• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.49 no.4
• /
• pp.329-334
• /
• 2021

Korean Air has set the goal of the first stage of the development of unmanned helicopters to perform in hovering flight by remote control. In order to achieve the development goal, Korean Air carried out system integration, ground test, and safety wire test in sequence after carrying out programmed depot maintenance and aircraft modification of manned aircraft, and verified the controllability and flight safety of the unmanned helicopter system step by step. In particular, it was confirmed that the safety wire test technique used in the final stage of verification was an effective method to verify flight safety and controllability for a fully unmanned helicopter system.

• Aerospace Engineering and Technology
• /
• v.11 no.1
• /
• pp.185-191
• /
• 2012

This paper developed Helicopter Chassis Dynamometer System(HCDS) to perform the bench test of the scaled rotor blade and to design a scaled model helicopter flight test bed and accomplished the scaled helicopter ground test. The scaled helicopter should be checked the relation of thrust and power input to maintain regular RPM by collective pitch angle versus throttle input. It showed hovering performance results of IGE with OGE, the max. F.M. was 0.76 without ground effect. The results of the chassis dynamometer test of scaled helicopter will usefully apply to design the scaled helicopter and evaluate the rotor blade performance.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2017.05a
• /
• pp.198-200
• /
• 2017

An Auxiliary Power Unit (APU) is a small gas turbine engine that is mounted on an aircraft and serves to supply energy for ground and air starting of the main engine. APU also supplies emergency and auxiliary power for the aircraft. APU for aircraft is simple and compact in structure, but because it is mounted on manned aircraft, high reliability is required, so it must be proved its reliability through qualification procedure. The Korea Aerospace Research Institute and Hanwha Techwin successfully completed the design / analysis, fabrication, assembly, development test and certification test of APU for helicopter based on accumulated domestic R & D capability and experience from 2007 to 2012. In this paper, the development and certification process of auxiliary power unit for helicopter is summarized.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2008.10a
• /
• pp.183-188
• /
• 2008

Engine control/performance model for helicopter simulator is one of the most important models which affect flight performance and handling quality. It is typical to develop the model based on the raw data and models from the engine designers/manufacturers. The approaches in this study were to develop the basic model based on the available resources and to tune and verify it based on the ground/flight test results. The maintenance manuals of TB3-117 which is installed in KA-32T were reviewed and the components to be simulated for the engine control model were categorized and modeled. Piece-wise linear modeling method was used for the engine performance model. The engine performance data in the engine maintenance manuals were incorporated into the engine steady state performance tables, which were incorporated with the transfer functions for the dynamic performance. Engine control/performance model was compared and tuned with the ground/flight test results. It was verified that the fidelity of the model was within the tolerances in FAA AC120-63.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.12
• /
• pp.2239-2246
• /
• 2008

Engine control/performance model for helicopter simulator if one of the most important models which affect flight performance and handling quality. It is typical to develop the model based on the raw data and models from the engine designers/manufacturers. The approaches in this study were to develop the basic model bated on the available resources and to tune and verify it based on the ground/flight test results. The maintenance manuals of TB3-117 which is installed in KA-327 were reviewed and the components to be simulated for the engine control model were categorized and modeled. Piece-wise linear modeling method was used for the engine performance model. The engine performance data in the engine maintenance manuals were incorporated into the engine steady state performance tablet, which were incorporated with the transfer functions for the dynamic performance. Engine control/performance model was compared and tuned with the round/flight test results. It was verified that the fidelity of the model was within the tolerances in FAA AC120-63.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.47 no.8
• /
• pp.582-589
• /
• 2019

The dynamic balancing test of helicopter main rotor blades is a blade rotation test conducted on the ground to make the track of each blade and the load on each pitch rod to a similar level before the flight tests. The purpose of the test is to reduce the vibration occurring on main rotor system as a result of dissimilarity of each blade. The RTB test has been performed for a long period at Whirl Tower Test Facility located in Goheung Flight Centre, accumulating its data. As the amount of the results has become increasingly enormous the needs for the development of database system has been raised to manage the data with effective method. This research aimed to describe the development of Dynamic-Balancing Database System for the RTB test results. For the design of the database system the informations of RTB test results have been categorized into properties, connecting each others according to its logical meaning, and comprised into a database system with relational elements. It has been shown in this paper that the Dynamic Balancing database system enables to effectively accumulate the RTB test data and to be utilized for the data analysis.

• Journal of Aerospace System Engineering
• /
• v.13 no.5
• /
• pp.87-93
• /
• 2019

This study suggests the development of the ALE (Automatic Link Establishment) system for the long-range communication with a helicopter at the lands or marines by HF (High Frequency) radios. In the condition of LOS or more than 35 NM, the communication success rate is significantly lowered when the frequency is manually selected because of the reduced transmission power and various strong RF environment noise signals. In this paper, we make an effort to overcome the difficulties of choosing the optimal frequency when the operating frequency selection is manually operated in long-distance communication or LOS uncertain environment. The ALE system is designed based on the frequency analysis propagation software and is verified that the communication success rate is increased by applying the proposed system. The ALE system was applied to the helicopter system and the ground/flight test was conducted. As a result, the superiority and efficiency of the proposed system were verified.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.38 no.6
• /
• pp.691-698
• /
• 2014

This paper describes the manufacturing processes for a flexbeam and torque tube made of composite materials, along with the procedures for testing their basic properties. A flexbeam and torque tube can be considered to be key structural components of a bearingless rotor hub system. A hinge offset effect can be realized by a large elastic deformation and twist of the flexbeam, and the blade pitch control forces are transferred by the rotation of the torque tube. The basic property tests included bending and twist tests to determine the flap stiffness, lag stiffness, and torsion stiffness of the flexbeam, torque tube, and blade, and these tests were performed prior to starting the whirl tower test. In addition, the estimated results were compared with experimental data, and the calculations were found to be a good match for the analysis results and had a similar tendency. Through these results, we could confirm that a flexbeam and torque tube made of composite materials satisfied the structural stiffness requirements.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.33 no.1
• /
• pp.33-38
• /
• 2005

Forcing at the rotor blade passing frequencies is responsible for the majority of vibration related problems on helicopters. Blade passing frequencies of helicopters are generally in the range 10~30 Hz and the interest modes of the helicopters also exist in the range. By the way, the installation of a heavy sensor at the front extremities of an imported helicopter may change the modal characteristics of the airframe and results in the resonance with rotor passing frequencies. To avoid too large a change in the dynamics of the overall airframe, we determined how to install a heavy sensor through conceptual approach and finite element analysis. The results of a ground vibration test for airframe with sensor mount system clearly demonstrate that the installation design is acceptable dynamically.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.44 no.5
• /
• pp.439-446
• /
• 2016

The characteristics of bearingless main rotor of helicopter are investigated through non-rotating tests and rotating tests. The stiffness and natural frequencies of rotor blades, flexbeam, and torque tube which are core components of baearingless rotor are measured to obtain input material properties for rotor analysis. The functional test on ground for assembly of one hub with damper, snubber, and no blade is carried out to check interfaces between components, kinematics of components, and pitch motion ranges under applied loads including centrifugal load. The 4-bladed bearingless rotor with 5.82m of rotor radius is tested on the whirl tower with rotation plane of 9.65m height. The thrust and power are measured to obtain hover performance and the frequencies and dampings of the rotor are obtained by excitation of cyclic pitch by hydraulic actuators.