Light Transport Aircraft Research Articles

Reducing the effect of engine failure on the aerodynamic performance of the light transport aircraft model

Recently, aircraft engine manufacturers have shown increased interest in developing hybrid powerplants, which are a combination of gas turbine engines (GTE) with electric motor-generators. The use of the hybrid powerplant makes it possible to increase the fuel efficiency of an airplane, as well as to create new configurations with improved aerodynamic and thrust characteristics. The fuel efficiency improvement is achieved as a result of optimizing the powerplant operation mode to meet the cruising flight requirements, compensating insufficient power during the takeoff and go-around procedures by activating battery-powered electric motors. The creation of new configurations with improved performance can be ensured due to the synergetic effect of the propeller-airframe interaction. Successful flight tests of the hybrid powerplant prototypes in light aircraft configurations allow us to rely on their possible application in the future regarding the projects of new propeller-driven aircraft. The potential benefits of using new powerplants on local airlines can lead to both fuel savings and carbon emission reduction. Short-term maintaining a safe flight mode is also practical in case of one engine failure when using multiple power sources. The power, generated by an electric generator connected to the running engine, can be used both for the electric motor drive of the tip propellers and for rotating the thrust producer of the failed engine. The paper presents the study results of the critical engine failure effect on the aerodynamic performance of the light transport aircraft model obtained as under available electrical transmission as under non-available one between a running and a failed engine. Experimental studies were carried out in a low-speed wind tunnel T-102 TsAGI. The simulation of the electric transmission operation was carried out by setting the operation mode of two power-plant simulators corresponding to the half value of the load factor of one engine propeller Bo in the take-off mode.

Забезпечення статичного балансування легкого транспортного літака під час зміни його маршових двигунів

The process of improving the existing aircraft fleet through the development of modifications has become widespread in both domestic and foreign aircraft manufacturing. Under modern conditions, no country in the world is capable of simultaneously modernizing all types of aircraft. Economic and scientific-technical resources are usually directed toward developing those types for which there is the greatest demand. Limiting the number of types in conjunction with developing modifications for existing aircraft significantly contributes to increasing the efficiency of the entire air transport system. Objectively, there are several reasons for modifications in transport-category aircraft. The first reason is associated with increasing discrepancies between technical and economic indicators. The second reason is related to the use of this type of transport in practical human activities, which is progressively expanding. The third reason is the influence of time. Creating modifications allows to a certain extent to resolve the contradiction between the deadlines for creating complex modern technology, which have increased, and the accelerated pace of scientific and technological progress. The subject of this study is the process of ensuring static balancing of a light transport aircraft during the replacement of its propulsion engines. The goal is to develop models for ensuring the static balancing of a light transport aircraft (LTA) in conditions involving changes in its propulsion engines and reconfiguring the lifting surface system while minimizing the aerodynamic quality costs for balancing changes in the LTA. Tasks: Determine the process of ensuring static balancing of transport category aircraft considering the coefficient of static stability degree; peculiarities of applying this coefficient in balancing a LTA; establish the correlation between the coefficient of static stability degree and the aerodynamic polar of a balanced LTA; quantitatively evaluate and minimize the losses of wing aerodynamic quality to achieve static balancing of the LTA. The obtained scientific results enable both the balancing of a LTA and the minimization of aerodynamic quality losses. Conclusions: Based on the obtained dependencies and their numerical analysis, it has been established that when replacing the engines of a light transport aircraft with a payload capacity of 9.1 tons, the coefficient of static stability of 0.15 complies with the requirements of the Airworthiness Standards for Transport Category Aircraft. During the numerical analysis, it was also determined that for such an aircraft, the aerodynamic quality losses amounted to 7%–9%, which is acceptable for the considered aircraft type.

Use of Poke-Yoke for Right Manufacturing and Installation

Hindustan Aeronautics Limited, Transport Aircraft Division, Kanpur manufactures HAL DO-228 a Light Transport Aircraft. Manufacturing of HAL DO-228 commenced as licensed production with Technology transfer from M/s Dornier GmbH, Germany. All the design data for manufacturing of parts, the manufacturing tooling and the processes were given under the agreement for Transfer of Technology. Number of aircraft have been built over a period spreading to more than two decades starting from the year 1984. In the recent years, we faced two distinct problems. One, defect occurred during manufacturing of two wing spar components. Another, operator faced problem due to wrong fitment of a part. We present these two interesting cases which were resolved by adopting poka-yoke methods.

