What is considered an authoritative source?

[Dfox071]

After seeing a link to some interesting F-14 videos, I ran across a video from the PeninsulaSrsVideoas series. I can't link the actual video here due to my lack of posts, but if you do a YouTube search you'll find the video, and at a time stamp of about 11 minutes in, the former SR-71 pilot makes the statement that the SR-71 had a RCS of about the same value as the F-104. In the CMANO database, the SR-71 is listed with a RCS of about 11.5 sq.m. whereas the F-104 is listed at about 2.5 sq.m. This seems like a rather large discrepancy.

I was wondering, would pilot's testimony like this be considered an authoritative source, or are there data out there contradicting an SR-71 RCS of about 2-3 sq.m?

[Rory Noonan]

Is that the long interview with an ex blackbird pilot? Great video, seemed quite reliable.

[Dfox071]

Yes, it's a 58 minute presentation/interview. It was recently posted though. It's called SR-71 Overview by Col. James H Shelton, Jr USAF (ret.), and was posted on Sept 12, 2016.

[Rory Noonan]

Not the one I'm thinking of then; that was a pretty informal interview with a (seemingly very reputable) ex pilot. I'll see if I can find a link because I think he said the exact same thing.

[kevinkins]

https://www.youtube.com/watch?v=ptPRi7R3Bfw

[Rory Noonan]

This is the one I was talking about https://youtu.be/CeBu6mRDaro

[Zaslon]

The line between an authoritative source and propaganda is very thin. So, developers are very careful.

[Dfox071]

The video posted by kevinkin is the one I'm referring to at about 11 minutes in. The entire thing is worth a watch too, if you have interest in the SR-71.

ORIGINAL: Zaslon

The line between an authoritative source and propaganda is very thin. So, developers are very careful.

This is why I asked if there is any information out there countering this claim. Bear in mind, these statements come from someone with a lot of first hand experience and the discussion is referencing an aircraft no longer in any active duty. So, for me at least, I think the temptation to spread propaganda is low, and the pilot certainly doesn't spread propaganda with reference to the top speed of the aircraft.

[thewood1]

For one thing, its kind of an offhand comment. Like saying my SUV has more room in the back than a car. Might be true, but is he really quantifying it or just throwing out a comparison. Maybe its like, compared to a B-52, it has the cross-section of an F-104. SR-71 pilots were probably better versed in the capabilities of their craft than a typical pilot, but is that something he can quantify? With that said, I would look for another source to corroborate and quantify for a database that measure RCS to 0.1m.

[Dfox071]

ORIGINAL: thewood1

For one thing, its kind of an offhand comment. Like saying my SUV has more room in the back than a car. Might be true, but is he really quantifying it or just throwing out a comparison. Maybe its like, compared to a B-52, it has the cross-section of an F-104. SR-71 pilots were probably better versed in the capabilities of their craft than a typical pilot, but is that something he can quantify? With that said, I would look for another source to corroborate and quantify for a database that measure RCS to 0.1m.

Well, for a start, just because Command shows two digits for RCS doesn't, at all, mean that they "measure RCS to 0.1m". First off, I'm pretty sure that the Command dev team does no RCS measurement at all, let alone to 2 or 3 significant digits.

Secondly, it's not as offhand a statement as you make out. The pilot is specifically going over the SR-71 capabilities, and he's in the middle of discussing the efforts to reduce RCS that are built into the aircraft. He discusses the presence of composite material and rudders tipped in.

Lastly, there's a world of difference between Command's current SR-71 RCS of 11.5 square meters, and anything close to an F-104. I believe the pilot uses the phrase "We got it down to where it's about the size of a 104. Now, the F-104 is not very long, but to take this 107 foot aircraft and reduce it down to that small a radar cross section.. So it's the first aircraft that had stealth capability." That doesn't sound like an off-hand remark to me.

Now, I'm not saying that pilot testimony is necessarily authoritative, but that's why I asked, and I'm wondering what evidence that you may have to doubt this testimony?

The Wikipedia lists the RCS as about 10 m^s, but the source is listed as SR-71 Revealed: The Inside Story, page 75. That page has no RCS information at all on it though. GlobalSecurity lists the SR-71 RCS at .1 m^2 (22 in^2). The Aviationists has it this way "With an RCS (Radar Cross Section) of a small light aircraft, when the SR-71 was found on radar it was too late for a SAM computer to estimate its direction for a successful kill."

