ANALYSIS OF ANTI-SUBMARINE ACTION BY AIRCRAFT
     
  General  
     
  Unit:  VC-9                  Unit Report No.  33 (a to g)             Incident No.  6433  
     
  Base of Operations  USS SOLOMONS  
     
  Squadron No. of Aircraft  T-12, T-33, F-17, F-23, T-11, T-1, T-32  
     
  Aircraft Type  TBF and FM  
   
  Location of Attack:       Latitude: 25-27S  
                                      Longitude:  05-30W  
     
  Date:  15 June 1944                Time  1021 GCT                   Zone  Zero  
     
  Approach and Attack  
              While flying on routine anti-submarine patrol, T-12 reported a contact at 1021 bearing 0700 (T), distance 50 miles from the carrier.  The weather was clear with scattered cumulus at 2,000 feet and moderate sea.  After his initial contact report, there was no further communication from T-12, and none of the crew were recovered.
              At 1414, T-33 took off to conduct a normal square gambit search over the reported contact position searching for both the survivors of the lost airplane and the submarine.  At 1722, while flying at an altitude of 1,500 feet, T-33 sighted the wake of a fully surfaced submarine on a course of 1200 (T) speed 15 knots.  A contact report was immediately made by voice and an attack run started.  AS the plane closed, the U/boat began to turn in circles of about 1,000 feet in diameter, successfully keeping the aircraft on its stern.  During these maneuvers intense anti-aircraft fire was directed towards the plane.  The submarine made no attempt to submerge so the pilot circled the U-boat at a range of 4,000 yards while awaiting assistance.  
              The entire attack on the submarine was made in three phases, commencing at 1746 (8 minutes after sunset) and ending at 1753.  
 
 
     

 

     
     
  Phase 1 - T-11, F-17 and F-23 had returned to the carrier after conducting a close search over the area of the contact previously reported.  They were about to be taken aboard when T-33’s contact report was received so they were vectored to the scene of the new contact.  The three planes arrived over the target at 1743.  F-17 and F-23 were directed by the OTC, T-33, to commence strafing attacks on the starboard and port quarters respectively.  T-11 was directed to coordinate the rocket attack with T-33.  F-17 started a strafing attack from 2,000 feet on the U/boat’s starboard quarter, pulling out at less than 100 feet directly over the conning tower amidst heavy anti-aircraft fire.  He effectively strafed the bandstand and the conning tower expending 400 rounds of 50 calibre ammunition.  F-17 was then ordered to return to the carrier because of a wing tank damaged by A/A fire which he was unable to jettison.  
              F-23 started his strafing run from 3,000 feet altitude on the U/boat’s starboard bow.  He made a steep dive through heavy anti-aircraft fire, peppering the deck and conning tower with 200 rounds of 50 calibre.  He pulled out at 500 feet to clear the target for the first plane making a rocket attack.  
              T-11 started his rocket attack simultaneously with the second strafing run.  He attacked from the starboard beam of the U/boat and fired eight rockets in four pairs commencing at 800 yards slant range.  Six rockets were reported to hit the water within lethal range slightly ahead of the conning tower.  The other two hit over the submarine.  After the last rocket was fired the pilot pulled out to his left, allowing his turret gunner to fire 100 rounds at the U/boat.  
              As T-11 entered his dive, T-33 commenced a rocket attack from the U/boat’s port beam.  At 600 yards slant range he fired six projectiles, in three pairs, which were reported to have hit the water within lethal range about 20 feet ahead of the conning tower.  
              During this first phase of the attack, all four planes passed over the U/boat within ten seconds.  The submarine had straightened out on a course of 1800 (T) at a slower speed, trailing oil and smoking around the conning tower.  Anti-aircraft fire was still being directed toward the planes but was reduced to short bursts about every ten seconds.  
  Phase 2 - T-32 and T-1 took off from the carrier at 1734 and arrived on the scene at 1751.  T-1 was directed by the OTC to make a rocket attack from the port beam.  F-23 preceded this attack with another strafing attack in which he effectively expended the remainder of his ammunition.  T-1 attacked the U/boat’s port beam, firing eight rockets in four pairs at 600 yards slant range.  Six rockets were reported to hit within lethal range directly in line with the conning tower.  Sparks caused by one of the projectiles hitting the deck of the U/boat were observed by the pilot as he maneuvered to evade anti-aircraft fire.  As the second phase of the attack ended, the submarine was still on a course of 1800 (T) but its speed had been reduced to about 3 knots.  In addition to the oil trailed by the U/boat as a result of the previous attacks, there were now large quantities of greenish-yellow oil on the surface.  
  Phase 3 - T-32 was directed to begin a depth charge run from the submarine’s port quarter.  Diving through the bursts of anti-aircraft fire, two Mark  
     
