action against the enemy (other than ASW) at any time during the period in question.

FLIGHTS SQUADRONS IN ACTION Number of flights, for all purposes including combat and attack, reported for a calendar month by a squadron reporting action against the enemy (other than ASW) during the same month. Data have been checked for erroneous reporting and failure to report and adjustments made. Not available on monthly basis prior to January 1944.

ACTION SORTIES Number of planes taking off on a mission which eventuated in an attack on an enemy target or in aerial combat, or both. This basis of tabulation was the number of planes of one squadron taking off on the mission. If any of these planes had action, the entire squadrons’s planes on the mission were counted as action sorties, including abortive planes, planes which reached the target but did not attack, and planes which escorted or patrolled but did not engage in combat. Thus if 16 VF took off as escort, 2 returned early, 2 engaged in combat, and 4 strafed, all 16 were counted as action sorties. Likewise if 8 planes took off for CAP, and only 2 engaged in combat, all 8 were action sorties. On the other hand, if 8 VF took off for escort, and none engaged in any sort of attack or combat, then none were counted as action sorties, even though they reached the target, and even though the escorted bombers attacked the target. Likewise, CAP planes missions, none of whose planes engaged in combat were not counted as action sorties.

LOSSES OF OWN AIRCRAFT Loss data have come primarily from two sources: (1) action reports, squadron and ship, covering losses from all causes on missions involving actual combat with the enemy, and (2) loss reports, covering losses from all causes whatsoever.

The losses on action sorties reported herein have been taken primarily from action reports, in which the exact 'cause of loss can be determined more accurately. Two major exceptions to this practice may be noted; (a) losses on unreported or poorly reported combat missions have been added from loss report sources; these may sometimes be inflated, because of a tendency in the early loss reports to ascribe to "combat" or "enemy aircraft" losses whose cause was unknown; (b) aircraft listed in action reports as seriously damaged rather than lost, and later indicated in loss reports to have been scrapped or jettisoned because of this damage; these have been added as losses on action sorties.

Losses other than on action sorties have been taken from the loss reports, with some confirmation from carrier and squadron reports. The accuracy of loss reports, particularly with respect to cause of loss and date of loss, is frequently debatable, and many adjustments have been made where indicated.

LOSSES ON ACTION SORTIES Includes all planes counted as action sorties, which failed to return to a friendly base or were destroyed in landing at base, plus planes returning and later destroyed because of damage sustained during the mission, plus planes lost on unreported missions which apparently involved action with the enemy. All losses on action sorties have been classified by cause under the three categories; Enemy A/A, Enemy A/C, and Operational. Where the exact cause was not given in the action report (planes reported missing) the cause most likely under the circumstances of loss described was arbitrarily assigned, or if the circumstances were not stated, the cause stated in the loss report was assigned.

Losses on Other Flights These are limited to losses, during each month, of planes assigned to squadrons which reported engaging in action against the enemy during that month. For these squadrons these figures represent all operational losses of airborne planes, on missions not involving action against the enemy; they include also planes later stricken because of operational damage sustained on such flights.

Losses on Ship or Ground These figures are also limited to losses, during each month, by squadrons reporting action during the same month. For these squadrons they included all losses, regardless of cause, of planes not airborne at the time of the loss, or at the time the damage was sustained that ultimately resulted in the loss of the plane. Principal causes of these losses included: Struck by aircraft landing, taking off or taxiing, or by automotive vehicles; explosions and fires; storms, typhoons; enemy bombing or strafing or suicide attacks on carriers; own gunfire. It should be noted that all losses of grounded aircraft to enemy action are not included (some such losses were of aircraft assigned to pools or to squadrons not in action), nor is the greater part of the listed losses on ship or ground attributable to enemy action. The carrier losses in this category, however, do include all carrier planes lost in enemy attacks on carriers.

It should be noted, in connection with all categories of loss, that the figures for carriers represent all losses in active carrier combat operations (excluding strictly patrol and escort operations) in Pacific combat areas, while the land-based figures represent the bulk of, but not all, the losses of squadrons in active combat areas.

DAMAGE BY ENEMY A/A AND ENEMY A/C Planes receiving major and minor damage from the causes stated, as reported in squadron action reports only.

OWN PLANES ENGAGING ENEMY AIRCRAFT Number of airborne aircraft firing guns at, or fired at by, airborne enemy aircrafts In fact, probably a number of planes are included which do not meet this definition, but were in flights, or in sections or divisions of flights, of which other planes did fire guns or were fired at. Also, reports for many early actions did not specify the actual number of planes engaging in combat by any definition, and it was frequently necessary to make arbitrary assumptions based on own and enemy losses in the engagement. On the whole, however, these figures reflect with fair accuracy the number of aircraft engaging in and/or exposed to action with enemy aircraft.

ENEMY AIRCRAFT ENGAGED In general, this figure tends to approximate the number of enemy aircraft observed in formations which were actively engaged in aerial combat. An attempt has been made to exclude formations or parts of formations which were not actively engaged by the reporting squadron, but frequently the action reports were so vague with respect to the number of enemy planes actually engaged that it was necessary to use the total number of enemy planes observed in the area, or to adopt an arbitrary figure based on the number shot down.

It should also be noted that the figures on enemy planes engaged were compiled on a squadron basis. In engagements involving two or more of our squadrons at one time and place it is therefore likely that the same enemy formations may have been reported as engaged by each of the squadrons. Thus from the viewpoint of our mission as a whole, the number of enemy planes engaged is inflated by duplication. On the other hand, from the viewpoint of the number of individual plane-to-plane engagements, the figures on enemy planes engaged probably represent an understatement.

It should be noted that data on number of enemy planes engaged are inherently the least accurate of any data in this report, because of the natural inaccuracy of aerial observation; estimates of the size of enemy formations may vary by 50 percent or more depending on the observer and the circumstances.

TYPES OF ENEMY AIRCRAFT ENGAGED AND DESTROYED:

BOMBERS Includes identified types of single-engine and twin-engine bombers; all unidentified twin-engine aircraft; flying boats; and for 1942, 1943 and 1945 only, transports. Approximately 90% of the total consists of identified single-engine and twin-engine bombers, though the proportion varies from period to period.

FIGHTERS (More properly entitled "Fighters and other types") includes identified types of single-engine and twin-engine fighters; all unidentified single-engine aircraft, all float planes; all trainers; and for 1944 only, transports. Approximately 90% of the total consists of planes identified as single-engine fighters, though the proportion may vary from operation to operation.

It may be noted that identification was frequently deficient, many instances having been noted of Japanese Army planes reported in exclusively Navy theaters, of confusion between dive bombers and fighters, and between various models of single-engine fighters, and twin-engine fighters and bombers.

ENEMY AIRCRAFT DESTROYED IN COMBAT Airborne enemy aircraft claimed destroyed by naval aircraft, in aerial combat only. Planes destroyed by own anti-aircraft fire or in suicide crashes are not included. Enemy aircraft reported as "probably destroyed" are not included. Squadron claims, as made in ACA-1 or other action reports, are the basis for these figures. They thus represent the evaluations only of the squadron intelligence officer, squadron commander, and in some cases the air group commander. However, rarely was there any further evaluation by higher authority of squadron claims with respect to airborne enemy aircraft.