Literature Review on Air Conditioning Heat load Analysis of a Cabin

Abstract: Air conditioning system is necessary in automobile to maintain the comfort condition. Therefore, it is important to study transient response of vehicle under real driving conditions. The Heat Balance Method (HBM) is used for estimating the heating and cooling loads which develops inside the vehicle cabin. The Load Calculation of Automobile Air Conditioning System is calculated and presented. An hourly cooling load is calculated in Tirunelveli region with respect to its latitude. Tons of refrigeration required is also found out from the cooling load calculation and a review on cooling load calculation is also presented. This study gives overall cooling load and AC power consumption which can be used by HVAC engineers to design more efficient car AC systems. Only by knowing the cooling load and source of thermal load, we can develop intelligent system to reduce AC consumption. Environmental Control System (ECS) is a generic term used in aircraft industry for maintaining the required air temperature and pressure inside passenger and crew compartment. The real challenge for an ECS is to operate and supply adequate cooling over a wide range of ground and flight conditions in a most reliable and efficient manner. The most important aspect of ECS is to know the cabin heat loads during air cooling or air heating phases. A precise calculation of aircraft heat load would be a long process requiring detailed knowledge of the aircraft structure and of the quantities involved in the mechanism of heat pick up and interchange in the cabin. This paper describes a method that may be applied in calculating the heat load for any aircraft and calculations are shown for a typical light transport aircraft under the conditions that, the cabin altitude is maintained within 0 ft to 8000 ft (2438.4m) for the aircraft altitude of 0 ft to 25000ft (7620m). The system shall be capable of maintaining temperatures within 59°F to 75°F (15°C to 30°C).

Analysis of the performance of an aircraft powered by hybrid propulsion

Travel is an inseparable part of human life. It is connected not only with private life but also with business life. People want to travel more, farther and faster. That is why air transport is currently one of the fastest-growing areas of passenger transport, and airlines carry more and more passengers from year to year. Due to the growing negative impact of air transport on the natural environment, research aimed at the development of technologies to reduce the negative impact of air transport is becoming more and more important. One of the possibilities for improving the situation is the use of alternative energy sources, limiting the emission of greenhouse gases into the atmosphere. The paper aimed to analyze the meaningfulness of replacing the classic power unit in a light transport aircraft with a hybrid, combustion-electric power unit. Analyzes were made with the use of simulation methods for the PZL M-28 aircraft.

Engine Exhaust Stub Sizing for Turboprop Powered Aircraft

Turboprop engines are widely used in the commuter or light transport aircraft (LTA) turboprop engines, because they are more fuel efficient than the propeller, which has a low jet velocity, at flight velocities below 0.6 Mach. For short distances, turboprop engines are more fuel efficient than jet engines, because the light weight assures a high power output per unit of weight. In addition, turboprops are known for their efficiency at medium and low altitudes. Turboprop engines require an exhaust stub (or nozzle) to duct the engine exhaust flue gas outboard of the aircraft. The design of these exhaust stubs is dictated primarily by the aircraft configuration. During the exhaust stub design, full flow at bends and in diffusing sections must be realized by following the established practice for the design of internal flow ducts. Otherwise, the flow will separate from the wall, causing unnecessary pressure loss and reducing the effective flow area. This paper discusses some of the many variations in exhaust stub design, and examines how they influence the performance of the engine, the performance of the aircraft, and the manufacturing aspect. The authors carried out a detailed analysis on the influencing parameters, such as the location, orientation, flange dimension, and geometric effective area of exhaust port. On this basis, the authors determined the jet temperature at exhaust stub exit and temperature at exhaust stub exit plane and nacelle midsection were determined at both static and cruise condition, laying the data basis for further analysis on the exhaust temperature effects over the nacelle and aircraft surfaces.

Relationship Between Wingspan and Fuselage Length in Aircraft According to Engine Types

The study aims to explain the size relationship between wingspan and fuselage length, which are the two basic design parameters that a designer is most curious about. Within the scope of the study, the relationship between take-off mass, fuselage length and wingspan of a total of 601 aircraft was questioned for single-piston, twin-piston, turboprop, and jet aircraft types. Power correlations were used for mass-based sizing of wingspan and fuselage length. In mass-based sizing, bad correlations were found for fuselage length for single-piston airplanes and good correlations for turboprops and jets. In terms of wingspan to fuselage length ratio (b/lfus) jets showed a more pronounced trend, ranging from 0.7 to 1.1, while other aircraft types showed different trends, ranging from 0.9 to 1.7. In general, racer, homebuilt, aerobatic, and light transport aircraft have low b/lfus ratios, while motor gliders, firefighters, patrol, and agricultural aircraft have high b/lfus ratios. The study is valuable in that it fills a gap in the literature by considering the relationship between wingspan and fuselage length both with correlations over mass and by revealing statistics according to aircraft types over proportional relationship.

