Page 437 - PPL-engelsk 2025

Principles of flight

Principles of flight

Indholdsfortegnelse Side

5.1 Introduction .............................................................................................. 441

5.2 The atmosphere ........................................................................................ 441

5.2.1 Aerodynamic fundamentals ................................................................... 443

5.2.1.1 Newtons 3. Law ................................................................................... 443
5.2.1.2 Bernoulli’s Principle ............................................................................ 443

5.2.1.3 Formulas for lift and drag .................................................................... 445
5.3 Airflow around the aircraft ....................................................................... 446

5.3.1 Airflow .................................................................................................... 446

5.3.1.1 Boundary layer .................................................................................... 446
5.3.1.2 Laminar flow, transition point and turbulence flow ........................... 446

5.3.2 Drag ........................................................................................................ 448

5.3.2.1 Profile drag .......................................................................................... 448
5.3.2.2 Form drag ............................................................................................ 448

5.3.3 Airflow around profiles ........................................................................... 450

5.3.4 The 4 forces that affect an aircragt during flight ................................... 451

5.3.5 Luftstrømning omkring vingeprofiler ..................................................... 451
5.3.5.1 Downwash ........................................................................................... 451

5.3.5.2 Wing shape .......................................................................................... 451

5.3.5.3 Wing profiles and lines ........................................................................ 452
5.3.6 Lift ........................................................................................................... 453

5.3.6.1 Pressure distribution around profiles ................................................. 454

5.3.6.2 Stagnation point .................................................................................. 455
5.3.6.3 Lift, speed, area ................................................................................... 456

5.3.6.4 The critical angle of attack .................................................................. 456

5.3.6.5 Relationship between lift and the angle of attack .............................. 457
5.3.7 Drag ........................................................................................................ 457

5.3.7.1 Profil drag ............................................................................................ 458

5.3.7.2 Induced drag and wingtip vortices ...................................................... 458
5.3.7.3 Ground Effect ...................................................................................... 460

5.3.7.4 Parasitic drag ....................................................................................... 461

Flight Theory PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 437