And what country can preserve its liberties if their rulers are not warned from time to time that their people preserve the spirit of resistance? Let them take arms. The remedy is to set them right as to facts, pardon and pacify them. What signify a few lives lost in a century or two? The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants.
Thursday, March 21, 2024
Direct Hit. Wonder what that sounded like inside the airplane
Military plane, to judge by exhaust. And probably one of two things happened: nothing/not much, or the whole system defaulted and needed a restart. Looked like the former, as the lights stayed on.
We had a Coast Guard C-130 that took a hit (I was not on it), there was a hole in the raydome in front and the guys in the back (SAR pallet installed, two seats at either side with observer windows) said that a "ball of lightning" came from the bulkhead and shot up the middle and disappeared out the back.
Been hit while flying. Just heard a "pop" at the flash, everything stayed online. Not unusual to wind up with a small hole (or two) on the skin of the airplane.
I've been on planes which were hit by lightning several times. Once we had a lightning strike on climbout and then again on descent into our destination. Maybe half a dozen times across 24,000 hours of flying.
Most of the time, unsurprisingly, you'll hear a big boom and see a bright flash, and from then, the cockpit indications are a great big nothing-burger. Very occasionally, the instruments might go dark for a second and then immediately return. On landing, we'd right it up as a "Suspected Lightning Strike" and the mechanics may, or may not find a very small pinhole.
BTW, here is a feature of planes that many may have not noticed. These are called "Static Wicks". https://i0.wp.com/aerosavvy.com/wp-content/uploads/2014/06/Static-Discharge-Wicks-2.jpg?fit=800%2C530&ssl=1 As the name suggests, they're designed to wick away any static buildup on the plane. And now that I've pointed them out to you, if you're looking at this page on a computer, look to your right, and you'll see them on the background image that CW uses for his blog.
Ball lightning, as described above, is real, but a very, very rare occurance. I never saw it in 34 years of flying.
Interesting, Rob. Way back when, I was doing engineering support for the USAF's AWADS radar system. We got the front end of a Coast Guard C-130 sent to us (in St. Louis) from the boneyard. (They had sawed it off right behind the flight deck, and we used it for designing interfaces and doing fit checks for the two R/Ts and the antenna.) I'm not sure if the radome we had was from the same bird, but it HAD suffered a lightening strike. More apparent on the inside; the fiberglass was delaminated around the pinhole for about 4-5 inches in diameter.
We also had the tail section of a B-52H, from when we built 20mm Vulcan tailgun mounts and search / fire-control radars.
Part of the daily inspection when an aircraft is done flying is to check the static wicks on the control surfaces and diverter strips on the radome for evidence of lightning damage. At period checks you get the tailstand in position and check the top of the vertical stabilizer, the dome over the satellite receiver is one of lightning's favourite entry points. An airliner will get hit once per year on average. I've found lightning strike damage when the pilots reported nothing as the airplanes are designed to be lightning proof. I've also seen pilots come in goggle-eyed after seeing the arc hit them. About 20 years ago as airplanes became more and more digital (fly by wire, etc) a new chapter was added to the maintenance manuals - L/HIRF for Lightning/High Intensity Radiated Fields. The fibreglass and composite fairings are non metallic so a hair-thin stainless steel foil is embedded in the top layer. The foil touches stainless steel washers at the attachment points to electrically connect the fairing to the aircraft through the screws. The paint on the wing fuel tank is loaded with aluminium powder so that lightning is dissipated on the surface in the paint layer. The primer layer below the paint is non-conductive so ideally the lightning will never reach the skin. The paint is tested regularly at several points with a megger, a special ohmmeter that measures insulation resistance at 10,000volts or more. If it fails the megger test you have to repaint the wing within a few months (the process is finicky and the outfits that can do it have waiting lists) and the aircraft will have restrictions regarding flying through known or suspected thunderstorms. Most aircraft have a stormscope installed, similar to weather radar it displays where lightning is occurring to the pilot so he can avoid flying through thunderstorms. Al_in_Ottawa
Fun fact: depending on where they fly, the average passenger-sized jet gets hit by lightning one to three times per year.
ReplyDeleteMilitary plane, to judge by exhaust. And probably one of two things happened: nothing/not much, or the whole system defaulted and needed a restart. Looked like the former, as the lights stayed on.
