There are certain types of military flights that require aircraft to operate in close proximity to one another. An example of such an operation is aerial refueling. For these circumstances a procedure known as MARSA has been created. MARSA stands for “Military Authority Assumes Responsibility for Separation of Aircraft.” It is used when two or more IFR aircraft will need to operate near each other with less than standard IFR separation. The pilots involved decide when to accept MARSA. Once MARSA is declared the controller may allow the aircraft to operate as they desire with respect to one another. During the rendezvous, controllers should not issue any instructions to the aircraft involved. Once the rendezvous is complete, issue instructions to the lead aircraft.
When the aircraft would like to separate, they must position themselves so that standard ATC separation exists. Once the controller has standard separation, he advises that MARSA is terminated, and assumes responsibility for separation between the aircraft.
Both civilian and military aircraft may operate as a formation. In these cases, the controller controls the formation as he would a single aircraft. The pilots involved in the formation have responsibility for separation from one another.
Pilots are expected to maintain a standard formation. A standard formation is one where all aircraft are within one mile of each other horizontally, and 100 feet vertically. A pilot may request a non-standard formation dimension; however, this must be approved by ATC.
The 7110.65 specifies additional separation for formation flights. Those will be covered in later lessons.
ATC only communicates with the lead aircraft of the formation. Only the lead aircraft is required to operate his transponder. All radio transmissions with the lead aircraft should end with the term "flight," to remind the controller and pilot that the instruction is to a group of aircraft. For example, "Air Force four zero zero three flight." When making traffic calls to other aircraft about a formation, include the number of aircraft in the formation. For example, "traffic twelve o'clock, five miles, opposite direction, a flight of four F-15s, one thousand feet above you."
When aircraft seek the breakup their formation, the pilots involved with the formation have responsibility for separating themselves until standard ATC separation exists and ATC issues clearances to each aircraft.
{Reference: FAAO 7110.65 2-1-11 and 2-1-13}