Citation: Sałaci´nski, M.; Puchała, K.;
Leski, A.; Szymczyk, E.; Hutsaylyuk,
V.; Bednarz, A.; Synaszko, P.; Kozera,
R.; Olkowicz, K.; Głowacki, D.
Technological Aspects of a
Reparation of the Leading Edge of
Helicopter Main Rotor Blades in Field
Conditions. Appl. Sci. 2022, 12, 4249.
https://doi.org/10.3390/app12094249
Academic Editors: Junwon Seo
and Jong Wan Hu
Received: 18 March 2022
Accepted: 21 April 2022
Published: 22 April 2022
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Article
Technological Aspects of a Reparation of the Leading Edge of
Helicopter Main Rotor Blades in Field Conditions
Michał Sałaci ´nski
1,
*, Krzysztof Puchała
2
, Andrzej Leski
3
, El
˙
zbieta Szymczyk
2
, Volodymyr Hutsaylyuk
2
,
Arkadiusz Bednarz
4
, Piotr Synaszko
1
, Rafał Kozera
5
, Klaudia Olkowicz
1
and Dominik Głowacki
6
1
Air Force Institute of Technology, Airworthiness Division, 01-494 Warsaw, Poland;
piotr.synaszko@itwl.pl (P.S.); klaudia.olkowicz@itwl.pl (K.O.)
2
Faculty of Mechanical Engineering, Military University of Technology, 00-908 Warsaw, Poland;
krzysztof.puchala@wat.edu.pl (K.P.); elzbieta.szymczyk@wat.edu.pl (E.S.);
volodymyr.hutsaylyuk@wat.edu.pl (V.H.)
3
Łukasiewicz—Institute of Aviation, 02-256 Warsaw, Poland; andrzej.leski@ilot.lukasiewicz.gov.pl
4
Faculty of Mechanical Engineering and Aeronautics, Rzeszów University of Technology,
35-959 Rzeszow, Poland; abednarz@prz.edu.pl
5
Faculty of Materials Science and Engineering, Warsaw University of Technology, 02-507 Warsaw, Poland;
rafal.kozera@pw.edu.pl
6
Faculty of Power and Aeronautical Engineering, Warsaw University of Technology, 00-665 Warsaw, Poland;
dominik.glowacki@pw.edu.pl
* Correspondence: michal.salacinski@itwl.pl
Abstract:
The Polish Air Force operates more than one hundred helicopters of the Mi family (man-
ufactured by Mil Helicopters), equipped with metal main rotor blades. The main rotor blades are
among the most stressed components of these structures. For this reason, they are subject to more
frequent inspections during operation than other components. One type of damage detected during
inspections is the local disbonding of fragments of the anti-erosion layer from the leading edge. This
harmless-looking damage is very dangerous, since it quickly leads to the complete detachment of
the layer. The leading edge, unprotected by the metal cover, erodes rapidly. The detached layer,
when thrown away at high speed, endangers other parts of the helicopter, such as the tail rotor,
and may cause damage to other helicopters if flying in formation. The technology supplied by the
manufacturer to date has not encompassed the field repair of this type of damage. Therefore, efforts
were made to develop repair technology for rapid repairs of blades in field conditions during missions
of the Task Force White Eagle in Afghanistan. This article presents the concept of repair technology
feasible in field conditions and presents the results of post-repair edge tests. Test results to identify
the materials used in the construction of the trailing edge are also presented. The results of materials
testing facilitated the development of technological processes, and, in the future, will aid the selection
of a substitute bonding paste system with similar parameters that are essential for repairs.
Keywords: bonding; composite repair; aviation; rotor blades; helicopter
1. Introduction
While the rotor blades of Mi helicopters differ in profile and dimensions, their general
design is similar for every type of helicopter (Figure 1) used by the Polish Armed Forces.
The aluminum alloy spar is the rotor blade component responsible for transferring the
main loads. The leading edge of the blade is equipped with an electric anti-icing device.
A rubber cover and metal shield protect the electric anti-icing device. The trailing section is
composed of a honeycomb metal sandwich structure. The trailing sections are bonded to
the spar.
Appl. Sci. 2022, 12, 4249. https://doi.org/10.3390/app12094249 https://www.mdpi.com/journal/applsci
