Excitement In The Straits Of Hormuz

GIThruster · Post by **GIThruster** » Tue Dec 20, 2011 8:30 pm

Roger wrote:If teenaged boys can fly these RC models, I just cant seem to be impressed by the RQ-170 or any other effort in this direction.

I've been designing, building, flying and mostly crashing RC aircraft for most of the last decade and I can attest to the fact it is harder to fly these aircraft than a real plane. It is however much easier for the RC craft to fly--meaning that scale of size and ability makes it much harder for full sized craft to fly than RC craft. It's very easy for example, to make a 3D RC craft that can copter and accelerate straight upward on a prop--something almost no prop powered aircraft can do.

Personally, I think the loss of the Sentinel is a tragedy. First of all, designing a really good flying wing is not simple. It's extremely complex. At RC scale its simple, but at the size of that craft, to have sufficient control and supreme stealth and flight endurance, that requires severe optimization. The craft won't tell anyone how to optimize for other missions than the one it was designed for, but it certainly does say how to build a recon drone. Just knowing the camber and cord of the wing is huge and if those are variable, this would be a true nightmare of classified tech disclosure. The pics recently released on the Sentinel say just what one would expect--this is a superbly engineered machine. It's truly tragic Iran has one.

Second things is, no matter what any source might say, odds are the entire craft is encased in state of the art stealth material. Anyone with a file can put some in a spectrometer and know just what they need to mix to get best results. Iran just jumped to the head of the class as nations go, in knowing what is the best radar absorbent material that can be mass produced. That's more than 50 years of steal material research, obtained in a single maddening episode from hell.

Third thing is sensors and avionics. Iran now has access to the best of the best and its a pretty simple matter of back-engineering to have their own. Especially our sensors are the envy of the world, and our avionics are a very close second.

How anyone can think this isn't a tragedy is beyond me. Someone needs to get fired.

Roger · Post by **Roger** » Tue Dec 20, 2011 9:27 pm

ladajo wrote: It is also known the the Germans did have their own air defense radar, as well as knew the brits did.

Right, so what are the odds that a Horton flew thru air defense radar areas, demonstrating reduced cross section?

Some googling reveals:

Northrop's 1/3 scale versions flew all over California for a year or two. I'm not sure that radar was installed in the area at the time. Certainly Pearl Harbor had Radar Sept '41.
https://docs.google.com/viewer?a=v&q=ca ... 5GhFzncaxw

Early US radar
http://en.wikipedia.org/wiki/SCR-270

German radar
http://en.wikipedia.org/wiki/Freya_radar

Neat picture of the MX-324

http://members.tripod.com/airfields_fre ... Mojave.htm

SO it may be that not until the full size Northrop wings flew at Edwards did Radar and the wing meet.

OTOH This website shows early SCR-270 & SCR-271 installed '42 '43
http://www.northamericanforts.com/East/masouth.html

And this might be the jack pot. These 2 bases were close together, about 95 miles SSE of Muroc.

Signal Aircraft Warning Battalion 554th
Located: July 1942, March Field, California

Signal Aircraft Warning Regiment 504th
Activated: 11 December 1941, Camp Haan, California

More info at
http://www.mobileradar.org/army_units_501_561.html

Van Nuys, Fresno, Oakland, Estrella, San Fran all had early units

And the Bingo moment

Company C
Deployed: January 1944, for training Muroc Army Air Base, California, and attached to 592nd SAW Bn for exercise.
Redesignated: 16 May 1944, Company C, 595th SAW Battalion

http://www.mobileradar.org/army_units_562_599.html#top

The N-1M first flew in July of '41 N-9M first flew in Dec '42. So it is possible these planes flew thru early radar.

MSimon · Post by **MSimon** » Tue Dec 20, 2011 9:59 pm

How anyone can think this isn't a tragedy is beyond me. Someone needs to get fired.

Unless the aircraft was "doctored".

BTW 1/2 of what a sensor can do is in the software. That is not so easy to reverse engineer. And if there are Trojans in the software as found?

