interesting article concerning 10 flaws and their interim and final fixes... except they don't seem to have a handle on either the problems or the scope... and this in addition to the software delays noted in a separate thread.
faro From Egypt, joined Aug 2007, 1540 posts, RR: 0
Reply 1, posted (3 years 4 months 4 weeks 1 day 19 hours ago) and read 7429 times:
It just gets better with time...I found this flaw in particular to be remarkable:
"The Problem: At transonic speeds -- generally between 0.95M and 1.05M -- air flow for any supersonic fighter starts getting "squirrelly", as pilots call it. In this regime, air can be flowing over one wing or parts of one wing at supersonic speed, while moving subsonically on the other wing. This is especially true when the fighter is maneuvering aggressively. In such disruptions, one wing has a tendency to "roll-off", a movement not quite as severe as the "wing drop" problem experienced by the Boeing F/A-18E/F Super Hornet and still on the list of concerns for the F-35C carrier variant. The F-35B has experienced wing roll-off in flight tests, which Lockheed says was expected.
The Solution: The F-35 is a fly-by-wire aircraft, so the plan is to counter the wing roll-off with a software change that sharpens the responses by the flight controls when such events occur. This is not expected to solve the problem completely, but it needs to be better. "You're never going to be perfect in that regime, but it needs to be acceptable," Lockheed says. "
You can't satisfactorily fix wing aerodynamics with FBW in a high-performance fighter for *all* flight regimes.
This smells of wing redesign tweaks...and associated cost...
seachaz From United States of America, joined Apr 2005, 220 posts, RR: 8
Reply 3, posted (3 years 4 months 2 weeks 6 days 8 hours ago) and read 6409 times:
#3 Auxiliary Air Inlet doors - Anyone else think all the doors on this plan were a bad idea from the start? How are these parts going to survive the rigors of combat if they can't even meet their designed aerodynamic loads? Just seems like an overcomplicated series of 'transforming' has to take place to go from horizontal to vertical flight on this bird - and a large Achilles heel. Maybe for a civilian aircraft that won't be getting shot at this would be okay.
LMP737 From , joined Dec 1969, posts, RR:
Reply 4, posted (3 years 4 months 2 weeks 5 days 11 hours ago) and read 6027 times:
The one that caught my eye was number four.
4. Parts reliability
The Problem: The F-35B's parts reliability is poor, even for a program at this stage of development. Complaints have been hears about everything from key components of the propulsion system to the rudder pedals.
The Solution: In the short term, Lockheed is simply ordering more parts stockpile. As this tends to increase costs without addressing the root problem, Lockheed also has a long-term plan. In the latest restructuring unveiled in January, Lockheed and it's key suppliers will receive new contracts to make investments to improve reliability of the thousands of parts and components.
Even if they fix all the other problems if they don't get a handle on the parts reliability all they are going ot have is a very expensive hangar queen.
JoeCanuck From Canada, joined Dec 2005, 5420 posts, RR: 30
Reply 5, posted (3 years 4 months 2 weeks 5 days 7 hours ago) and read 5909 times:
The whole premise of the F-35 was that it was going to be a relatively inexpensive 5th gen fighter/bomber. That has long gone out the window. It has become a hangar queen while still being years from entering service and is going to be at least as expensive as other planes which are proving themselves now.
It''s turning out to be too little, too expensive and too late. I will not be in the least surprised if orders start getting canceled.
Pull the plug on this turkey...or at the very least, euthanize the resource sucking B model.
The Gripen NG is looking like a sweeter deal every day. I think Canada would be way better off teaming up with the Swedes and developing a semi home grown military aerospace program than continuing to suffer through the F-35 soap opera.
SAS A340 From Sweden, joined Jul 2000, 778 posts, RR: 0
Reply 6, posted (3 years 4 months 2 weeks 5 days 3 hours ago) and read 5837 times:
Quoting JoeCanuck (Reply 5): The Gripen NG is looking like a sweeter deal every day. I think Canada would be way better off teaming up with the Swedes and developing a semi home grown military aerospace program than continuing to suffer through the F-35 soap opera.
gphoto From United Kingdom, joined Aug 2004, 829 posts, RR: 25
Reply 9, posted (3 years 4 months 2 weeks 4 days 20 hours ago) and read 5680 times:
AIRLINERS.NET CREW DATABASE EDITOR
Anyone for building more Harrier II's ? Maybe reworking a few parts with lighter materials to improve performance a little. I know it's not a cutting edge design, but is it good enough? If the A-10 and B-52 among others have shown that a good design can keep on giving, even when very old, why not the Harrier concept?
What do you think of the pro's and con's? I know the Harrier has it's drawbacks, but it is a proven design and there is good experience of how to deal with the negatives already. I'm not suggesting this is actually done , just interested to see what you all think in light of further problems with F-35B. Should it pushed on with until the problems are solved or is it time to cut the losses and run? After all, there is not a lot of money in the Western kitty at the moment.
