Following this attack plane began series of strafing runs on the U/B which were continued until it sank. At first, U/B which had started smoking heavily and leaking oil, made series of tight circles while attempting to return fire. Pilot and crew believe rudder was out of control and that sub was slightly down by the stern. All guns were manned and fire was steady.

         Approximately 15 minutes later U/B straightened out on northerly course - average 340⁰ T - altering as plane came in for strafing runs to use guns to most advantage and present beam target. At 0804 made unsuccessful attempt to submerge, clearing decks of personnel in preparation. But in the effort it appeared to almost lose control and sink, submerging completely without diving, then resurfacing in the same spot with difficulty, stern completely awash (see photo #10).

        Partially regaining trim, it resumed gun battle, stern becoming progressively awash as it got under way along it's former course.

        At 0840, a Brazilian Hudson was seen coming to scene from northeast. 74-P-7 drew sub's fire while he made approach to attack. Cutting it short, he crossed sub's bow from stbd, releasing two Mk 17 DC's in salvo from an altitude of 300' speed approximately 220. Drop was short, explosion observed 150' (angle 45⁰) off bow of U/B. The spray reached U/B bow which had turned to stbd in a maneuver just prior to Hudson's attack, apparently sighting plane only as it started run and opened fire. This attack caused sub to describe half-circle to stbd before returning to straight course of 340⁰ T. The Hudson departed immediately, but at 0840 a Brazilian PBY was sighted 30 miles away. (Both Brazilian planes had been assigned coverage of sortie JT-3, then in progress from Rio harbor.) Again sub's fire was engaged, and PBY closing in, and firing guns attacked from the port quarter (target angle 210⁰) releasing 3 Mk 44 DC's spaced at 50' at 160 knots. The sub attempted to alter course between 340⁰ T and 60⁰ T before this attack. Detonation as observed by 74-P-7's crew are as follows: nearest D/C swirl was tangent to port quarter of U/B. First two D/Cs short (see sketch).

        The PBY then circled sharply to port and returned for the kill up-stern, dropping the one (1) remaining charge on submerged stern of U/B. (Bow was all that then remained above surface.) The U/B sank immediately (23-47 S, 42-56 W). Many of the crew abandoned ship and were in the water at time of second PBY drop. Both planes dropped life rafts and remained in area until relieved by 74-P-2 which assisted USS BARNEGAT in the recovery of 12 men, including the U/B Commander.

        The sub had traveled about eight miles from point of first attack until it sank at 0902 P.

        Comments concerning the attack from a standpoint of joint operations and coordinated action.

        The plan of the day called for the Brazilian PBY to cover the sortie of JT-3 from Rio Harbor, then to sweep ahead. Mariner seven was detailed to make a barrier sweep to the harbor approaches paralleling the convoy route. Mariner seven developed a radar contact and attacked at 0718. When the base received this report at 0720 Brazilian Air was immediately notified and advised to dispatch the PBY and a Hudson to the scene. At the same time two additional Mariners plus the BARNEGAT were ordered to proceed.

        Mariner four, the first U.S. plane to get off, was distracted and diverted from the actual scene of attack first, by the incorrect position given by 74-P-7, and second by the appearance of a Brazilian Hudson, who was engaged in depth bombing a school of whales. By this time the second Brazilian Hudson arrived over the real scene of action and hurriedly dropped short. At 0900, 1 hour and 42 minutes after the PBM attack, the Brazilian PBY arrived and delivered two attacks on the crippled U/B while Mariner seven drew the U/B's fire. The first PBY drop was observed to be slightly short off the port quarter but the second exploded directly over the submerged stern of the U/B. The U/B sank in 3 seconds. Unfortunately all film in Mariner seven's camera had been used up on his own attack and no photographs were obtained of the Brazilian attack.

        Mariner four, who was then still looking for the interesting area, was ordered to take up Mariner seven's barrier sweep. Mariner two, the second PBM, was ordered to relieve number seven who had received three hits in the engine nacelle. Mariner two performed an excellent job of directing the BARNEGAT to the area and aided materially in the rescue of the 12 survivors.

        It is difficult to explain how or why the two Brazilian aircraft arrived so promptly over the U/B position when the original position reported was in error by 35 miles.

        Attention is invited to the fact that the U/B forced beam attack on 74-P-7; that he pressed home his attack deliberately and vigorously in the face of heavy A/A fire; that his second attack was nearly bow on - both attacks being the most difficult to deliver and that in spite of the above he so crippled the U/B that it was not able to submerge and that it had to stay surfaced and fight it out until the final blow was dealt by the PBY. At this point the writer points with pride to the fact that the pilot of the PBY was recently checked out and trained in the art of ASW by VP74 at Aratu Sea Base. The results are extremely gratifying, and full credit for the final kill is credited to the pilot and crew of this plane.

        The pilot of 74-P-7 was not justified in changing the Squadron doctrine in regards of the D/C spacing from 72 to 65 feet.

        Better photographs of this action might have been obtained had this squadron received the 16 mm. gun camera film requested last May.

        The usual good performance of the BARNEGAT in recovering the survivors is again noteworthy. The complete operation from attack to recovery of survivors took only four hours and 45 minutes.

        The U/B Commander stated that he lost most of his men by gun fire from the Mariner. The removal of the bow turret from this type aircraft will be sorely missed.

        The Brazilian airforce is deserving of special credit for the success of this action, especially because of their inexperience and the inferiority of their equipment.

                                                                                                         J. C. TOTH.