Obstacles, Flaps And Ground Effect

1. Obstacles, Flaps And Ground Effect Linday GreenSuperiorlabs.inc SuperLabs Inc

2. Table of Content • Take-off & Landing Phase of aircraft • Clearing Obstacles • Climb Gradient • Correct Flap Settings • Reduced AoA • Slats • Crosswinds SuperLabs Inc

3. Take-off & Landing Phase of aircraft • Most aircraft misadventure happen during the take-off and landing phase of the flight. • Collisions with obstacles during climb out, runway overruns on landing occur every now and then. • In this presentation, we introduces some facts which helps in the performance of Aircraft in this part of the flight. SuperLabs Inc

4. Clearing Obstacles • Advisable to clear any obstacle in your flight path by at least 50 ft. • Check your aircraft climb gradient during preflight, • Information about the airports you are going to visit on obstacles near the climb Out and/or landing path.  • Check the latest NOTAMs for any new obstructions not listed on the charts or in the AIP. SuperLabs Inc

5. Climb Gradient • Calculating the height gain per mile (climb gradient) is easy: [Rate-of-climb (ft/min) / Ground Speed (NM/min)] • For example: • 500 ft/min climb and a ground speed of 66 Kts (1.1 mile per minute) •  Dividing 500 ft / 1.1 NM gives a height gain per mile of 454 ft / NM. • This will give you a good indication if you will be able to maintain safe terrain and obstacle clearance. SuperLabs Inc

6. Climb Gradient(contt..) • Start with a no wind situation for this calculation, any headwind component will increase the climb gradient to your advantage. SuperLabs Inc

7. Correct Flap Settings • Flaps reduce aircraft stalling speed by increasing lift. •  it enables you to lift-off at a lower airspeed. • Resulting in a shorter ground run. • It also reduces the rate of climb (and angle) due to a somewhat higher drag. • You must always use the recommended flap setting for the given circumstances. SuperLabs Inc

8. Correct Flap Settings (contt..) • Never, ever reduce a flap setting while in a turn or on final. • In a turn stall speeds are higher and reducing flaps could mean a low level stall / • Extending flaps to the first position usually adds quite some lift and a small amount of drag spin event. • the second position will increase both lift and drag SuperLabs Inc

9. Correct Flap Settings (contt..) • the third position adds much more drag and almost no lift at all. • The increase in drag helps to stabilize the airspeed. SuperLabs Inc

10. Reduced AoA • Keep in mind that with flap extension the wing will stall at a lower angle of attack. • In turbulent conditions a wing drop is more likely then. • Especially so when the flap and ailerons are combined, • E.g. flaperons. Pipistrel aircraft are known for this 'feature'. SuperLabs Inc

11. Slats • Slats are leading edge flaps. • have the effect of increasing AoA, camber, lift and wing area thus reducing stall speeds. • either move forward or are extended from below the leading edge automatically or under pilot control. SuperLabs Inc

12. Crosswinds • While on approach to a runway with a considerable amount of crosswind, it is wise not to use full flaps on some type of aircraft without proper training from a qualified instructor. • On these aircraft the full flap setting does not lower stall very much, but they increase drag enormously.  • The glide angle will be very steep. • need to add power to reduce the flight path angle.  • Do maintain power until touchdown, especially so in crosswinds. SuperLabs Inc

13. Crosswinds(contt..) • With flaps extended your groundspeed is even lower and the effects of the crosswind will be that much higher. • Make sure enough runway is available, else you need to change to a more favorable runway or divert to another airport. SuperLabs Inc

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