Bericht der Wellington B 172 Sq. (engl.)
APPENDIX "C" S E C R E T
On the night of the 12/13th March, 1944, Wellington "B" of 172 (L.L.) Squadron was flying on a course of 000° T at a height of 1,000 feet on his way to A/S patrol in fine weather but with haze on the sea and the moon obscured by 10/10 strata cumulus cloud (Base 1,500 ft).
At 0147Z on the 13th March, a Radar contact was obtained at a range of 8 miles 20° to Port. The A/C turned to home, reduced height to 50 ft. and at 0151 in position 46°13'N. 27°28'W. on a course of 350°T when 1/2 mile from the contact the searchlight was switched on illuminating a fully surfaced U/boat bearing 2° Green on a course estimated to be 110°T at 4 knots.
The Captain, 2nd Pilot and Navigator/Front Gunner saw clearly a man scramble over the back of the C/T, run to a gun about 20 ft. aft, and a single stream of Tracer of Reddish Orange colour swept from aft of the U/boat in an arc up to B/172s port side from 1/4 m. distance and continued during the run in. THe Captain altered course to starboard to bring the U/boat's C/T dead ahead, the Navigator/Front Gunner meanwhile raking the U/boat with his single .300" gun. The Captain went in to attack and 6 D/Cs were dropped from 30 ft., 4 to starboard and 2 to port, straddling the U/boat athwart the C/T from starboard to port; it is believed the A/Cs trailing aerial was carried away at this point.
A.A. fire ceased immediately after the A/C passed over the U/boat when the Rear Gunner opened fire with 4 .303 guns raking the U/boat which was still illuminated by L.L. The Rear Gunner saw clearly a mass of D/C explosion plumes on the U/boat's starboard and two separate explosions on port side, the stick straddling and throwing water over the C/T -- he states that the D/C nearest to the U/boat was the inner on the starboard side which exploded about 15 to 20 ft. from the U/boat's hull. The Rear Gunner states that the U/boat heeled over to starboard.
Three flame floats were dropped with the D/Cs - of these two were immediately extinguished, the third remained alight on the port side of the U/boat. The Captain took evasive action, climbed to 1,000 ft. and came in again over the U/boat - nothing however could be seen.
At 0153Homing transmissions were commenced but were not successful in result as the A/C which would have homed to the attack was returning to base, over 450 miles away, with mechanical trouble.
One Marker Mk.II was dropped about a mile West of the flame float at 0155 by which time the U/boat was no longer visible to the naked eye. The Captain decided to shadow while homing and patrolled at 2,000 ft. on a course approximately North and South 2-1/2 miles down moon of the U/boat returning and running over the site of the attack several times at 300 ft in the hope that the clouds would break and a sighting be made by moonlight - this opportunity did not in fact occur. During this period continuous Radar contact on the U/boat was maintained and remained steady relative to the marker until 0330 when the contact disappeared. The Captain immediately investigated, and in obscured moonlight saw an oil patch about 25 ft wide and 100 ft long where the attack had taken place.
At 0345 another Mk.II Marker and at 0355 - Mk.II Parachute flare were dropped and the site investigated with the searchlight switched on. This confirmed the presence of the blank oil patch but nothing else was seen. Patrol and homing transmissions continued.
At 0445 B/172 dropped one Mk.III Marker (2 hours delay) and s/c base as the crew had been briefed that weather at base on return might necessitate a diversion to Sao Miguel - a further 45 minutes flying time - and weather on Patrol was deteriorating.
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