In evaluating pilot claims for ACA-1 reports squadron intelligence officers were instructed to follow the definitions of "destroyed" established for the command or theater. Subsequent to early 1944 this was the standard Army-Navy definition that the plane must be seen to crash, disintegrate in the air, be enveloped in flames, descend on friendly territory, or that its pilot and entire crew be seen to bail out. Prior to this time the definitions varied between commands, but the definitions used in the principal naval theater (SoPac) were at least equally stringent.

The degree to which squadron intelligence officers and commanders succeeded in eliminating duplicating and optimistic pilot claims is not known, but it is believed the amount of overstatement is relatively low. Since 93% of all enemy aircraft claimed destroyed by Naval aircraft were claimed by single-seat fighters and the bulk of the remainder were claimed by two-place dive bombers and by lone search planes, the tremendous duplication of gunners’ claims experienced by air forces operating large formations of heavy bombers with multiple gun positions is largely eliminated. Duplication of claims between fighter planes can be more easily controlled by careful interrogation.

Over-optimism has always been difficult to control. During the early part of the war, before standard definitions were in force, before full-time trained Air Intelligence Officers were available to apply them, and before the need for conservative operational intelligence was fully appreciated, action reports may often have overstated enemy losses. Evidence from the Japanese has tended to indicate that in some of the early actions, and even as late as the Rabaul raids of early 1944, there was such overstatement.

It must be remembered, however, that the bulk of Naval aerial engagements in the Pacific did not involve the mass combat of Europe. Even the large-size engagements seldom involved more than 30 of our planes against 30 of the enemy’s at any one time within visible range of any one point. By far the greatest number of engagements involved only 1 to 8 of our planes, or the same number of the enemy's. Thus in the main the claims under this heading, offset as they are by the exclusion of planes classified as "probably destroyed", are believed to be near the truth, with only local exceptions, and to be as conservative as those of any major airforce.

ENEMY AIRCRAFT DESTROYED ON GROUND In the case of carrier operations, these figures represent the number of non-airborne enemy aircraft reported by the task force commander as destroyed on ground or water, or on enemy carriers. These figures were normally based largely on photographic assessment, and only planes visibly burned out or obviously unrepairable were included unless there was other positive evidence to warrant their classification as destroyed.- Assessment was on a field-by-field basis, eliminating duplication of squadron claims. For small-scale early operations, where no report was available from the task force commander, an estimate was made by Op-23-V-3, based on all available squadron and ship action reports, eliminating duplication of claims. For land-based operations, in view of the small volume involved, the claims in action reports were used.

TONS OF BOMBS ON TARGETS Calculated for each mission by taking the number of bombs of each type (plus clusters, torpedoes and mines) expended on targets, multiplying by the nominal weight of each, and rounding the total to the nearest ton. Bombs jettisoned are not included, nor bombs in abortive planes, nor bombs hanging up, nor rockets fired. In the case of search planes, particularly PB4Ys on single-plane long-range searches, tonnage dropped is understated by these figures, because of the large number of missions wherein less than 1/2 ton was dropped per mission, the tonnage being rounded down to zero in the figures. For 1945 this difference is approximately 120 tons for PB4Ys, and less for other types of VPB. For other types of planes there may be small differences in either direction, due to this rounding of tonnages.

THEATER OF OPERATIONS For operations by land-based Naval and Marine aircraft, the breakdown by theater of operations (Tables 4 and 18) is based on the area command under which the operations were conducted. Thus operations by planes based in the South Pacific Area were included under that area even though they attacked targets in the Southwest or Central Pacific. The official limits of each command were used throughout, except that actions in the first few months of the war, before establishment of the area commands, were distributed on the basis of the commands subsequently established.

The method of assigning carrier operations to areas is explained in the text referring to Table 4.

AREA (GEOGRAPHICAL) OF TARGET OR ENGAGEMENT Each geographical area includes not only the land areas covered by its name, but all coastal waters. Engagements and shipping attacks far at sea were allocated to the nearest area. Most area names are believed self-explanatory, but the following additional explanations are given:

PURPOSE OF MISSION OF OWN AIRCRAFT Assigned primary mission of aircraft at time of takeoff, regardless of later changes. Thus a search mission which finds and attacks shipping is classified as a search mission, a fighter sweep diverted to defense of force is still an attack mission. Note that in this report only action sorties - planes in actual action against the enemy - are classified by purpose of mission, and the large volume of negative patrols and searches, as well as the small volume of abortive offensive aircraft, are not included in the data. Classifications by purpose of mission differed in the 1944 machine tabulations from those for other years, and additional detail is thus provided for 1944, not available for other years.

BASE OF OWN AIRCRAFT The base is that from which the planes operated on the mission in question, thus carrier aircraft temporarily operating from land bases are classified as land-based.

PLANE MODEL OF OWN AIRCRAFT Because of lack of detail in many action reports and limitations in the IBM system it has not been possible to distinguish between modifications or different manufacturers of the same basic aircraft. Thus "F4U" in the tables may include F4U and FG aircraft of all modifications, "F6F” will include the -3, -5, -3N and -5N, "TBF" or "TBM" may include modifications of either or both. However, the F4F and the FM-2 have been distinguished throughout.

SORTIES ATTACKING TARGETS There are two definitions for this item, one for 1944, and one for other years , because of the differing methods used in preparing IBM machine cards.

1942, 1943, 1945 Each plane attacking targets is counted only once per mission, regardless of how many targets it attacked successively, with bombs, rockets or guns.

1944 Each plane attacking targets is counted once for each major type of target attacked with bombs, rockets or guns. This permits one plane to be counted as making two or more attacks on one mission. The number of "sorties attacking targets" as reported on this basis for 1944, is believed on the average to be about 15% greater than if recorded on the 1945 basis.

Note that "sorties attacking targets" differs from "action sorties" in all years, by excluding planes taking off which did not individually attack targets.

ROCKETS ON TARGETS Number of aircraft rockets (of all sizes) expended on targets by planes attacking targets, as defined above.

AMMUNITION EXPENDITURES For 1944 these figures represent expenditures on enemy targets, by planes attacking targets, and expenditures in aerial combat are excluded. For 1943 and 1945 the figures represent total expenditures on targets and in aerial combat. Because of a general failure to report rounds expended prior to late 1943, ammunition expenditures for 1942 and early 1943 are not given herein.

TARGET TYPE CLASSIFICATION Two moderately diverse systems of classifying the types of targets attacked have been used in compiling these statistics, one for 1944, the other for the remainder of the war. These differences, combined with the varying methods of counting sorties attacking targets, require some discussion as to their effect on the statistics.

For 1944, as has been noted, planes attacking targets were counted once for each major type of target attacked on the same mission. In carrying out this tabulating procedure the exact number of planes making primary or secondary attacks on a target was allocated to that precise type of target. Thus if from one 8 plane fighter mission 6 planes bombed a destroyer, 2 bombed a large tanker, and 4 in addition strafed small fishing craft, the statistics on the 1944 basis would show 6, 2 and 4 planes attacking unarmored warships, large merchant vessels, and small merchant vessels, respectively, and the ordnance expended would be distributed accordingly.

