busdriver Posted February 12, 2013 Posted February 12, 2013 WTF? What are they doing with this thing to even need something like that? Have I had my head buried in the sand? It's there for battle damage reasons.
Tonka Posted February 12, 2013 Posted February 12, 2013 WTF? What are they doing with this thing to even need something like that? Have I had my head buried in the sand? OBIGGS provides NEA for the Ullage... (reduces the % of O2 in fuel tank vapor space). Theory: no O2, no boom. Debatable if the risk outweighs the cost/weight of protection on any/all aircraft (especially if you think the risk is only from lightning). There were a couple of aircraft (commercial) accidents in the last few decades that were a result of mostly empty fuel tanks (i.e. lots of vapor) near a heating/spark source in the aircraft, and on a warm day (oversimplified report). While there is a potential for lightning to cause the spark/heat in the fuel vapor, IMO it isn't a high probability... i.e. we don't often hear of airplanes getting hit by lightning and instantly exploding, at least not enough to warrant everyone w/o such a system to stay away from lightning potential areas. The fuel venting system must be so limited in its ability to reduce the fuel vapor ignition-potential in the tank(s) that it is working in a manner opposite of a normal OBIGGS, and increasing the potential for a "boom".... So, it's not what they are doing with the aircraft, it is what the aircraft is not able to do: control fuel-vapor ignition-risk.
FallingOsh Posted February 12, 2013 Posted February 12, 2013 Or you could put foam in the tanks like the Hawg designers did 40 years ago. What's the point of saving weight if the system doesn't work?
Lord Ratner Posted February 12, 2013 Posted February 12, 2013 "A poor design for the fuel tank venting system also means that when the single-engine jet is below 20,000 feet, its descent rate is limited to no more than 6,000 feet per minute" I thought that one was fun. Getting chased by the mighty F-35 Lightning II? Nothing a Split-S can't solve. 1
Fuzz Posted February 13, 2013 Posted February 13, 2013 "A poor design for the fuel tank venting system also means that when the single-engine jet is below 20,000 feet, its descent rate is limited to no more than 6,000 feet per minute" I thought that one was fun. Getting chased by the mighty F-35 Lightning II? Nothing a Split-S can't solve. Either that or it was a subtle misinformation to our enemies, never know what the spooks in the intel community are up too. I can see Supreme Gen. Achmed of the Iranian AF briefing his pilots that you can out run the filthy infidel if you stay below FL200 and pull a slit-S, and then wonders why none of his pilots come back.
HossHarris Posted February 13, 2013 Posted February 13, 2013 Oh sure, just give away all of our propaganda secret weapons .... Thanks. Meow it's gonna be much harder .... 1
Day Man Posted February 13, 2013 Posted February 13, 2013 fatty driver question: when the article refers to turn performance/sustained G's, does that mean max G's w/o bleeding airspeed?
Muscle2002 Posted February 13, 2013 Posted February 13, 2013 (edited) fatty driver question: when the article refers to turn performance/sustained G's, does that mean max G's w/o bleeding airspeed? Essentially, yes. Technically, a sustained turn occurs at Ps=0. Thus, the max sustained G and turn rate occur at the airspeed at which G and turn rate are maximized along the Ps=0 curve on an E-M diagram. Edited February 13, 2013 by Muscle2002
billy pilgrim Posted February 13, 2013 Posted February 13, 2013 (edited) fatty driver question: when the article refers to turn performance/sustained G's, does that mean max G's w/o bleeding airspeed? The heavier a fighter is and the smaller the wing is the worse turn performance it will have. For a 40,000lb aircraft the wing has to generate 280,000lb of lift for a 7g turn. A bigger wing can generally do that at lower angle of attack and subsequently less drag. Less drag and you stay faster, stay faster and your engines make more power (to a point) as there's more air moving through them and they can generate more thrust. It all translates into all-around better performance. You can add all the technology you want to a turd but you will still have to deal with the laws of aerodynamics and physics. Edited February 13, 2013 by billy pilgrim
Prozac Posted February 14, 2013 Posted February 14, 2013 Did these same guys design the MiG-28? No one's been close enough to tell. 1
17D_guy Posted February 14, 2013 Posted February 14, 2013 I know it's the "B" variant, but I thought it would be interesting anyway - https://www.reuters.com/article/2013/02/13/lockheed-fighter-idUSL1N0BDB0A20130213 Pentagon, Navy lift flight restrictions on F-35B jets * Fleet of 25 F-35B jets grounded after fuel line detached * Pentagon says hoses with problems to be replaced
MKopack Posted February 22, 2013 Posted February 22, 2013 All F-35's grounded after cracked turbine blade found: Pentagon grounds entire Joint Strike Fighter fleet Stars and Stripes WASHINGTON – All Joint Strike Fighter operations have been suspended after an inspection revealed a cracked turbine blade in an engine at Edwards Air Force Base in California, officials said Friday. The blade has been sent to Pratt & Whitney’s Engine Facility in Connecticut for more tests, but all F-35s will remain on the ground until the investigation is finished and experts determine what caused the crack, according to the Joint Strike Fighter program office. The Marine variant of the fighter jet had just resumed flying last week after an engine malfunction prompted a 30-day suspension. The $396 billion F-35 Joint Strike Fighter program, the Pentagon’s largest weapons program, is seven years behind schedule. The jet is still in the test and development phase and not yet fully operational. Defense Secretary Leon Panetta said in December that the Joint Strike Fighter will see its first overseas deployment in 2017, to Marine Corps Air Station Iwakuni in Japan. The fighter program is billed on its website as the DOD’s “focal point for defining affordable next generation strike aircraft systems for the navy, Air Force, Marines, and our allies.” The jets are built by Lockheed Martin and powered by Pratt & Whitney engines.