Edit: after some searching, the correct RCS quote from SR-71 Revealed: The Inside Story, should be this, on page 139: "SR— 71 represented a target about the size of a j—3 Piper Cub". I don't know the RCS of a piper cub however.

Lockheed Martin itself, has this to say about the SR-71 RCS: "With tests carefully scheduled to avoid Soviet satellite observations, the results were impressive: The Blackbird model, more than 100 feet in length, would appear on Soviet radar as bigger than a bird but smaller than a man. The team had succeeded in reducing radar cross section by 90 percent."

[thewood1]

You are putting words in my mouth. I saying the same ting you are. There nothing quantitative in the pilot statement. Its like saying I got my trucks weight down to the same as my Ford Focus. Its all relative. From 11 to 2.5. OK, but is it 3.5? 4.5? What did the pilot consider close. How much difference does an Spoon Rest operator see between 5.5 and 2.5?...or even 11 and 2.5. And the answer has to be somewhat translatable to the game. Even if you have an "authoritative" source, that is the real question.

Now the devs can guess, which I am sure they have to do a lot. Even if you search something like global security on RCS, you get a simple diagram comparing SR-71 to other aircraft. That is a little more helpful.

http://www.globalsecurity.org/military/ ... ft-rcs.htm

[Dfox071]

ORIGINAL: thewood1

You are putting words in my mouth. I saying the same ting you are. There nothing quantitative in the pilot statement. Its like saying I got my trucks weight down to the same as my Ford Focus. Its all relative. From 11 to 2.5. OK, but is it 3.5? 4.5? What did the pilot consider close. How much difference does an Spoon Rest operator see between 5.5 and 2.5?...or even 11 and 2.5. And the answer has to be somewhat translatable to the game. Even if you have an "authoritative" source, that is the real question.

Now the devs can guess, which I am sure they have to do a lot. Even if you search something like global security on RCS, you get a simple diagram comparing SR-71 to other aircraft. That is a little more helpful.

link removed

Yes. So, my apologies for putting words in your mouth. It certainly wasn't my intention. I would have linked that chart, but I'm not yet allowed

[mikmykWS]

If its a credible source we'll definitely consider it however we do look for multiple sources and some consensus among them.In some cases though you can actually check things by looking at a photos etc. which can give you a better picture[:)]

F-104 and SR-71. What does this tell you?

[AlGrant]

This won't help with RCS figures/comparisons but makes gives a good background on the SR-71 development:
"Design and Development of the Blackbird: Challenges and Lessons Learned"
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090007797.pdf

[Dfox071]

ORIGINAL: mikmyk

If its a credible source we'll definitely consider it however we do look for multiple sources and some consensus among them.In some cases though you can actually check things by looking at a photos etc. which can give you a better picture[:)]

F-104 and SR-71. What does this tell you?

Honestly? Not much.

We already know the F-104 is much smaller physically, but the F-104 is a bare metal fighter with no allowance for any RCS reduction. This is considerably different from the SR-71.

Once again, per Lockheed Martin:

Reducing the size of the Blackbird’s radar image meant an even further reduction in the likelihood that the plane would be perceived and shot down. Though the initial test results were good, rumors of Soviet radar advances led the U.S. government to ask for an even smaller radar profile.

Surfaces had to be redesigned to avoid reflecting radar signals, the engines moved to a subtler mid-wing position, and a radar-absorbing element was added to the paint. Then a full-scale model of the Blackbird was hoisted on a pylon for radar testing at a Skunk Works’ secret location in the Nevada desert. With tests carefully scheduled to avoid Soviet satellite observations, the results were impressive: The Blackbird model, more than 100 feet in length, would appear on Soviet radar as bigger than a bird but smaller than a man. The team had succeeded in reducing radar cross section by 90 percent.

This statement seems to line up pretty well with what is reported at GlobalSecurity and with what the pilots actually said, rather than the Wikipedia number derived from what they said. Maybe Lockheed is overstating things, but without any contradicting evidence, and I see none, why would we assume the RCS of the SR-71 is 11.5 square meters?

What should I be getting from that image?

[Dfox071]

ORIGINAL: AlGrant

This won't help with RCS figures/comparisons but makes gives a good background on the SR-71 development:
"Design and Development of the Blackbird: Challenges and Lessons Learned"

Interesting document. Thanks!

The images in this document are the same ones as presented in the video as well.