The simplified tabulating system adopted for 1945, and carried back to 1942 and 1943, provided for counting only once per mission each plane attacking targets, and for assigning only one target per squadron per mission. The target classification assigned was that receiving the greatest weight of attack. Thus the example above, if included in 1945 statistics, would show 8 sorties, and all ordnance, expended on unarmored warships.

The 1944 system undoubtedly provided much greater statistical precision, but involved an inordinate amount of labor in tabulation. There is some question whether, in the end, the precision was much greater than in the 1945 system, because: (a) the number of missions splitting targets, while substantial, is not a large proportion of the total, and (b) over a number of missions the errors may well cancel, e.g. a target type which is secondary on one split mission becomes primary on another split mission.

A rough estimate of the relative statistical effects of the two systems is as follows: the 1944 system, by giving full weight as attack sorties to secondary strafing and rocket runs on the types of targets normally attacked on such runs over-emphasized the weight of attack on such targets; the 1945 system, ignoring those types of targets which seldom receive the major weight of attack, under-emphasizes the amount of effort expended on them. The principal type of target affected is undoubtedly small shipping under attack by carrier aircraft; there is probably a major effect in the case of minor military targets but this is small when compared to the total weight of attack on military targets; there is probably a minor effect on the "harbor areas" and "land transportation" target classifications. On the whole, it is not believed that these factors unduly distort the overall picture of the proportion of the Naval air offensive expended against the various classes of enemy targets.

Major differences in classification of specific items between 1944 and the other years may be briefly noted as follows:

(1) The 1945 classification "Airfields" includes parked aircraft, runways, hangars and other airfield buildings, and all airfield defenses. The 1944 figures for airfields probably exclude most, but not all attacks on airfield buildings, but include all the other target sub-types listed. (The 1944 attacks on "airfield runways" undoubtedly include some attacks on buildings and guns also). Airfield buildings not included under airfields for 1944 are covered under "Other Military Targets".

(2) "Harbor Areas" for 1945 includes waterfront A/A defenses. For 1944 some of these may be included in "Other Military Targets".

COMPLETENESS OR ACCURACY OF DATA

1. Completeness and Accuracy In General

Accuracy of Machine Tabulation: All general tables, and special tables of aerial combat and anti-aircraft data (Tables 1 - 29 inclusive) have been cross-checked to assure complete internal consistency within each table and between tables, except as specifically noted in individual cases.

All tables containing breakdowns by type of target, by geographical area, and by type of ordnance, have been checked to insure that no significant discrepancies are present. In the case of these tables the complications of machine tabulation have made a certain number of minor discrepancies inevitable; these were considered not to warrant expenditure of the inordinate amount of time required to correct them, since none can have any effect on conclusions to be drawn from the data.

For data on night operations no master check data were available. Spot checks were made, and the totals and breakdowns appear to be generally reliable.

Accuracy of Compilation: Human error, when thousands of coding cards are prepared from action reports of variable and confused patterns by personnel of clerical grade, is inevitable. The most thorough preparation of definitions and instructions, and constant supervision, do not eliminate the need for constant exercise of judgment by such personnel, when reducing to simple statistics an operation as complex as an action by Naval aircraft bombing, rocketing and strafing a multiplicity of targets and engaging in aerial combat. To this inherent difficulty the lack of uniform report forms during the first half of the war, and the lack of uniform quality of reports in the last half, contributed. However, every possible source of error has been either (a) anticipated and provided against, (b) checked and corrected, (c) checked and the data eliminated as not susceptible to accurate compilation, or (d) checked and presented with footnotes and reservations as expressed hereafter. It is the opinion of those responsible for this compilation that the data contain no significant biases resulting from the statistical compilation methods used, which are not fully noted in connection with the items affected.

Accuracy of Reporting: It is axiomatic that observations made in the heat of fast-moving air action are subject to a large margin of error. It is also well known to those who have participated in carrier operations, and in land-based operations under the front-line conditions which have prevailed in such areas as the Solomons and Okinawa, that the obstacles in the way of full interrogation of pilots, evaluation of the data received, and preparation of thorough action reports, have been extreme. The data herein suffer much more from the latter factor than from the basic difficulty of inaccurate observation, since the bulk of the statistical items do not depend upon aerial observation.

Accuracy of observation enters into only two major items in these tables; enemy aircraft engaged and enemy aircraft destroyed in combat, and the second of these has generally been the subject of the most careful interrogation and evaluation prior to reporting. The inability of the intelligence officer to perform his duties at an optimum quality level may affect a larger number of items, particularly those concerning attacks on targets; the number of planes actually attacking each target, and the number and type ordnance actually expended on each. The effect of these deficiencies on the statistics herein cannot be measured; items wherein it was believed to be large have been eliminated from the tabulations, and in the remaining items it is believed to be moderate, subject to a few specific exceptions described under individual items.

Completeness of Reporting: So far as is known, all carrier air action against the enemy during the entire war is completely covered herein. It is believed that 98% or more of every category of action by land-based planes is covered for the period from the latter months of 1943 to the end of the war. For the period from 7 December 1941 to mid-1943 it is known that a substantial amount of action by land-based planes has not been covered by the reports available, and is thus not included. The amount excluded is not believed to exceed 10% of the total reported for this period. Practically all of this deficiency was in the Solomons area.

For 1942 and 1943 particularly, and to a limited extent in later years, data were not always available to indicate whether escort fighters on a given mission strafed or were fired at by enemy A/A. Where no information was available it was assumed that escort fighters did not meet the definition for action sorties. Thus the number of fighter action sorties, and fighter sorties attacking targets, may be understated for the early part of the war. It should be noted that the number of fighter sorties attacking targets (and offensive filter action sorties), as reported herein will in all years be less than the number of fighters over target (a figure not compiled), by the number of escort fighters not actually attacking or engaging the enemy. The difference became progressively smaller in 1944 and 1945, however, as the increased ratio of filters to bombers, the emphasis on strafing of parked aircraft and A/A guns, and the installation of bomb racks and rocket launchers on VF, resulted in attacks by a larger proportion of the fighters reaching a target area.

2. Accuracy and Completeness with Respect to Specific Items

(Items not mentioned have no specific individual deficiencies, but are subject to the general qualifications above).

Planes on Hand, and Flights: Original data have been arbitrarily edited to remove obvious errors; see discussion under Definitions. Items are subject to inaccuracy in reporting, but no particular bias is suspected.

Action Sorties: Subject to incomplete reporting (for land-based units only), and undercounting of fighters over target, as noted above.

Own Aircraft Losses: Losses to enemy aircraft are probably overstated by up to 25% for 1942-43 because of the lack of an adequate system for reporting cause of loss accurately. Operational losses are probably understated, but to a lesser amount, the difference being chargeable to losses on ground. This item is not affected by incompleteness of action reports, because of the check available in the independent strike reports.

Own Aircraft Engaging in Air Combat: Probably slightly understated for 1942-43, because of failure of action reports to specify exact number engaging, and slightly overstated thereafter because of inclusion of entire flight in some cases where only a part actually engaged.

