• Journal of the Korea Convergence Society
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• v.11 no.12
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• pp.131-135
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• 2020

In this study, the models with three, five and ten wings of the propeller which made a light aircraft fly were performed by air flow analyses. As for the flow model A with the shape with five wings, Model A can be seen to be the most ideal flow of air. The flow of air through the number of wings, which is not too many or too few, shows the most smooth flowing form. The smaller the number of propeller blades, the smaller the flow of air. Model A is applied under pressure of up to 0.5631 MPa at the front of air flow. Also, models B and C are applied under pressures of 0.5758 MPa and 0.5589 MPa, respectively. Comparing the pressure contours for each model of flux, model B can be shown to have the highest pressure distribution. The result of this study can be used to investigate the air flow without actual testing. It also seems to be helpful in the aesthetic convergent design of light aircraft propeller.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.1
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• pp.108-117
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• 1995

The primary purpose of this extensive test effort was to observe real-time operational performance characteristics associated with automotive grade fuel utilized by piston engine powered light aviation aircraft. In fulfillment of this effort, baseline engine operations were established with 100LL aviation grade fuel followed by four blends of automotive grade fuel. A comprehensive sea-level-static test cell/flight test data collection and evaluation effort were conducted to review operational characteristics of a carbureted light aircraft piston engine as related to fuel volatility, fuel temperature, and fuel system pressure. Presented herein are results, data, and conclusions drawn from test cell engine operation as well as flight test operation on 100LL aviation grade and four blends of automotive grade fuel.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.7
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• pp.552-560
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• 2013

Airplane Buhwal is the first light airplane which is designed and made in South Korea. Restoration of airplane Buhwal is designed based on the one made by Korean Airforce in 2004 but there are some changes also. It uses aluminum main wing, electronic indicator, BRS(Ballistic recovery parachute) and black box for improved performance. In this paper, for the restorated Buhwal, major design changes are introduced, structure, aerodynamic and stability analysis are reviewed and improved performances which is proven through flight test are shown. This study will be a big help for domestic light airplane development.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.891-896
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• 2007

This paper contained the flight test calibration for the airspeed indicator and the altimeter of the light airplane ChangGong-91, which is the first type certified aircraft from Korean Ministry of Construction and Transportation, as a part of the flight test validation. The flight test for airspeed position error calibration was performed using tower fly by method in order to calibrate swivel head testboom which is attached to the right wing tip of the airplane, and using system to system method for airspeed indicator. The altimeter calibration was calculated using flight test data for airspeed calibration. The flight test was conducted at the basis of the 'Korean Airworthiness Standard' regulation of Korean Ministry of Construction and Transportation.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.762-767
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• 2008

Estimated values for maximum lift coefficients of a light airplane, ChanGong-91, derived from an analytical method using a test database, a computational fluid dynamic method, a wind tunnel test, and a flight test are compared. The DATCOM method and VSAERO code are applied as the analytical method and the computational fluid dynamic method, respectively, in order to estimate the maximum lift coefficients of a light airplane. The wind tunnel test is conducted using a 1/14.5 scaled model installed in a closed circuit type wind tunnel. For the flight test approach, the wings-level power-off stall tests are performed to obtain the maximum lift coefficients. As a point of reference for the flight test results of the maximum lift coefficients, the differences of both estimates derived from the DATCOM method and the wind tunnel test data are smaller than those derived from VSAERO.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.4
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• pp.308-315
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• 2007

This study is performed to find out the climb performance of light airplane, Chang Gong-91, as a part of flight test to acquire the certification. Chang Gong-91 is a 5-passenger light aircraft of normal category with single reciprocating engine, and the first officially certified by Korean Ministry of Construction and Transportation in 1993. These flight test procedure and data for climb performance are used to get type certification. We have got maximum climb rate for operating altitude, best angle of climb speed, best rate of climb speed, and absolute ceiling of Chang Gong-91 using drag polar data reduction method from sawtooth climb flight data. Also we compare the form drag coefficient from the results of climb performance and Oswald's effectiveness coefficient to design values using lift-drag curve of light airplane.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.16 no.3
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• pp.1-6
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• 2008

The stalling speed flight test of light airplane, ChangGong-91, was performed to acquire the certification. With power-off engine condition, the wings level stall flight tests were conducted at the aircraft configuration of various flap angle - clean, 20degree, and full flap, respectively. They were performed considering with the combination of the maximum and minimum test weight, and forward and afterward center of gravity. The stalling speeds and the minimum speeds of light airplane were determined from the results of flight test. Also, the appropriateness of stall warning speeds are evaluated through the flight test measures. The airplane is recoverable only with pitch control and engine throttle from stall state without exceptional operation.

• Journal of Aerospace System Engineering
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• v.16 no.3
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• pp.1-9
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• 2022

In this study, for development of the MDO (Multi Disciplinary Optimization) framework, the flight dynamic characteristic parameters of the ChangGong-91, a light aircraft, were extracted by an analytical method based on various semi-empirical methods, and the flight test method was compared and evaluated. The semi-empirical analysis methods for comparative subjects were the Perkins method, McCormick method, and Smetana method. The major stability/control derivatives and dynamic factors were calculated, using each method. As the comparison criteria, the flight test derivative estimates and dynamic factors were processed, using the output error method. Additionally, the flight characteristics of the light aircraft were analyzed and evaluated according to the provisions of the Korean Airworthiness Standard (KAS) of the Ministry of Land, Infrastructure and Transport, and MIL-F-8785C for the U.S. military.

• Aerospace Engineering and Technology
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• v.12 no.2
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• pp.202-208
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• 2013

This paper describes establishment of a pilot training plan, training and an outcome for Human Powered Aircraft which can take off, landing and fly using the energy generated by only human muscle without using mechanical power. To achieve these, a special trainer made a plan by considering physical trait of each pilot and each pilot was performed an indoor training for principle physical improvement, an outdoor training for generating sustainable power, a simulation training to learn maneuver ability. The pilot mastered the basic maneuver ability needed to fly and each pilot was lose their weight and experienced their improved physical strength via the training.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.3
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• pp.39-49
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• 2003

The delta operator approach and the singular perturbation technique are introduced. The former reduces the round-off error in the numerical computation. The latter reduces computing time by decoupling the original system into the fast and slow sub-systems. The aircraft dynamics consists of the Phugoid and short-period motions whether its model is longitudinal or lateral. In this paper, an approximated solutions of lateral dynamic model of Beaver obtained by using those two methods in compared with the exact solution. For open-loop system and closed-loop system, and approximated solution gets identical to the exact solution with only one iteration and without iteration, respectively. Therefore, it is shown that implementing those approaches is very effective in the flight dynamic and control.