The permitted removal window for a component with a 350 hour Time Between Overhaul is within which range?

The permitted removal window for a component with a 350 hour Time Between Overhaul is within which range?

• A. 315 to 385 hours
• B. 300 to 400 hours
• C. 320 to 370 hours
• D. 340 to 360 hours

Answer: (A)

The window is defined as a range from 90% to 110% of the Time Between Overhaul (TBO). For a TBO of 350 hours, that means 350 × 0.90 = 315 hours and 350 × 1.10 = 385 hours. So the permitted removal window is 315 to 385 hours. This matches the range that spans 315–385 hours, which is why that option is correct. The other ranges either extend beyond that envelope or don’t cover the full 90–110% window around 350 hours.

The window is defined as a range from 90% to 110% of the Time Between Overhaul (TBO). For a TBO of 350 hours, that means 350 × 0.90 = 315 hours and 350 × 1.10 = 385 hours. So the permitted removal window is 315 to 385 hours. This matches the range that spans 315–385 hours, which is why that option is correct. The other ranges either extend beyond that envelope or don’t cover the full 90–110% window around 350 hours.