Nomad559
join:2002-12-29
Fresno, CA | 747 Struck By Lightning
A 747 Is Struck By Lightning
![]() |
|
CigaR
Premium
join:2004-08-24 | Cool Video. No real trouble for the airplane though. They are built to sustain lightning strikes. They will however make an emergency landing as a precaution.  |
|
Lurch77
Stop looking at me.
Premium
join:2001-11-22
Oconto, WI
 ·CenturyLink
 ·HiOconto
| No real trouble as far as safe flight for landing, but it will wreak havoc on the electronics. As an aviation electrician in the military, I can remember changing the radios and radar system on one of our C-130s after a strike. The air framers also had to replace the radome (nose cone) due to it having a foot wide hole blown through it.
--
TV shows that make you think are almost as bad as books. |
|
Piedone
join:2000-10-20
S California | Awesome vid and details @ Lurch77, thanks! |
|
Marduk
join:2004-09-05
West Chester, PA | reply to Nomad559
They're not grounded, whats the problem? |
|
Lurch77
Stop looking at me.
Premium
join:2001-11-22
Oconto, WI | The problem is they still conduct the energy. And that causes damage. |
|
Marduk
join:2004-09-05
West Chester, PA
 ·Comcast
| said by Lurch77  :The problem is they still conduct the energy. And that causes damage. Really? Please explain. When there is no grounding, I fail to see how it would even bother an object in air. |
|
Lurch77
Stop looking at me.
Premium
join:2001-11-22
Oconto, WI
·CenturyLink
·HiOconto
1 edit | Read my first post in this thread.
Here's one for you. What will happen to a 20 gauge wire, for example, if you put 100 amps through it? It's not grounded, but I bet you fry that wire. Same goes for electric motors. Put a 2amp motor in place of a 20 amp motor. That little motor does not need to be grounded to fry the windings. Every conducting material in the world has an ampacity limit. Fine electronics like those in an aircraft are not able to withstand the 10,000 to 200,000 amperes typically found in a lightning bolt.
I should add that most aircraft have steps involved to dessipate the enery mostly harmlessly. But damage still can and does happen. This is why lightning strikes are handled with the pilot making an emergency landing. |
|
CigaR
Premium
join:2004-08-24
·Bell Sympatico
| said by Lurch77 :Read my first post in this thread. Here's one for you. What will happen to a 20 gauge wire, for example, if you put 100 amps through it? It's not grounded, but I bet you fry that wire. Your example is ambiguous on the term "not grounded". You are basically describing a short. |
|
Marduk
join:2004-09-05
West Chester, PA
·Comcast
| reply to Lurch77
said by Lurch77 :Read my first post in this thread. Here's one for you. What will happen to a 20 gauge wire, for example, if you put 100 amps through it? It's not grounded, but I bet you fry that wire. Same goes for electric motors. Put a 2amp motor in place of a 20 amp motor. That little motor does not need to be grounded to fry the windings. Every conducting material in the world has an ampacity limit. Fine electronics like those in an aircraft are not able to withstand the 10,000 to 200,000 amperes typically found in a lightning bolt. I should add that most aircraft have steps involved to dessipate the enery mostly harmlessly. But damage still can and does happen. This is why lightning strikes are handled with the pilot making an emergency landing. 2amp motor? WTF? That's DC, meaning direct current, the current has a + and a -.
You can put that wire on the positive and the motor will be fine.
If there is no complete circuit there is no problem.
Tell you what, you can take 4000000000000000 volts and put it through your ipod speaker wire, as long as there is no ground or return, that wire will be fine. Hell I'd put it in my mouth if I was not grounded. |
|
leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
clubs: 
| reply to Marduk
said by Marduk :Really? Please explain. When there is no grounding, I fail to see how it would even bother an object in air. There are two very important points that you are missing. The first mistake is that you assume that there is no grounding.
The second is the fact that the metallic aircraft exterior (typically aluminum) is a much better conductor for electricity than the air that surrounds it. Air is such a bad conductor that is being considered an isolator below the breakdown voltage (about 3 million volt per meter of air) while aluminum conducts electricity almost as well as gold (37.8 vs. 45.2 million S/m).
What is really happening is that the lightning chooses the aircraft as a shortcut on the way to the ground.
The complete circuit is therefore:
- electrically charged cloud
- some poorly conducting air
- the aircraft which is an excellent conductor
- some more poorly conducting air
- planet earth (a.k.a. ground)
--
Got some spare cpu cycles ? Join Team Helix or Team Starfire! |
|
Lurch77
Stop looking at me.
