LATAM Airlines finds bullet hole in B767

[peekay4]

Latam Airlines finds bullet hole in Boeing 767 in Brazil | Reuters (http://www.reuters.com/article/us-latam-airlines-brazil-idUSKBN1522KL)

REUTERS -- Latam Airlines Group found a bullet hole in a wing of a Boeing 767-300 during maintenance in Brazil, the company said on Wednesday, the jet having flown to New York, Barcelona and Lima in the past week.

The aircraft, which runs long-range routes out of international airports in Rio de Janeiro and Sao Paulo, went in for routine inspection on Sunday, a Latam representative said.

"There is no way to be certain where it happened," she said. "The airplane flies various routes."

In a statement, the airline said it had notified federal police and civil aviation authority ANAC, which it was still investigating. ANAC said it was supporting a police investigation.

"Latam underscores that the incident did not compromise the security of its operation," said the airline, Latin America's largest carrier.

AvHerald has some additional details and a picture:

Incident: LATAM B763 at Sao Paulo on Jan 15th 2017, aircraft being shot at (http://avherald.com/h?article=4a3abd27&opt=0)

http://i.imgur.com/75Dm1AL.jpg

[e1229]

Being a 7.62, it's probably from an AK47 that are common around Rio de Janeiro. Given the routes for that plane, I'd bet it was shot while landing at GIG. Probably after flying over some "favela", a straight-up shot could reach it.

And considering that drug dealers use to fire just to practice or for fun, I bet someone just aimed and shot.

Luckily, no serious damage was done nor a passenger was hit.

[AF1]

More from this report: B767 shot on approach to Rio (http://flightservicebureau.org/)


http://i2.wp.com/flightservicebureau.org/wp-content/uploads/2017/01/Wing.png?w=1550

http://i2.wp.com/flightservicebureau.org/wp-content/uploads/2017/01/Bullet.png?w=1340

http://i1.wp.com/flightservicebureau.org/wp-content/uploads/2017/01/Bullet-hole.png?w=1370

http://i1.wp.com/flightservicebureau.org/wp-content/uploads/2017/01/PT-MSY.png?w=1940

[glad rag]

hmm looks spent to me......

[lomapaseo]

looks fake to me

[Lonewolf_50]

Loma, I am with you. The tip of that projectile is not deformed at all. I'd have thought that it hitting a flying plane might have an impact on the tip ...

[PersonFromPorlock]

The tip of that projectile is not deformed at all. I'd have thought that it hitting a flying plane might have an impact on the tip ... Spin-stabilized bullets tend to keep the orientation they had when they left the barrel, not streamline. It's entirely possible that the bullet was falling base-first when the plane hit it.

[MickG0105]

7.62 is also NATO standard.
7.62 x 51mm is NATO, 7.62 x 39mm is Soviet where 51mm and 39mm refer to the length of the casing. Standard NATO spitzer point, boat-tail, full metal jacket (ball) projectiles are 33.3mm long. The round in the photo is almost certainly a 7.62 x 39mm projectile.

[lomapaseo]

Spin-stabilized bullets tend to keep the orientation they had when they left the barrel, not streamline. It's entirely possible that the bullet was falling base-first when the plane hit it.


I'll accept that.

I agree with lonewolf about the tip but I was making my jugements about the damage to the skin is not from a ballistic impact >500 ft/s

[cooperplace]

how much damage would you expect in a hard-tipped bullet hitting aluminium? Would be nice to hear from a ballistics expert.

[megan]

It's evident from the photo that the bullet hit the LE flap whilst it was extended, and the mushrooming about the tip in the first photo shows that it entered tip first. From experience I would guess the aircraft was probably at about 2,000 feet when hit, if the fire were vertical, of course lower if oblique, which would seem to be the case with LE extended. One occasion I had a crewman sitting on the floor with his back against my seat and we took a burst of AK while flying at 2,000. He jumped up with an expletive and found a round had penetrated the outer skin and caused just a dent to the floor where his buttocks were positioned. It was generally assumed that at 1,500 you were safe from AK.

[MickG0105]

It's entirely possible that the bullet was falling base-first when the plane hit it.
Actually, it's not. Look at the AV Herald photo, it shows that the bullet penetrated the skin of the LE flap in the usual fashion, tip first.
Also, bear in mind that the round in question looks like a FMJ military round; they will only deform if they strike a material that is harder than their jacket. The skin on the LE flap is probably 2090-T84 aluminium-lithium alloy or possibly 7475-T73 alloy; both are controlled toughness alloys with reasonably high strength that are fracture and fatigue crack resistant. However, they are not particularly resistant to penetration.
Given the minimal penetration and lack of deformation it does not appear to have been a particularly high energy impact. If I had to hazard a guess I'd say that the projectile was descending at the point of impact.

