At 09.56 hours on 18 Nov 1942 U-43 fired a spread of four torpedoes at convoy SC-109 and observed two hits after 1 minute 44 seconds on an ammunition freighter, which exploded with a column of fire rising about 200 meters. The next shot missed a tanker and hit a ship beyond and the last hit and stopped the tanker. Schwantke claimed the sinking of two steamers of 5000 grt each and the tanker as damaged.

Only the hit on Brilliant (Master Soren Sorensen) in station #73 can be confirmed from Allied reports. The torpedo struck between the #5 tank and the pump room, opening a hole about 40 feet in diameter in the side, destroying three tanks and causing leaks in three other tanks on the port side. The cargo was set on fire and the whole ship abaft the bridge began to burn. The watch below immediately secured the engines and the master, three other officers, three crewmen and two armed guards lowered a boat intending to stay with the tanker. The rough seas and the headway caused this boat to swamp, tossing the men in the water. They were later picked up by the British rescue ship Bury. The surgeon on this ship denied the master´s request to return to his ship and took them to Glasgow.
The remaining men on the Brilliant, in charge of the junior third officer, who earned the Merchant Marine Distinguished Service Medal for this action, put out the flames and brought the tanker at three knots over 300 miles into Buena Vista Bay, Newfoundland on 24 November. The entire complement of nine officers, 33 men and 18 armed guards (the ship was armed with one 4in, one 3in, four 20mm and two .30cal guns) survived.

On 18 Dec 1942 the Brilliant (Master Andrew Lagan) left St. Johns in convoy WB-17 for Sydney because the tanker could not be repaired and discharged in Newfoundland. Due to gale force winds and rough seas, the master turned back to the port of departue the next day.
On 18 Jan 1943 the Brilliant departed again in tow of the tug HMS Frisky (W 11), escorted by HMS Chelsea (I 35). Two days later she broke in two in heavy gales and rough seas in 46°13N/58°38W. The forepart sank immediately, taking all eleven men on this section with her. These men were the master, two officers, four crewmen, three armed guards and the coast pilot. The afterpart drifted for some days with 44 men aboard 150 miles to the southeast until a lifeboat from the tug and a boat from HMCS Goderich (J 260) took the survivors off and brought them to Argentia, Newfoundland on 24 January. The afterpart was taken in tow to Placentia, Newfoundland, but sank in 45°18N/55°12W the next day.