Under which condition is a formation considered "Nonstandard"?

A formation is considered "Nonstandard" when ATC has approved other than standard formation dimensions. This indicates that the parameters of the formation flight deviate from the typically established or expected guidelines. In formation flying, standard dimensions refer to the distances between aircraft, which are usually defined for safety and operational efficiency. If ATC approves modifications to those standard dimensions, this indicates that the flight is operating under specific circumstances that require different spacing or arrangements than normally prescribed.

In contrast, the other conditions mentioned do not inherently denote a nonstandard formation. For example, flying below 1,000 feet AGL does not automatically imply a deviation from standard formation, but rather a standard flying altitude requirement. Similarly, while 2 NM lateral separation can be a factor in operational procedures, it must be assessed against standard definitions set forth in relevant regulations or guidance. Finally, the lack of visual contact between the flight leader and other formation members does not directly define the formation as nonstandard; it simply illustrates a potential challenge in maintaining formation integrity or safety protocols, but may not disrupt the standard dimensions of the formation itself.