[lomapaseo]

how much damage would you expect in a hard-tipped bullet hitting aluminium? Would be nice to hear from a ballistics expert.

edges don't roll and cracks don't spread.

[onetrack]

If I had to hazard a guess I'd say that the projectile was descending at the point of impact.I'd hazard a guess that your guess is wrong. The reasonably-accurate article in the link below indicates that falling bullets tumble and often fall blunt end first.
I'll hazard a guess it was a bad shot, aimed upwards, and the bullets energy was largely spent upon contact with the flap. :)
It may even have been a "celebratory fire event".

Forensic Outreach.com - library - the falling bullet myths legends and terminal velocity (http://forensicoutreach.com/library/the-falling-bullet-myths-legends-and-terminal-velocity/)

[EEngr]

I'll hazard a guess it was a bad shot, aimed upwards,

'Upwards' could describe quite a few trajectories. A shot straight up will lose it's kinetic energy and tumble on the way back down. But a shot fired with some elevation (say 45 degrees) will still follow a ballistic trajectory past its maximum altitude. So it is possible that this round was fired in such a manner and encountered the LE slat from above while still flying pointy end first with significant kinetic energy.

[MickG0105]

I'd hazard a guess that your guess is wrong.

Did you read that reasonably-accurate article by any chance?

In keeping with what EEngr said, The Forensic Outreach Team make the point that;

If fired at an angle between 20 to 45 degrees or even more, then the bullet will travel farther with a greater probability of hitting something (or someone). The uninterrupted ballistic trajectory will make it far less likely to engage in a tumbling motion, and allow it to continue at a higher speed over terminal velocity.

For the sake of clarity allow me to amend my earlier statement to read,

If I had to hazard a guess I'd say that the projectile was descending on an uninterrupted ballistic trajectory at the point of impact.

[er340790]

It was generally assumed that at 1,500 you were safe from AK.

Well, that's the 'effective' range..... but you'd still want to keep your head down at double that. :eek:

[cwatters]

If I had to hazard a guess I'd say that the projectile was descending on an uninterrupted ballistic trajectory at the point of impact.

I agree. It certainly looks like it was travelling downwards point first when it hit.

[Machinbird]

In ancient history, when my squadron was flying in a hot war, the briefing was that the small arms envelope extended up to 3000 ft. and could be considered dense.
That should still be a fairly good number for shoulder fired, gunpowder propelled, projectile weapons.

[RealUlli]

In ancient times, when I was in basic training in the German army, we learned the safety distance for a G3 (7.52x51) was 3000m, the effective combat range of the same gun when mounted was 900m.

I don't know at what point the projectile goes transonic (and starts to tumble), but I guess it's probably at 2000+ m.

I heard the AK47 has a somewhat shorter barrel, so the bullets should be a bit slower, but they still should reach up a few thousand feet.

[FakePilot]

I'm guessing that some of the marks on the bullet may have been from pulling it out. I'd guess if it stayed lodged it was in there pretty good.

[EEngr]

at what point the projectile goes transonic (and starts to tumble)

Cause and effect. Going trans-sonic doesn't necessarily cause a projectile to tumble if it's spin rate, kinetic energy and aerodynamics are 'correct'. On the other hand, tumbling will make one go subsonic pretty quickly.

[Ritam]

In ancient times, when I was in basic training in the German army, we learned the safety distance for a G3 (7.52x51) was 3000m, the effective combat range of the same gun when mounted was 900m.

I'm guessing your training involved projectiles travelling in a mostly horizontal direction. In a vertical shot, gravity is acting directly against the direction of travel, which means the downward acceleration of gravity is 100% against the direction of the forward momentum.

[HighAndFlighty]

In ancient times, when I was in basic training in the German army, we learned the safety distance for a G3 (7.52x51) was 3000m, the effective combat range of the same gun when mounted was 900m.

I don't know at what point the projectile goes transonic (and starts to tumble), but I guess it's probably at 2000+ m.

I heard the AK47 has a somewhat shorter barrel, so the bullets should be a bit slower, but they still should reach up a few thousand feet.

There's more to it than barrel length. The AK uses a smaller cartridge (7.52 x 39) which, in turn, contains both a smaller charge and a slightly shorter and lighter bullet. Then, of course, there are a variety of rounds, of varying construction, purpose and quality, available for each.

In broad terms, the AK has both a lower muzzle velocity (approx 2350ish ft/s versus approx 2700ish ft/s) and less energy (approx 2000 ft-lb-ish versus approx 2500 ft-lb-ish.) than a typical 7.62 x 51 caliber firearm. The rate at which velocity and energy will degrade is significantly affected by the ballistic path.

