To maintain a safe level of separation, the JetBlue aircraft halted its climb and leveled its altitude before eventually climbing again to cruising altitude. During communications between the aircraft and ATC, Curaçao‘s control center confirmed that the military tanker was not visible on their screens either.
With its transponder not switched on, the aircraft would also not have been visible to JetBlue‘s Traffic Collision Avoidance System (TCAS), which relies on transponder signals from nearby aircraft to warn of potential collisions. While this near-miss occurred during daylight hours, the situation could have been a lot worse if it happened at night during minimal visibility.