Enemy Aircraft Engaged: Overstated throughout. See discussion under Definitions.

Enemy Aircraft Destroyed: See discussion under Definitions. Also, slight understatement for 1942-43 (land-based only) because of incomplete reporting.

Bomb Tonnage on Targets: Believed slightly understated for 1942-43, because of incomplete reporting (land-based only), and failure to report full bomb load in some instances (carrier-based and land-based). Affected somewhat by rounding bomb tonnage per mission to nearest ton; see discussion under Definitions.

No. of Squadrons in Action: Affected in 1942—43 by failure of some land-based squadrons to report action.

Sorties Attacking Targets: Affected by incomplete reporting, by inadequate reports (especially VF, see above), and by difference between 1944 and 1942-43-45 coding systems (see discussion under Definitions). Note that, even for 1944, and increasingly for other years, the total number of sorties attacking targets is greater than the number attacking either with bombs, or with rockets, or strafing, considered separately, because included in the figure are sorties which attacked with only one of these three types of attack, as well as sorties combining two or three methods.

Rocket Expenditures: Subject to some under-reporting, particularly by CV fighter squadrons in late 1944 and early 1945, and to considerable carelessness in the reports of some squadrons.

Ammunition Expenditures: Not shown for period prior to late 1943 because of almost total failure to report this item. Believed partially incomplete for late 1943 and first half of 1944, for land-based VSB and VTB operating in the Solomons. A tendency to report expenditures on an arbitrary basis, such as 1000 rounds per plane per mission, has been observed in the case of some fighter squadrons, and it is certain that for a large proportion of the action reports the ammunition expenditure figures were the roughest of estimates. To what extent this may bias the overall figures or figures for any single plane model, it is impossible to say, but it is doubted that the error is in excess of 25% low or high.

Own Planes Damaged by A/A or Enemy A/C: These figures are probably considerably understated for many 1942-43 actions, and slightly understated for 1944-45, because of failure to report all instances of minor damage, and damage inflicted by one of these agents to planes lost from another cause.

Purpose of Mission: Subject to personnel error in coding. The only probable general bias would be to favor an offensive classification at the expense of reconnaissance, but the extent of this would be small. It should be noted that defensive and reconnaissance missions are included in these tables only if they actually engage or attack the enemy, and thus are considerably understated from the point of view of total missions flown.

Type of Target: Subject to errors of classification in coding, and to systematic errors resulting from the two coding systems used (see discussion under Definitions). The net effects of these factors are approximately as follows:

1944: An overstatement of attack activity in comparison with other years, but a relatively accurate distribution of attacks, bombs and rockets by target type. Ammunition, usually arbitrarily distributed by the coding clerk between the several targets on a mission, is subject to considerable error, but the direction of the bias, if there is any general bias, cannot be estimated.

1942-43-45: A general bias in favor of large assigned primary targets attacked in force by the majority of a mission’s planes, at the expense of small secondary targets attacked by one or two of the mission’s planes or on second runs over target. The net effect is probably to understate the amount of attacks, bombs, rockets and ammunition expended on small merchant vessels, on land transportation targets, and on harbor areas, and to overstate expenditures on large vessels, airfields, and military targets.

Type of Bomb: This item was subject to coding errors, which have been largely detected and corrected. However, instances of inadequate reporting may also have resulted in slight errors as to size and type of bomb, and number expended on target, but not sufficiently to affect the general validity of the figures.

Models of Enemy Aircraft Destroyed: Subject to a major degree to mis-identification by pilots, and presented only as a matter of general interest, and as reliable only with respect to the major type classifications (fighters, bombers, float planes, etc.).

– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –

PART A.
GENERAL DATA ON FLIGHTS, ACTION SORTIES, BOMB TONNAGE DROPPED, ENEMY AIRCRAFT DESTROYED, AND OWN AIRCRAFT LOSSES

The tables in this section of the report (Tables 1-18) provide a broad overall picture of Naval and Marine air operations as a whole. There are three general subdivisions in this section:

1. General summaries of both carrier and land-based air operations, including breakdowns between carrier and land-based, between Navy and Marine, by plane model, by theater, and by months. (Tables 1-7).

2. General data on carrier operations, including breakdowns by plane model and by type of carrier, by operations, by areas, and by months, plus special tabular analyses of carrier operating ratios during various periods. (Tables 8-15).

3. General data on land-based air operations, including data broken down between Navy and Marine, by plane model, by theater, and by months. (Tables 16-18).

In general the tables will be allowed to tell their own story, but for each table or group of related tables a narrative commentary will call attention to significant items or relationships, and note any special qualifications applying to the data-presented.

1. General Summaries of Carrier and Land-Based Operations

TABLE 1. CONSOLIDATED SUMMARY OF NAVY AND MARINE CARRIER AND LAND-BASED AIR OPERATIONS AND RESULTS FOR ENTIRE WAR – By Model of Aircraft Employed

TABLE 2. SUMMARY OF AIR OPERATIONS AND RESULTS, FOR ENTIRE WAR – By Type and Model of Aircraft (Land and Carrier, Navy and Marine Combined)

TABLE 3. SUMMARY OF MONTHLY OPERATIONS AND RESULTS FOR ALL CARRIER-BASED AND ALL LAND-BASED NAVAL AND MARINE AIRCRAFT

TABLE 4. COMBAT AIR OPERATIONS AND RESULTS, CARRIER-BASED AND LAND-BASED, BY THEATRE AND BY YEAR.

TABLE 5. NUMBER OF SQUADRONS IN ACTION, AND ACTION SORTIES FLOWN, MONTHLY – By Model of Aircraft

TABLE 6. ACTION SORTIES, BY PURPOSE OF MISSION – By Plane Type, Carrier-Based, and. Land-Based, by Years.

TABLE 7. ACTION SORTIES, BY DETAILED PURPOSE AND OBJECTIVE OF MISSION, 1944 ONLY – By Type of Aircraft, Carrier-Based, and Land-Based

2. Carrier Operations, General Data

TABLE 8. SUMMARY OF CARRIER AIR OPERATIONS AND RESULTS FOR ENTIRE WAR, – By Type of Carrier, by Plane Model, and by Service (Navy-Marine)

TABLE 9. LOSSES, LOSS RATES, AND OPERATIONAL DATA, CARRIER-BASED NAVAL AND MARINE AIRCRAFT, PACIFIC ONLY, 1944-1945 ONLY – By Carrier Type, Plane Model, and Service (Navy-Marine)

TABLE 10. SUMMARY OF CARRIER AIR OPERATIONS AND RESULTS, MONTHLY

TABLE 11. ANALYSIS OF CARRIER AIR OPERATIONS DATA, FOR SUCCESSIVE PERIODS IN 1944-45 (PACIFIC ONLY) – By Type Carrier and by Model Aircraft

TABLE 12. CARRIER AIR OPERATIONS DATA AND OPERATING RATIOS, – By Type of Carrier, Monthly from August 1943 to August 1945, Pacific Only.

