In an emergency landing of a 250 tonne aircraft, with a 70 m wingspan and an aerofoil chord averaging 8 m; the pilot has selected the angle of attack to be near stall. Estimate the minimum landing speed if: a) (i) Slotted flaps are not used, (ii) only one slotted flap is used, and (iii) two slotted flaps are used. b) Furthermore, the aircraft instruments stop working so the pilot no longer has access to the elevation and temperature measurements and therefore he/she assumes that they are landing at standard sea-level conditions. Compute the percentage increase or decrease in the emergency landing speed if the aircraft is to land: (i) In Whakapapa Village where the elevation is 1135 m; (ii) at sea level during a very cold winter (approximately -40C), and (c) at seal level during a very hot summer (approximately 50C). Chen Configuration L 3 1 3.5 - 3.48 3.5 3.0 - 3. Double-slotted T 3.0 flap 2 2.5 2.67 N - T 2.5 2. Slotted flap 1 2.0 2.0 C 1.5 - -1.52- T 1.5 1. Clean (no flap) 1.0 - 1.0 1 0.5 -- 0.5 -5 0 5 10 15 20 Angle of attack, a (deg) (a) Lift coefficient versus angle of attack 0 0.05 0.10 0.15 0.20 0.25 0.30 Cp (b) Lift-drag polar In an emergency landing of a 250 tonne aircraft, with a 70 m wingspan and an aerofoil chord averaging 8 m; the pilot has selected the angle of attack to be near stall. Estimate the minimum landing speed if: a) (i) Slotted flaps are not used, (ii) only one slotted flap is used, and (iii) two slotted flaps are used. b) Furthermore, the aircraft instruments stop working so the pilot no longer has access to the elevation and temperature measurements and therefore he/she assumes that they are landing at standard sea-level conditions. Compute the percentage increase or decrease in the emergency landing speed if the aircraft is to land: (i) In Whakapapa Village where the elevation is 1135 m; (ii) at sea level during a very cold winter (approximately -40C), and (c) at seal level during a very hot summer (approximately 50C). Chen Configuration L 3 1 3.5 - 3.48 3.5 3.0 - 3. Double-slotted T 3.0 flap 2 2.5 2.67 N - T 2.5 2. Slotted flap 1 2.0 2.0 C 1.5 - -1.52- T 1.5 1. Clean (no flap) 1.0 - 1.0 1 0.5 -- 0.5 -5 0 5 10 15 20 Angle of attack, a (deg) (a) Lift coefficient versus angle of attack 0 0.05 0.10 0.15 0.20 0.25 0.30 Cp (b) Lift-drag polar