What must an aircraft transmit when it is blind?

When an aircraft is "blind," it means that the pilot has lost visual contact with the formation and may be unable to determine their position relative to other aircraft visually. In this context, the correct transmission includes the phrase "Blind," which specifically communicates to other formation members that visual reference has been lost. The inclusion of the altitude in feet provides additional information necessary for other pilots to understand the situation and assist if needed.

The phrase used in this context indicates that the aircraft is still operational and functioning; however, it highlights the critical need for communication to maintain safety and awareness within the formation. By using "Blind," the pilot clearly conveys their situation, which allows other members of the formation to respond appropriately.

In contrast, other options use different terms that do not convey the same urgency or specifics. For instance, phrases like "Lost" or "Clear" suggest different situations that do not accurately reflect the blind condition. Visual references suggest that contact is still maintained, which contradicts the condition being described. Thus, the phrasing of the correct answer is crucial for ensuring clarity and safety in formation operations.