Аннотация:One of the spheres of use of a group of drones is group patrolling and observation of large territories. The organization of group patrolling presuppose solution of the problem of planning the flights rotes of a group of drones. At the same time a very popular approach to the formulation and solution of the given problem consists in the reduction it to the multiply traveling salesman problem. The paper considers the problem of planning drones flight routes during group patrolling of large territories. It is assumed that the patrolled territory has an elongated shape and it is divided into a chain of adjacent patrol zones. The territorial waters of State may be as an example. The territory is divided into patrol zones prescribed by individual drone passes through adjacent zones. The flights task for each drone consists in its moving to the given flight zone and also in data operative gathering and in the transmitting of these data to the control point (center, station). Tasks have been fulfilling periodically. The optimization aspect of the routes planning is to minimize the maximum deadlines for completing tasks. This problem is formalized as an integer linear programming problem and solved using a genetic algorithm in the MATLAB environment using the Global optimization Toolbox mathematical package.