Quote: At that time, Griffith had taken one of the initial F-35A test aircraft to 583 KCAS (exceeding Mach 1.2). Now, as the pace of testing continues to accelerate despite earlier delays caused by an inflight dual generator failure, and problems with the integrated power package (IPP), the jet has been flown to Mach 1.61.
Quote:
The aircraft has also been flown to 9.9g – which is 0.9g beyond the operational limits.
On the stealth signature:
Quote: The aircraft “is meeting or exceeding the low observable requirements, so we know we have a stealthy aircraft which is fantastic.”
It sounds like the F-35 can be pushed pretty hard in terms of performance. It seems like the claims that F-35 won't be able to exceed Mach 1.5 (i.e. from Sweetman) are shot to pieces.
Max Q From United States of America, joined May 2001, 3289 posts, RR: 19 Reply 2, posted (1 year 5 months 1 week 5 days 23 hours ago) and read 10642 times:
Yes, it's very slow, by any standard, at least it's incredibly expensive though..
The best contribution to safety is a competent Pilot.
nomadd22 From United States of America, joined Feb 2008, 1562 posts, RR: 0 Reply 3, posted (1 year 5 months 1 week 5 days 17 hours ago) and read 10448 times:
The US tends to understate military capability. The F-22 was often quoted at M1.6 supercruise, but was hitting M1.78 when tested.
The Janes figures often quoted tended to use those understated figures while using somewhat optimistic numbers for certain other nations hardware.
Autothrust From Switzerland, joined Jun 2006, 1480 posts, RR: 8 Reply 4, posted (1 year 5 months 1 week 5 days 17 hours ago) and read 10446 times:
Just as comparison:
The Typhoon has reached during "real-life" tests 10,6G. It can be sustained for indefinte periods even the pilot can give speak commands through the anti G suite dragonfly.
wingman From Trinidad and Tobago, joined May 1999, 1838 posts, RR: 5 Reply 5, posted (1 year 5 months 1 week 5 days 17 hours ago) and read 10432 times:
Auto, I think it's safe to say no American made aircraft will ever meet or exceed the performance of European aircraft or that of their European pilots. Why these Yanks even try is beyond me.
flagon From France, joined May 2007, 133 posts, RR: 0 Reply 6, posted (1 year 5 months 1 week 5 days 16 hours ago) and read 10387 times:
Quoting ThePointblank (Thread starter): The aircraft has also been flown to 9.9g – which is 0.9g beyond the operational limits
I think given the maturity of the program this detail is worth mentioning...
Quoting Autothrust (Reply 4): The Typhoon has reached during "real-life" tests 10,6G
9g is the usual manoeuvre limit set for combat aircrafts, probably based on the rationale that the human body can not sustain very much in practical terms. That said the actual structure is sized against a load of 9G times an ultimate factor which in civil aviation is 1.5, and may even be greater in military aviation, which means that the structure of any combat aircraft is in principle capable of withstanding loads of about 13-14G.
I remember reading in article where a pilot from the agressor squadron in Miramar pulled its F21 to 13G to avoid a collision with an F14. I know you would probably want a source but I don't have it. Just saying that this kind of event happens more often than one thinks.
Quote:
At that time, Griffith had taken one of the initial F-35A test aircraft to 583 KCAS (exceeding Mach 1.2). Now, as the pace of testing continues to accelerate despite earlier delays caused by an inflight dual generator failure, and problems with the integrated power package (IPP), the jet has been flown to Mach 1.61.
Quote:
The aircraft has also been flown to 9.9g – which is 0.9g beyond the operational limits.
On the stealth signature:
Quote:
The aircraft “is meeting or exceeding the low observable requirements, so we know we have a stealthy aircraft which is fantastic.”
It sounds like the F-35 can be pushed pretty hard in terms of performance. It seems like the claims that F-35 won't be able to exceed Mach 1.5 (i.e. from Sweetman) are shot to pieces.
All that said, many many problems exist in the F-35 program and are significant enough that DoD itself has recommended a reduction in the LRIP rate. Some of the problems are identified as "major". One of the majors is classified and I would guess (and it is a guess) that it relates to stealth. High angle of attack buffet, the helmet system, and "mission systems" are also identified as major.
Quote:
The Euthanasia Coaster is an art concept for a steel roller coaster designed to kill its passengers...The ride's seven inversions would inflict 10 g on its passengers for 60 seconds
I know the Rafale pilot is used to the effects of g, and probably trained for this demonstrator mission specifically, and is wearing a g suit but...blimey!
Devilfish From Philippines, joined Jan 2006, 4429 posts, RR: 1 Reply 9, posted (1 year 5 months 1 week 5 days 14 hours ago) and read 10254 times:
Quoting flagon (Reply 6): I remember reading in article where a pilot from the agressor squadron in Miramar pulled its F21 to 13G to avoid a collision with an F14.
