Performance

Aircraft Weight

For the same aircraft, an increase in weight generally results in poorer performance.

A heavier aircraft will normally have:

• higher stall speed
• higher take-off speed
• longer take-off distance
• reduced climb performance
• higher fuel consumption
• higher landing speed
• longer landing distance
• greater braking requirements after landing

The heavier the aircraft, the more lift is required to support its weight.

Key point

Increasing aircraft weight increases stall speed and take-off and landing distances, while reducing climb performance.

Engine Failure — Best Glide Speed

Following an engine failure, the aircraft should normally be flown at the recommended best glide speed.

Best glide speed corresponds approximately to the aircraft's best Lift/Drag ratio (L/D) and provides the greatest distance for the height available in still air.

Key point

For maximum gliding distance following an engine failure, fly at best range — best L/D speed.

Flaps and Landing Performance

Extending flaps increases both lift and drag.

During landing, flap allows the aircraft to:

• fly safely at a lower airspeed
• have a lower stall speed
• use a steeper approach angle
• reduce the tendency to float during the landing