Costco Wholesale

The aircraft is at 1850 ft and 164.6 kt, clearly in departure/climb phase from KBFI (Δhdg 4°, 8 nm behind). KBFI is the home base and the only ALIGNED candidate within plausible range for a short hop; the plane likely just departed and is turning back or doing a local maneuver. Past predictions show a strong pattern of returning to KBFI from nearby airports (e.g., 2026-05-29 KHLN→KBFI correct). KLAX is ALIGNED at 842 nm but too far for a climb-out leg, so it's a plausible alternate if this is a longer departure.