The forty Backfires consequently sent by C-in-C Northern Fleet to attack the CAVALRY convoys were routed individually to a rendezvous point midway between Newfoundland and the entrance to the English Channel. The approach of the Backfires to their targets was not detected in time for a fully effective air defence disposition to be taken up by the CAVALRY convoy escorts, several of which were busily engaged in prosecuting submarine contacts. The Backfire attacks, with AS-6 air-to-surface missiles, therefore caught the NATO force at something of a disadvantage. The Aegis-fitted support group was racing to position itself with the main body of the convoys. The casualties were heavy. Seven transports were hit, four of which sank quickly. The loss of life was appalling. Of the eighty AS-6 missiles launched by the Backfires, from ranges of 220 down to 160 kilometres, no less than thirty reached a target. The escorting warships suffered as well as the transports. Only the fact that in some cases two, or even three, missiles hit the same ship limited the number of escorts sunk or damaged to five. Fifteen Backfires were destroyed.
Within two hours of the Backfire attack, the next submarine attack took place. This was less successful than the Russians had hoped. Owing to the timely arrival of a British support group, a drastic alteration of course by the convoys during the air strike, and harassment by maritime patrol aircraft, the Soviet submarines were unable to co-ordinate their attack either with each other or with the Backfires. During the next twelve-hour period three Soviet submarines were sunk, for the loss of only one more transport.
The number of Soviet submarines now in position to attack the convoys was less, in fact, than either C-in-C Northern Fleet or SACLANT had expected. There were several reasons for this. First, four Soviet submarines in transit, at high speed, had been destroyed by ASW operations in the Greenland-UK gap, unknown as yet to the Soviet commander-in-chief. Second, signals to certain Soviet submarines, ordering them to take up new patrol positions, had not been received. This involved mainly the submarines which had been sent on anti-shipping patrol prior to the declaration of the War Zone. Third, two diversionary fast convoys had been sailed twenty-four hours before the CAVALRY convoys, one along a more northerly route and another along a more southerly one. Each had attracted a group of Soviet submarines towards intercepting positions. The diversionary convoys, being free to follow highly evasive courses, which were carefully judged, had succeeded in reducing by a quarter the number of submarines which could be brought into contact with the CAVALRY convoys, once the Soviet command had realized what was going on. Finally, the use of unusually high speeds by these submarines, under orders to intercept CAVALRY at all costs, had led to several of them being detected by various means and attacked by maritime aircraft from Iceland and the Azores.
In addition to the most welcome reinforcement of the sadly depleted CAVALRY escort force by the British support group, of which the anti-submarine cruiser HMS Invincible formed part, two of JACWA’s escort groups, one with a British escort carrier, and a number of Dutch and German, as well as British frigates and destroyers, had joined the convoys by 12 August. It looked as if the worst part of the ocean transit was now over. CAVALRY would soon come under the umbrella of the United Kingdom Air Defence Region.
