Sharpshooting through chopper wash

[mljdeckard]

This has bugged me in a couple of movies, and I have to ask.

In "SWAT" and "Spy Game", there are scenes with snipers taking long distance shots under the blades of a hovering chopper. Is this possible at all? Will the downthrust and general chaos make it impossible to make any kind of precise shot?

Now that I think about it, in "Last of the Breed" by Louis L'Amour, a guy makes a shot into a chopper with an arrow.

Is there some kind of trick or rule that makes it possible?

 

[huckster]

yes it's possible.

USA snipers actually practice shooting out of moving helicopters.

 

[skinewmexico]

Never done it, but I sure like Louis L'Amour. I would imagine that a disturbance that early in the bullet flight has less effect downrange.

 

[TRGRHPY]

Having been in my fair share of military helicopters, I can tell you that it must be a helluva lot harder....those things shake, "bounce", bob....I imagine that it's quite a feat. Although I had a firearms on them, I never tried aiming out of one during flight.

wind values at the shooters position is going to have a greater effect on the bullet than a wind value down-range. I'm sure that if they practice shooting, or have some sort of class, that the wind value of each different helo has probably been determined.

 

[heron]

I doubt that a bullet will spend long enough in the rotor-wash to notice it.

 

[Tankcommander]

The Military Channel had the lastest best Sniper competition on at Fort Benning and one of the events was shooting from a moving and hovering Blackhawk. They showed the actual event and stated that it was practiced in Iraq. It also takes alot of practice.

TC

 

[benzy2]

The earlier the bullet is pushed by the wind the more down range effect is has. Think about it. If you push the bullet .1 of an inch at 10 yards from the barrel that is a much bigger angle from point of aim than the same wind pushing the bullet .1 of an inch at 100 yards. I would think you would have to spend a TON of time in a helicopter shooting to become anywhere near proficient.

 

[Beagle-zebub]

I think I remember reading that Randy Shughart did this with his M14.

 

[Apachedriver]

When firing from a helicopter, you have multiple ballistic effects (exterior and aerial) on any projectile fired and considerations based on the aircraft's flight profile. Some really generalized considerations are:
- hovering in ground effect or out of ground effect
- in forward flight, how large of an off-axis shot is being taken (airspeed affects the placement of the rotor downwash in relation to the weapon.)
- how smoothly tracked is the rotor system.

I'm not going to elaborate on anything for shooting a helicopter. However, modern military helicopters are quite resilient due to materials and redundant systems used. If you thought a Huey (All hail the mighty Huey - whopwhopwhopwhop)could take a beating, you should see what an Apache or Blackhawk can handle and still fly. You would stand in awe, I know I have, time and again.

Can you take a shot from a helicopter? Yes
Are aircraft smoother flying now than years ago? Yes (depending on flight control systems incorporated, maintenance, and pilot skill)
Does it take enormous skill on the shooter's part regardless? No doubt.


Jesus Nut - there's something I haven't seen or haven't heard in years. Man, some of you guys must be oolllldddd.

 

[Diamondback6]

Late-twenties, but two words: "Hardcore Wingnut"--I was raised by a retired USAF Master Sergeant, and was ID'ing aircraft on sight before I even started school.

I've seen photos of shot-up Apaches and Blackhawks, and while they were nothing compared to Hawgs I've seen that limped home it was still impressive how much punishment they'd take.

 

[Apachedriver]

Ok you win.

 

[Diamondback6]

Sorry, wasn't tryin' to start a peein'-contest. If, as your handle implies, you're hands-on, you trump me--every time I've saddled-up in the simulator on rotary-wing I've ended up a smoking hole in the ground.

 

[Lucky]

French converted medical helicopters to gunships first, back in the 1950s, putting guys with MGs in the litters on the sides. The helicopters weakest point was the pilots. Like Diamondback said. French put hard armored seats in, and armored the pilots with heavy blankets. Maybe new helicopters can fly themselves, but old ones couldn't.

Apache armour diagram is out there, and it shows the same pattern, pilots being most heavily armored part of the thing. Iirc Apaches were shot down with small arms and chewed up badly earlier in Iraq when they'd use the cold-war hover tactics. And the canopy appears to just be plexi.

 

[usmc1371]

when shooting form a choper the bullet is only in the rotor wash for a split second so not long for it to affect the round. I would thing the real problem is how much the dam things shake "float" that would make it a pia to actuly aim.

 

[Justin]

If you want to discuss the challenges of making a shot from a helicopter and the variables therein, no problem.

If you want to discuss shooting down helicopters, you'd best go find yourself a forum where you can commune with others of the tinfoil beanie brigade.

 

[CWL]

I think I remember reading that Randy Shughart did this with his M14.

Both Gary Gordon and Randall Shugart were Delta snipers. Recall that their mission was to provide aerial support fire from their chopper, it was only at their own insistence that they were allowed to land in order to provide support to crashed Blackhawk helo in Somalia.

Kinda proves to me that snipers can and shoot from moving helicopters.

