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https://ntrs.nasa.gov/search.jsp?R=19960000737

 

What does the board think of the document above?  It's a 200 page 1995 NASA study on technologies and their impact on fighter agility.  It seems to explain why the F-35 was not made more agile than the F-16.  TLDR:  Not cost effective.

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18 minutes ago, Domus Acipenseris said:

https://ntrs.nasa.gov/search.jsp?R=19960000737

 

What does the board think of the document above?  It's a 200 page 1995 NASA study on technologies and their impact on fighter agility.  It seems to explain why the F-35 was not made more agile than the F-16.  TLDR:  Not cost effective.

 

SMSgt Mac had a writeup on a similar study.

 

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1 hour ago, Domus Acipenseris said:

https://ntrs.nasa.gov/search.jsp?R=19960000737

 

What does the board think of the document above?  It's a 200 page 1995 NASA study on technologies and their impact on fighter agility.  It seems to explain why the F-35 was not made more agile than the F-16.  TLDR:  Not cost effective.

Excellent first post. Welcome to SH.

 

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2 hours ago, Domus Acipenseris said:

https://ntrs.nasa.gov/search.jsp?R=19960000737

 

What does the board think of the document above?  It's a 200 page 1995 NASA study on technologies and their impact on fighter agility.  It seems to explain why the F-35 was not made more agile than the F-16.  TLDR:  Not cost effective.

 

Welcome to SH!  I dig the username.

 

The F-35 is more agile than the F-16, at least in some respects.  We know, for instance, that the F-35 has at least double the AOA limit of the F-16, and airshow footage suggests that its roll rate is a little better as well.  On the other hand, the F-16 probably beats the F-35 in sustained turn rate and transonic acceleration.

 

Bottom line is that fighter agility has a lot of different parameters, and design choices that favor certain parameters of agility harm other parameters.  A tailless delta will favor instantaneous turn rate and roll rate at the expense of sustained turn rate and cruise efficiency, for instance.  Getting the best possible agility isn't just an issue of cost, it's a trade off with other performance parameters.

 

We have a thread about these tradeoffs, at least in the context of WWII fighter design.

 

My take on the F-35A's performance is:

+Very good high AOA performance and AOA limit; comparable, possibly better than the super hornet based on leaked reports and soforth.

+Very good instantaneous turn rate as a result of the excellent high AOA performance.

+Very good roll rate as a result of wing planform and good software harmonization of the control surfaces.

+Absolutely bonkers fuel capacity.  The F-35A carries more fuel than a Tomcat.  That's not relatively more fuel than a Tomcat, that's more gallons of fuel.

+The advanced flight control software and good airflow at high AOA allow the F-35A to perform screwy new maneuvers like the J-hook.  How useful this will be in actual combat is debatable.

-Transonic acceleration doesn't sound so hot, although a fourth generation fighter would have to be carrying a very modest air to air load to actually best the F-35, since the F-35 is always clean.

-Sustained turn performance doesn't sound so hot, but again, a fourth generation fighter would need a fairly modest load to actually exploit this.

-Top speed is rather low, but top speed with heavy air to surface loads is probably unmatched (except maybe by the SU-57 or J-20).  External stores are very draggy.

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On 3/17/2018 at 8:05 PM, Collimatrix said:

The most interesting thing I've learned about the F-35 lately is that the nose radome is apparently sealed.  To service the radar... you don't.  The active emitter portions of the radar are so reliable that they are expected to out-last the airframe.

 

It looks like the USMC agrees that AESA radar is much easier to maintain than mechanical

http://www.janes.com/article/78735/usmc-to-upgrade-hornets-with-new-aesa-radar

Quote

USMC to upgrade Hornets with new AESA radar

he US Marine Corps (USMC) is to replace the radars of its Boeing F/A-18 legacy Hornets with a new active electronically scanned array (AESA) system.

A request for information (RFI) issued by the Naval Air Systems Command (NAVAIR) on 20 March calls for a new AESA system to replace the incumbent Raytheon AN/APG-73 radar on the USMC’s fleet of F/A-18C/D aircraft.

“The AN/APG-73 has been subject to ongoing maintainability, supportability, and readiness issues,” the RFI noted, adding, “AESA solutions are required due to the increased reliability and sustainability requirements, as well as the associated capability improvements.”

 

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16 minutes ago, Ramlaen said:

Lockheed supposedly wants to sell Japan some sort of F-35/F-22 hybrid.

 

Probably an F-35 tweaked to focus on air combat.

