Aces High Bulletin Board
General Forums => The O' Club => Topic started by: Wolfala on March 09, 2007, 02:19:43 AM
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This past weekend my wife, assisted by Ramzey and I were underneath degreasing the bird. As she worked out to the wings, next to the pitot tube she saw a hole - not not the kind you would normally see. Being just inbord of the pitot tube, it seemed to have an impact angle suggesting it was a rock sent into orbit from the propeller - but the angle doesn't seem to match it comming from the prop because the impact is at a very shallow angle, but imparted enough force to blow through the paint and drive down through the core.
Fast forward a few days.
To recap from this evening:
I removed the wingtip to have a look inside. I could see clear down to the tip to the wing tank, and on both sides of the wing spar. The spar covers up the damaged portion of the skin. I did a coin tap and couldn't find any evidence of delamination.
However, 3 mechanics came over - their first reaction: "Were you shot at?"
Which brings up an interesting point - even a lead core low velocity .22 or NATO .223 would penetrate and then just discintigrate - not even into fragments but just powder. Granted I cannot see the damaged area b/c of the spar, but in looking at the point of entry, it seems to have come from below and not at a shallow entry angle like I first thought.
We're all stumped. Granted it was at a military base all last week and i'd balk at the idea of getting pinged - but the location being where it is, the normal suspects don't make sense. No one could've backed into it with another aircraft without leaving a streak or taking out the pitot tube. There isn't a scratch around the impact area.
A rock bouncing up from underneath it from the prop - good luck. Rock from another plane - impact angle and then having enough energy left over for penetration is the problem.
I'm fairly certain we would've caught a hole like this during the annual back in December.
I'm out of ideas.
(http://i145.photobucket.com/albums/r207/wolfala/SR-20%20damage/DSC_1634.jpg)
(http://i145.photobucket.com/albums/r207/wolfala/SR-20%20damage/IMG_8785.jpg)
(http://i145.photobucket.com/albums/r207/wolfala/SR-20%20damage/IMG_8809.jpg)
(http://i145.photobucket.com/albums/r207/wolfala/SR-20%20damage/IMG_8787.jpg)
(http://i145.photobucket.com/albums/r207/wolfala/SR-20%20damage/IMG_8788.jpg)
(http://www.northoltwing.com/ramzey/dzisweb/images/IMG_8766.jpg)
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LTARMoil to the principals office
Seriously though, maybe its a matter of perspective in the pics but that hole almost looks too small to even be from a .22? How big are those screw heads right next to it?
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If the impact is hard enough into a composite, the impact point will turn into a bunch of individual fibers that sort of "remember" where they used to be, but have no strength. Little of the material will actually vanish, so it looks like a very very tiny hole but you can fairly easily push through a metal rod the same size as the projectile that went through originally.
The tear triangle looks like the projectile was moving from the inside out... That definately could be a rock hit from the prop especially if it bounced off the ground on the way to the wingtip. You need to look at both the paint triangle and the tear triangle to figure out what direction the impact occurred at. The hole is in the left wing, and the bottom of the prop arc goes towards the left...
That sure is an unlikely location though. And you have NO idea how much damage is actually in there. If it was a boat, you'd be cutting out a square around it and patching it from the inside. Dunno what you do about that sort of thing with an airplane. That's why I want an RV... Aluminum is pretty straightforward to fix :)
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id guess a rock ... even if the angle of impact looks wrong , theres a good chance it was a ricochet off another object .
Either that or you musta caught a horn while Cow Tippin .
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Another aircraft may have blown a rock into your airplane on a ramp. Its the avitation equivilant of a door ding.
Pretty sure it isn't a bullet whole.
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More wet t-shirt plane-washing pics, please.
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A .22 isn't going to revert to a "powder" after impact on fiberglass. Hell it doesn't do that hitting steel. There would be fragments of the lead peeling back and inside the wing if it hit metal at near muzzle velocity. After traveling a while it would have even less tendency to fragment into small chunks. A round from an M16 (5.56mm) also would tend to leave frags of jacket material since they don't shoot plain lead slugs like the rimfires. If a round had enough energy to penetrate fully there should also be evidence of an impact in the wing on the opposite side of the entry point
It could simply have been a rock strike and or one on a missed bubble in the glass.
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What about a .17 being shot into the air?
I'm just taking a shot in the dark here... (BADA BING!)
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Size of the hole is about 1/4 inch. Surrounding dimple area is roughly 1 inch around the POI.
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Looks like another case for http://www.theboxotruth.com
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Well...
We bore scoped the hole today to look for any damage on the wing spar then covered up the hole with tape used for propeller abrasion guards. Couldn't find the bullet - but the concensus is that it was a bullet impact with it breaking the skin and richoeting off.
The local FBI office called and is poking around for any other damage reports in the area. Sure the FAA will be preparing the anal probe for later this week.
Let the fun begin!
Wolf
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Dude you're supposed to leave air combat to the virtual life. :rolleyes:
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It could be a bullet mark. Someone firing, some crazy man, firing on your aircraft could have loaded the 'golden BB' and got lucky although a lot of the momentum would be gone by the time it reached your altitude. Thus the low impact and the missing bullet.
On the other hand have you considered the possibility of, not a rock but a bolt or a rivet picked up by the prop during take off and flung onto the wing? It could look like a bullet mark.
During take off once, something hard whacked the right side of my aircraft while I was at full speed. Hell of a fright for me but even worse for the nervous flyer beside me. There is always some kind of potential FOD on runways.
Aluminium would just have dented, leaving little evidence. But composite might tear.
The thought of a bullet is scary, although not unheard of.