billy pilgrim Posted February 22, 2013 Posted February 22, 2013 I found the problem: "The jets are built by Lockheed Martin and powered by Pratt & Whitney engines." 1
TreeA10 Posted February 23, 2013 Posted February 23, 2013 Wouldn't want this to be like the F-16. Old joke: How to you get your own F-16? Buy an acre of land near Luke and wait.
MKopack Posted February 23, 2013 Posted February 23, 2013 Reminds me of back when we were receiving the first "Big Mouth" Block 30 F-16C's - straight from the factory - at MacDill AFB in '88/89. During the incoming inspections we found cracked turbine buckets on F110-GE-100's that had less than ten running hours on them from new. As I recall at least one pilot and aircraft was lost and they convicted (and imprisoned) the President of the GE subcontractor that was supplying "recycled" metal that went into the engines. Bad scene.
17D_guy Posted March 7, 2013 Posted March 7, 2013 The limitations and restrictions are typical of an aircraft still in development testing “but very atypical of a fighter aircraft used for student training,” he wrote. “Only a very limited set of full mission systems capability are working,” he wrote. https://www.bloomberg.com/news/2013-03-06/air-force-trains-on-f-35s-with-balky-radar-limited-views.html Wow
Fuzz Posted March 7, 2013 Posted March 7, 2013 What the heck is with the Thunderchicken paint job? I'll miss the day when the Viper is no longer the Thunderbird airframe, hopefully it's a long way off.
StoleIt Posted March 7, 2013 Posted March 7, 2013 What the heck is with the Thunderchicken paint job? Either photoshop or a 3D rendering.
HU&W Posted March 7, 2013 Posted March 7, 2013 LM did a mockup last year of the F35 in TB paint. Click through the slideshow if you care.
papajuice77 Posted March 7, 2013 Posted March 7, 2013 From the Bloomberg article - The pilots also complained about difficulty seeing outside the cockpit canopy when wearing the helmet. One pilot said the cockpit layout makes it “nearly impossible” for pilots to check “their six o’clock” position -- behind them --in high- stress maneuvers, according to the report. Another pilot said limitations on such “aft visibility” during close combat “will get the pilot gunned down every time.” This “could turn out to be a significant problem for all F-35 pilots,” Gilmore said, “especially in more tactical combat training” such as basic fighter maneuvering. Really? Couldn't tell that just by looking at the darn thing? I guess that was supposed to be remedied by the newest magical helmet. Taking cues from 70's Soviet designs with 0 aft visibility probably wasn't wise for a *cough* fighter - even with a new wizard's hat that's supposed to let you look through the floor to see around you. McNamara's Folly take 2.
billy pilgrim Posted March 7, 2013 Posted March 7, 2013 From the Bloomberg article - Really? Couldn't tell that just by looking at the darn thing? I guess that was supposed to be remedied by the newest magical helmet. Taking cues from 70's Soviet designs with 0 aft visibility probably wasn't wise for a *cough* fighter - even with a new wizard's hat that's supposed to let you look through the floor to see around you. McNamara's Folly take 2. Dude - you obviously don't get it. With all the stealth and other capes it would be basically impossible for a bandit to end up behind a fighter that advanced. How do you control zone BFM that which has no control zone?! I hate the F-35.
B52gator Posted March 7, 2013 Posted March 7, 2013 (edited) It's amazing they haven't cancelled this thing yet. I'm all for better tech and replacing an aging fleet, but this is getting ridiculous. Kinda looks like it has a stache...and lipstick on. Edited March 7, 2013 by b52gator
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