I think the problem with military aerospace, like with any commercial concern, is that you have to keep creating new stuff to keep the design and development staff (& sales teams?) in a job. It's the hamster wheel that has to keep spinning.
The downside is that the next generation has to be a major advance on what went before otherwise you just tweak what's already there.
More generally, the problem (from a US standpoint, at least, since they're one of the primary movers for the F-35) is that since the collapse of the USSR... who is the enemy? Or who is the enemy going to be that requires such advanced weaponry to be developed? Russia? China? Europe? What threat does this enemy pose, & why? Religion/philosophy? Resources?
Or is it just a matter of developing the most advanced weaponry?
LMP737 From , joined Dec 1969, posts, RR:
Reply 14, posted (3 years 4 months 2 weeks 3 days 17 hours ago) and read 5152 times:
Quoting AirRyan (Reply 8): But the foolish US Marines have banked their entire future on the F-35B, we can't cancel it!
And then of course the US Navy would be hit with a whole new class of aircraft carriers that can only carry helicopters.
I don't have a problem with it considering most of the problems listed are related to the F-35B. The DOD should have cut their loses and cancelled the VSTOL version instead of putting it on "probation". Then you tell USMC they have the choice between the F-35C or the F-18E/F.
arniepie From Belgium, joined Aug 2005, 1265 posts, RR: 1
Reply 15, posted (3 years 4 months 2 weeks 3 days 8 hours ago) and read 4988 times:
Just using this thread to seek clarification.
Has the following (date March 4) , rather important, issue been resolved already, it was supposed to be one of the biggest advantages the JSF was supposed to have over its contempories and seems like the crucial center part of its very futuristic integrated sensor package ??? http://www.aviationweek.com/aw/gener...ense&id=news/asd/2011/03/04/02.xml
Quoting from the article: Lockheed Martin, prime contractor for the F-35 Joint Strike Fighter, has begun looking for an alternative helmet system for the stealthy aircraft, as problems with the current Vision Systems International helmet continue to plague the program.
Lockheed issued a March 1 draft specification for proposals on an alternate helmet-mounted display system that makes use of commercial, off-the-shelf night-vision goggles, according to John Kent, a Lockheed spokesman. A final request for proposals is expected by the end of the month, and a selection will be made by the end of June. Candidates include BAE Systems, Gentex and VSI, Kent says.
Quoting from the article: Joint Strike Fighter: Restructuring Places Program on Firmer Footing, but Progress Still Lags
After more than 9 years in development and 4 in production, the JSF program has not fully demonstrated that the aircraft design is stable ,the GAO says in its latest report. (LM photo)
DOD continues to substantially restructure the JSF program, taking positive actions that should lead to more achievable and predictable outcomes. Restructuring has consequences—higher up-front development costs, fewer aircraft in the near term, training delays, and extended times for testing and delivering capabilities to warfighters.
Total development funding is now $56.4 billion to complete in 2018, a 26 percent increase in cost and a 5-year slip in schedule compared to the current baseline. DOD also reduced procurement quantities by 246 aircraft through 2016, but has not calculated the net effects of restructuring on total procurement costs nor approved a new baseline.
Affordability for the U.S. and partners is challenged by a near doubling in average unit prices since program start and higher estimated life-cycle costs. Going forward, the JSF requires unprecedented funding levels in a period of more austere defense budgets.
After more than 9 years in development and 4 in production, the JSF program has not fully demonstrated that the aircraft design is stable, manufacturing processes are mature, and the system is reliable. Engineering drawings are still being released to the manufacturing floor and design changes continue at higher rates than desired. More changes are expected as testing accelerates. Test and production aircraft cost more and are taking longer to deliver than expected. Manufacturers are improving operations and implemented 8 of 20 recommendations from an expert panel, but have not yet demonstrated a capacity to efficiently produce at higher production rates. Substantial improvements in factory throughput and the global supply chain are needed.
Development testing is still early in demonstrating that aircraft will work as intended and meet warfighter requirements. Only about 4 percent of JSF capabilities have been completely verified by flight tests, lab results, or both. Only 3 of the extensive network of 32 ground test labs and simulation models are fully accredited to ensure the fidelity of results. Software development—essential for achieving about 80 percent of the JSF functionality—is significantly behind schedule as it enters its most challenging phase.
in 2016 the US Air Force will buy 70 F-35As for $8.5 billion, for an average price of $121.4 million for each aircraft. Note that FY2016 will be the tenth year of JSF production.
That same year the US Navy will buy 20 F-35Cs for $2.9 billion, or $145 million per aircraft, while the Marine Corps plans to buy 18 F-35Bs (assuming this variant survives) for $2.9 billion, or $161 million per aircraft.
These figures are significantly higher than the $60-70 million unit prices quoted by Lockheed Martin to foreign customers.