Autothrust From Switzerland, joined Jun 2006, 1480 posts, RR: 8 Reply 10, posted (1 year 5 months 1 week 5 days 14 hours ago) and read 10252 times:
Quoting flagon (Reply 6): 9g is the usual manoeuvre limit set for combat aircrafts, probably based on the rationale that the human body can not sustain very much in practical terms.
Wrong, new anti g suits like the dragon fly G-Multiplus can enable trained pilots to sustain 9g even without pressure breathing and Eurofighter pilots to fly with 10g for a indefinite time.
flagon From France, joined May 2007, 133 posts, RR: 0 Reply 11, posted (1 year 5 months 1 week 5 days 13 hours ago) and read 10202 times:
Quoting Autothrust (Reply 10): Quoting flagon (Reply 6):
9g is the usual manoeuvre limit set for combat aircrafts, probably based on the rationale that the human body can not sustain very much in practical terms.
Wrong, new anti g suits like the dragon fly G-Multiplus can enable trained pilots to sustain 9g even without pressure breathing and Eurofighter pilots to fly with 10g for a indefinite time.
That's not wrong, as 9G is the usual load limit against which most of fighters have been designed to so far (Typhoon may be an exception I don't know but that's not the point). This limit, whether it 7G or 9G or whatever it has to be according to the aircraft specifications, is driven by human limitations since structurally speaking there is nothing preventing the plane designer from designing the structure so that it can withstand silly accelerations like 50G, appart from the fact that this would add ridiculous and unecessary amount of weight in the airframe.
I just wanted to point out that when you see an operational limit of 9G or something quoted for a given aircraft, that does not mean it cannot be exceeded in the real life (providing that the pilot can sustain it one way or another via g-suits or seats "a la F-16" maybe) as there is additional structural margin baked into the design via an ultimate factor as mentioned in my previous post.
Powerslide From Canada, joined Oct 2010, 482 posts, RR: 1 Reply 12, posted (1 year 5 months 1 week 5 days 8 hours ago) and read 9990 times:
Quoting Autothrust (Reply 10): Wrong, new anti g suits like the dragon fly G-Multiplus can enable trained pilots to sustain 9g even without pressure breathing and Eurofighter pilots to fly with 10g for a indefinite time.
Why it makes the eurofighter the number one choice for airshows.
vzlet From United States of America, joined Mar 2004, 820 posts, RR: 0 Reply 14, posted (1 year 5 months 1 week 4 days 18 hours ago) and read 9687 times:
Quoting ThePointblank (Thread starter): It seems like the claims that F-35 won't be able to exceed Mach 1.5 (i.e. from Sweetman) are shot to pieces.
Mach 1.5 has indeed been met and exceeded, but not without pain:
"Finally, recent testing at Air Force Flight Test Center, Edwards AFB, revealed excessive structural heating with the afterburner on for extended periods. Flight tests to speeds up to Mach 1.6 with the afterburner engaged for several minutes generated enough heat to damage the horizontal tail (peeling and bubbling of coating about the size of a fist). There was also some degradation of thermal panels in the engine. While solutions are being evaluated, the program office has established aircraft operations limits, reducing the top speed to Mach 1.0 with afterburner operations limited to 1-2 minutes. In order to get full afterburner performance back in the aircraft, it may be necessary to change the material and or add structure to the tail."
connies4ever From Canada, joined Feb 2006, 3857 posts, RR: 13 Reply 16, posted (1 year 5 months 1 week 4 days 14 hours ago) and read 9587 times:
Quoting Powerslide (Reply 15): Excellent news. They found and issue during flight testing, you know, what they are supposed to do, and will soon have the problem corrected.
When in doubt, rationalize. This is still a deeply troubled program.
kanban From United States of America, joined Jan 2008, 2468 posts, RR: 21 Reply 17, posted (1 year 5 months 1 week 4 days 11 hours ago) and read 9479 times:
Quoting Powerslide (Reply 15): They found and issue during flight testing
Once again an obvious engineering miscalculation that should have been identified in computer modeling is found in flight test... so how many airframes will require extensive rebuild.
I'ts time to stop production entirely until all the miscalculations are identified, resolved and tested. what good will 60+ birds waiting for rebuild do anybody.
Devilfish From Philippines, joined Jan 2006, 4429 posts, RR: 1 Reply 18, posted (1 year 5 months 1 week 4 days 10 hours ago) and read 9435 times:
Quoting kanban (Reply 17): I'ts time to stop production entirely until all the miscalculations are identified, resolved and tested. what good will 60+ birds waiting for rebuild do anybody.
Apart from price and offset arrangements, could that be the reason why Japan's defense ministry is holding out on making an announcement and confirming its choice?
