VESTNIK of Samara University. Aerospace and Mechanical EngineeringVESTNIK of Samara University. Aerospace and Mechanical Engineering2542-04532541-7533Samara National Research University312510.18287/2541-7533-2016-15-3-178-188UnknownMathematical description of the interaction between a probing microwave signal and the helicopter main rotor bladeDanilinA. I.<p><span lang="EN-US">Doctor of Science (Engineering), Professor<br />Head of the Radio Engineering Department</span></p>aidan@ssau.ruZhukovS. V.<p><span lang="EN-US">postgraduate student </span></p>zhukovsv91@inbox.ruPopovM. S.<p><span lang="EN-US">postgraduate student </span></p>maxpopov1990@mail.ruSamara National Research University091220161531781880901201709012017Copyright © 2017, VESTNIK of Samara University. Aerospace and Mechanical Engineering2017<p>The paper deals with the non-contact method of monitoring the integrity of the main rotor blades of a helicopter. The available methods of monitoring the integrity of the main rotor blades of the helicopter are labor-intensive to implement, their reliability is low and they do not allow drawing a general picture of the state of rotor blades in flight. To solve this problem a method based on illumination of the blades by a probing microwave signal is proposed. Particular attention is given to the calculation of the power of the signal reflected from the helicopter main rotor blades. In deriving analytic equations it is assumed that a rotor blade is an undeformed flat metal surface. As a result, a spatial-temporal model of a probing SHF signal reflected from a helicopters main rotor blade has been obtained and the parameters of the model make it possible to assess the operational status of the main rotor of the helicopter.</p>Effective radar cross-sectionsignal powerbladehelicoptermain rotorprobing microwave signalarea of exposed surfaceЭффективная отражающая площадьмощность сигналалопастьвертолётнесущий винтзондирующий СВЧ-сигналплощадь облучаемой поверхности[1. Moir Ch.I. Helicopter blade position detector: Patent US, no. 8190393. Publ. 29.05.2012, PCT/GB2007/001823.][2. Borisov Y.A., Levko G.V., Muravev A.Y. Sposob izmereniya nesokonusnosti lopastey nesushchego vinta vertoleta i ustroystvo dlya ego osushchestvleniya [Method to measure non-in-track condition of helicopter rotor blades and device for its realization]. Patent RF, no. 2415053 C1, 2011. (Publ. 27.03.11, bull. no. 9).][3. Antropov V.F., Martynov A.K., Burakov G.B., D'yachenko A.S. Eksperimental'nye issledovaniya po aerodinamike vertoletov [Experimental study of helicopter aerodynamics]. Moscow: Mashinostroenie Publ., 1980. 240 p.][4. Vertolet Mi-8. Tekhnicheskoe opisanie. Kniga 1 [Helicopter MI-8. Technical details. Book 1]. Moscow: Vneshtorgizdat Publ., 1986. 120 p.][5. Finkelshtein М.I. Osnovy radiolokatsii [Basics of radiolocation]. Moscow: Radio i Svyaz' Publ., 1983. 536 p.][6. Saybel А.G. Osnovy radiolokatsii [Basics of radiolocation]. Moscow: Sovetskoe Radio Publ., 1961. 384 p.][7. Shelukhin O.I. Radiosistemy blizhnego deystviya [Short-range radio systems]. Moscow: Radio i Svyaz' Publ., 1989. 230 p.][8. Bronshtien I.N., Semendyaev K.A. Spravochnik po matematike [Reference book on mathematics]. Leningrad: OGIZ Publ., 1948. 556 p.]