TY JOUR TI Assessment of the economic efficiency of combining navigation tools to ensure the reliability of air navigation in special conditions KW air navigation KW Arctic KW oceanic flights KW payback period KW sparsely populated areas KW cost efficiency JO Journal of Applied Research AU Sagitov, D.I. AU Titova, K.A. AU Sidorkina, A.E. PY 2026 IS 0 PB ITBO University