Obviously there are no hard numbers regarding RCS, but there's some interesting information about the RCS issue anyway:

Meanwhile Lockheed struggled to produce a viable design. Tentatively called the U-3 in early Skunk Works
studies, the airplane had to meet stringent RCS requirements to make it more survivable than the U-2 was to hostile
anti-aircraft defenses. Kelly Johnson developed and discarded numerous designs in an attempt to meet the CIA’s
specifications. While he could design an airplane capable of attaining high speeds and altitudes, he found it difficult
to significantly reduce the radar signature. For a while it appeared likely that the contract would go to General
Dynamics/Convair.

Johnson subsequently proposed the A-12 with the J58 engines in a mid-wing arrangement to reduce
the airplane’s side profile. Chines along the forebody reduced fuselage sloping while providing additional lift
and stability. The single vertical stabilizer was replaced with two all-moving vertical fins, one on top of each
engine nacelle. These were canted inward for further RCS reduction. Serrations on the wing edges
incorporated radar-absorbent materials.

To meet customer requirements for RCS reduction as well as for high speed, Lockheed spent a great deal of time
and money investigating high-temperature radar-absorbing materials. These included pioneering work with
first-generation composites and high-temperature plastics. Lockheed’s innovative methods of reducing total and
incidental RCS became the basis for virtually all U.S. low-observables studies and hardware to follow, eventually
leading to development of true “stealth” aircraft that would be virtually invisible to radar.

There are other points from the document, even outlining the competing designs, but it is clear from the document that reducing RCS was a major design goal for the SR-71, unlike the more traditional story that the SR-71 wasn't really a stealth aircraft.

[thewood1]

For another thing we don't even know what the relationship is between physical cross section and the actual RCS as the game defines it.

I would also suggest in the future put something like this ion the database thread and you might get a little faster attention from people a little more in the know about game implications.

[gosnold]

The A-12 program (which the SR-71 is derived from) was launched by CIA as a successor to the U-2, and stealth was an objective from the start. You can read about that in the book "the wizards of Langley". If I remember correctly in the end the plane was not stealthy enough to make a big difference in operational use, but they tried anyway.

[Dfox071]

ORIGINAL: thewood1

For another thing we don't even know what the relationship is between physical cross section and the actual RCS as the game defines it.

I would also suggest in the future put something like this ion the database thread and you might get a little faster attention from people a little more in the know about game implications.

Typically, the actual return is specified in decibels. RCS is just used as a convenient way to understand that. For instance, the current database value for the SR-71, from the side, in the A-D band is 13.3 dBsm. For the F-104, that number is 6.3 dBsm. This can be compared directly to the chart from GlobalSecurity for some values. The typical conversion used is

dBsm = 10 x log10(RCS/m^2)

The game does not use physical cross section, as far as I know, to determine RCS or RADAR returns. There's a value stored for each asset that specifies the RCS/dBsm.

[mikmykWS]

ORIGINAL: Dfox071

ORIGINAL: mikmyk

If its a credible source we'll definitely consider it however we do look for multiple sources and some consensus among them.In some cases though you can actually check things by looking at a photos etc. which can give you a better picture[:)]

F-104 and SR-71. What does this tell you?

Honestly? Not much.

We already know the F-104 is much smaller physically, but the F-104 is a bare metal fighter with no allowance for any RCS reduction. This is considerably different from the SR-71.

Once again, per Lockheed Martin:

Reducing the size of the Blackbird’s radar image meant an even further reduction in the likelihood that the plane would be perceived and shot down. Though the initial test results were good, rumors of Soviet radar advances led the U.S. government to ask for an even smaller radar profile.

Surfaces had to be redesigned to avoid reflecting radar signals, the engines moved to a subtler mid-wing position, and a radar-absorbing element was added to the paint. Then a full-scale model of the Blackbird was hoisted on a pylon for radar testing at a Skunk Works’ secret location in the Nevada desert. With tests carefully scheduled to avoid Soviet satellite observations, the results were impressive: The Blackbird model, more than 100 feet in length, would appear on Soviet radar as bigger than a bird but smaller than a man. The team had succeeded in reducing radar cross section by 90 percent.

This statement seems to line up pretty well with what is reported at GlobalSecurity and with what the pilots actually said, rather than the Wikipedia number derived from what they said. Maybe Lockheed is overstating things, but without any contradicting evidence, and I see none, why would we assume the RCS of the SR-71 is 11.5 square meters?

What should I be getting from that image?

Thanks for the info. If we feel something is incorrect we'll address in a future update.

Thanks!

Mike