24 April 1970 – On 18 April, Abrams requested authority from the Joint Chiefs of Staff to utilize U.S. tactical aircraft based in South Vietnam for a 30-day period. These aircraft would be acting in concert with Operation Menu, the highly classified bombing of PAVN sanctuaries and Base Areas in eastern Cambodia by USAF B-52 bombers. Two days later the Joint Chiefs granted his request. All communications and messages concerning the operation were to be sent through special, secure channels and aircraft conducting the missions were assigned cover targets in Laos in the same way that the B-52s of Menu were assigned false targets in South Vietnam.
The first strike of the operation was launched on 24 April and plans called for the operation to last for only 30 days, until the third week of May. The aircraft were authorized to strike targets in northeastern Cambodia extending 8 miles (13 km) west of the South Vietnamese border. On 25 April, the boundary was extended to a depth of 18 miles (29 km). The onset of the Cambodian Campaign by U.S. and South Vietnamese forces on 29 April forced an early termination on 4 May after only 156 had been flown.
Operation Patio was quickly superseded by the much more extensive and destructive Operation Freedom Deal.
Source: Wikipedia