ReplyDeletemethinks what you are thinking is exhausts are landing lights. I thought the same thing at first, too.
DeleteC'mon, fellas. Nav lights; red port, green stbd, white aft.
DeleteThat should be enough to tell direction of flight respective to your position.
We had a Coast Guard C-130 that took a hit (I was not on it), there was a hole in the raydome in front and the guys in the back (SAR pallet installed, two seats at either side with observer windows) said that a "ball of lightning" came from the bulkhead and shot up the middle and disappeared out the back.
ReplyDeleteBeen hit while flying. Just heard a "pop" at the flash, everything stayed online. Not unusual to wind up with a small hole (or two) on the skin of the airplane.
ReplyDeleteWas mech at an airline. One of our took a hard hit. No bad structural issues but we chased avionics gremlins for a year.
ReplyDeleteSomewhere up front of the tube, a cushion was sucked into a rectum...
ReplyDeleteRetired airline pilot here.....
ReplyDeleteI've been on planes which were hit by lightning several times. Once we had a lightning strike on climbout and then again on descent into our destination. Maybe half a dozen times across 24,000 hours of flying.
Most of the time, unsurprisingly, you'll hear a big boom and see a bright flash, and from then, the cockpit indications are a great big nothing-burger. Very occasionally, the instruments might go dark for a second and then immediately return. On landing, we'd right it up as a "Suspected Lightning Strike" and the mechanics may, or may not find a very small pinhole.
BTW, here is a feature of planes that many may have not noticed. These are called "Static Wicks".
https://i0.wp.com/aerosavvy.com/wp-content/uploads/2014/06/Static-Discharge-Wicks-2.jpg?fit=800%2C530&ssl=1
As the name suggests, they're designed to wick away any static buildup on the plane. And now that I've pointed them out to you, if you're looking at this page on a computer, look to your right, and you'll see them on the background image that CW uses for his blog.
Ball lightning, as described above, is real, but a very, very rare occurance. I never saw it in 34 years of flying.
azlibertarian
You're a marvel AZ.
DeleteInteresting, Rob. Way back when, I was doing engineering support for the USAF's AWADS radar system. We got the front end of a Coast Guard C-130 sent to us (in St. Louis) from the boneyard. (They had sawed it off right behind the flight deck, and we used it for designing interfaces and doing fit checks for the two R/Ts and the antenna.) I'm not sure if the radome we had was from the same bird, but it HAD suffered a lightening strike. More apparent on the inside; the fiberglass was delaminated around the pinhole for about 4-5 inches in diameter.
ReplyDeleteWe also had the tail section of a B-52H, from when we built 20mm Vulcan tailgun mounts and search / fire-control radars.
Part of the daily inspection when an aircraft is done flying is to check the static wicks on the control surfaces and diverter strips on the radome for evidence of lightning damage. At period checks you get the tailstand in position and check the top of the vertical stabilizer, the dome over the satellite receiver is one of lightning's favourite entry points.
ReplyDeleteAn airliner will get hit once per year on average. I've found lightning strike damage when the pilots reported nothing as the airplanes are designed to be lightning proof. I've also seen pilots come in goggle-eyed after seeing the arc hit them.
About 20 years ago as airplanes became more and more digital (fly by wire, etc) a new chapter was added to the maintenance manuals - L/HIRF for Lightning/High Intensity Radiated Fields.
The fibreglass and composite fairings are non metallic so a hair-thin stainless steel foil is embedded in the top layer. The foil touches stainless steel washers at the attachment points to electrically connect the fairing to the aircraft through the screws.
The paint on the wing fuel tank is loaded with aluminium powder so that lightning is dissipated on the surface in the paint layer. The primer layer below the paint is non-conductive so ideally the lightning will never reach the skin. The paint is tested regularly at several points with a megger, a special ohmmeter that measures insulation resistance at 10,000volts or more. If it fails the megger test you have to repaint the wing within a few months (the process is finicky and the outfits that can do it have waiting lists) and the aircraft will have restrictions regarding flying through known or suspected thunderstorms.
Most aircraft have a stormscope installed, similar to weather radar it displays where lightning is occurring to the pilot so he can avoid flying through thunderstorms.
Al_in_Ottawa