Roger · Post by **Roger** » Tue Dec 20, 2011 10:30 pm

GI Model RC planes have the same thickness boundry layer of air around the model as a real planes does. This is very apparent in the smaller scales and manifests itself in control issues.

The common way to make up for that is to make control surfaces proportionally larger. Which as you know is one of the attractions of the larger scales, better input response. Are you into rotary or 4 sroke?

I was more into Nitro cars with 2 spd trans, oil dampened coil over shocks in the 60 to 80 Mph range, than planes. I've ported the intakes on more than a few sleeves and a modded few crankshafts in my day. Those 2 strokers are so basic.

Have you ever seen an articulated arm with a milling head working on a 15ft + piece of alloy, in a clear 30+ ft case, with 100's of gallons of water splashing around to keep things cool, and see the finished product become the rear fuselage section of an E class Prowler?

odds are the entire craft is encased in state of the art stealth material.

A light sand colored radar absorbing coating? But hey, when I worked for a subcontractor for Eaton, it was 30 years ago, so WTF do I know.

Now that was effin cool.

Roger · Post by **Roger** » Tue Dec 20, 2011 11:14 pm

RC Horton with no apparent vertical surfaces
http://youtu.be/4meQYdaeT58

Home built B-2 no vertical surfaces
http://youtu.be/rygu6qpNSTo

This model was first available circa 1999
Propeller Megatach ready to fly B-2 with no apparent vertical surfaces.
http://www.rcplanetalk.com/megastealth.html

Ducted fan B-2
http://youtu.be/74tV0H4FfEQ

GIThruster · Post by **GIThruster** » Wed Dec 21, 2011 12:40 am

Roger wrote:GI Model RC planes have the same thickness boundry layer of air around the model as a real planes does. This is very apparent in the smaller scales and manifests itself in control issues.

Sounds like you've had some fascinating experiences. I'm not sure from your post we disagree, but I'll try to make more plain what I was trying to say.

As the size and weight of a craft increases, the ability to make it fly decreases. This is just as true with birds as with planes. It's true of inanimate objects as well. So RC craft can be made to fly, and even fly well, with pretty poor engineering. There are lots of RC craft that use planks of foam as lifting surfaces. You can't do that with a 35' wingspan.

That's all I'm saying. IMHO, the craft just crashed. Flying wings, and especially those wings optimized around endurance, are extremely vulnerable to pitch catastrophe, where the craft pitches down after stall, and pitches through a series of 360* rotations. Such a craft could make a relatively soft crash. Leaves often do the same. This vulnerability is unique to the flying wing because there is almost no mass behind the center of lift. . .no moment arm to resist rotation in pitch. IIRC, we lost an experimental flying wing to this very trouble back in the late 40's. Boeing and NASA have been working on the Blended Wing Body and this trouble for almost three decades. Skunkworks obviously forced through the trouble to get an extremely high endurance craft. Odds are, they allowed pitch catastrophe could happen and decided in an unmanned craft, this was an acceptable risk.

In the pics of the captured craft, the bottom of the wing is behind a banner. We can't tell how much damage it has, nor even if the landing gear was deployed, so there's little intel to analyze.

What we do know is that the general rule in situations like this is, that everyone lies.

I personally find it very unlikely the Iranians took control of the craft and forced it to land. Seems much more likely to me it encountered a microburst, went unstable and crashed.

Roger · Post by **Roger** » Wed Dec 21, 2011 1:26 am

GIThruster wrote:
In the pics of the captured craft, the bottom of the wing is behind a banner. We can't tell how much damage it has, nor even if the landing gear was deployed, so there's little intel to analyze.
.

Yeah the shroud, my first reaction was, "the landing gear is broken". Though there is a crush mark on the left wing, near the leading edge. And you can see in the video what looks like separation lines, where the wings detach, much like the 1/3 scale Northrops and the Hortons.

Now you know why the Prowlers had such a strong airframe. Back in the early 80's that was, "dont look to your left, keep walking straight ahead, you dont see that" kind of secret.

