Summary
We are revising an earlier proposed airworthiness directive (AD) for all Boeing Model 757-200, -200PF, -200CB, and -300 series airplanes. The original NPRM would have required an inspection of the two spring arms in the spin brake assemblies in the nose wheel well to determine if the spring arms are made of aluminum or composite material, and repetitive related investigative/corrective actions if necessary. The original NPRM resulted from reports of cracked and broken aluminum springs. This action revises the original NPRM to include a parts installation paragraph and to provide options for terminating the repetitive actions. We are proposing this supplemental NPRM to detect and correct cracked or broken springs. A cracked or broken spring could separate from the airplane and result in potential hazard to persons or property on the ground, or ingestion into the engine with engine damage and potential shutdown, or damage to the airplane.