Paul, I wouldn't worry unless you plan to operate your van on a mountain top in one of those impressive upstate NY lightning storms.
As for protecting aircraft, first you spec out all avionics to survive a brief 500 V blast on any wiring that goes outside the fuselage (typically antenna cables). Then you make sure that all metal joints and faying surfaces have a DC resistance not more than .0025 ohms. Via Ohm's Law, you'll see that 250 K amps and .0025 ohms comes out to 500 V. Also, all avionics boxes will have dedicated bonding straps to the airframe. Other considerations get right down into the design of the avionics boxes. All antennas are DC grounded to the fuselage. Last, but certainly not least, you talk with the folks who write the aircraft operating manuals and put in an instruction that tells the crew not to fly into thunderstorms and to avoid flight in areas likely to produce lightning. Then you hope and pray that, during their flight training, they were taught how to spot weather conditions likely to spawn lightning. I was. My instructors drilled that weather info into my feeble brain until I could recite in my sleep and spot a potential lightning strike area and avoid it. You can get a pretty good idea of this stuff in an FAA publication. It has the exciting title DO-160-? The ? is for whatever the latest version is. Happy New Year, Dick ----- Original Message ----- From: "Paul Yonge" <[EMAIL PROTECTED]> To: <[email protected]> Sent: 30 December, 2005 16:23 Subject: Re: [Repeater-Builder] polyphaser Help On Dec 30, 2005, at 7:10 PM, Dick wrote: > After a lot of years at Lockheed designing lightning protection for > military aircraft, I've developed a very healthy respect for the > stuff. Out of curiosity, how does one design lightning protection for aircraft? I've avoided worrying about lightning protection for the mobile repeater van I'm putting together. Should I be worrying? Paul Yonge WQDY219 MIDLAKES REPEATER Syracuse, New York Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
