Weights for flight testing

[dougbush]

What type of weights are recommended or typically used to simulate passengers and cargo for flight testing at various gross weights and CG locations?

[Auburntsts]

I recommend using something that can used for another purpose post flight. I used 40# bags of mulch. Others have used bags of water softener salt, cement, potting soil, sand, dog food, cases of water, etc. I also recommend putting down a plastic sheet/tarp under whatever you use just in case a bag rips.

[martymayes]

lead shot bags used to be the aviation standard. 25 lb bags and you can work in 25# increments. They are also great for semi permanent ballast. Oh, they are also the most $$$

[CHICAGORANDY]

As others have said, use things for which you have a later use. One caveat re: bags of sand/soil, most Big Box stores have outdoor garden centers where rain could add considerable weight to exposed bags so that supposed 30# bag of sand could really weigh a lot more. Weigh before use. Dog food is a GREAT donation to your local shelter, cat litter makes a very good oil spill absorbent for a garage floor or as winter traction assist.

[Auburntsts]

As a side note for possible ballast once you’re in Phase II, I use collapsible 5-gal plastic water containers typically used for camping. I can easily add or dump water as required and the empty containers take up little space or weight. Very handy for flights where you are solo for one leg and then pick up pax/cargo on another away from home base.

[FlyingRon]

I'd recommend against water. The problem occurs if your water container breaks or otherwise leaks. Your 5 gallons of water is now 40 pounds of ballast that may end running way aft and putting you irrecoverably out of CG. It's happened in gliders (who often take water ballast along).