EAA Sport Aviation - December 2009

members forum

hand in hand. I think this is a neat little device, but this project has some serious electrical safety issues and could be made much safer for just a few more dollars spent.

The main issues are the exposed live electrical parts at 110 volts and the lack of proper grounding of the appliance. (Anything you plug in is considered an appliance.) 110 volts AC has the potential to shock, burn, and yes, kill you. Electrical arc flash is measured in thousands of degrees. That’s instant third-degree burns.

The National Electrical Code requires the grounding of an electrical apparatus. It is not an option as the article suggests, unless the device is double-insulated and there is no risk of electrifying metal parts. The National Electrical Code (NEC) is governed by the National Fire Protection Agency. Its main purpose is the prevention of fire, property damage, and personal injury, due to improper and unsafe wiring methods. Nearly every non-commercial hangar I visit is wired improperly according to the law of the NEC. Hangars are similar to automotive service stations, and gas stations, all with a very specific set of rules to follow for wiring methods. But that is a topic for another time.

Imagine using this engine dryer in an airplane hangar, where there may be fuel, oil, water, or other flammables found. Airplanes drip fuel and oil and vent other flammable gases, perhaps from the battery or fuel vent. There may be water on the floor. We all know water and electricity don’t mix well. This dryer is entirely exposed. To leave it unattended in your hangar would be foolhardy. You could see your dream airplane go up in smoke because of poor and unsafe wiring methods. Or worse, you could get electrocuted trying to use it.

I have a solution that I think will make this a much safer device. The cost would be minimal. A 4- or 6-inch electrical box attached to the jar lid would be all you need. PVC or metal would be fine. You can cut holes in the bottom to allow for the purge valve and the air lines. A vent above the purge valve can be cut in and screened off. The air lines can be routed out the side of the box. The receptacle can be cut into the cover of a plastic box and a standard wall plate used over it. Or if you use a metal box, standard size receptacle covers are made for these boxes.

You must use a grounded cord, with proper connectors

in the side of the box. Ground the receptacle (green screw is ground, white screw is neutral, and brass screw is hot) and all other metal parts including the lid of the jar. If a metal box is used, ground it as well. You should also be plugging it into a ground fault circuit interrupter (GFCI) receptacle. This will help prevent you from getting a shock if something does go wrong.

One other item to consider is the glass jar. Wrapping it with bubble wrap, foam, or something similar would help prevent accidental breakage of the jar and light bulb. Breaking the bulb while lit may cause sparks or could shock you.

I hope these comments are taken as constructive criticism, with a solution. Electricity at any voltage is something that demands respect and knowledge.

Daniel Kapinos, EAA 858831

East Hampton, Massachusetts

Correction to IFR Currency

Catching up on my reading, and saw the “Staying Current on a Budget” article by Robert Rossier in the September issue. It gives great ideas on how to keep your head in the flying game without spending a lot of money on avgas. However, there is one error which could unnecessarily add to the cost of staying current.

The table accompanying the article says that for IFR currency, six holding patterns and six interception tracking events are required, but this isn’t so. 14 CFR 61. 57(c) (both the version in effect when the article was written/published and the new version effective 10/20/2009) requires only that the pilot have performed and logged holding, interception, and tracking without any minimum number of events. The only task requiring six events is approaches, and the performance of any non-radar approach [i.e., not airport surveillance radar (ASR) or precision approach radar (PAR)] covers the interception and tracking requirement implicitly. Thus, one need only be able to look back and find six approaches (including at least one non-radar approach) and one holding pattern in the preceding six calendar months to meet this requirement. Just don’t forget to log that holding pattern explicitly, whether you do it in flight or in an approved flight simulation device.