barundus

Another motivational pic!

Turning for the break! Snapped this one with a 1/1250 sec shutter.

For those interested: here's an example of a real-world (practice) ATHS digital fire mission employing the Copperhead laser-guided 155mm artillery round. Pertinent to this discussion is the lag between the digital messages being sent back and forth, and what is actually occurring. All the "actual" coordination to fire the mission is conducted via voice, with the digital messages being sent in conjunction. Pay close attention to the messages displayed on the left side of the screen: You'll see "Ready", "Fire", "Shot", "Designate", and a time-of-flight countdown timer on the right. You'll notice the timing of the digital messages becomes de-synced with what's actually happening. This is due to the technical limitations of the system. Had the crew waited to designate according the the digital prompts, the round would have never captured laser energy and become a lost round. Everything is backed via voice. That said; Link16 is a far more capable protocol, and is gaining more widespread use, even in the Army with the Apache "E" model. The idea of digital interconnected aerial battle force is somewhat of a fallacy, particularly when considering cross-service operations. Forget about joint national and coalition operations. Just getting voice radios to work is a major undertaking IRL.

Great question Ramsey, and shows you've done some research! ATHS was antiquated by the mid-2000s, and replaced with JVMF (Joint Variable Message Format) protocol. The ATHS remained in the aircraft, however it wasn't ever used for anything after 2004 or so. I believe PC will implement some form of digital messaging replicating some of the functions of JVMF, but I'm not 100% sure what. IRL the sad truth is that; due to various reasons in which the services chose to upgrade and modernize their aircraft, the Army's use of digital messaging for targeting was extremely limited. There was no digital inter-connectivity with fixed-wing platforms for targeting. Also, because the artillery branch and aviation branch modernized their programs in a changing budget environment, priorities and requirements changed and eventually incompatibilities developed. Also: There just wasn't much need for digital fires coordination in the last 15 years, so it wasn't used much (at all). That said, a limited capability did exist, and for gameplay purposes I'd like to see some functionality too.

In regards to the video posted previously; Lest you think these two chuckleheads were completely terrible at their job; they were trying to stop (without killing) the guys on the motorcycle, so that a ground response team could apprehend them. Often the value of intelligence gathered from detainees would prove valuable, or; the ROE (Rules of Engagement) prevented the KW crew from outright shooting the fleeing shitheads. If the KW crew did not directly witness the motorcycle guys committing a hostile act such as planting an IED, the ROE prevented them from taking more direct action. In effect they'd try to scare them into stopping until a ground response team could roll up and detain them for questioning. Had they wanted to smoke those guys, it wouldn't have been hard...

SCAS had up to 10% control authority over each axis of flight control. In essence it smoothed-out external variables such as wind burbles, turbulence, etc. by comparing the pilot-induced control inputs against what the flight control gyros were sensing. If the rate-gyros sensed movement that didn't correlate with pilot control inputs, the SCAS would provide small corrective inputs to counteract, up to 10% of the full control authority. If you didn't mess with the cyclic and pedals constantly, it made for a very nice, smooth and stable platform. The SCAS provides a "heading hold" but does not have an "auto-hover" capability IRL. This should not be confused with a "stable" platform in the sense that it resists change in direction. The semi-rigid ("soft-in-plane" in Bell-speak) fully-articulated rotor system is very responsive, and the fully-hydraulic augmented flight control system is sensitive and requires only the very lightest control touch. However, while smooth and stable, it is very agile, and responds instantly to control inputs. This is in contrast to the underslung-type rotor systems, which 'in comparison' are more slow to react to control inputs.

