PLT179: Ground Weigh Off And Load
What code PLT179 covers, why the FAA tests it, and how to study Ground Weigh Off And Load before your checkride.
Recall balloon - ground weigh-off / static equilibrium / load
What this means for your checkride
During the weigh off, the crew brings the balloon to neutral buoyancy on the ground so it is balanced against its total load before release. Ballast is added or removed until the balloon sits in equilibrium, and then a measured amount of ballast is removed to establish the desired positive buoyancy and ascent rate. Testing the buoyancy by letting the balloon lift a few feet several times confirms the load is set correctly before the final hands off release.
Correctly weighing off against the load prevents launching too heavy or too light and sets a controlled ascent.
The weigh off is not just a headcount of who is aboard. It is a physical balance of the whole system against buoyancy for that day's conditions.
Where to study it
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.