back with her guns but was eventually forced to dive. The next morning, the patrolling Swordfish reported a U-boat sighting and was never heard from again. It was because of these last engagements that aircraft were ordered to fly in pairs, they were forbidden to fight it out with surfaced submarines and only to attack if it was diving. That afternoon a Swordfish sighted and attacked a U-boat diving only from the convoy. The same U-boat, , was located and sunk by two of the escorts, , a , and , a . On 13 May, the convoy had come within range of RAF Coastal Command Consolidated Liberators and Short Sunderlands. Two Swordfish took off at dawn and discovered two surfaced U-boats, which were attacked by a patrolling Sunderland of No.423 Squadron RCAF from RAF Castle Archdale. Another U-boat was located by a Swordfish at 09:00 and attacked as she was diving with no visible effect. Two U-boats were engaged by aircraft and escorts and sunk; these were U-456, sunk by HMS Opportune and a Liberator of No. 86 Squadron from RAF Aldergrove, and HMS Lagan, and U-753, sunk by the and HMS Lagan. Convoy SC 129 With HX 237 now under land-based aircraft cover, the C-in-C Western Approaches ordered Biter and her escorts south, where the eastbound convoy SC 129 was being threatened by a gathering wolfpack. On 15 May, light winds over the flight deck, and the inability of the Swordfish to use the catapult launch rail, limited their bomb load to two bombs. Just before they closed on the convoy a Swordfish attacked a surfaced U-boat. The two bombs caused no damage to the submarine which returned fire, damaging the plane and wounding the air observer. Their relief shadowed the submarine until it dived when it carried out another unsuccessful attack. At 13:45, Biter closed with the convoy and commenced anti-submarine patrols. The convoy reached Britain on 16 May without any loss, and Biter was ordered to the Clyde. As a result of Biter′s experiences on these early convoys, the complement of aircraft carried was increased to 15 bombers and six fighters, with a 50% increase in air crews. Homing beacons were to be fitted to all carriers together with a Type 237 blind approach beam system for use in poor visibility. Convoy HX 265 On 19 October 1943, Biter with six Swordfish and six Martlets of