 

[sscoyote]

While competing at the '04 International Tactical Riflemen's Championships near Gillette, WY one of the stages was trying to hit a target out of a chopper with an AR. I think one of the teams hit it. We didn't, with mutiple shots.

 

[Slinky]

My experience is with a door mounted machine-gun vice a precision rifle but I don't imagine things changing much.

By far hardest thing was holding the gun steady. As usmc1371 pointed out, birds SHAKE, the barrel would catch the rotor wash much as your hand does when held out the window of a moving car. Compensating for this could turn into quite the work-out as you would be bracing with your legs and "wrestling" the gun with your arms.
As for aiming, we usually used Irons but had a Red-Dot + Laser available for night missions. Our sights would be zeroed to a specific range, altitude, and airspeed briefed by the pilot. (If he was smart he'd fly the gun patterns like he briefed them) Further adjustments for range, speed, and angle off axis, were done "on the fly".

While I can't make any claims to one-shot pinpoint accuracy I was certainly capable of minute-of-bad guy at 1000 meters and consistent groups closer in.

In summary, It is possible to make pin-point shots from a moving helicopter, (I’ve seen it done) there's just some tricks to it.

 

[Float Pilot]

A 7.62mm NATO projectile with a muzzle velocity of 2650 fps would be exposed to rotor wash for 0.01321 of a second. Assuming a the projectile traveling about 35 ft inside a rotor wash area. The unstable platform, motion and vibration has a much greater effect.

One of our PJs once tried using an M-79 (yes they are still out there in use) from the rear ramp. Now firing a slow projectile, downward, in the opposite direct of aircraft travel did present some problems.

 

[benzy2]

What is the wind speed under the blades of a helicopter? Again the most important area of wind on a bullet is at the muzzle. A very VERY slight push at the muzzle is worth the same as a huge push down range. A 2 MOA change at 1 yard is hardly more than .02" change. Have that bullet travel out 500 yards and you are pushing 10.5" from aim. I would think if you knew the travel speed of the helicopter as well as the height adjustment and a fixed value for what the blade wind changes impact that you could get a zero. How fast is the wind coming off the blades of a helicopter in hover? I know that the pitch of the blades change causing different amounts of lift but what is the general wind speed right under the blades? 300mph? When I ran the ballistics on federal gold medal match the wind drift at 10 yards in a 300mph wind is 2 MOA. I really don't know what the wind speed is under a blade in hover so I am just picking a number. Maybe its half that and its only 1 MOA change. Don't know.

 

[Slinky]

Any shot requiring MOA accuracy will probably be made in a hover or slow creep to minimize turbulence. The wind-speed of the rotor wash will depend on density altitude and collective setting.

That said, Airspeed, Altitude, and Angle off Axis have a far greater effect on *POA vs. POI than the rotor wash. As such most crews make their attack runs at a pre-computed speed/altitude/angle so the gunners don't waste time fumbling with their sights.

All in all its not much different from shooting skeet/clays or any other moving target. the real skill/difficulty comes from trying to hold yourself and the weapon steady while getting buffeted by turbulence and your own aircraft's "Evasive Actions".

*Point of Aim versus Point of Impact

 

[Slinky]

Double post,

PS: The SH-60 Tactics Manual contained a chart of pre-computed sight adjustments for each flight regime. (Hover, Creep, etc...)

 

[CZguy]

If, as your handle implies, you're hands-on, you trump me--every time I've saddled-up in the simulator on rotary-wing I've ended up a smoking hole in the ground.

Helicopters were never meant to fly.

 

[Apachedriver]

Again the most important area of wind on a bullet is at the muzzle.

This is very true. As the projectile leaves the muzzle, it is immediately affected by a variety of exterior and aerial ballistic forces.

One example is Vertical Plane Gyroscopic Effect aka Projectile Jump. When the round is fired in any direction other than directly into the relative wind, it's flight path will change with the crosswind effect at a point that is 90 degrees later in it's rotation.
So if the wind hits the projectile from the left as it travels forward, the projectile will jump downward. If from the right, then it will shift upwards. This is due to gyroscopic precession.
That's just one of the ballistic effects to be dealt with when firing.

If the aircraft is traveling forward instead of hovering, you compound the shot with a number of other effects that will move the POI regardless of whether its a 7.62 round or 30mm round. Some of these effects will vary depending which side of the aircraft the shot is taken when it is in forward flight and some effects will actually cancel each other out.

As for vibrations, there is a big difference in firing from an airfame mounted weapon or one you are bearing the weight of as you fire.
Also, advanced helicopters have integrated systems that very basically help smooth out the control inputs and effects of the wind on the airframe. Maintenance tasks such as rotor smoothing play a huge part in vibration reduction as well.


And yes, helicopters don't fly, they beat the air into submission.

 

[CZguy]

And yes, helicopters don't fly, they beat the air into submission.

I know what you mean................but just the thought of having my wings rotate around my head, makes me kind of dizzy.

All joking aside, I have a tremendous respect for helicopter pilots.