Algorithm for Optimizing the Design Parameters of a Light Transport Aircraft at the Stage of Preliminary Design

In this paper, the optimization of design parameters of light transport aircraft has been carried out. The proposed algorithm, in this paper, provides the calculation of the optimal values of take-off weight and fuel efficiency coefficient taking into account the geometric parameters of the aircraft wing, i.e., aspect ratio and taper ratio using genetic algorithm for multi-objective optimization. The design parameters obtained by the Pareto front are presented and compared with the similar type of aircraft.

Laki transportni avion De Havilland DH104 Dove u naoružanju Jugoslovenskog ratnog vazduhoplovstva

The paper deals with the history of the use of the De Havilland DH104 Series 2B Dove light transport aircraft in the Yugoslav Air Force. Two aircraft of this type were ordered in Great Britain at the end of 1951, based on military aid. They were completed in June 1953. Upon arrival in Yugoslavia in September 1953, both aircraft were handed over to the 119th Aviation Regiment by order of the Commander of the Air Force from October 2, 1953. Dov YU-ABN received military registration number 9571 and YU-ABO number 9572. Later, YU-ABN received a new military registration number 72201 and YU-ABO number 72202. One of the two Dovs was transferred to the Aviation Military Academy in 1957. In July 1969, the Dov that flew in the VVA was transferred to the overhaul institute for repairs, but it was abandoned. Already in September, the plane that was in the 119th Aviation Regiment was transferred to the VVA, where it will remain until December 1970, when both planes will be scrapped

Effect of engine failure on aerodynamic characteristics of a light transport aircraft model

In-flight engine failure has always been a hazardous situation in case of a single-engine aircraft associated with losing altitude and making a landing within the available gliding range. In the event of a multi-engine aircraft, this situation improves markedly due to the potential flight continuation. The necessary conditions to continue a flight are available excess thrust, satisfactory aerodynamic performance, and a fixed-wing control. If the half of engine thrust is lost, which adversely affects a rate of climb, the most critical flight modes are the take-off and go-around procedures performed at low altitudes using the engine asymmetric thrust. Ensuring flight safety in these modes requires extensive experimental studies in wind tunnels to simulate the basic flight envelope with an inoperative engine. The aim of studies is the effect of a critical engine failure on the aerodynamiccharacteristics of an aircraft model as well as ensuring the required efficiency of the flight controls to dampen the yaw and roll moments that arise during an asymmetric thrust flight. The complexity of solving the problem is determined by the necessity of recovering from the substantial yaw, roll moments and by a significant decrease in the wing lifting efficiency along with an increase in a drag force which limits a climb rate and aircraft control. This article presents an analysis of the effect of critical engine failure on the aerodynamic characteristics of a light twin-engine transport aircraft model in the wing take-off and landing configurations. The aircraft aerodynamic configuration is made according to the classic pattern with the high-mounted tapered wing and deck-type empennage. The high lift devices comprise a double-slot hinged flap with a fixed deflector. The aircraft is equipped with a loading ramp with a relatively short flat rotatable part of the lower fuselage surface. Experimental studies of the longitudinal and lateral characteristics of the model with installed simulators of a power plant were carried out in TsAGI low-speed wind tunnel T-102. The analysis of engine failure effect on the model aerodynamics was executed in changing the load factor within the range B = 0.3…2. The capabilities to dampen the yaw and roll moments, using the primary flight controls (rudder and ailerons), were determined.

Strategi Pemilihan Pesawat Angkut Militer Produksi PT. Dirgantara Indonesia Untuk Mendukung Industri Pertahanan Dalam Negeri

