Autorotation application analysis for the safe-landing field-tests

Aeronautical and Space-Rocket Engineering

Dynamics, ballistics, movement control of flying vehicles


Аuthors

Morozov A. A.1*, Ilyukhin S. N.2**, Khlupnov A. I.1***

1. Moscow helicopter plant named after M.L. MiL, 26/1, Garshina str., Tomilino, Moscow region, 140070, Russia
2. Bauman Moscow State Technical University, MSTU, 5, bldg. 1, 2-nd Baumanskaya str., Moscow, 105005, Russia

*e-mail: morozov_bmstu@mail.ru
**e-mail: iljuchin.stepan@bmstu.ru
***e-mail: fkz1913@mail.ru

Abstract

This article is devoted to the topical issue of applying the autorotation phenomenon in emergencies while helicopter engine malfunctioning to ensure safe landing. In the beginning of the article, the basic theoretical data on the physics of the helicopter rotor autorotation process is presented, and the conditions for the occurrence of a stable autorotation mode are considered. The objective of the overrunning clutch is described on the example of the MI-8 helicopter. Further, the characteristic sets of initial conditions and spatial zones of the autorotation commence are considered, staying in which ensures or does not ensure a safe landing. It was emphasized that the key for the correct entry performing into autorotation is maintaining the rotor rotations. Two techniques for the rotor speed drop terminating in emergencies are presented. Besides, the article considers the pilot’s actions in case of an emergency associated with engine malfunctions in Mi-8, 24, 28 helicopters, ensuring stable autorotation mode and a safe landing. Based on the results of a series of field tests, a scientific substantiation was also presented for the main parameters selection, allowing the helicopter landing with idle engines, as well as recommended landing profile for the rotor self-rotation was elaborated. By the results of processing of video recording of ten landings, the values of the height of the helicopter pitch increasing commence are presented. The pitch angle value and height, at which this pitch angle was reached, as well as vertical and horizontal components of landing velocities are presented as well. In conclusion, the landing technique while autorotation mode performing, formed as the result of flight test data analysis with the listing numeric parameters of the flight is presented.

Keywords:

rotor self-rotation, emergency helicopter landing, autorotation modes, control algorithm

References

  1. Snyder R. Occupant Impact Injury Tolerances for Aircraft Crashworthiness Design. SAE Technical Paper 710406, 1971. DOI: 10.4271/710406

  2. Shanahan D.F. Human Tolerance and Crash Survivability. Paper presented at the RTO HFM Lecture Series on “Pathological Aspects and Associated Biodynamics in Aircraft Accident Investigation”, held in Madrid, Spain, 28-29 October 2004; Königsbrück, Germany, 2-3 November 2004, and published in RTO - EN-HFM-113. URL: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.212.5449&rep=rep1&type=pdf

  3. Pronin M.A., Ryabykina R.V., Smyslov V.I. Experimental study of the aircraft forced vibrations while the engine blade break-away. Aerospace MAI Journal, 2019, vol. 26, no. 2, pp. 51-60.

  4. Haddon D., Colombo P.G. Workshop background, objectives. Helicopter Ditching, Water Impact & Survivability Workshop (5-6 December 2011, Cologne, Germany), https://www.easa.europa.eu/newsroom-and-events/events/helicopter-ditching-water-impact-survivability

  5. Nedelko D.V., Safiullin A.F. Finite element method application for determining water landing parameters of airplanes and helicopters of various types. Aerospace MAI Journal, 2018, vol. 25, no. 2, pp. 61-72.

  6. Permyakov C.H., Savel’ev E.A. Izvestiya Samarskogo nauchnogo tsentra Rossiiskoi akademii nauk, 2014, vol. 16, no. 1(5), pp. 1536-1539.

  7. Luo C., Liu H., Yang J.-L., Liu K.-X. Simulation and Analysis of Crashworthiness of Fuel Tank for Helicopters. Chinese Journal of Aeronautics, 2007, vol. 20, no. 3, pp. 230-235. DOI: 10.1016/ S1000-9361(07)60037-5

  8. Kindervater C.M. Aircraft and Helicopter Crashworthiness: Design and Simulation. Crashworthiness of Transportation Systems: Structural Impact and Occupant Protection. NATO ASI Series (Series E: Applied Sciences), vol. 332, pp. 525-577. DOI: 10.1007/978-94-011-5796-4_20

  9. Lazutin E.A., Chubarev I.V. Inzhenernyi zhurnal: nauka i innovatsii, 2017, no. 12(72). DOI: 10.18698/2308-6033-2017-12-1713

  10. Bisagni C. Crashworthiness of helicopter subfloor structures. International Journal of Impact Engineering, 2002, vol. 27, no. 10, pp. 1067-1082. DOI: 10.1016/S0734-743X(02)00015-5

  11. Nikolaev E.I., Nedelko D.V., Shuvalov V.A., Yugai P.V. External airbags application onboard a helicopter. Aerospace MAI Journal, 2019, vol. 26, no. 3, pp. 91-101.

  12. Kim H., Kirby B.P.D. Investigation of External Airbags for Rotorcraft Crashworthiness. AIAA Journal of Aircraft, 2006, vol. 43, no. 3, pp. 809-816. DOI: 10.2514/1.17506

  13. Lu Zi, Seifert M, Tho Cheng-Ho. Inflating rotorcraft external airbags in stages. Patent US 9452843B1, 27.09. 2016.

  14. Na L., Zhefeng Y., Yi F. Shock absorber using inward-folding composite tube and its application to a crew seat: numerical simulation. Aerospace MAI Journal, 2018, vol. 25, no. 4, pp. 178-188.

  15. Littell J.D., Jackson K.E, Annett M.S., Seal M.D., Fasanella E.L. The development of two composite energy absorbers for use in a transport rotorcraft airframe crash testbed (TRACT 2) full-scale crash test. American Helicopter Society 71st Annual Forum (Virginia, 5-7 May 2015). URL: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160005978.pdf

  16. Coltman J.W. Rotorcraft crashworthy airframe and fuel system technology development program. U.S. Department of Transportation. Federal Aviation Administration. October 1994. URL: http://www.tc.faa.gov/its/worldpac/techrpt/ct91-7.pdf

  17. Morozov A.A. Molodezhnyi nauchno-tekhnicheskii vestnik, 2013, no. 8. URL: https://docplayer.ru/47287337-Razrabotka-metodiki-issledovaniya-avtorotacii-pri-avariynyh-situaciyah.html

  18. Aviatsionnye pravila. Ch. 29. Normy letnoi godnosti vintokrylykh apparatov transportnoi kategorii (Civil Aviation Safety Regulations. Part 29. Airworthiness standards for rotorcraft in the transport category). Moscow, Aviaizdat, 2018, 185 p.

  19. Padfield R.R. Learning to Fly Helicopters. McGraw-Hill Professional, 1992, 354 p.

  20. Kalugin V.T. (ed.) Aerodinamika (Aerodynamics), Moscow, MGTU im. N.E. Baumana, 2017, 608 p.

  21. Karman T. Aerodynamics: selected topics in the light of their historical development. N.Y., Cornell University Press, 1954, 203 p.

mai.ru — informational site of MAI

Copyright © 1994-2020 by MAI