TABLE 13. CARRIER AIR OPERATIONS DATA AND OPERATING RATIOS, – By Type of Carrier and by Model of Aircraft, for Selected Months of Major Operations (Pacific Only)

TABLE 14. AIR OPERATIONS AND RESULTS, FOR INDIVIDUAL CARRIER OPERATIONS AND PHASES THEREOF.

TABLE 15. MARINE CARRIER AIR OPERATIONS AND RESULTS, 1945 – Monthly, By Model of Aircraft and Type of Carrier

3. Land-Based Operations, General Data

TABLE 16. LOSSES, LOSS RATES, AND OPERATIONAL DATA, LAND-BASED NAVAL AND MARINE AIRCRAFT, PACIFIC ONLY, 1944 - 1945 ONLY, – By Service (Navy-Marine) and Plane Model

TABLE 17. MONTHLY OPERATIONS AND RESULTS, FOR LAND-BASED AIRCRAFT, – By Type of Aircraft and by Service (Navy-Marine), Pacific Only

TABLE 18. CONDENSED MONTHLY DATA ON OPERATIONS AND RESULTS, NAVAL AND MARINE LAND-BASED AIRCRAFT – By Operational Theatre and by Type of Aircraft

PART B.
SPECIALIZED DATA, BY SUBJECT MATTER

This section of the report is composed of six sub-sections covering specific types of data, as follows:

1. Detailed Data on Aerial Combat, by both Carrier-Based and Land-Based Aircraft, including loss rates and combat ratios. Breakdowns are provided for Navy vs. Marine, and by plane model, type of carrier, year, month, area, and mission of own aircraft. Data on models of enemy aircraft destroyed are also included. (Tables 19-28).

2. Anti-Aircraft Loss and Damage, and Loss Rates, with breakdown by plane model, carrier and land-based, yearly. (Table 29).

3. Attacks on Targets, by Geographical Area. Detailed breakdowns of attacks on targets, and total bomb tonnages expended on target, monthly and yearly, by area, and broken down between land and ship targets, with special emphasis on shipping targets. (Tables 30-35).

4. Attacks on Targets, by Type of Target Attacked. Attack sorties and bomb tonnage, for carrier-based and land-based aircraft, yearly, by plane model attacking, and monthly detail on shipping attacks. (Table 36-40).

5. Details of Ordnance Expenditures. Types of bombs used, and torpedo, rocket and ammunition expenditures, broken down by plane type, by type of target, yearly and monthly and by operation. (Tables 41-54).

6. Night Air Operations. Data on night attacks and aerial combat, for carrier-based and land-based aircraft, monthly and by plane model. (Tables 55-59).

7. Long Range Search Plane Combat Operations, 1945. Detailed data on PB4Y and PBM performance. (Tables 60-61).

* * *

1. Aerial Combat Data in Detail (Own and Enemy Planes Engaged and Destroyed; Loss Rates and Combat Ratios)

TABLE 19. AERIAL COMBAT DATA, FOR ENTIRE WAR – By Model of Aircraft, Carrier-Based and Land-Based, and for own VF, by Type of Carrier and by Service (Navy-Marine)

TABLE 20. AERIAL COMBAT DATA, BY YEARS – By Model of Aircraft, Carrier-Based and Land-Based, (Principal plane models only)

TABLE 21. AERIAL COMBAT RATIOS, BY YEARS – By Type of Aircraft, Carrier-Based and Land-Based

TABLE 22. AERIAL COMBAT DATA, MONTHLY

TABLE 23. OWN SORTIES AND LOSSES, AND COMBAT WITH ENEMY AIRCRAFT, BY MISSION OF OWN AIRCRAFT – By Type of Aircraft, Carrier-Based and Land-Based, for Entire War.

TABLE 24. ENEMY AIRCRAFT DESTROYED IN AERIAL COMBAT BY ALL NAVAL AND MARINE AIRCRAFT – By Base, Mission, and Type of Own Aircraft Accomplishing their Destruction, Monthly.

TABLE 25. OWN SORTIES AND COMBAT LOSSES, AERIAL COMBAT DATA, AND ENEMY AIRCRAFT DESTROYED ON GROUND, BY AREA, FOR ENTIRE WAR

TABLE 26. OWN SORTIES AND LOSSES, AERIAL COMBAT DATA, AND ENEMY AIRCRAFT DESTROYED ON GROUND, MONTHLY, IN MAJOR AREA CAMPAIGNS

TABLE 27. JAPANESE AIRCRAFT DESTROYED IN AERIAL COMBAT BY ALL NAVAL AND MARINE AIRCRAFT – By Type and Allied Code Name, Monthly

TABLE 28. AERIAL COMBAT RESULTS, INDIVIDUAL MODELS OF OWN VS. JAPANESE AIRCRAFT, 1 SEPTEMBER 1944 – 15 AUGUST 1945

2. ANTIAIRCRAFT LOSS AND DAMAGE

TABLE 29. ANTIAIRCRAFT LOSS AND DAMAGE – By Plane Model, Carrier-Based and Land-Based, by Years.

Data on number of planes lost to enemy A/A fire, from which can be calculated loss rates in terms of action sorties flown, will be found in many of the preceding tables of this report. In Table 29, are additional data on number of planes damaged by enemy A/A, and loss and damage rates in terms of (a) Number of sorties attacking targets, and (b) Number of sorties attacking targets in the face of enemy A/A fire.

On first glance at Table 29 the predominant impression will be the diversity of the figures. It may be granted that some of the smaller figures involved are affected by chance (and possibly poor reporting). Yet upon closer inspection a number of fairly consistent relationships become visible:

(a) Loss rates to enemy A/A were highest in 1942, and generally lowest in 1943, increasing slightly from then until the end of the war. The 1942 rates reflect the predominance of large enemy warships among the targets for that year, figures for 1943 and subsequent years the relatively lower but increasing effectiveness of Japanese land A/A. Actually enemy A/A material improved and increased in volume at a far greater rate, but this trend was offset by the improved performance characteristics of Naval aircraft, and improved tactics against A/A.

(b) Loss rates for carrier-based aircraft were consistently higher than for land-based aircraft, despite inclusion in the latter of the relatively vulnerable VPB. The reason is that land-based aircraft generally were assigned to attack the less well-defended rear area targets, already well beaten down by the carrier forces, such as those in the Marshalls and Philippines. Also their campaigns against such heavily defended targets as the Rabaul area were of long duration, and by the later stages enemy A/A guns had been greatly reduced in number and ammunition supplies depleted. Carrier aircraft, on the other hand, were constantly reaching out toward the most heavily defended targets, pressing their attacks close to wipe out such small and vital targets as grounded aircraft, warships and merchant vessels, and seldom staying long enough to enjoy the benefits of the reduced A/A defenses resulting from their attacks.

(c) The lesser effectiveness of enemy A/A against our land-based planes did not result from an appreciably lower rate of hits per sortie attacking defended targets, but from a generally lower lethal effect of hits. A smaller percentage of the land-based planes hit by A/A was lost. In part, also, the lower rate of losses for land-based planes reflected the extensive use of the less vulnerable SBD, while the carriers were shifting to the highly vulnerable SB2C.

(d) The SBD, carrier-based or land-based, had consistently the best record of any plane model. It generally received slightly less hits per sortie than other planes, and in addition had the lowest ratio of losses to hits of any single-engine plane.