Indonesian Navy flights as an integral part of the SSAT have several functions, one of which is to provide rapid logistical support. Based on considerations of function and mobilization capabilities, medium-sized military transport aircraft are the main choice in providing rapid logistical support. The advantages of this function and mobility also make military transport aircraft capable of carrying out additional tasks assigned to their guiding squadron, namely the 600 Air Wing Squadron. The additional tasks are Search and Rescue (SAR), Air Medical Evacuation (EMU) and VIP Flights. Currently, there are 11 elements of the NC212-200 aircraft owned by Puspenerbal, with a description of 7 active elements, 4 disposal processes. In 2017, Puspenerbal received the Beechcraft King Air 350i light transport aircraft, but several operational requirements were not met to carry out the main function as an element of fast logistics support provider, so this element was prioritized to carry out additional functions such as VIP flights. The results of the analysis using the Analytic Hierarchy Process (AHP) method with the help of the Expert Choice 11 Application show the weight of the criteria for selecting medium military transport aircraft, namely Navigation and Communication Equipment 46.4%, Short Take-off and Landing (STOL) Ability 31.7 %, Transportability 15.3%, and Flying Ability 6.7% with an Inconsistency value of 0.07. This shows that the calculation of the correspondent is still within the inconsistency threshold, which cannot be more than 0.1. While the order of priority for the alternative types of medium military transport aircraft from high to low is the CN 295 type 80.5% and the Alenia C27J Spartan type 19.5%. Based on this value, it can be seen that the CN 295 Medium Military Transport Aircraft is the right alternative to be chosen.

Study of aerodynamic characteristics of an aircraft during approach to landing in a disturbed atmosphere

An approximate method is proposed for determining the aerodynamic effect of coherent vortex structures (CVS) of atmospheric turbulence on an aircraft. As a source of the CVS the vortex wind wakes arising when the atmospheric wind flows around the mountain massif of the Son Tra peninsula, located near the Da Nang airport, and the vortex wake behind the Su-27 type aircraft in the landing configuration are considered. Modeling the formation of a vortex structure is carried out by the grid method within the framework of the boundary value problem for the Reynolds-averaged Navier—Stokes equations. The evolution and stochastics of the far wake are modeled in a two-dimensional approximation by discrete Rankine vortices. The assessment of the increment of forces and moments from the effect of the vortex system on the aircraft was carried out within the framework of the panel method. The situation is considered when a light transport aircraft gets into a vortex wake behind an aircraft with a swept wing and a passenger aircraft of the MS-21 type, approaching for landing at the CVS from a mountainous terrain.

Experimental and numerical investigation on the effect of turboprop engine exhaust gas impingement on pusher aircraft

Abstract Turboprop engines require an exhaust nozzle or stub to duct the engine exhaust flue gas outboard of the aircraft. The design of these exhaust stubs are dictated primarily by the aircraft’s configuration. In pusher aircraft, the exhaust stubs are designed to minimize the exposure of the flue gases from the engine exhaust on the propeller blades and fuselage. A fluid-thermal-structure coupling analysis is performed to understand the thermal effects of the engine exhaust jet flow on the thermo-mechanical behavior of pusher configured light transport aircraft propeller and structure. The steady thermal flow field of the aircraft with forward and reverse thrust, in which propeller blade angle variations were analyzed for different aircraft speed. The present work investigates a three-dimensional analysis of flow around the nacelle-airframe and the effect of exhaust flue gas impingement on the propeller blade surface. Based on the insights from the numerical results, the designed exhaust duct was integrated on the aircraft and carried out ground static and flight testing for various flight operating conditions in which propeller blade and fuselage surface temperature were measured. Numerical and experimental results are compared and validated for certain flight conditions and found satisfactory.

Про перспективи розвитку фірми АНТОНОВ у сучасних умовах

The features of the functioning of the domestic aviation industry in the Soviet period and during Ukraine's independence, as well as the world experience of developed countries in supporting aircraft manufacturing companies in the creation of advanced aviation technology are considered. Abroad, such an industry works with the assistance and under the control of the state, including private companies. The main directions of the development strategy of ANTONOV Company in modern conditions are shown. Effective options for ensuring the enterprise activities in the absence of state funding are disclosed, which made it possible to save the domestic school of aircraft engineering and continue the development of new aircraft. The main principles used in the formation of plans and promising directions of ANTONOV Company activity developed, including the priority implementation of state orders, constant monitoring of market needs in aviation technology, the modernization of existing ANTONOV aircraft, the development of aircraft modification families to meet market demands at minimal cost and in a short time, the assessment of all possible risks of new work. The result of the analysis carried out following the stated principles is the development of an aircraft creation program, considering the financial capabilities of the enterprise, the availability of the necessary scientific and technical reserve, and competent engineering and design staff, as well as the state of production. The latest developments of ANTONOV aviation equipment, created during the years of Ukraine's independence, are presented: the multi-purpose aircraft An-38, the regional passenger aircraft An-140, An-148, An-158, the light transport aircraft An-132D, the medium military transport aircraft of short takeoff and landing An-70. The policy of the enterprise in the social sphere is shown, aimed at ensuring the save of qualified personnel, as well as the training of engineering and technical personnel and workers of aviation specialization. Priority work programs of the enterprise have been identified: airworthiness support, repair, and modernization of ANTONOV aircraft; completion of the program for creating the An-178 aircraft; airworthiness support, repair, and support in the operation of aircraft of ANTONOV Airlines; completion of the import substitution program for materials and components; restoration of serial production and sales of An-148 and An-158 passenger aircraft. The main directions of exploratory research of new projects of competitive aircraft are planned.

