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Basically the R4M was toy compared to the 2.75 FFAR. It weighed about 46% of what the early 2.75 FFAR did.I'm curious how the R4M's accuracy and range compare to the 2.75 FFAR
Shortround,
It's smaller, but I get the vibe that it was much more accurate: The 2.75 FFAR seemed abysmal; the Soviet 57mm seemed closer to the FFAR. Why did we **** up the FFAR so much?
The Germans seemed to not have too many complaints about the R4M, and I've seen footage of them firing and they didn't look as bad as the FFAR.And where does this "vibe" come from?
I didn't know there were any rules on that here, but I'll reign it in.Language!!!!!!
So that means even if the dispersal followed the pattern accuracy would be 180-300 meters?Dispersal figures are useless without the range they were obtained/achieved.
The Dispersion figure for the US rocket may have been obtained at a much longer range and since dispersion, at best, follows a geometric pattern (double the distance doubles the size of the pattern) a longer range of engagement would naturally have a a much larger dispersion pattern.
I was told they miscalculated the spin-stability and used a smaller number off fins: How did they miscalculate the spin and why did they reduce the number of fins?Somewhere in the 2.75 FFAR's developement they changed the nozzle design.
The early 2.75 evidently depended only on the pop out fins for spin stability, meaning when first launched they took some time to spin up for good stability.
I usually saw them corkscrew and fish-tall everywhere[/QUOTE]Sometimes you'd see shots that would make you think, "was he aiming for that ? " because it was that good, and then other times you'd question just what were they aiming at.
It was the only reference I had, sorry.Finding actual firing tests is difficult on the web but one should view statements like "blanket a football field" with suspicion as it sounds like a press release for a non-technical audience.
40 meters dispersal over 1500 meters is 27 mils right?A test I have found from 1961 (US Army) while evaluating the 2.75 rocket for helicopter use after modifying the rocket nozzles for spin says.
"Impact patterns showed excellent area coverage, with the initial pair of rockets impacting approximately 10 - 20 meters apart and succeeding pairs impacting at approximately 15 meters greater range with the same lateral spacing. Employing a ripple of 46 rockets, a beaten zone of approximately 40 x 400 meters resulted at an opening range of 1500 meters from 150 to 200 feet absolute altitude and 70 knots indicated airspeed (IAS)."
40-50 mils seem to conform to the 100 yard @ 3400m estimateThis is obviously for air to ground use and it was noted earlier in the report that the unmodified rockets when fired at zero air speed had a dispersion of 40-50 mils
Now, that's an improvement: This would result in the ability to have put the rockets in a ring 24-25 yards wide at a distance of 3400 meters. This is actually inside the R4M's ballistics in effective range.the modified rockets had a dispersion of 10-12 mils in a Navy test.
Of course: I'm not sure if they had the ability to produce the higher flight speeds in those days.Saying the US made a mistake in reducing the number of fins might be correct and might not be as it takes no account of the other differences in the two rockets like the much more powerful motor in the 2.75 and the higher flight speed. It takes no account of differences in burn time of the motors. And so on.
Was the propellant as stable as the early AIM-9 and AIM-7's[/quote]The RM4 that the Luftwaffe used were probably used about as soon as they were delivered to the airfield, the 2.75s the Americans and allies used later might have been in storage for decades.
Very good points...There are also some significant differences between firing fin stabilized rockets from helicopters and fixed wing aircraft.
I would have thought they'd have much longer burn time...It claims the 2.75 rocket accelerated to about 106fps in it's own launch tube and accelerated at 40-49 Gs until burn out in 1.7 seconds with a peak speed of 2415fps.
less than 1g probably...They were generally firing the rockets up at 70-85 degree angles so speed may differ a bit from horizontal fire but at 40-49 G acceleration I doubt the difference amounts to much.
From what I recall it'd be more, possibly something to do with L/DAltitude (range?) at burn out was about 2000ft. after burn out the rocket decelerated at -16Gs to start with.
My critique had little to do with speed... the speed is a good thing. The problem was that pilots had even said that they were amazed they'd hit anything with them.The US made the choice to use a high speed rocket (compared to the R4M) due to the nature of the target/s and the hoped for fire control system.
They were expecting to use them on aircraft ranging from propellers to subsonic jets at the very least. The F-102 seemed to be designed initially to be able to shoot down subsonic and supersonic jets (it wasn't very successful in this role as it wasn't as fast as desired, hence the F-106), though its primary armament was 6 x AAM's.The rocket system was introduced to destroy Soviet bombers of at least TU-4 (B-29) performance if not higher performing aircraft (US was flying B-47s in squadron service and introducing B-52s) and not B-17/B-24/Lancasters.
That I know about to some degree, and the problem wasn't the computer but the projectile used. It corkscrewed and fish-tailed all over the place. Had the ballistics been more like that of a cannon-round or projectile it's odds of success would be greater.The US was also building/introducing collision course fire control radar aiming systems. The radar and on board fire control computer would generate a firing solution (aiming point) for the rockets at several thousand yds range even from a near 90 degree intercept angle.
Probably with the fire-control mostly. I'm not sure how they concluded the rockets were okay...All of this took a number of years to introduce and with the stakes being destroying possibly nuclear armed bombers there was a fair amount of testing done.
Turns out the system never worked as well as hoped/needed and even early air to air guided missiles were judged superior.