An interesting relationship between Iwo Jima and the B-29’s at Saipan. In fact Nimitz made an order today the 24th to focus on Iwo Jima to protect the B-29’s.
http://www.ibiblio.org/hyperwar/USN/USN-Ops-XIV/USN-XIV-1.html
The first B-29 from the United States landed on Saipan on 12 October, and by the end of November there were enough to launch the first strike against Japan.12 Before that happened the Japanese, realizing what they were in for, counterattacked the Saipan fields twice, and ineffectively; but after the first B-29 raid against the Japanese homeland, on 24 November, they hit back hard. Early on the 27th, as the Superforts were loading bombs for a second strike, two twin-engined Japanese bombers came in low, destroyed on B-29 and damaged eleven others. Around noon the same day 10 to 15 single-engined fighters evaded the radar screen, destroyed three more B-29s and severely damaged two. These raids, which continued intermittently until 2 January, succeeded in damaging six and destroying eleven B-29s.
Since the loss of a B-29 was serious, strenuous efforts were made to intercept or stop these raids. Vice Admiral John H. Hoover, Commander Forward Area, stationed two destroyers 100 miles northwest of Saipan as early warning pickets. They detected some raids, but not all. Since it was rightly suspected that the Japanese bombers staged through Iwo Jima, Admiral Nimitz gave that island top priority on 24 November. He ordered the curtailment of VII A.A.F. strikes on bypassed islands and shipping in order to concentrate a joint aerial bombing and naval bombardment on Iwo, 8 December.