Which light can be inoperative for a CAT II approach?

• A. SFL (Rabbit)
• B. CL
• C. TDZ
• D. HIRL

Answer: (A)

For CAT II operations, not every component of the runway lighting system must be working, because the primary cues come from the instrument approach and the main runway lights. The sequencing flashing lights, often called Rabbit lights, provide an additional visual cue along the approach but are not essential to determine the runway position during a CAT II approach. They can be inoperative and a CAT II approach can still be conducted safely as long as the critical lighting that supports depth perception and runway alignment remains operational. In contrast, touchdown zone lights, runway centerline lights, and high-intensity runway lights supply key visual references required for low-visibility approaches, so their failure would prevent CAT II operations. Therefore, the light that can be inoperative for a CAT II approach is the Sequenced Flashing Lights, the Rabbit.