[megan]

It was generally assumed that at 1,500 you were safe from AK.
Well, that's the 'effective' range..... but you'd still want to keep your head down at double that.er340790, as I said that's when flying ie a vertical shot. As my anecdote explained, at 2,000 feet the round was pretty much spent, penetrated one thin sheet of aluminium and just caused a dent in the next. For 50 cal 4,500 feet in the vertical taken to be "safe".

Photo is of a nav light flasher relay that took an AK round when we were either on the ground or low flying. Penetrated the outer skin of thin aluminium before impacting. Round came to rest in the relay with a mushroomed head. Range indeterminate, never even heard the shot.

[RealUlli]

I'm guessing your training involved projectiles travelling in a mostly horizontal direction. In a vertical shot, gravity is acting directly against the direction of travel, which means the downward acceleration of gravity is 100% against the direction of the forward momentum.

That's what I thought at first, too. Then I did a quick calculation:

The bullet leaves the barrel at about 700m/s. It gets slowed down by gravity by about 10m/s^2.

Assuming the bullet is travelling straight up and has no air resistance, it passes through 1500m (~4500ft) a bit over two seconds later, still doing slightly less than 680m/s.

Since the bullets usually don't reach much further up, I guess gravity effects can mostly be ignored.

Or did I miscalculate somewhere?

[Chu Chu]

Assuming no air resistance isn't a very safe assumption. If you just consider gravity, the bullet would reach about 24,000 meters. . .

But I guess that in itself demonstrates that gravity plays a relatively small role in slowing a bullet fired vertically. In fact, if you assume that the bullet's velocity is zero at 1500m, and slows at a linear rate, gravity would act on it for 4 seconds instead of two, and account for the loss of 40 M/S instead of 20. Still pretty small potatoes.

[WingNut60]

A typical 7.62 NATO projectile will drop sub-sonic at around 800 - 900 M after a time of flight of about 1.8 secs (say about 2700 ft after leaving the barrel) - this is affected very little by angle of firing.
At that velocity and range it is STILL imbued with more than 400 ft/lbs of energy and is a very dangerous item to have land in your lap.
It is quite capable of punching right through a refrigerator.
I would, arbitrarily, say that it would need to drop below 500 ft/sec before I would consider it to be relatively harmless to either human or aircraft skin.
Unfortunately, when fired vertically, it will still be traveling at more than 600 ft/sec at an altitude of 6000 ft.

And the maximum altitude reached is going to be somewhere in the vicinity of 9000 ft before it begins falling to earth.
Which pretty much fits in with ....
.....when I was in basic training in the German army, we learned the safety distance for a G3 (7.52x51) was 3000mWhen leaving the barrel it would have been rotating at a rate approaching 200,000 RPM.
That is faster than most small vehicular turbochargers and not that far behind a dentists drill.

The ability to maintain stabilised flight is largely dependent on the ballistic characteristics of the projectile and the rifling pitch of the rifle from which it was dispatched.

If in doubt, please refer to standard ballistics calculators from any of the ammunition / projectile manufacturers.
I used Hornady, because they accommodate vertical firing, either up or down

[Pali]

If I remember well, on our military training (many, many years ago) we were warned that AK-47 projectile can be lethal up to 2400m distance – depending on type of bullet and cartridge.

[andy148]

hen leaving the barrel it would have been rotating at a rate approaching 200,000 RPM.
That is faster than most small vehicular turbochargers and not that far behind a dentists drill.

Not true, it you actually spin (rotate) things at 200'000 Rpm, the projectile actually becomes more unstable and is more prone to spalling (tumbling). Its been a while since I've had my hands on an AK47, but IIRC it has a uniform right hand twist in the rifling of the barrel, which causes the round to spin and come out of the barrel on the 'upwards' part of the rifling which gives the round it's elliptical trajectory and will be about 3000rpm.
I'd have to check my notes but to give you an idea, a modern artillery piece that fires out to 17km, only gives it's projectile a slow rotation speed.
AK's are renowned for their inaccuracy, (having been on the receiving end) anything over 500 meters and its hard to hit things accurately. This was mostly likely celebratory fire, or from a scoped weapon?

[WingNut60]

...... and will be about 3000rpm.

Not sure how relevant to the original post this is, but I think that you're wrong.
Spin rate is relative to velocity and rifling twist rate (pitch).
Standard calc is Bullet RPM = MV X 720/Twist Rate (in inches)

I was using typical numbers for a NATO round and that gives about 180,000 RPM when fired from a barrel with 10 inch pitch - again, very typical.
Are you sure you didn't mean 3,000 Revs / sec?
The rest of your post seems pretty right. For instance 8 inch pitch and high velocity can cause over-stabilisation; which is actually unstabilisation.