Premium
join:2001-11-22
Oconto, WI
·CenturyLink
·HiOconto
| reply to Marduk
You have little idea what you are talking about, don't you? You can stop trying to show me how this stuff works. Many years of electrical schooling and many more years of real world experience has taught me enough. I worked as an electrician for 9 years, and currently work with high voltage equipment. I know how electricity works.
Here's a big key component you are failing to address. There is a complete circuit! There would be no lightning if there were no complete circuit. Clouds to earth is the circuit. The plane is part of the conductor in that circuit.
DC motor? What are you talking about? You have gone and completely lost me there. It does not matter what current that a motor is designed for, direct or alternating, both have an amperage rating that cannot be exceeded. You understand that the windings in a motor are simply a conductor, right?
--
TV shows that make you think are almost as bad as books. |
|
WickedWinter
join:2003-08-02
USA
1 edit | reply to Marduk
said by Marduk :WTF? That's DC, meaning direct current, the current has a + and a -. You can put that wire on the positive and the motor will be fine. If there is no complete circuit there is no problem. Tell you what, you can take 4000000000000000 volts and put it through your ipod speaker wire, as long as there is no ground or return, that wire will be fine. Hell I'd put it in my mouth if I was not grounded. Your just trolling right?
In case your not - here is the answer to your 4 statements.
1)Lightning is also DC current.
2)An underated motor would melt with high current and a big load.
3)Anything can be a circuit if there is enough current, even air, that's why lightning occurs.
4)The poster was taking about high current, not high voltage. Their not the same thing. 
|
|
Marduk
join:2004-09-05
West Chester, PA
·Comcast
| reply to Lurch77
said by Lurch77 :DC motor? What are you talking about? You have gone and completely lost me there. It does not matter what current that a motor is designed for, direct or alternating, both have an amperage rating that cannot be exceeded. You understand that the windings in a motor are simply a conductor, right? Ya, you got me.
Though it would be hard to cook windings without a ground. |
|
Marduk
join:2004-09-05
West Chester, PA
·Comcast
| reply to WickedWinter
said by WickedWinter :said by Marduk :WTF? That's DC, meaning direct current, the current has a + and a -. You can put that wire on the positive and the motor will be fine. If there is no complete circuit there is no problem. Tell you what, you can take 4000000000000000 volts and put it through your ipod speaker wire, as long as there is no ground or return, that wire will be fine. Hell I'd put it in my mouth if I was not grounded. Your just trolling right? In case your not - here is the answer to your 4 statements. 1)Lightning is also DC current. 2)An underated motor would melt with high current and a big load. 3)Anything can be a circuit if there is enough current, even air, that's why lightning occurs. 4)The poster was taking about high current, not high voltage. Their not the same thing. NO, you are wrong.
Lightning does ZERO harm to things that are not grounded.
Where is lightning going dumbass? |
|
Thane_Bitter
join:2005-01-20
London, ON
·Bell Sympatico
| said by Marduk :NO, you are wrong. Lightning does ZERO harm to things that are not grounded. Google 'lighting rod' & learn.
--
The Wagon Queen Family Truckster; sure you think you hate it now, but wait till you drive it. |
|
Lurch77
Stop looking at me.
Premium
join:2001-11-22
Oconto, WI
·CenturyLink
·HiOconto
| reply to Marduk
You just need to stop. You apparently have no grasp of basic electrical theory.
Lets involve some resources. I don't need any of this, since I have personally repaired lightning damage on aircraft. But you really need to read this.
»www.nzherald.co.nz/nz/news/artic···10518941
»www.newton.dep.anl.gov/askasci/w···0024.htm
»journalsip.astm.org/JOURNALS/FOR···/243.htm
»jdchapdelaine.com/lightning.htm
»www.deas.albany.edu/deas/bvonn/707wingt.html
If you cannot understand this stuff, I'm just going to let you think you won. Puff out that chest big guy.
--
TV shows that make you think are almost as bad as books. |
|
Marduk
join:2004-09-05
West Chester, PA
·Comcast
| I'll probably just have another beer |
|
Marduk
join:2004-09-05
West Chester, PA | reply to Lurch77
And also, lightning does no damage to an airplane, you've sources, I do not.
Uhhh, that's it, otherwise we'd have no planes in the air. |
|
Lurch77
Stop looking at me.
Premium
join:2001-11-22
Oconto, WI | Just go have another beer. |
|