(e) The F6F appears to have had considerable advantage over the F4U when flown under the same conditions. Receiving about the same number of hits per sortie in comparable operations, the F6F had a far lower rate of loss per plane hit.

(f) The TBM loss rate appears to have been lower than that of the SB2C. It received more hits per sortie, but showed greater ability to survive hits. Both SB2C and TBM were somewhat more subject to A/A loss than fighters.

(Note that in the above statements allowance has been made for non-comparable employment of the various plane models, not shown in the table, and particularly for the heavy use of the TBM in CVE support operations against targets whose A/A defenses had already been well reduced. The TBM A/A loss rate on fast carriers was 50% greater than on CVEs, but was still less than the fast carrier rate for SB2Cs. The following table shows loss rates per 100 action sorties for the entire war:

(g) The loss rates for VPB were generally higher than for single-engine planes, but not excessive considering the effectiveness of the minimum altitude attack tactics customarily used. The PBJ is an exception; the bulk of its attacks were made from higher altitudes against rather poorly defended targets, and its loss rate is correspondingly low.

The following table combines and summarizes the data for the principal models of both carrier-based and land-based planes for the entire war. In utilizing it, it should be noted that the use of F6Fs, SB2Cs and TBMs predominantly in carrier operations, and of F4Us and SBDs mainly in land-based operations tends to distort the relationships between these planes, and produces rates differing from those which would be expected from figures based on performance in comparable operations.

3. ATTACK DATA, BY GEOGRAPHICAL AREA

(It should be noted that, because of mechanical difficulties arising from the use of several different machine tabulations made at different times, there are slight discrepancies between the tables covering attacks on targets, broken down by area and by target type. None of these are sufficient to affect the validity or essential accuracy of the data.)

This section of the report breaks down the offensive effort of Navy and Marine carrier and land-based aircraft by the geographical areas in which the targets were located, with further detail in some cases on the types of targets attacked in each area. Offensive effort is expressed only in terms of (a) sorties attacking targets (see definition of this term, and note difference between definitions for 1944 and for other years), and (b) tons of bombs expended on targets. Data on rockets and ammunition expended will be found in subsequent sections, but not broken down by area.

Table 30 is the comprehensive picture of the effort placed upon each major type of target in each major area, for the entire war, by all of Naval aviation.

Table 31 breaks down the area totals of sorties attacking targets between land targets and ship targets, and by years.

Table 32 breaks down on a monthly basis the attack sorties and bomb tonnage for the four areas where the most important long campaigns were carried on: the Solomons-Bismarcks area, the Philippines, the Ryukyus, and Japan. Data are given separately for carrier-based and land-based attacks, for land targets and ship targets, on a monthly basis.

Table 33 gives data on a monthly basis, for attacks on land targets in the principal Central Pacific island groups. Tables 34 and 35 show monthly shipping attack sorties, for 1944 and 1945, for all major areas.

TABLE 30. SORTIES ATTACKING TARGETS, AND BOMB TONNAGE EXPENDED ON TARGETS (CARRIER-BASED AND LAND-BASED COMBINED) – By Type of Target, and by Target Area, for Entire War

TABLE 31. SORTIES ATTACKING LAND TARGETS AND SHIP TARGETS (CARRIER-BASED AND LAND-BASED COMBINED) – By Target Area and by Years

TABLE 32. SORTIES ATTACKING TARGETS , AND BOMB TONNAGE EXPENDED ON TARGETS, IN MAJOR AREA CAMPAIGNS – Monthly, for Carrier-Based and Land-Based Attacks, on Land and Shipping Targets.

TABLE 33. NAVAL AND MARINE AIR ATTACKS ON PRINCIPAL CENTRAL PACIFIC ISLAND GROUPS (LAND-BASED AND CARRIER-BASED COMBINED) – Sorties Attacking, and Tons of Bombs Expended, on Land Targets Only, Monthly

TABLE 34. SORTIES ATTACKING SHIP TARGETS, MONTHLY, 1944. – By Area, Carrier-Based and Land-Based (Pacific Only)

TABLE 35. SORTIES ATTACKING SHIP TARGETS, MONTHLY, 1945 – By Area, Carrier-Based and Land-Based

4. Attack Data, by Type of Target Attacked

TABLE 36. PERCENTAGE OF CARRIER-BASED AND LAND-BASED OFFENSIVE AIR EFFORT DIRECTED AGAINST EACH MAJOR TYPE OF TARGET, BY YEARS

TABLE 37. SORTIES ATTACKING TARGETS, BY PLANE MODEL AND TYPE OF TARGET ATTACKED, FOR ENTIRE WAR – With Percentages for Each Type of Aircraft, Carrier and Land-Based

TABLE 38. SORTIES ATTACKING TARGETS, BY DETAILED TARGET TYPE AND BY PLANE MODEL, CARRIER-BASED AND LAND-BASED, 1944 ONLY

TABLE 39. ATTACKS, AND ORDNANCE EXPENDITURES ON TARGETS, BY ALL CARRIER-BASED AND LAND-BASED AIRCRAFT, 1944 ONLY. – By Detailed Type of Target

TABLE 40. ATTACKS ON SHIPPING, BY ALL NAVAL AND MARINE CARRIER-BASED AND LAND-BASED AIRCRAFT – By Type of Ship Attacked, Monthly

5. Ordnance Data

This section of the report consists of three separate groups of tables-

Tables 41-42, providing summary data on ordnance expenditures of all types, and average ordnance expended per attack.

Tables 43 to 49, giving data on bomb expenditures by type of bomb, with detail by plane type, target type, and operation.

Tables 50 to 54, giving data on rocket and ammunition expenditures, with detail by plane type, target type, and month.

a. Ordnance Expenditures, in General

TABLE 41. ATTACK SORTIES, AND ORDNANCE EXPENDED, ON LAND AND SHIPPING TARGETS, FOR ENTIRE WAR – By Plane Model, Carrier-Based and Land-Based

TABLE 42. SUMMARY OF BOMB, ROCKET, AND AMMUNITION EXPENDITURES – By Model of Aircraft, Land-Based, and Carrier-Based by Type of Carrier, 1945 ONLY

b. Bomb and Torpedo Expenditures

TABLE 43. ANNUAL ORDNANCE EXPENDITURES BY ALL CARRIER-BASED AND LAND-BASED AIRCRAFT – By Type of Ordnance

TABLE 44. TONS OF BOMBS, CLUSTERS, TORPEDOES AND MINES EXPENDED BY VARIOUS MODELS OF NAVAL AND MARINE AIRCRAFT, 1945 ONLY – By Type of Ordnance

TABLE 45. NUMBER OF BOMBS, CLUSTERS, TORPEDOES AND MINES, AND THEIR PROPORTION TO TOTAL TONNAGE, EXPENDED ON TARGET BY ALL NAVAL AND MARINE CARRIER AND LAND-BASED AIRCRAFT, 1945 ONLY – By Type of Ordnance and Type of Target

