NOTES TO TABLE 42

Because of the varying periods, conditions, and plane types involved, and the incompleteness of ammunition expenditure data for 1942-43, it has not been thought desirable to prepare data on average ordnance expenditures per attack covering the entire war as a whole. The above table provides such data for 1945 only. For the most part the 1945 performance in respect to ordnance expenditure per plane is believed superior to that for previous years.

Most significant item in the above table is the relatively low average bomb and rocket load expended by carrier VF per sortie attacking targets. It is also interesting to note that both the average bomb load and the average rocket load were greatest for CVE-based VF, least for CV-based VF. It would not appear from these data that maximum advantage was taken of the offensive ordnance-carrying capabilities of carrier VF, or that the fighter bomber successfully Competed with the dive and torpedo bombers it displaced, so far as offensive use of heavy ordnance was concerned.

The table indicates that credit must be awarded to the CVE forces, for placing 750 lbs. Of bombs and rockets on target per F6F attack, against less than 600 lbs. per CV F6F; for putting an average of 3 3/4 rockets on target per attacking fighter (against a per-plane capacity of 6 and a fast carrier average of 2.5); for placing over 5 rockets on target per TBM attacking, and a total bomb-and-rocket load per TBM nearly equal to the CV-CVL average; and for out-strafing CV and CVL planes of the same types.

The table indicates that land-based fighters, though free from the take-off limitations of the carrier VF, and less burdened by air combat, also did not average in practice the rocket and bomb carrying capabilities urged in behalf of VBF by advocates of the fighter-bomber; they carried more bombs but far fewer rockets than carrier fighters.

Carrier VSB and VTB in general averaged 80% or better of their standard maximum loadings of 1,500 lbs. and 2,000 lbs, respectively. CVE VTB carried less weight of bombs but made up for it with the largest average rocket loadings of any plane.

Land-based SBDs reported excellent loadings relative to their normal loadings; land-based SB2Cs and TBMs carried less ordnance than the same types on carriers.

PBJs, performing largely short-range bombing missions, generally carried their maximum loads of 1 - 1.5 tons, depending on type of bomb carried. Other types of VPB, usually flying long-range search, rarely tried to carry or expend full bomb loads on the targets of opportunity encountered, and often destroyed them with only a part of the load carried.

In ammunition expenditure the carrier fighter excelled, averaging 500 to over 600 rounds per action sortie, exceeded among major types only by the PB4Ys’ 1,570 rounds - PB4Y strafing has set afire and destroyed many a small vessel and silenced many an A/A gun. The PV and PBM averaged less than half as many rounds per sortie, and single-engine bomber expenditures were consistently under 200 rounds. Land-based VF averaged only 60% as high a rate of expenditure as carrier VF, largely because the types of targets generally encountered were less vulnerable to strafing.

An interesting inquiry in the field of ordnance expenditures is the total weight of ordnance of all types expended on target per plane lost to anti-aircraft. This provides a rough measure of attack effectiveness against targets, although the limitations are obvious. The differing nature of the targets, and of the defenses of these targets, attacked by fast carrier, CVE, and land-based planes affect the figures. Also, tonnage measurements, while they may reflect with fair accuracy the effectiveness of rockets, probably do not do justice to the value of strafing fire. Subject to these limitations, the following figures are presented:

The relatively higher efficiency of the TBM over the SB2C is apparent above; the extent to which a lesser bombing accuracy may reduce its superiority is not known. The apparent relative ineffectiveness of VF is conditioned by the consideration that 50% or more of the total weight of ordnance carried by carrier VF was rockets or ammunition (20% to 30% was ammunition) which may have been more effective, ton for ton, than bombs.

The apparent CVE superiority over fast carriers of course reflects the use of their planes against targets previously partially neutralized by fast carrier planes and surface gunfire. The apparent superiority of land-based VF, VSB and VTB and PBJs reflects their use against thoroughly neutralized by-passed bases, and targets with light defenses, and in the case of PBJs reflects the effect of medium altitude bombing in addition. Yet the superior performance of the SBDs, operating largely in the Philippines, may well be noted.

The PB4Y and PBM averages reflect use of only partial bomb loads, coupled with heavy strafing, in masthead attack.