And hell, I was building test benches for Def avionics for the B-1, its not like I had no clearance at all.

SO do you fly 2 or 4 stroke, or radial engines?
Insane 6.9 hp 9 cyl:
http://www.chiefaircraft.com/evo-e999.html

GIThruster · Post by **GIThruster** » Wed Dec 21, 2011 2:13 am

Roger wrote: So do you fly 2 or 4 stroke, or radial engines?l

I'm presuming L-M has a turbine in the Sentinel. Less efficient at sea level, but this craft is optimized for 50,000'. Web says it's a General Electric TF34 Turbofan, surprisingly; same as mounted in the A-10 Thunderbolt.

I'd find it very surprising if they used internal combustion.

Roger · Post by **Roger** » Wed Dec 21, 2011 2:45 am

Roger wrote: SO do you fly 2 or 4 stroke, or radial engines?
Insane 6.9 hp 9 cyl:
http://www.chiefaircraft.com/evo-e999.html

Lets try that gain.

GIThruster · Post by **GIThruster** » Wed Dec 21, 2011 2:49 am

No good at 50,000'. Internal needs forced aspiration and drops efficiency hugely.

For 50,000', one needs a turbine. What's surprising is the A-10 uses such a motor.

MSimon · Post by **MSimon** » Wed Dec 21, 2011 3:47 am

And hell, I was building test benches for Def avionics for the B-1, its not like I had no clearance at all.

I have worked for more than a few defense contractors without official clearance. When I was at Recon Optical I was taken to a "private" show room by a show off engineer to see his latest and greatest.

And the small bit of code I did on the SR-71 was not official. The guy who was supposed to do the job was overloaded and he gave me the job of fixing the code. Took about a day for the fix and another day for the review.

Stuff leaks.

The fact that I once held a "secret" no doubt colored the events. Still. It was a breach.

Roger · Post by **Roger** » Wed Dec 21, 2011 4:07 am

Roger wrote:
Roger wrote: SO do you fly 2 or 4 stroke, or radial engines?
Insane 6.9 hp 9 cyl:
http://www.chiefaircraft.com/evo-e999.html
Lets try that gain.

GI, you said you fly RC planes, I linked to a 9 cyl radial engine that puts out 6.9 horsepower. This is specifically for RC planes of historic models. Something like a Wildcat or a B-29.

If you know something about RC glow engines for planes, you should recognize the engine. Or maybe not.

Lets try that gain

MSimon, yeah but that milling machine was way cool, even if it was 30 years ago.

MSimon · Post by **MSimon** » Wed Dec 21, 2011 2:20 pm

Nice Iranian drone photos about 7 1/2 minutes in:

http://www.pjtv.com/?cmd=mpg&mpid=174&load=6437

The whole video is good (if a little slow) on the current Iranian situation.

GIThruster · Post by **GIThruster** » Wed Dec 21, 2011 2:32 pm

Roger wrote:
GI, you said you fly RC planes, I linked to a 9 cyl radial engine that puts out 6.9 horsepower. This is specifically for RC planes of historic models. Something like a Wildcat or a B-29.

If you know something about RC glow engines for planes, you should recognize the engine. Or maybe not.

Sorry, I fly all electric. Gas requires a lot more work and mess, IMHO.

ladajo · Post by **ladajo** » Wed Dec 21, 2011 3:05 pm

Roger,
Thanks for the links to the wings. I am also an electric flyer. But my taste runs to old warbirds. Currently flying 40inch wing P-51 (when my wife lets me).

Thepoint in RC models is that you can pretty much make anything fly. Just apply enough thrust. The materials and thrust to wieght do not scale however. The other issue is manned verses unmanned. RC are manned. Although, that said, I have seen some nice work done by a a guy with accellerometer stability packages with his garage projects. Very cool and simple.

I still maintain that wings are hard to build and fly reliably, especially real life ones. And also think that it is even harder to do unmanned. Either way, the bottom line is that the RQ-170 was a Christmas present to Iran. They for sure will get something out of it. And, that exploitation will take time. And they may never fully exploit it.