2012-NM-094-AD The Boeing Company Model 747‑100, 747‑100B, 747‑100B SUD, 747‑200B, 747‑200C, 747‑200F, 747‑300, 747‑400, 747‑400D, 747‑400F, 747SR, and 747SP series airplanes; and certain Model 757-200, -200PF, and -300 series airplanes