Quote: "Several major Japanese publications cited sources as saying that Tokyo favoured the F-35A in the 40-aircraft deal, and suggested that the decision will be officially announced on 16 December. The deal is expected to value $8 billion, they said.
Japan's defence ministry declined to confirm when an announcement will be made, adding: 'the government has not yet decided the type of aircraft'."
Of course, the reports did not mention which year.
faro From Egypt, joined Aug 2007, 1445 posts, RR: 0 Reply 19, posted (1 year 5 months 1 week 4 days 10 hours ago) and read 9436 times:
Quoting Powerslide (Reply 15): Excellent news. They found and issue during flight testing, you know, what they are supposed to do, and will soon have the problem corrected.
You must be joking. "Several minutes" of afterburner use that may end up forcing you to add *structure* to the tail. You call that a routine oversight?...sigh...
In the words of connies4ever: deeply troubled. The quicker the program is put out of its misery the better for everyone.
flagon From France, joined May 2007, 133 posts, RR: 0 Reply 20, posted (1 year 5 months 1 week 4 days 9 hours ago) and read 9369 times:
I could easily understand if the programme was troubled by various software and system issues. However the amount of fatigue and crack issues they seem to have to deal with at this stage of the programme still amazes me as nowadays you would expect this kind of things to be a lot more under control, especially with the experience and the lessons learnt from the F22 which I believe uses roughly the same airframe design phylosphy (internal parts metallic, external parts composite wherever possible).
I guess the complexity of the programme does not help, the F35B variant alone with all the moveables everywhere must be quite challenging....
Oh, here we go again, people who think they are smarter or can do a better job than the engineers at Lockheed. There hasn't been ONE single aircraft in production since the beginning of time that hasn't had issues during testing. I guess they should have cancelled the Raptor program when it landed wheels up. Somehow, the anti-jsf fanboi's think the F35 should be PERFECT after the first rivet is installed.
connies4ever From Canada, joined Feb 2006, 3857 posts, RR: 13 Reply 22, posted (1 year 5 months 1 week 4 days 4 hours ago) and read 9247 times:
Quoting Powerslide (Reply 21): Oh, here we go again, people who think they are smarter or can do a better job than the engineers at Lockheed. There hasn't been ONE single aircraft in production since the beginning of time that hasn't had issues during testing. I guess they should have cancelled the Raptor program when it landed wheels up. Somehow, the anti-jsf fanboi's think the F35 should be PERFECT after the first rivet is installed.
How long since FF ? How many prototype, SDD, and LRIP a/c produced and flying ? And there are still so many issues that the DoD itself is recommending cutting back production so the problems can (possibly) be sorted out. The 'secret' problem we don't know. So, as Rummy would have said, it's an unknown unknown.
Powerslide From Canada, joined Oct 2010, 482 posts, RR: 1 Reply 23, posted (1 year 5 months 1 week 4 days 4 hours ago) and read 9243 times:
Quoting connies4ever (Reply 22): And there are still so many issues that the DoD itself is recommending cutting back production so the problems can (possibly) be sorted out
connies4ever From Canada, joined Feb 2006, 3857 posts, RR: 13 Reply 24, posted (1 year 5 months 1 week 4 days 4 hours ago) and read 9225 times:
Quoting Powerslide (Reply 23): Quoting connies4ever (Reply 22):
And there are still so many issues that the DoD itself is recommending cutting back production so the problems can (possibly) be sorted out
You say this like it's a bad thing.
After this long long period of testing, and now using production a/c, yes, it is a bad thing. It's an indicator that the overall design is possibly not robust, and that the production process is not well controlled, if controlled at all.
This was supposed to be a "super fighter", best in brand, produced by the smartest brains money could buy (money apparently not being an object in this exercise), and using the best computer-aided design and production tools available.
And what is the result to date ? Oh, well, near the afterburner there is evidence of heat damage. Who would have ever thought surfaces near the AB would get hot ? The helmet system not working. High AoA buffet, high AoA ability being touted as one of the a/c's strengths. And of course the "classified" problem - whatever that might be.
Where/when does this end and how much more will civilians, who foot the military bill, be soaked for ? {Apologies for my dangling participle}
Nostalgia isn't what it used to be.
