On 3 September 1942, "Avenger", under the command of ex-Swordfish pilot Commander Anthony Paul Colthust, left Britain for Iceland to take part in Convoy PQ 18. The weather was cold, and in heavy seas one of her Sea Hurricanes broke its restraints and was lost over the side. The ship was located at sea by a Luftwaffe Focke-Wulf Condor, and shortly after arriving in Iceland, "Avenger" was subjected to a bombing attack by another Condor. Both of the bombs it dropped missed the ship, but two houses ashore were demolished. In their determination for PQ 18 to be a success, the Royal Navy created the largest escort force ever assembled for an Arctic convoy up until that time. Under command of Rear-Admiral Robert Burnett, the force included "Avenger"—the only aircraft carrier—which was joined by the anti-aircraft cruiser and 16 fleet destroyers, plus the normal complement of close support sloops, corvettes, and minelayers. "Avenger" and "Scylla", with the close escort destroyers and , left Iceland and joined the convoy late on 9 September 1942. One of her Swordfish aircraft was immediately sent up on an anti-submarine patrol. Bad weather prevented any flying for the following two days, but the weather cleared by noon on 12 September. The clearer skies revealed a Blohm &amp; Voss BV 138 flying boat shadowing the convoy. Four Hurricanes took off to intercept it but could not find it in the clouds. Later the same day, a Swordfish on anti-submarine patrol sighted two U-boats; they had dived by the time the escorts got into position.