TABLE 46. REPORTED ORDNANCE EXPENDITURES OF NAVAL AND MARINE SBDs AND TBFs, 1942-1943

TABLE 47. ORDNANCE EXPENDITURES OF ALL CARRIER-BASED AIRCRAFT, BY TYPE OF ORDNANCE AND BY OPERATION, 1944 (Figures are in tons)

TABLE 48. ORDNANCE EXPENDITURES OF ALL CARRIER-BASED AIRCRAFT, BY TYPE OF ORDNANCE, MONTHLY, 1945

TABLE 49. AERIAL TORPEDOES EXPENDED ON TARGETS, MONTHLY

c. Rocket and Ammunition Expenditures

TABLE 50. NUMBER OF ROCKETS EXPENDED ON TARGETS, MONTHLY. – By Model of Aircraft, For Land-Based and Carrier-Based Aircraft, and By Type of Carrier

TABLE 51. ROCKET EXPENDITURES ON TARGETS, 1945 – By Plane Model, Carrier-Based and Land-Based, and by Target Type

TABLE 52. MONTHLY EXPENDITURE OF ROCKETS, BY ALL NAVAL AND MARINE CARRIER AND LAND-BASED AIRCRAFT, BY TYPE OF TARGET, 1945

TABLE 53. AIRCRAFT AMMUNITION EXPENDITURES ON TARGETS (IN THOUSANDS OF ROUNDS) – 1945 Carrier-Based and Land-Based, by Target Type, Monthly

TABLE 54. AIRCRAFT AMMUNITION EXPENDITURES ON TARGETS (IN THOUSANDS OF ROUNDS), DURING 1944 – Carrier-Based and Land-Based, by Type of Carrier, and by Type of Target

6. NIGHT AIR OPERATIONS

(a) Night Attack

Tables 55 and 56 give brief statistical data on Navy and Marine night attacks on targets. While the number of sorties attacking targets at night was only 2 percent of total attack sorties by Naval aircraft, the total volume is more impressive than might ordinarily be thought, amounting to 5,800 sorties and 3,000 tons of bombs, largely by land-based planes. For some types of aircraft, mainly the flying boats, land-based F6F night fighters, and to a lesser extent PVs and PBJs, night attacks constituted a major portion of their offensive activity.

For the PBY, too slow and vulnerable for day attack on defended targets, night work constituted a profitable and principal employment. The 1,058 attacks made by PBYs on 997 sorties were divided between ship and shore targets. Black Cats from New Guinea flew low level night bombing missions against Jap ships in the Bismarck Sea area in the winter of 1943-44, and Black Cats in the Solomons cooperated with PT-boats in spotting and attacking Jap barges and shore installations. PBYs were also used for night heckling raids on Jap bases throughout the South and Southwest Pacific, and for minelaying, and were still pursuing Jap shipping as far west as Celebes in late 1944.

PBMs and PB2Ys made a number of night attacks, largely on shipping (plus two PB2Y long-range night raids on Wake), but these two plane types were largely used for anti-sub patrol and sector search in quiet areas, and thus flew far fewer night attack missions.

PBJ night missions fell into two principal classes: night heckling missions over Rabaul and Kavieng, constituting the bulk of the sorties, and night rocket attacks on shipping, principally in the Bonins area. PV night missions were principally attacks on the Northern Kuriles, flown over the 600 miles from Attu under difficult weather conditions. PB4Ys flew few night missions; a few heckling sorties over Rabaul, and some minelaying flights.

The number of night missions by single-engine land-based planes is surprisingly large. Those by TBFs were predominantly for minelaying in the Solomons area, but included also night heckling attacks and shipping attacks there, and in 1945 some heckling missions at Okinawa.

The F6F night missions were flown almost entirely by Marine night fighter squadrons. Those from November 1944 to March 1945 were flown against Palau and Yap, in preparation for those in subsequent months in the Okinawa area, where substantial support was given our ground forces by regular heckling missions over enemy lines.

Carrier night offensive missions were flown largely by VF(N) and VTB(N), which came aboard in early 1944 and in September 1944 respectively, although pre-dawn attacks accounted for a number of sorties flown earlier. The number of night attacks flown increased greatly in the Okinawa operation, as a night CV and a night CVE made available full night air groups for regular neutralization attacks on enemy airfields and attacks on shipping.

Surprisingly low loss rates were reported for night operations by land-based F6Fs and PBJs. PBYs, considering their vulnerability in minimum altitude attacks, and PVs, considering the difficult conditions of the North pacific, also reported remarkably low losses. Carrier loss rates, though higher than the day rates, were not excessive considering the hazards involved and the value of the work done.

(b) Night Air Combat

U.S. Naval and Marine aircraft during World War II shot down a total of 202 enemy aircraft at night and lost only 7 planes in night aerial combat, or 1/29 of the enemy losses in the same actions. If operational losses on missions involving night combat are included, 15 enemy planes were destroyed per own plane lost. It should be noted that the chance of over-optimistic claims of enemy aircraft destroyed in night combat is negligible, since most enemy planes crash in flames visible for miles, and usually only one or two aircraft are engaged at a time.

103 of the enemy planes were shot down by carrier night fighters, or planes acting as night fighters, 90 by land-based night fighters, and 9 by patrol bombers.

Of the 7 losses to enemy aircraft, only one involved a carrier-based F6F(N), and only 2 involved land-based F6F(N)s, which became the standard night fighters for land and carrier use, and accounted for three-fourths of the enemy planes destroyed in night combat.

The first night fighters consisted of a small Marine squadron of PVs converted to night fighters, sent to the Solomons in late 1943 to discourage the nightly "Washing Machine Charlie" raids. This squadron accounted for 11 enemy planes between November 1943 and May 1944, including 7 float planes and 4 bombers, and lost one plane in air combat. It was supplemented by a Navy squadron of F4Us equipped with intercept radar gear. This squadron accounted for 4 floatplanes and 4 bombers, with no air combat losses. Another F4U (N) squadron (Marine) brought down two Bettys in the Marshalls, with one loss.

After these three squadrons all land-based night fighters were the new F6Fs with AI intercept gear, and all were in Marine squadrons. Their first night air combat was in October 1944, when they knocked down a float plane in the Palau area, and in December, when they destroyed 3 Jap fighters in the Philippines. They had no further night combat until April 1945, when the three Marine VF(N) squadrons sent to Okinawa began their campaign which resulted in the destruction, in a 4-month period, of 64 enemy aircraft, against 2 air combat losses and 1 operational loss sustained in these engagements.

The first carrier night fighters to engage in combat were a pair of standard F6Fs, guided by a radar-equipped TBM, which intercepted a Jap bomber attack in the Gilberts area in November 1943. One of the F6Fs (piloted by Cdr. O’Hare) was shot down by the Japs, and the TBM reversed the concept of the team by shooting down two of the Japs.

In early 1944 these makeshift teams were replaced by 4-plane teams of AI-equipped F6Fs (and for a few months some AI-equipped F4Us) assigned to each CV. These planes accomplished little in night combat until the Marianas campaign, when they shot down 11 Jap planes. In September a night air group equipped with F6F(N)s was placed aboard the CVL INDEPENDENCE, and during the five months of its service its planes shot down 15 Jap planes at night, while the CV teams accounted for 5 more. This group was succeeded by a CV night group aboard ENTERPRISE, which in its 5 months of intermittent service made 18 night kills, and was in turn succeeded by a third group which in August brought down 6 Jap planes.

