Guarding the Straits of Gibraltar: March - October 1943

Complementing the Bay of Biscay operations by the 479th Antisubmarine Group were the efforts of the 1st and 2d Antisubmarine Squadrons in the Moroccan Sea Frontier. The AAF Antisubmarine Command moved these two squadrons from St. Eval, Great Britain, to Port Lyautey, Morocco, in March 1943 to shore up scanty Allied antisubmarine defenses in the Atlantic approaches to the Straits of Gibraltar. German U-boats had very recently sunk four ships in an Allied convoy about a hundred miles off the coast of Portugal. Over the long term, the Allies wanted to increase air antisubmarine patrols and convoy coverage to protect their preparations for the impending Tunisian offensive and the subsequent invasion of Sicily.

The 1st and 2d Antisubmarine Squadrons operated fifteen B-24s from Port Lyautey, joining two U.S. Navy PBY Catalina squadrons patrolling from Morocco. The two squadrons were assigned to the Northwest African Coastal Air Force for administration and placed under the operational control of the U.S. Navy's Fleet Air Wing 15, which answered to the commander of the Moroccan Sea Frontier. (The Northwest African Coastal Air Force was the Allied organization responsible for air operations in the Mediterranean Sea.)  The AAF units flew their first mission on March 19, despite shortages of spare parts, equipment, and maintenance personnel. Ordinarily, three B-24s flew daily on operational missions, covering an area as far south as 30°N, as far north as Cape Finisterre, Spain, and as far west as a thousand nautical miles from Port Lyautey. Much of the time, the Liberators flew convoy coverage for ships sailing from or approaching the Straits of Gibraltar.

On March 22, three days after the squadrons' first mission, 1st Lt. W. L. Sanford scored the first U-boat kill in the North African campaign. Flying "Tidewater Tillie," he attacked and sank U-524 in the Canary Islands area, more than six hundred miles southwest of Port Lyautey. Patrolling in scattered clouds at twelve hundred feet, the aircrew made a surface-radar contact at a range of about five miles. A few seconds later, the copilot sighted a broad wake. The pilot flew into a cloud and turned to follow the wake. As the aircraft emerged, the crew spotted the submarine. With the sun behind him, Sanford flew two hundred feet above the water at two hundred miles per hour until the B-24 crossed the U-boat. Because of the aircraft's camouflage and Sanford's careful approach, enemy lookouts did not spot the aircraft until it was too late to dive. The bombardier released four depth bombs sixty feet apart, and their explosion broke open the submarine's stern. In less than two minutes, the submarine sank, leaving several survivors clinging to debris.

By June, the B-24 aircrews had spotted and attacked several enemy submarines but they had not sunk another one. The situation improved dramatically in July, following the June 19 reorganization of the 1st and 2d Antisubmarine Squadrons into the 480th Antisubmarine Group, under the command of Col. Jack Roberts. In late June, Dönitz doubled the number of submarines screening the approaches to Gibraltar. In July, under intense pressure from the Bay of Biscay offensive, the U-boats began hugging the Spanish coast as they left their French ports. The coastal mountain ranges of Spain formed a backdrop that interfered with microwave radar detection of surfaced submarines. Once past Cape Finisterre, the U-boats sailed southwesterly off the coast of Portugal. Thus, many submarines were concentrated in a relatively small area of the mid-Atlantic between the Azores and the Straits of Gibraltar, well within range of the 480th Group's B-24s.

From July 5 to July 15, the 480th Antisubmarine Group sighted fifteen U-boats, detecting twelve of them with radar at an average range of eighteen miles. One sighting occurred at nigh. That relatively high number of detections can be attributed to several factors: advanced microwave radar, carefully planned patrols, and the use of Ultra information to plot probable locations. Of the fifteen U-boats sighted, the group attacked thirteen, sank three, and damaged several more. The firs kill was U-951, sunk by a B-24 of the 1st Antisubmarine Squadron on July 7, over four hundred miles west of Lisbon. The next day, a Liberator of the 2d Antisubmarine Squadron destroyed U-232 about two hundred miles northwest of Lisbon. The 1st Squadron scored again on July 12 when it sank U-506 about five hundred miles west of Cape Finisterre.

Sightings tapered off after mid-July as submarines began to travel submerged or at night as near the coast line as possible. Dönitz redeployed most U-boats further west in the mid-Atlantic, beyond the Liberators' range. There they became prey to the U.S. Navy's escort carriers. Between June and October, the escort carriers, guided by Ultra intelligence, located and destroyed nine of the ten refueling submarines operating in the mid-Atlantic. this dealt a sever blow to the offensive capabilities of the entire German submarine fleet.

Although the 480th Antisubmarine Group located no submarines in August, it did engage in antiair operations. The Luftwaffe mounted intense air patrols in the Moroccan Sea Frontier with the long-range, four-engine Focke-Wulf 200 Kondor maritime patrol airplane (FW 200). On the 17th, two FW 200s attacked a single B-24. With two engines knocked out and a wing aflame, the Liberator had to ditch, but not before destroying one enemy aircraft and badly damaging the other. Seven U.S. crew members were rescued at sea. Overall, the 480th's record against German aircraft can be counted a limited success: three aircraft lost versus five enemy FW 200s downed from August through October 1943.

During its peak effort, between March and August 1943, the 480th Antisubmarine Group flew 8,832 combat hours, including 5,742 on antisubmarine patrols, searching for surfaced U-boats. The remaining 3,090 hours were spent escorting convoys approaching the Straits of Gibraltar from four hundred to eight hundred miles out in the mid-Atlantic, beyond the range of U.S. Navy Catalinas.

As the submarine threat decreased in the mid-Atlantic and the approaches to Gibraltar, the Allies redeployed some of their antisubmarine forces to support landings in Italy. Thus, on September 23, the 1st Antisubmarine Squadron moved with ten B-24s from Port Lyautey to Protville, Tunisia. This base was located between Tunis, on the east coast, and Bizerte, on the north coast about thirty-five miles northwest of Tunis. For the first fourteen days, the 1st Squadron operated under the Northwest African Coastal Air Force. On September 4, the B-24s began searching for enemy submarines and shipping between Sicily and Naples. the squadron covered this area twenty-four hours a day until the landing of the U.S. Fifth Army at Salerno, Italy, on September 9, when it extended antisubmarine patrols to cover the sea west of Sardinia and Corsica. One B-24 destroyed three German flying boats northwest of Sardinia. In addition to the antisubmarine patrols, the 1st Squadron flew escort for several Allied convoys and covered the escape of Italian naval vessels from Genoa and Spezia to Malta following Italy's surrender. After returning to Port Lyautey on September 18, the 1st Squadron operated in the Moroccan Sea Frontier until it moved to the United States in November 1943.

That return to the United States marked the final stage in the AAF's withdrawal from its antisubmarine mission. On July 9, 1943, the U.S. Army and the U.S. Navy had agreed that the AAF would withdraw from antisubmarine operations. On August 31, the AAF disbanded the Antisubmarine Command, although the 479the Antisubmarine Group in Great Britain and the 480th Antisubmarine Group in Morocco continued operations through October 1943. The 479th was dissolved on November 11, and its personnel and equipment went to the Eighth Air Force. the 480th returned to the United States in November, to be disbanded on January 29, 1944.