Rick, The "high/left" shift is just a boresight error due to the gun mount design. Typically the M3P boresight was just a tad off, because the armament guys could never quite get it aligned properly to the aircraft centerline. So we resorted to drawing two "pippers" on the windscreen, one for rocket, the other for the gun. To dispersion; The M3P dispersion was still pretty significant, but not as noticable as XM296. And you're right: pilot-induced dispersion was by far the greatest contributor. In the hands of an experienced pilot, M3P dispersion was 'not bad'. Also, the higher cyclic rate helped. In order from worst to least (in relative terms) for dispersion: XM296 M3P GAU19 The GAU had a really tight beaten zone, but of course never fielded to operational units.

At risk of jumping in and chumming the waters of internet opinions, I'll offer a couple points for consideration. Acknowledging that we all have our own experiences and judgements derived from them, I'm going to comment by offering my own observations and some lessons learned over the years. To the points above: Hellfire: While the hold-back mechanism does indeed require up to 600 lbs of force to release the missile, the launch thrust is so great and happens so fast there is really no time for the moment of inertia in the aircraft to be overcome in the split-second it takes the missile to leave the rail to produce a 'significant' yaw. By 'significant' I mean enough for the pilot to perceive. Rather, I attribute any noticeable yaw to pilot-induced control pressures at the moment of firing; in fact most likely in cyclic movements as he presses the fire button. It doesn't take much, and the act of pressing the fire switch and tensing on the controls will be noticeable in unwanted motions of the entire airframe. Obviously I don't know your own experiences or experience, but I offer that a measured yaw affect attributed to missile thrust would have been noted in test and documented accordingly. The engineers would have cried "foul" at induced yaw, as this would have directly contributed to tumbling the gyros as the missile leaves the rail. As to firing the .50 cal: there shouldn't be any noticeable difference between the XM296 and the M3P in terms of 'yaw' produced. They're firing the same bullet, so no difference in applied forces due to firing. Again, perceived yaw and dispersion when firing either .50 cal is mostly due to pilot-induced control movements. For the benefit of those who haven't had the pleasure of firing the gun on this aircraft; the event is emotionally significant, as the muzzle is about two feet and slightly back from the left-seater's door. The muzzle shock-wave, especially of the M3P, will rattle your teeth if you're not paying attention, and forget to close your mouth when the right-seater pushes the trigger. Further; I'd offer that most newer pilots tense on the controls when firing, and coupled with the "unusual" firing button arrangement which places the weapon fire button underneath the thumb instead of a more standard "trigger", there is a natural tendency to tense the arm. But mostly; it's pedal control (or rather, overcontrol) which leads to the perception there is significant yaw going on. The dispersion pattern of XM296 vs M3P was significantly different, due to the mount structures on the pylon, and cyclic rate of each gun. The low-slung cage of the XM296 has a longer "arm" than the M3P, and recoil thus caused much more movement. Both being recoil-operated with a heavy reciprocating bolt sliding back-and-forth on a single barrel, the resultant vibration and harmonics produced are significant. But mostly dispersion is due to the pilot adding unintended control inputs when firing. <edit> I acknowledge there is some yaw induced due to the physics of firing .50 cal rounds on one side of the airframe, however I am willing to argue that "perceived" yaw is mainly attributed to flawed technique during the firing sequence. The M3P has a known flaw in that it was generally accepted to fire high and left due to a design flaw in the mount. It was difficult to boresight in-line with the rockets at a specified range. So; first rounds generally were off-target based on a "natural" sight picture and learned aircraft setup when compared to a similar distance rocket sight-picture. This tended to influence the perception of some pilots that a "yaw" was induced when firing. Coupled with other generally unperceived control inputs at the moment of firing, it's easy to believe that gun firing is producing a consistent "yaw". Last - when bringing GAU-19 into the mix; that gun was sweet. Because it was electrically driven and had no reciprocating mass to cycle rounds, the transferred recoil to the airframe was very different than the single-barrel guns. The mount was also much more robust and stiff. On firing, there was much less dispersion, and the rounds impacted in a very tight beaten zone. In the hands of a capable pilot, it was much easier to drop a higher percentage of rounds on the intended target. Now rockets...oof. That's a whole 'nother rant.