Study on oil-cooler location for a pusher type turbo prop aircraft using numerical simulation

PurposePusher configured turbo-prop aircraft receive inadequate ram air cooling due to the lack of propeller slipstream, particularly during ground operations. However, flow entrainment can be exploited to a greater extent by placing the oil-cooler duct close to downstream of the propeller at a suitable radial location. But this method has a detrimental effect on the propeller thrust. The purpose of this paper is to discuss the results of numerical simulations carried out to simulate the performance of the propeller with and without oil cooler.Design/methodology/approachIn this paper, three-dimensional (3D) numerical simulations are carried out to simulate the propeller in a rotating domain using an unstructured grid. A computational fluid dynamics solver is put forward to analyze the effect of thrust loss by solving 3D Navier-Stokes equations using a second-order upwind finite-volume scheme. In this study, the impact of thrust loss incurred in the propeller flow field with and without oil cooler duct for three different locations at various rotational speeds is carried out to assess the propeller performance and to identify the optimum position to get a sufficient mass flow rate.FindingsThe findings from this study are simulated thrust values of an uninstalled five-bladed propeller of light transport aircraft (LTA) match well with original equipment manufacturer propeller thrust data. The tip speed velocities simulated for different operating conditions are in good agreement with the theoretical calculations. The influence of oil-cooler effect on the propeller flow field is less in low velocity to high-velocity operating condition due to flow transition from laminar to turbulent. The presence of the oil cooler, which influences the thrust loss, is studied at propeller upstream and downstream locations in detail for 30%, 40% and 50% of propeller radius cases.Research limitations/implicationsSimulations with finer and structured hexa grids can be applied to this problem to get closer results and save solver time as future work.Practical implicationsThe recommended system is installed in the production standard aircraft of LTA. After installation oil cooler performance is better compared to the previous arrangement.Originality/valueResearch work about pusher aircraft is very limited. The problem addressed in this study is unique which resolves the major issue of pusher aircraft. This work highlights the difficulty involved in LTA engine oil cooling, and solution methodologies are also provided. Numerical simulation with oil-cooler assembly is a new area of research that gave the solution for this oil-cooling issue through various oil-cooler case studies.

Analysis of the propellers-airframe interaction of the light transport aircraft

In the design of multi-engine aircraft, one of the important issues is the interaction between the propellers and airframe configuration components, especially in take-off and go-around procedure modes. Modern propeller-driven aircraft concepts in the pulling configuration are characterized by a high disk loading and an increased number of propeller blades used to increase cruising speed and reduce excessive noise. The first problem arising due to high disk loading is the direct impact of forces by operating propellers (thrust, normal force) on fixed-wing stability, especially at angles of attack different from a zero value. The second one involves a high-energy level of the propeller slipstream, having a significant indirect impact on the aircraft’s aerodynamics, stability and controllability. This impact is primarily associated with the interaction of propellers slipstream with other aircraft’s configuration elements. The complexity of taking into account the slipstream-wing interaction and other airframe components stipulated the application of experimental methods to study the problems of propellers – airframe interaction while designing propeller-driven aircraft configurations. This article presents an analysis of the experimental studies results of the operating propellers- airframe interaction for a light twin-engine transport aircraft. The aerodynamic aircraft’s configuration is executed using the conventional pattern of a high-wing and the carrier-on deck type empennage. The high-lift wing device is a fixed-vane doubleslotted flap. The wind-tunnel tests of the model in the cruising, takeoff and landing configurations were carried out in TsAGI lowspeed wind-tunnel T-102. Measurement of forces and moments, acting on the model, was performed by means of an external sixcomponent wind-tunnel balance. Measurement of forces and moments, acting on the propeller, was conducted using strain gauge weighers installed inside the engine nacelles of power plant simulators. The simultaneous combined use of external and internal balances allowed researchers to determine the direct and indirect contribution of operating propellers to the model longitudinal aerodynamic characteristics under variation of loading factor B ranging from 0 to 2.

