robert7467 Posted January 16, 2013 Report Posted January 16, 2013 I heard that you can magnatize the airplane if you vacuum it... Any truth to this? Quote
jlunseth Posted January 16, 2013 Report Posted January 16, 2013 I also have read that you can magnetize a Mooney by running an active power cord over it. I use a wet vac with a long hose, so no power that is in contact with the aircraft. The cure is to degauss. Quote
Marauder Posted January 16, 2013 Report Posted January 16, 2013 I heard that you can magnatize the airplane if you vacuum it... Any truth to this? Our steel frames can be magnetized by current passing over it, so in theory yes. I have had to swing my compass numerous times over the years. When my up avionics upgrade was done, they did find current carrying wires running over the cage (tie wrapped to the cage). Quote
robert7467 Posted January 16, 2013 Author Report Posted January 16, 2013 So long hose, or would I have any issues with one of those handheld dustbusters? Quote
xftrplt Posted January 16, 2013 Report Posted January 16, 2013 Don't believe you can using AC. With DC certainly a probability. EE, Physics majors? Quote
jlunseth Posted January 16, 2013 Report Posted January 16, 2013 So long hose, or would I have any issues with one of those handheld dustbusters? Its the power cord, so handheld battery powered dustbuster would be ok, but a handheld dustbuster that uses a power cord which would pass over the wing or fuselage, could be a problem. That is what people are saying. Quote
gamefreak32 Posted January 17, 2013 Report Posted January 17, 2013 Don't believe you can using AC. With DC certainly a probability. EE, Physics majors? Correct. AC applied to a metal moves the electrons back and forth and does not allow them to migrate very far before they migrate back. DC only moves them in one direction. Magnetization occurs when the electrons get "stuck" at one end of a material. Its the power cord, so handheld battery powered dustbuster would be ok, but a handheld dustbuster that uses a power cord which would pass over the wing or fuselage, could be a problem. That is what people are saying. Exact opposite. Handheld battery powered vacuums would be worse because they are DC powered. Wall operated vacuums are AC and I would not expect them to magnetize the plane. I would not expect to have any magnetization on an airframe with a simple vacuum considering that it is such a large surface and the current carrying wires are not touching it. Does a vacuum create a magnetic field and mess with a compass? Yes, but only as long as the vacuum is running and close. Any electric motor is a large inductor and creates a magnetic field when you apply current to it. Any piece of conductive material with current on it creates a magnetic field to some extent. When you turn the avionics on, you have a large number of wires in close proximity to the compass with current on them which is why the compass is incorrect and has a magnetic deviation card. Quote
BigTex Posted January 17, 2013 Report Posted January 17, 2013 My plane was magnetized by just throwing the extension cord over the cowl in from of the windshield. This is a huge problem... Specially with the pre-J models. So keep all AC power cords far away from your aircraft! Quote
N601RX Posted January 17, 2013 Report Posted January 17, 2013 I place the shop vac in the luggage compartment and the hose is long eough to reach up front. Quote
xftrplt Posted January 17, 2013 Report Posted January 17, 2013 I leave my Tannis heater plugged in for months at a time with the cord connected at the oil filler door. No problems. However, if I place an iPad on the glare shield, the whiskey compass swings 20 degrees. Quote
larryb Posted January 17, 2013 Report Posted January 17, 2013 I leave my Tannis heater plugged in for months at a time with the cord connected at the oil filler door. No problems. However, if I place an iPad on the glare shield, the whiskey compass swings 20 degrees. iPad speakers have magnets, so no suprise. It's been over 25 years since my physics classes. but I don't believe AC will magnitize anything. De-Gaussing is a high frequency AC process. Quote
bd32322 Posted January 17, 2013 Report Posted January 17, 2013 I leave my Tannis heater plugged in for months at a time with the cord connected at the oil filler door. No problems. However, if I place an iPad on the glare shield, the whiskey compass swings 20 degrees. Same here .. No problem with pre-heater cables plugged in for 8 hours before every flight in the winter in the north east Quote
robert7467 Posted January 17, 2013 Author Report Posted January 17, 2013 Do the DC battery powered vacuume could be worse? Isnt everything in the plane DC? Quote
Marauder Posted January 17, 2013 Report Posted January 17, 2013 Same here .. No problem with pre-heater cables plugged in for 8 hours before every flight in the winter in the north east I think the difference is where the current is going. In the case of the engine heaters, you may be magnetizing the engine mount but it shouldn't affect the compass. The steel cage surrounding the cockpit is a different beast. For years I struggled to keep a wet compass swung, even went to the length of having the plane degaussed. But in a few months, it was wrong again. Eventually, I bought a vertical card compass with the balancing balls option. It was the only and easy way to keep the compass swung. It wasn't until this past avionics upgrade that the root cause may have been found (current carrying wires strapped to the cage). I have been spoiled as well with both Aspens having remote compasses. No doubt now. Quote
Marauder Posted January 17, 2013 Report Posted January 17, 2013 Do the DC battery powered vacuume could be worse? Isnt everything in the plane DC? All of the plane's currents will be in DC (either 14 or 28 VDC). The problem isn't the DC or AC current, it is the magnetizing of the steel cage where our compasses mount. If you ever did that experiment as a kid where you ran a coil of wire around a screwdriver and got it to become magnetized, it's the same concept. In my case, we believe we found the problem. A series of current carrying wires were physically mounted to the cage. Time will tell... Quote
Marauder Posted January 18, 2013 Report Posted January 18, 2013 Found the link to the Mooney SB on magnetism. http://www.mooney.com/images/pdfs/sb-pdf/sbm20-150A.pdf Quote
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