Page 439 - PPL-engelsk 2025

Principles of flight

5.7.2 Degrees of stability ................................................................................. 485

5.7.3 Longitudinal stability .............................................................................. 486

5.7.3.1 Design for longitudinal ........................................................................ 487
5.7.4 Lateral stability ....................................................................................... 488

5.7.5 Directional stability – stability around the vertical axis ......................... 489

5.7.5.1 Lateral center (Lc) ............................................................................... 490

5.7.5.2 Stalling ................................................................................................. 491
5.7.6 Airplane controls and trim ..................................................................... 492

5.7.6.1 Fixed trim tabs..................................................................................... 492

5.7.6.2 Aerodynamic balancing ....................................................................... 492
5.7.6.3 Servo tab ............................................................................................. 493

5.7.6.4 Anti servo tab ...................................................................................... 493

5.7.6.5 Adjustable trim tab ............................................................................. 494
5.7.6.6 Static balancing of controls ................................................................. 494

5.7.7 Aeroelasticity .......................................................................................... 495

5.8 Limitations ................................................................................................... 496

5.8.1 Airspeed indicator limitations ................................................................ 496

5.8.1.1 Maximum maneuvering speed ........................................................... 497
5.8.2 The load factor ....................................................................................... 498

5.8.2.1 Limit load factor and ultimate load factor .......................................... 499

5.8.2.2 Relationship between load factors and damage to aircraft ............... 500
5.9 The influence of the propeller on the maneuvering ................................... 502

5.9.1 Propeller slipstream ............................................................................... 502
5.9.2 P-factor ................................................................................................... 502

5.9.3 Gyroscope effect .................................................................................... 503

5.9.4 Torque .................................................................................................... 503

5.10 Phases of flight ............................................................................................ 504

5.10.1 Takeoff ............................................................................................................. 505

5.10.1.1 The nature of the runway ................................................................. 506
5.10.1.2 The importance of wind for the take-off run .................................... 507

5.10.1.3 Density altitude ................................................................................ 508

5.10.1.4 Performance tables .......................................................................... 508

Flight Theory PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 439