Extreme Conditions

Definition

-Weight and balance extreme condition or adverse condition check

  • Load plane nose and tail heavy

  • Does CG fall outside limits?

  • Paper and pencil exercise

Figure 1

Forward Extreme Conditions

  • Useful load in front of forward CG limit loaded

  • Useful load behind forward CG limit not loaded

  • Minimum fuel shown if located behind forward CG limit

  • Minimum Fuel = METO hp/2

Aft Extreme Conditions

  • Useful load behind aft CG limit loaded

  • Useful load in front of aft CG limit not loaded

  • Pilot’s seat cannot be empty if in front of aft CG limit

  • Minimum fuel shown if forward of aft CG limit

Example Condition Check

-Calculating adverse forward and aft checks

  • Seat, baggage, fuel data shown

  • CG limits shown

  • Forward checks useful load located in front of 89”

-Additional Specifications:

  • Airplane Empty Weight 1,850 lb

  • Empty Weight CG +92.45”

  • CG Limits: +89” to +99”

  • Maximum Weight 3,200 lb

  • Fuel Capacity

    • 45 gal at +95” (44 usable)

    • 40 gal at +102” (39 usable)

-Remember: Total Arm is airplane CG

-Total Arm = Total Moment/Total Weight

Forward Check

Figure 2

-Is this forward CG within limits?

  • Minimum fuel only load behind forward limit

  • Minimum fuel: 375hp/2 = 187.5 lb

  • Pilot and passenger seats in forward position of 82”

-CG within limits, aircraft can fly

Aft Check

Figure 3

-Is this CG within limits?

  • Pilot the only load in front of aft limit 88”

  • Fuel tank at 102” filled (minimum fuel)

-CG is out limits by 0.6” Aircraft should not be flown