Advanced Weight Balance Why Does Weight Matter Aircraft

Advanced Weight & Balance

Why Does Weight Matter? • Aircraft are NOT minivans • You can’t load everything you want into them and go off and fly • PIC must make decision – Fuel or Load? • Overweight Aircraft: • • Longer Takeoff Higher Takeoff Speed Reduced Rate of Climb and Angle of Climb Shorter Range Reduce Cruising Speed Higher Stall Speed Longer Landing Distance © 2015 Coast Flight Training. All Rights Reserved.

Overweight Dangers • May affect performance (last slide) • Undue stress on the aircraft structure upon landing/taxi • Exclusive testing is done at the Max Ramp and MGTOW • Section 2 of the POH – Limitations • Changed only by Airworthiness Directive © 2015 Coast Flight Training. All Rights Reserved.

Why Does Balance Matter? • Not a matter of how much weight there is, but where it is placed • Center of Gravity Limits • Datum Reference Point • Center of Pressure and Center of Gravity • Boldmethod © 2015 Coast Flight Training. All Rights Reserved.

C. G. Forward of Limits • Benefits • Increases Stability • Easy Stall Recovery • Disadvantages: • Increase in stall speed • Increase in drag • On landing, harder to roundout © 2015 Coast Flight Training. All Rights Reserved.

C. G. Aft of Limits • Benefits • Decrease Stall Speed • Disadvantages: • • More unstable Harder to recover from stall Less Drag – Higher Airspeed Tail Heavy © 2015 Coast Flight Training. All Rights Reserved.

Utility vs. Normal Category • Category has to do with the G loading of an aircraft • Utility • 4. 4 Magnum • No inverted approved • Normal • 3. 8 Special • No inverted approved © 2015 Coast Flight Training. All Rights Reserved.

Categories Use • Utility • Limited Aerobatics • Normal • Use the plane for its original purpose (no extreme maneuvers) • Transport Category • No excessive maneuvers • Aerobatic Category © 2015 Coast Flight Training. All Rights Reserved.

Terms (POH 1. 7 and 1. 8) • Basic Empty Weight • Engine oil and unusable fuel and empty airplane • Unusable Fuel • Fuel that can’t be removed from the system • Payload • Weight of occupants, cargo and baggage • Useful Load • Takeoff Weight - BEW © 2015 Coast Flight Training. All Rights Reserved.

The Weight and Balance Document • Part of ARROWE • Updated by Mechanic • For light pistons only once forever unless changed • If changed: • New Weight and Balance to be completed © 2015 Coast Flight Training. All Rights Reserved.

The Weight Formula • WAM • Weight X Arm = Moment • Basic Algebra says: • Moment / Weight = Arm • Think of Children on a Seesaw • How much weight is applied? • How far from the fulcrum is their weight applied? © 2015 Coast Flight Training. All Rights Reserved.

Calculating Position and C. G. • Shifting Weight to Move C. G. • Move the larger child towards the datum • Computation Table or Graph • The Envelope © 2015 Coast Flight Training. All Rights Reserved.

The Weight Shift Formula • MEMORIZE THIS FORMULA: Weight Moved Total Weight of System = Distance C. G. Moved Distance between C. G. Arms © 2015 Coast Flight Training. All Rights Reserved.

The Flight Computer

The Two Sides • Computer Side • Wind Side © 2015 Coast Flight Training. All Rights Reserved.

Computer Side • Time, Speed, Distance • Fuel Consumption • Estimate vs. Actual • Airspeed and Density Altitude © 2015 Coast Flight Training. All Rights Reserved.

Wind Side • Favorable Winds • Conversions • Dead Reckoning formula © 2015 Coast Flight Training. All Rights Reserved.

References • Jeppesen Private Pilot Guided Flight Manual • Pilot’s Handbook of Aeronautical Knowledge • Piper Archer II POH © 2015 Coast Flight Training. All Rights Reserved.