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buckets full of corrosive material in the form of electrolyte that allow the chemical process of electricity to occur any time you turn your master switch on. Lead acid batteries contain sulfuric acid, and Nickel-Cadmium (NiCad) bat- teries contain Potassium Chloride, both of which make quick work of eating metal.
Lead acid batteries are typically sealed, so there’s a lower chance of a leak, but that chance is never zero unless the battery is empty. NiCad batteries, more commonly found in turbine airplanes, require maintenance, so they’re not sealed and are more prone to spillage. It doesn’t take a lot of electrolyte to eat away primer or corrosion inhibitor on its way to bare aluminum. Spills should be taken care of as soon as they’re spotted. Baking soda and water will neutralize lead acid spills, and a 10:1 mixture of water to boric acid will neutralize NiCad spills. In both cases, you should flush the area diligently with clean water to ensure all the contamination is gone.
If you’re operating an airplane with a chemical lavatory, special care should be taken. Keep an eye on the skin, cables, wire bundles, etc. under the lav because blue juice, while it doesn’t contain corrosive salts, does contain mois- ture and other contaminants that will promote corrosion over time. The lav sits over a portion of the airplane that only gets looked at during periodic inspections, typically every 12 to 18 months. If an inspector was less than thor- ough for even one inspection cycle, you could be sitting on a festering pile of neon blue-colored corrosion. Any shop worth their salt (no pun intended), will be happy to provide you with photos of the area under the lav since all the interior and floor panels must be removed for the shop to get a completely unobstructed view of every square millimeter of the belly.
There are quite a few inexpensive but very effective borescopes on the market now, and there’s really no down- side to owning one. For a few hundred dollars, I bought a borescope from Depstech that connects via Bluetooth to my iPad or iPhone and provides a clear picture from which I’m able to record video and take still photos. If you suspect you have a leak, it’s much easier to gain enough access to get
A NiCad battery with Cadmium plated hardware isn’t immune to the effects of corrosion.
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October 2022 / TWIN & TURBINE • 9