Моделирование когерентных структур в атмосфере и оценка их воздействия на самолет

The paper introduces an engineering method for assessing the aerodynamic effect of disturbed atmosphere on an aircraft. As a source of vortex structures, we can consider vortex wind wakes that arise when the atmospheric wind flows around the landscape, large structures, moving or stationary aircraft-carrying platforms, vortex wakes behind aircraft, etc. In this study, we consider the situation when a light transport aircraft and an aircraft of the MC-21 type get into the vortex wake behind the super-heavy aircraft A-380 when flying along the glide path. A coherent vortex structure behind the A-380 is formed by the grid method within the framework of the boundary value problem for the Reynolds-averaged Navier —Stokes equations. The evolution and stochastics of the far wake are carried out using the author’s computer code written in the MATLAB system, within the framework of discrete vortices with a Rankine core. The assessment of the increment of forces and moments from the effect of the vortex system on the aircraft was carried out using the panel method.

Порівняльна оцінка модифікацій літаків транспортної категорії за частковими та інтегральними показниками ефективності

The subject of the article is a method for evaluating the effectiveness of modifications of transport category aircraft by partial and integrated indicators, including the marketing cost of the flight and the cost of aircraft hours of air transportation, the amounts of which provide the relationship of economic indicators and parameters used in the design. The aim is to increase the efficiency of modifications of transport category aircraft relative to the basic ones. Objectives: to develop models for estimating modification changes according to integrated cost indicators; to carry out a comparative assessment of different modifications of the transport category aircraft in terms of partial and integrated cost indicators. The methods used are analysis and synthesis of research indicators, mathematical approaches for their evaluation based on the solution of systems of equations. The following results were obtained. According to the analysis and synthesis, the shortcomings of the above partial cost-effectiveness indicators were identified, Optimization of modifications on this indicator gives the maximum economic effect. Taking into account this circumstance, to assess the cost-effectiveness of modifications of transport aircraft, models have been developed that allow determining the cost of LC modifications with a variant change of the modified parameters, such as takeoff mass, flight performance, declared resource, etc., which are laid before modification. making conceptual decisions when creating it. Five modifications of a light transport aircraft are considered, in which such parameters as take-off mass and flight performance were changed. It is accepted that the change in takeoff mass is associated with an increase in the transported cargo, and the change in flight performance - with an increase in range from 2000 to 4000 km. Based on mathematical approaches for estimating existing partial and newly introduced integrated indicators, these five possible modifications of light transport aircraft are analyzed. There is a clear inadequacy in assessing the effectiveness of the developed options for partial and integrated indicators of their effectiveness. Conclusions. The scientific novelty of the obtained results is as follows: a method for estimating the total cost of LC modifications of transport category aircraft, taking into account the characteristic parameters of the modification: flight performance in the form of the characteristic "cargo - range"; the declared resource of modification, and also partial criteria, such as cost of air-hour of air transportation; the cost of transportation of 1 ton of cargo per 1 kilometer; full cost per flight of a transport category aircraft. The proposed method has significantly expanded the information based on which decisions can be made on the competitiveness of various modifications.

Modeling of self-induced deployment of brake flaps of a light transport aircraft during landing approach

Failures during the landing of a light transport aircraft associated with the self-induced deployment of brake flaps are analyzed. The options for their asymmetric deployment are considered. The results of modeling the aircraft landing trajectory with such failures are presented. Recommendations for piloting in such situations are given. Keywords: brake flaps, flight safety, failure, landing, self-induced deployment kudriavtzeff.aleksei@yandex.ru

Three-dimensional visualization of flow pattern near transport airplane model with operating propellers in wind tunnel

This paper presents the experiment results of three-dimensional visualization of flow pattern behind the wing and fuselage of the light transport aircraft (LTA) model with operating propellers in the T-102 TsAGI subsonic wind tunnel (WT). Studying the flow pattern, it is possible to recognize the features of the flow and aerodynamic interference of model elements. As a result of the analysis of the flow pattern and comparison with the previously obtained integral characteristics, the model elements for improving the aerodynamic perfection of the aircraft are revealed. It is shown that at operational angles of attack behind the main landing gear fairing, the vortex flow forms, increasing drag and, apparently, negatively affecting the longitudinal stability characteristics. Vortices are formed behind the flattened tail of the fuselage. Thus, the visualization of the flow with dacron ribbons is an effective method of obtaining flow pattern around the airplane model elements in WT.