Flying became dangerous in the heavy seas and poor visibility. One Sea Hurricane was damaged beyond repair after a serious crash into the safety barrier and another crashed into the sea with the loss of the pilot. The Swordfish crews fared little better. Three aircraft and one crew were lost during the same period. On 9 May "Vindex"s aircraft lift broke down with a burnt out motor. The crew had to resort to manually cranking the lift up and down, taking an hour to go each way. They eventually repaired the lift by moving the capstan motor through holes burned into the bulkheads. During the second deployment by "Vindex" her aircraft flew over 400 sorties in 13 days. The strain on the aircrews began to show and only 35 per cent of the original Swordfish crews were still with the ship when they returned to port. It was during this second deployment that one of the ships officers, Sub-Lieutenant J.M. Morrison invented a blind landing system soon to be used on all the Royal Navy carriers. He modified an ASV radar set which was placed on the flight deck. The system employed the Air Directing Officer guiding aircraft to within of the ship. They could then be picked up on the ASV and brought in astern of the carrier at a height of .