I think this is bigger news than it seems to be. A hybrid of F-35 and F-22? They're almost definitely talking about a twin engine derivative. If that's true, there's no way it's just for Japan. It could mean a lot for the USAF, as they need more F-22 than they have right now, but the production is closed. This could be a way to get more F-22.

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9 hours ago, Mighty_Zuk said:

I think this is bigger news than it seems to be. A hybrid of F-35 and F-22? They're almost definitely talking about a twin engine derivative. If that's true, there's no way it's just for Japan. It could mean a lot for the USAF, as they need more F-22 than they have right now, but the production is closed. This could be a way to get more F-22.

 

I also think there are bigger implications here. However, what the USAF really needs is not more F-22s, but an F-22 replacement.

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PCA is a concept for a 6th gen fighter. It's not even really defined yet so I think just an upgraded Gen 5 warplane won't get us there. Or is it not really a 6th gen but closer to the YF-23?

 

Either way, I think these news penetrated a lot of us.

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I'm dubious.

 

BmdKTRr.png

When stealth aircraft are flown around casually, they wear devices that increase their RCS dramatically.  These are corner reflectors or Luneburg lenses.

W2luBdQ.jpg

 

Not only do these devices obfuscate the RCS of the stealth aircraft when it is clean, they also allow it to show up on civilian air traffic control radar, which is a useful safety consideration.

Even assuming that passive radar would be a helpful guide to the RCS of the aircraft, why wouldn't it be thrown off by these measures?

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Any radar can detect stealth aircraft, it's a fallacy to treats it as a Romulan cloaking device. The question is how far and what level of detail your frequency range will produce.

 

The actual concept behind their passive radar seems reasonable, but the HF and below frequency range is probably useless.

Edited by Ramlaen

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    • By LostCosmonaut
      Compared to the most well known Japanese fighter of World War 2, the A6M “Zero”, the J2M Raiden (“Jack”) was both less famous and less numerous. More than 10,000 A6Ms were built, but barely more than 600 J2Ms were built. Still, the J2M is a noteworthy aircraft. Despite being operated by the Imperial Japanese Navy (IJN), it was a strictly land-based aircraft. The Zero was designed with a lightweight structure, to give extreme range and maneuverability. While it had a comparatively large fuel tank, it was lightly armed, and had virtually no armor. While the J2M was also very lightly built, it was designed that way to meet a completely different set of requirements; those of a short-range interceptor. The J2M's design led to it being one of the fastest climbing piston-engine aircraft in World War 2, even though its four 20mm cannons made it much more heavily armed than most Japanese planes.
       
       

       
      Development of the J2M began in October 1938, under the direction of Jiro Hirokoshi, in response to the issuance of the 14-shi interceptor requirement (1). Hirokoshi had also designed the A6M, which first flew in April 1939. However, development was slow, and the J2M would not make its first flight until 20 March 1942, nearly 3 ½ years later (2). Initially, this was due to Mitsubishi's focus on the A6M, which was further along in development, and of vital importance to the IJN's carrier force. Additionally, the J2M was designed to use a more powerful engine than other Japanese fighters. The first aircraft, designated J2M1, was powered by an MK4C Kasei 13 radial engine, producing 1430 horsepower from 14 cylinders (3) (compare to 940 horsepower for the A6M2) and driving a three bladed propeller. The use of such a powerful engine was driven by the need for a high climb rate, in order to fulfill the requirements set forth in the 14-shi specification.
       
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      Sources:
       
       
      https://www.docdroid.net/gDMQra3/raiden-aeroplane-february-2016.pdf#page=2
      F6F-5 vs. J2M3 Comparison
      http://www.combinedfleet.com/ijna/j2m.htm
      http://www.wwiiaircraftperformance.org/japan/Jack-11-105A.pdf
      https://babel.hathitrust.org/cgi/pt?id=mdp.39015080324281;view=1up;seq=80
      https://archive.org/stream/corporationrepor34unit#page/n15/mode/2up
      http://users.telenet.be/Emmanuel.Gustin/fgun/fgun-pe.html
      http://ww2data.blogspot.com/2016/04/imperial-japanese-navy-explosives-bombs.html
      https://www.pacificwrecks.com/aircraft/j2m/3008.html
      https://www.pacificwrecks.com/aircraft/j2m/3013.html
      https://www.pacificwrecks.com/aircraft/j2m/3014.html
       
       
      Further reading:
       
      An additional two dozen Raiden photos: https://www.worldwarphotos.info/gallery/japan/aircrafts/j2m-raiden/
       
       
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