 
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  47 depth bombs were released from an altitude of less than 50 feet, the depth bombs were observed to strike the deck of the submarine causing a violent explosion which engulfed the plane and started a fire in the bomb bay and center cockpit.  The pilot was apparently still able to maintain control of his plane, and after making a 1800 turn landed in the water about 500 yards on the port bow of the U/boat.  The crew was not recovered.  T-33 preceded the depth bomb run with a strafing attack after which he pulled up into a chandelle to the right, enabling his turret gunner to fire several bursts at the conning tower of the submarine.  
              While the three torpedo planes still over the target were getting into position to make further attacks, the U/boat sank bow first.  Thirty to forty survivors and three life rafts were observed in the water.  About 2330 the USS STRAUB recovered twenty-one survivors from the stricken U/boat including the captain, executive officer and engineering officer.  
     
  Plotting Room Opinion - U-860 was sunk by this attack.  
     
  Analysis  
     
              The Preliminary Report on the Interrogation of Survivors by Op-16-Z dated 6 July, 1944 provides the following evidence:  
              a)  At about 1200 German time (1000 GCT) an aircraft warning was picked up on U-860’s GSR set.  Shortly thereafter on plane appeared and commenced its attack.  Four attacks were delivered by this plane.  No hits were made on the submarine.  During the forth run-in, 20 mm hits were scored on the plane which plunged out of control into the sea about 1,00 meters from the U/boat.  Search was made for possible survivors but without success.  NOTE - This was undoubtedly T-12’s attack  
              b)  Later, six planes were sighted.  The first attack consisting of four planes apparently scored hits in the forward part of the U/boat.  One survivor stated that immediately after this attack all telephone connections with the forward torpedo room were broken off.  The resulting starboard list was believed to have been caused by a water entry in the forward torpedo room.  NOTE - This was Phase 1 of the action report.  
              c)  The second attack consisting of four planes scored hits in the warrant officer’s room and in the bilges below the control room.  Water entry in both sections was said to have been reported.  One prisoner said chlorine gas developed after this attack and killed many men.  Another described a “shot” as landing a few meters away from the U/boat and reappearing on the other side.  A very pronounced list was noticed after this second attack.  NOTE - This was Phase 2 of the action report.  
     
 
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              d)  The third attack consisting of two planes sank the U/boat very quickly.  Two bombs were seen to fall.  These landed directly on the U/boat in front of the conning tower and were believed to have exploded on contact.  The resulting pressure dazed everybody, many of them coming to only when the U/boat sank from beneath them and they found themselves in the water.  NOTE - This was Phase 3 of the action report.  
              e)  The gunners aboard the submarine were well protected by armor because despite concentrated strafing attacks they continued to fire until the submarine went down.  Only one survivor was wounded by the strafing attacks.  Prisoners stated only one man was killed outright by the strafing.  
     
  Tactical Analysis Officer’s Opinion  
     
              1)  U/boat in this case Known Sunk (A)  
              2)  Credit for this sinking to be shared equally by:        T-11 and T-33 (Phase 1)  
                                                                                                T-1                  (Phase 2)  
                                                                                                T-32                (Phase 3)  
              3)  Since P/W evidence indicates that the attack by T-12 (shot down) and by the strafing planes F-17 and F-23 did no damage and failed to reduce the A/A fire, these planes are not considered to share in the credit for the sinking.  
     
              Assessed___________________________  
              Credit to____________  By____________   
     
     
     
     
     
     
     
     
     
 
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