Descending

For note:

This presentation is intended as an aid to a pre flight briefing it is incomplete and is not a substitute supplement for serious study and / or a full lecture.

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Objectives

To understand

• Forces
• Effect of Wind

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To be able to fly

• Glide descent
• Cruise descent
• Raise awareness of engine considerations

Forces

W

Weight is now contributing to thrust so for a given speed less power is required

T

Minimum Glide Angle

• The best glide speed (maximum horizontal distance to height lost) occurs at the speed where drag is a minimum.
• Or equally where the ratio of lift to drag is at a maximum.

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Minimum Rate of Descent

• The minimum rate of descent occurs at an angle of attack and airspeed where this equates to minimum power required.
• It is typically speed of 75% of the minimum angle speed (i.e. max L/D).
• Limited use except save to rectify an engine failure.

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Effect of Wind

Wind

Pre Descent Considerations

1. Airspace and altimeter setting
2. Lookout
3. Engine
• Temperatures & Pressures
• Cowl flap

The Glide Descent�Entering the Descent

• Power
• Reduce to RPM to idle
• Maintain heading, balance and lateral level
• Attitude
• Hold attitude until the speed is 60kts
• Lower nose to glide attitude
• Trim
• Progressively adjust and then fine tune

Cruise Descent

• Power
• Reduce to RPM to desired setting to achieve desired rate of decent
• Maintain heading, balance and lateral level
• Attitude
• Lower nose to maintain IAS
• Trim

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Maintaining the Glide

• Maintain
• Heading
• Balance
• Lateral Level
• Lookout
• Warm Engine
• Every 500’ increase RPM for 20 secs
• Monitor T & Ps

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Levelling Off

• Power
• Open cowl flap
• By sound & feel increase power to cruise RPM
• Maintain heading, balance and lateral level
• Attitude
• Adjust pitch to cruise attitude
• Trim
• Progressively adjust and then fine tune RPM and trim
• Lookout

Questions