25 ThePointblank: Every past fighter has had issues. The F-15 had buffet problems until the wing tips were raked. The F-22 had software and thermal problems. These issu
26 prebennorholm: I think that few people realize the magnitude of work which goes into developing a modern fighter which really has a performance edge on existing pla
27 HaveBlue: Thank you for a great counterpoint to the naysayers. Any program is going to have its share of difficulties, but all the more so when pushing the edg
28 kanban: Maybe it's the pot calling the kettle black... I have 35 years in the business... if your profile age is correct, I wonder where the "knowledge" come
29 L-188: Take a look at some of the photos of the F-100. All of them pretty much have heat discoloration on the fuselage forward of the empanage from the engi
30 ThePointblank: Indeed. Finding cracks during testing is normal and is to be expected. If you aren't finding cracks during testing, then you have heavily overbuilt t
31 kanban: some at the envelope extremes yes, those within the "really safe" end of the envelope no... the bulkhead cracking is the latter, not the former. We a
32 Powerslide: Nothing is built perfect the first time. This is why the first F35 off the line didn't go straight into service. This program is no different than an
33 connies4ever: Quite. And none of these a/c were designed using CAD and numerical windtunnels. Edge issues will often bite you and that's what the two tools aforeme
34 GDB: At least there have been no instances of the pilot's O2 supply being lethally deficient, several years AFTER entering service. It's the same with the
35 par13del: Here's the issue I have with this principle being applied wholesale to all new programs. We are supposed to be in the age of computers when complex s
36 kanban: Look nobody is saying items don't crop up in a test program, what I'm saying is some of the problems in this program should not have cropped up.. The
37 L-188: I think the guys from Saab might disagree
38 connies4ever: Got me on that one. I missed it in the list.
39 prebennorholm: Ha ha! And he sure knows what he is talking about. That same Bud Anderson, throughout his professional career, when he didn't fly an A model, then it
40 checksixx: I guess I'm slow in the mornings...since no F-22 has landed wheels up (as far as I know), what is the meaning behind the statement?
41 GST: One has in flight testing after computer problems affecting flight controls. http://www.youtube.com/watch?v=faB5bIdksi8
42 cmf: I think you have unrealistic expectations. Computer designs takes away a lot of uncertainty but not all. They have provided all of that. But then it
43 KC135TopBoom: I guess that is why Europeans bought so many F-86s, F-104s, F-4s, and F-16s? France also bought several F-100s. Also, what is the actual kill ratio o
44 KiwiRob: You can say whatever you like to Powerslide but he's the biggest fanboy I've ever seen, this program could be canned and he would still sing it prais
46 474218: That area you say is "heat discoloration" is in fact titanium. Titanium was used because of the heat produced by the afterburner.
47 GDB: British and French veterans of Suez might disagree - an action (rightly) stopped by US pressure. Then the RN and RAF pilots in 1982, even with aircra
48 David L: And let's not forget the UK's contribution to Top Gun (the real thing, not the movie) - "the RN shows the US how to fly to the edge of the envelope".
49 Arniepie: Common, let's put things in perspective here, The kill ratio of both US and European pilots is next to negligible post WWII and Korea, fact is that m
50 faro: I'm really having trouble rationalising this. If the heating problem ends up needing only material changes that should not be too much of an issue. B
51 474218: There was never a material change! The aft body, that section aft of the fuselage break used for removing and replacing the engine, was titanium on t
53 YTZ: These stats are nice and all and the F-35 has to meet specs. But the truth of the matter is that, if you're getting an F-35 into a turning fight, you'
54 HaveBlue: That was probably true until the Blackbird, and the Blackbirds 93% titanium is a record that will almost surely never be broken.
55 474218: If you mean the SR-71 (it had no official name) I am very familiar with the amount of titanium used. After my four months of Airframe Repair (sheet m
56 faro: I was in fact referring to the F-35; reply 14 that I quote refers to the F-35. Faro
57 HaveBlue: I'm pretty sure everyone here knows what I'm referring to when I say Blackbird...
59 checksixx: Err...no, you're mistaken then...I'm afraid you're confusing a YF-22 with a production F-22. It was simply a prototype. A production F-22 is very dif
60 Arniepie: Wiki is quoting 50 Aircraft lost, including 6 lost MiG29 in air combat, most (not all) of the others destroyed on the ground like in this instance "A
61 ThePointblank: More information: it appears that the Pentagon has probably inflated the costs for the structural modifications on existing aircraft by get this: 75%!
62 cmf: Pretty poor article using very poor arguments to make blind followers fight for the cause. "Squeezing the F-35 program like toothpaste makes no sense
63 ThePointblank: Not necessarily, it means development costs are amortized over a larger number of units. The B-2 is the prime example; the per unit cost ballooned, w
64 faro: Agreed but total cost program cost remains the bottom line. A production dollar remains just as weighty as a R&D dollar. By producing more aircra
65 gigneil: That isn't true... at least not in most accepted accounting principals now in use. The methods for accounting each are separate and the R&D can b
66 rheite: Outside of the developement issues which any sort of new gen platform faces, I can tell you that in so far as the USMC is concerned, a replacement for
67 cmf: Absolutely necessarily. Let's say R&D is 1,000. Let's say each unit is 100. Producing 10 will cost you 2,000 meaning 200 per unit. Producing 20 w
68 rheite: The F-35B is doing quite well, and other than the procurement questions, is on track. I'd be curious if the heating issues are related to the other va
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This is still a deeply troubled program.
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