Level Turn & Pull-up Maneuver Udit Vohra Aerospace Engineering - PowerPoint PPT Presentation

AE-705: Introduction to Flight Level Turn & Pull-up Maneuver Udit Vohra Aerospace Engineering Department PEC University of Technology, Chandigarh AE-705 Introduction to Flight Lecture No 14 Capsule-07

LAYOUT • Coordinated Turn • Turning flight parameters • Fastest turn • Tightest turn • Turning in vertical plane AE-705 Introduction to Flight Lecture No 14 Capsule-07

Watch the video carefully LETS FLY IN A LOOP AE-705 Introduction to Flight Lecture No 14 Capsule-07

Watch the water level during the turn ! AE-705 Introduction to Flight Lecture No 14 Capsule-07

How do they do that ? COORDINATED TURN AE-705 Introduction to Flight Lecture No 14 Capsule-07

Coordinated Turn 1. Constant Altitude 2. Banking of the a/c in horizontal plane 3. No tangential acceleration 4. Turn without a sideslip 5. Coordination b/w Ailerons and Rudder Rudder for Use of Rudder in yaw and a turn … why ?? ailerons to roll we will see that later on AE-705 Introduction to Flight Lecture No 14 Capsule-07

skid UNCOORDINATED TURN AE-705 Introduction to Flight Lecture No 14 Capsule-07

Adverse Yaw The reason why we use rudder in a turn http://www.boldmethod.com/learn-to-fly/aerodynamics/the-aerodynamics-of-a-turn-in-an-airplane/ AE-705 Introduction to Flight Lecture No 14 Capsule-07

TURNING FLIGHT EQUATIONS AE-705 Introduction to Flight Lecture No 14 Capsule-07

Equations of motion L ϕ LCos ϕ = W ----(1) mV 2 LSin ϕ = ----(2) R ϕ (2) / (1) W V 2 Tan ϕ = Rg L n = W ( load factor) n = 1 Cosϕ = Sec ϕ AE-705 Introduction to Flight Lecture No 14 Capsule-07

Turning Flight Parameters Load Factor (n) L n = W Depends on aircraft design parameters Banking Angle Represented in g’s Φ = Cos −1 ( 1 n) Related to turn rate Steady coordinated turn is not possible without banking the a/c AE-705 Introduction to Flight Lecture No 14 Capsule-07

turn radius Turn Radius mV 2 W V 2 R = g R = R W n 2 − 1 V 2 R = R g n 2 −1 depends on V and n AE-705 Introduction to Flight Lecture No 14 Capsule-07

Turn rate Turn Rate ω ω dθ V ω = dt = R Degrees travelled per sec Similar to Angular Velocity g n 2 −1 ω = V depends on V and n AE-705 Introduction to Flight Lecture No 14 Capsule-07

Effect of bank angle Bank angle in a turn results in: Higher rate of turn • Smaller radius of turn • Higher loading on the wings • Higher stall speed • Pilot’s Handbook of Aeronautical Knowledge AE-705 Introduction to Flight Lecture No 14 Capsule-07

Fastest turn • Max. turn rate • Measure of a/c’s maneuverability • Depends on a/c design parameters V should be min n should be max Sustained turn rate when Thrust/weight • Wing loading • Aspect Ratio • AE-705 Introduction to Flight Lecture No 14 Capsule-07

Tightest turn • Min turn radius • Measure of maneuverability What is V min and n max ?? What are constraints on n max • Depends on design parameters Find out yourself ! Report on Moodle V should be min n should be max Instantaneous turn rate when • Thrust/weight • Wing loading • Altitude AE-705 Introduction to Flight Lecture No 14 Capsule-07

Continue.. http://people.clarkson.edu/~pmarzocc/AE429/AE-429-12.pdf AE-705 Introduction to Flight Lecture No 14 Capsule-07

http://people.clarkson.edu/~pmarzocc/AE429/AE-429-12.pdf AE-705 Introduction to Flight Lecture No 14 Capsule-07

Instantaneous & Sustained turn Dogfight are generally dependent on rate of turn • Aircraft which can turn faster will get into an • advantageous firing position quickly ITR is a measure of how quickly an aircraft is able to turn at the beginning of the turn The turn rate which can be maintained for a period of time is called the STR (Sustained turn rate) AE-705 Introduction to Flight Lecture No 14 Capsule-07

Tejas vs. F-16 Which one is better and how? What do you think ? v/s AE-705 Introduction to Flight Lecture No 14 Capsule-07

Continued.. Depends on wing loading & Thrust to weight ratio Tejas wing loading : 247 kg/m² F-16C Block 50 wing loading : 431 kg/m² Lesser the wing loading more will be the ITR https://www.quora.com/search?q=instantaneous+turn+of+an+aircraft AE-705 Introduction to Flight Lecture No 14 Capsule-07

http://thebetacoefficient.blogspot.in/2015/04/lca-tejas-versus-f-16-in-combat-part-i.html At horizontal plane STR, ITR > STR the LCA outperforms the F-16A/B at high Mach numbers and the F-16C/D under all Mach number regimes. AE-705 Introduction to Flight Lecture No 14 Capsule-07

Tejas v/s F-16 T:W is favorable for the F16, though the difference is smaller (1.09 v/s 1.07 ) STR of F-16 > Tejas at slower speeds (< M = 0.65) Tejas dominates at speeds greater than 0.65 Dogfights generally happen at M > 0.65 • @ M < 0.65 Tejas = F-16 • AE-705 Introduction to Flight Lecture No 14 Capsule-07

Outcome of a dog-fight is difficult to predict because it depends on • the pilot, • the initial positions of the aircraft • the aircraft specs. Made in INDIA Tejas will dominate the F-16 in a majority of engagements based on the aerodynamic characteristics AE-705 Introduction to Flight Lecture No 14 Capsule-07

Source: https://giphy.com/ TURNING IN VERTICAL PLANE AE-705 Introduction to Flight Lecture No 14 Capsule-07

Turning in Vertical plane Aerobatic and combat a/c maneuvers • Required during takeoff and landing • AE-705 Introduction to Flight Lecture No 14 Capsule-07

Pull-Up Maneuver Flight along a curved path with altitude increasing F r = L – W = W( n - 1) V 2 F r = m R V 2 R = g(n−1) g(n−1) ω = V AE-705 Introduction to Flight Lecture No 14 Capsule-07

Dive Pullout Part of descent flight During this nose-down attitude, • the AOA and the airspeed The smooth flow of air over the • wing begins again, lift returns, and the aircraft begins to fly again. pilot_handbook_2016.pdf AE-705 Introduction to Flight Lecture No 14 Capsule-07

Team Assignment No 4 Design and Fabrication of a Glider AE-705 Introduction to Flight Lecture No 14 Capsule-07

Glider Design Competition  Design a Glider for max. Range & Endurance  Launch from third floor of Foyer in LHC  No limit on material, or dimensions  Best of two launches for each Team  Technical Report to be submitted  Relative Scoring Scheme (to be announced) AE-705 Introduction to Flight Lecture No 14 Capsule-07

Location of the Competition AE-705 Introduction to Flight Lecture No 14 Capsule-07

Example AE-705 Introduction to Flight Lecture No 14 Capsule-07

Professional flyers How do birds turn during a flight ? No vertical tail No Ailerons Aerodynamics of Avian Flight AE-705 Introduction to Flight Lecture No 14 Capsule-07