The undercarriage design for A320-200 Bashar Alfadli ID:@00569809 12/9/22 INTRODUCTION: One of the most critical components of an aircraft is its undercarriage, which is the part that carries the aircraft's

total weight during its journey. It is important that the design of the component is done properly to meet the requirements of airworthiness certification. The design of the Airbus A320-200's undercarriage was the focus of this section. The component had to meet various requirements to ensure that it performs properly. 4320 Figure 1: Airbus A320-200. A320 AIRBUS MAIN OBJECTIVE: The main objective of this report is to design and discuss the undercarriage for the A320-200. COMPRESSED 419.10 mm (16.50 in) EXTENDED X-20 266 mm (797.87 in) TIE 58.40% AMCKI 2 506 mm (98.66 in) 2978.70 mm (117.27 in) 1005 mm (39.57 in) 80230 RETRACTION ANGLE Y-3 795 mm (149.41 in) 780 mm (30.71 in) Figure 2:the undercarriage layout for A320-200. (Airbus, 2022) Figure 2 shows a mechanism that consists of four main components: a crank, a coupler, a follower, and a reference. The lengths of these components were calculated based on the angle between the horizontal reference and the crank. Thetal refers to the angle between the horizontal reference and the crank, while theta3 is between the follower and the vertical reference. Calculations: Parameter MTOW Wing area Density AR Wing sweep Gravity acceleration value dCL/da CL max Take-off CL cruise (For 50% fuel, n=1.48) Cl max with no flaps de/dt Dihedral angle B thickness Delta angle Tyre type Tyre mass External tyre diameter Tyre width Entire leg mass Value 75500kg 122.4 m² 1.225 kg/m³ 9.5 25° 9.81 4.116 2.23 0.551 1.46 4 5.11 34.09 7.58 10 Goodyear 48x18-22 90.17kg 1.2192m 0.43561m 901.7kg Table 1:A320-200 parameters. Source All janes [1] All janes [1] Wikipedia All janes [1] All janes [1] Wikipedia Payload report ADE lecture notes eq.2.16 [3] Altitude-speed report ADE lecture notes eq.2.16 [3] ADE lecture notes [3] Hamburg [5] All janes [1] All janes [1] estimated Goodyear [6] Goodyear [7] Goodyear [6] Goodyear [6] Calculated Figure 2 and 3 have the information required to do the undercarriage calculations. A step by step calculation will be shown below: 1- Step 1 is to estimate the angles for undercarriage layout Cases 03 Gear down -90 Gear retracting -130 Pull up position 40 -175 Table 2: Angles estimations for the undercarriage for three different cases. The angles estimated from a drawings done by hand. One example of the gear down case is shown blow: Cases Gear down Gear retracting Pull up position 01 -40 -10 40 2- step 2 is to use the matrix method to find k for the angles: [cos 0¹ cos 03 cos 03 Matrix A-1 Matrix A-1 *B 03 -90 -130 -175 = = Figure 3: Gear down case. 01 -40 -10 A - cos 0 1] [cos(0¹-0¹)] - cos 0 1 |k₂| = cos(02-03) - cos 0³ 1 lk₂] [cos(0³-03) Figure 4: Matrix Equation. (ADE, 2022) 6.12574E-17 -0.76604 -0.64278761 -0.98481 -0.9961947 -0.76604 01= -40° 1.003819838 0 1.621647827 -4.57115 2.242254306 -3.5017 1.467524 0.911859 1.341312 C 1 1 1 -1.003819838 2.949502612 2.259450086 k1 k2 k3 Figure 4: Solving the matrix by using Excel. 03 = -90° * k1 k2 k3 B 0.642788 -0.5 -0.81915