During the Okinawa campaign the brunt of the night-fighting was borne by the CV night fighter teams, which brought down 11 Japs in March, 27 in April, and 6 in May. In all, carrier-based single-engine VF(N) destroyed 60 Jap planes in night combat during the Okinawa campaign, and land-based night fighters an additional 64. These 124 planes were brought down at a cost of four losses, combat and operational.

Attention is invited to the large proportion of enemy planes destroyed to enemy planes engaged, especially in actions involving the F6F and F4U. Once our night fighters came within shooting range of the enemy planes, few escaped.

As would be expected, over half of the total enemy planes destroyed were twin-engine fighters or bombers, or flying boats. Of the single-engine types destroyed at night, half were float planes (See Table 59).

TABLE 55. SORTIES, BOMB TONNAGE, AND LOSSES IN NIGHT ATTACKS BY NAVAL AND MARINE AIRCRAFT, FOR ENTIRE WAR – By Plane Model, Land-Based and Carrier-Based

TABLE 56. NUMBER OF NAVAL AND MARINE AIRCRAFT ATTACKING TARGETS AT NIGHT – By Plane Model, Carrier-Based and Land-Based, Monthly

TABLE 57. NIGHT AERIAL COMBAT RECORD, FOR LAND-BASED AND CARRIER-BASED NAVAL AND MARINE AIRCRAFT, MONTHLY

TABLE 58. NIGHT AERIAL COMBAT RECORD, BY PLANE MODEL, FOR ENTIRE WAR

TABLE 59. TYPES OF ENEMY AIRCRAFT DESTROYED BY NAVAL AND MARINE AIRCRAFT IN NIGHT AERIAL COMBAT, FOR ENTIRE WAR

7. LONG RANGE SEARCH PLANE OPERATIONS

Attention has been paid, in previous sections of this report, to the air combat record of PB4Y patrol planes, and to the substantial proportion of their attack effort which was directed against shipping. Unfortunately, in those analyses the PB4Y record was somewhat smothered under the much larger figures covering action by carrier planes and by the large number of land-based single-engine planes. Thus this brief additional section is provided to give full credit to the long range search planes for their combat achievements.

Emphasis herein is placed on 1945, and on PB4Ys. PBMs, included in one of the tables, turned in many noteworthy performances during 1945, and in 1944 PB4Ys performed, on a smaller scale, with even greater individual brilliance then in 1945. The 1945 figures, however, present a more impressive set of data, and fuller detail can be provided.

Table 60 above gives 1945 monthly data for all PB4Y and PBM squadrons which reported action during the respective months. Not all squadrons in the Pacific are included, since during each month there were some which flew only negative patrols. The squadrons included were based in the Philippines, the Marianas, and ultimately at Iwo and Okinawa.

Average squadron strength was 14 aircraft, and each plane on the average made 11 or 12 flights -- largely sector searches of 600 to 1000 miles, per month. A squadron normally flew 2 to 5 sectors daily, each covered usually by single planes, sometimes by 2-plane teams. Occasionally additional anti-shipping search and attack teams were sent out; rarely were larger strike missions flown.

As the table indicates, 7 out of 8 flights were negative with respect to action with the enemy, but the average plane attacked targets or engaged enemy aircraft once or twice a month. The majority of their attacks were on enemy shipping - large merchant vessels and warships when they were sighted, small vessels when nothing larger was available - and land targets were normally attacked only in sectors where shipping had entirely disappeared.

Starting with attacks in the Philippines and the Bonins area in January, the planes worked up to the Ryukyus, the Formosan coast, the North China Coast, the Yellow Sea and the Coasts of Korea, and the shores of Kyushu, Shikoku and Southern Honshu, as new forward bases became available. From the Philippines they also worked down the South China coast, to Indo China, Malaya, and Borneo. Initially in each area a substantial residue of large vessels remined, but as attacks mounted the which were not sunk were withdrawn, or kept in harbor by day, so that the bulk of the vessels remaining at sea were the small coastal types of 50 to 300 tons on which the Japs had in the end to rely for supplying their distant forces and returning vital materials to Japan.

These were the vessels the search planes attacked, usually in single plane bombing and strafing attacks at 50 to 200 feet altitude. When such tactics are used, accuracy is such that bomb tonnages dropped are no measure of the results obtained. In a study of reports on 870 PB4Y masthead attacks on ships of all sizes, it was found that 370 attacks, or over 40%, resulted in hits, and that over 18% of all bombs dropped were hits. These figures do not include any measure of the hits by small incendiary bombs normally dropped in clusters on the smaller vessels, or of the effect of strafing. Dozens of small vessels were destroyed by fires caused by incendiary hits or strafing alone, and most of the smaller vessels attacked could be sunk by a direct or underwater hit by one 100-lb. or 250-lb. bomb.

During 1945 PB4Ys alone dropped over 4,000 bombs, plus over 500 incendiary clusters, in attacks on probably 600-800 different vessels, and expended over 2,000,000 rounds of ammunition in strafing these vessels. It is probable that as a result of the 1945 PB4Y and PBM attacks some 300-500 of these vessels were sunk. (No final evaluation or assessment of the claims regarding small vessels has yet been made). The effect was to cripple the remaining Japanese sea transport in most areas, and to cause withdrawal of many vessels not yet sunk, because of the danger of attack, and because of fuel shortage resulting from the sinking of tankers.

Table 60 shows the steady building up of anti-shipping attacks in 1945, to the peak operations of May, June and July, largely in the Yellow Sea and off Korea and Japan itself. In June and July an average of 8 or 9 attacks on ships were made daily.

The above table shows the ordnance expended in the attacks by PB4Ys alone, and illustrates the predominance of small bombs, incendiary clusters and strafing which were all that were required against the smaller targets, though, as will be noted, heavier bombs were used against the larger vessels. Normally, mixed bomb loads were carried, to permit a choice of bombs depending on the type of target met. Despite the 3 to 4 ton bomb capacity of the PB4Y, rarely were loads of more than 2 tons carried, and the normal load was usually about 2,500 pounds, because of the extra fuel required for long-range searches.

In the minority of attacks which were directed against land targets (in the absence of ships), land transportation (including railroads, bridges, trains, and trucks) was the favorite type of target. Airfield installations, miscellaneous military buildings, and harbor areas of small coastal villages, were the other principal targets attacked.

Table 60 also shows the monthly air combat record of PB4Ys and PBMs. The 292 patrol planes which engaged in combat met 541 enemy aircraft, and shot down 150, or nearly 30% of them. Losses in air combat were 9 planes, only 6% of the number of enemy planes destroyed, and only 3% of the number of our VPB engaging in combat. The best records were in February and March, when 51 enemy planes were shot down with only 1 combat loss.

Losses to antiaircraft fire in these low level attacks were slightly over 2% of the planes attacking. Operational losses were 1/3 of one percent of the total number of flights.

APPENDIX – JAPANESE SHIPPING SUNK BY NAVAL AIRCRAFT