Some authors have stated heavy losses in carriers and veteran aircrews at Midway permanently weakened the Imperial Japanese Navy. Parshall and Tully, however, have stated that the losses in veteran aircrew, while heavy (110, just under 25% of the aircrew embarked on the four carriers), were not as bad for the Japanese naval air-corps as a whole. The Japanese navy had 2,000 carrier-qualified aircrew at the start of the Pacific war. A few months after Midway, the JNAF sustained similar casualty rates at both the Battle of the Eastern Solomons and Battle of Santa Cruz. It was these battles, combined with the constant death of veterans during the Solomons campaign, which weakened Japan. However, the loss of four large fleet carriers, and over 40% of the carriers' aircraft mechanics and technicians, plus the flight-deck crews were very damaging to the Japanese carrier fleet. After the battle and were the only large carriers of the original Pearl Harbor strike-force left for offensive actions. Of Japan's other carriers, was the only Fleet carrier that could be used with "Shōkaku" and "Zuikaku", while , , and , were second-rate ships. By the time of the Battle of the Philippine Sea, while the Japanese had somewhat rebuilt their carrier forces, the planes were flown by inexperienced pilots. 