PLT021: Weight and Balance
What code PLT021 covers, why the FAA tests it, and how to study Weight and Balance before your checkride.
Calculate weight and balance
What this means for your checkride
Weight and balance confirms the airplane is loaded within its maximum allowable weight and that its center of gravity sits between the forward and aft limits. You find it by multiplying each item's weight by its arm to get a moment, then dividing total moment by total weight.
An overweight airplane or one loaded outside its CG range changes stall speed, control authority, and stability, so the FAA tests both the arithmetic and the ability to read the manufacturer's loading graphs and tables.
A frequent error is checking total weight but not CG, or leaving fuel in gallons instead of converting to pounds, either of which can make an unsafe load look legal on paper.
Where to study it
Practice questions on this code
Real questions from the Aviator IQ bank that test this exact area. Answer each to see the correct choice, the full rationale, and the FAA source.
In weight and balance terms, what is the center of gravity (CG) of an aircraft?
Oral checkride defense
A code on your report is an area the examiner can revisit. Here is how an examiner might probe it, and how to explain it out loud.
Show me how you determined this aircraft is within CG for today's flight.
Walk through the loading table: each item's weight times its arm gives a moment; total moment divided by total weight is the CG. Confirm total weight is under max gross and the CG falls between the forward and aft limits on the POH envelope. Mention converting fuel from gallons to pounds so the math is right.
What happens if you load aft of the aft CG limit?
Explain reduced longitudinal stability and less elevator authority, a smaller stall recovery margin, and a nose-up tendency that makes the airplane harder to recover from a stall. That is why you verify CG position, not just that gross weight is legal.
A code on your test report is an area of deficiency. An authorized instructor must review it with you and endorse that review before you take the practical test, and the examiner may revisit it during the oral. Study it until you can explain it out loud, not just recognize the answer.