We are adopting a new airworthiness directive (AD) for all Learjet Inc., Model 45 airplanes. This AD was prompted by changes to the Airworthiness Limitations Section (ALS) of the maintenance manual, which adds life-limits, revises life-limits, or adds inspections not previously identified. This AD requires revising the maintenance program to include new or more restrictive life-limits and inspections. We are issuing this AD to limit exposure of flight critical components to corrosion, cracking, or failure due to life-limits, which if not corrected, could result in loss of roll control, fatigue cracking, or loss of structural components.