Operational Performance Comparison: Viper, Beagle and Stubby

[n3sk]

Relating to this. https://www.iaeme.com/MasterAdmin/uploa ... 06_026.pdf

One thing I do not see mentioned is the position of the control surfaces in these model tests. Did they move the controls surfaces to be accurate with the changes in AoA and if so to what degree?

Also, what aispeed does the water flow replicate or relate to?

[sprstdlyscottsmn]

One thing I do not see mentioned is the position of the control surfaces in these model tests. Did they move the controls surfaces to be accurate with the changes in AoA and if so to what degree?

That was my thought as well. I suspect they did not.

[gta4]

Relating to this. https://www.iaeme.com/MasterAdmin/uploa ... 06_026.pdf

One thing I do not see mentioned is the position of the control surfaces in these model tests. Did they move the controls surfaces to be accurate with the changes in AoA and if so to what degree?

Also, what aispeed does the water flow replicate or relate to?

Normally they do not move control surfaces, because it should be stated otherwise. It will decrease the aerodynamic efficiency for both aircraft, so only the trend should be noted, not specific numbers.

[garrya]

You can see in that old Doc posted again from swiss how good the upgraded 66 might have been:

During the field trials on a BAC-1-11 test aircraft, the APG-66(V)2’s performance surpassed expectations; it was possible to demonstrate the radar in the high electromagnetic interference environment of the Netherlands and in the high clutter environment of the fjords of Norway. According to company officials, the demonstration radar doubled range detection, reduced false alarms by a factor of 10, and simulated six AMRAAM shots. Ground mapping was improved and demonstrated out to 80 nautical miles, and the buyers had the opportunity to see the full-color display. In demonstrations to other potential buyers, engineers emphasized design maturity and growth potential. The upgraded radar’s performance was nearly that of the APG-68(V) installed in the F-16C/D,

I found this chart a while back, APG-68v2 and v3 is still a little bit better than APG-66v2 and v3

[swiss]

Nice find garrya. And thanks for your explanation about the missile charts

[garrya]

Nice find garrya. And thanks for your explanation about the missile charts

You are welcome.
BTW, does anyone have higher resolution version of this:

APG-66A.gif (56.54 KiB) Viewed 44320 times

[spazsinbad]

Tried to make it better from the poor quality image above....

[knowan]

Could you explain those charts for me, particularly how the R-27 charts compare with the AIM-7, AIM-120 and R-77 charts?

For R-27ER and R-27P charts
_ H represents altitude, you can see the have some number with some pointer at the circle, they have 3 altitude marks: 1km -5km-10 km. I highlight these in red color
_ The lines cutting into the circle represents the aspect of the target relative to the shooter, start from the left with 0° meaning it is the head on aspect, end on the right with 180° meaning it is the tail chase situation. I highlight those in purple
_ The horizontal scale at the bottom and the vertical scale in the middle of the chart represent engagement distance. I highlight those in Green
_ The dotted circle represent range when both shooter and target are flying at 1100 km/h, the full circle represent range when shooter and target are both flying at 900 km/h

1F1FC9F0-52BD-4E82-B9A4-707D3AC05B67.png

For R-77,AIM-120A, AIM-7 charts
_ The vertical scale in the middle is the height
_ The horizontal scale at the bottom is range, on the right is head on, on the left is tail chase.
_ They have a little table showing V-max and V-min for each altitude. You can see that higher V-max improve head on range but reduce tail chase range. There is a slight different here, they use m/s instead of km/h like in these R-27 charts

2E3A36EB-4D58-455B-AEEC-F46A047839DF.png

Thank you for the reply, I appreciate it.

Another question however:
For head-on shots, the maximum range appears to be 35 km for the R-27P and 65km for the R-27ER. How comparable are those figures to the charts for the AIM-7 (~110 km), AIM-120A/B (~130 km) and RVV-AE (~100 km) for head-on shots?

[viper12]

If my memory serves, in a documentary series from the late '90s about the Air Force's history, at least from WW2 (if not earlier) till the Gulf War, which mainly (exclusively ?) interviewed the top brass, one of the generals recalled that when flying in the F-15, he could see the flaps move on their own multiple times a second, or rather ordered by the flight control system, which goes to show that stability isn't a clear-cut definition.

Now if someone knows which documentary I'm talking about, I'd be happy to know the name, as my Googlefu couldn't retrieve it. In particular, one of the generals said something like "a treasure of experience" which was learned during the Vietnam War and applied to the Gulf War.

To answer my own question (on page 73) over 6 months later...

The quote comes from the documentary Beyond the Wild Blue: A History of the U.S. Air Force, episode 4, Rebuilding for Space.

Starting at around 24:50, General Larry Welch said of the F-15: "You got the impression flying the airplane that you really had good hands. Landing the airplane was a very smooth thing, most of the time you could hardly tell you touched the ground. Air refueling behind the tanker was the same sort of thing; you pulled in behind the tanker and it just sat there. And so you got the impression that "Boy, I am really good", but if you ever watched the airplane from the outside, you'd see what was happening, and all the ailerons were flopping around and the elevators were flopping around, the controls were flopping all over the place, but you weren't doing it, the flight control computer was doing it."

[eloise]

My sim can do guided and unguided bombs, but not AG missiles at the moment. Given the increase in range and much faster looking body design I think it goes a bit faster but also burns for longer. A complete WAG though.

Is the SD-10 range and speed too good compared to its real life counterpart or is the AIM-120C too bad compared to the real life version?

[sprstdlyscottsmn]

The DCS AIM-120 C5 has inconsistent guidance. I can fire ten of them at one target and get four flight profiles observed.

[gta4]

I think the SD-10 is buffed too much. The speed retention is almost as good as AIM-54

[eloise]

The DCS AIM-120 C5 has inconsistent guidance. I can fire ten of them at one target and get four flight profiles observed.

But in term of speed retention and range ,which one do you think behave more like real missile? SD-10 or AIM-120C