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Problemen med JAS 39 kontra F-35

Postat: 16 jan 2012, 11:14
av DB605
Kommer ni ihåg hur det lät i media på 80- och 90-talet om 39:an? Det var sågning jäms med fotknölarna och 39:an var det sämsta som fanns etc. Nu har nog jänkarna det ännu värre. Undrar vad engelsmännen, norrmän och övriga tänker nu när detta har publicerats? Kanske kan det hjälpa SAAB att sälja 39:an också.

F-35 Lightning II News
>
> U.S. Navy and U.K. Royal Navy F-35 unable to get aboard ship.
>
> January 8, 2012 (by Eric L. Palmer) - The U.S. Navy F-35 Joint Strike
> Fighter (JSF) known as the F-35C is at serious risk of never being able to
> land aboard an aircraft carrier. This also poses a risk to the U.K.
> aircraft carrier program which is supposed to use the F-35C at the end of
> the decade.
>
> CF-1 takes off on its first flight on June 6, 2010. Pilot for the 57 minute
> flight was Lockheed Martin Test Pilot Jeff Knowles.
>
> Back in 2007, a Lockheed Martin year in review video stated that the F-35C
> carrier variant (CV) JSF had passed critical design review (CDR). The video
> and similar public statements said, "2007 saw the completion of the critical
> design review for the F-35C. The completion of CDR is a sign that each F-35
> variant is mature and ready for production."
>
> Yet, a November 2011 U.S. Department of Defense (DOD) quick-look report
> relating to engineering challenges arising from what is being called
> "concurrency issues" revealed that all eight run-in/rolling tests undertaken
> at NAS Lakehurst in August 2011 to see if the F-35C CV JSF could catch a
> wire with the tail hook have failed.
>
> The report also mentions that the tail hook on the F-35C CV JSF is attached
> improperly to the aircraft. The distance from the hook to the main landing
> gear is so short that it is unlikely the aircraft will catch the landing
> wires on a ship's deck. This graphic from the review explains part of the
> problem. It illustrates the distance between the main landing gear and the
> tail hook of previous warplanes qualified to operate from aircraft carriers
> and compares these distances with that found on the F-35C CV JSF. In this
> regard, the report refers to the F-35C CV JSF as "an outlier".
>
> An industry expert who is a graduate Flight Test Engineer (FTE) of the U.S.
> Naval Test Pilot School (USNTPS), Peter Goon, stated that, "Given the
> limited amount of suitable structure at the back end of the JSF variants,
> due primarily to the commonality that was being sought between the three
> variant designs and the fact that the STOVL F-35B JSF is the baseline
> design, there was always going to be high risk associated with meeting the
> carrier suitability requirements."
>
> He also points to well known and well understood military specifications
> that address tail hook design requirements, such as MIL-A-81717C and
> MIL-D-8708C. (update: the first one should read MIL-A-18717C not
> MIL-A-81717C as first reported)
>
> When asked how such things could have been missed, Peter suggested they
> likely weren't, at least by the engineers, but their concerns would have
> just as likely been ignored.
>
> He said this should come as no surprise, given the level of stove-piping
> that had been applied to the F-35 program's engineer community and the
> dominance of "form over substance" and "a total indifference to what is
> real" being hallmarks of the program - "Affordability is the cornerstone of
> the JSF Program" being but one example.
>
> It is highly probable that this design fault could be the last straw for the
> F-35C. The program will attempt some more rolling tests with a different
> hook design, but this does not address the problem of the poor location of
> the tail hook on the airframe.
>
> Other F-35 program problems identified in the QLR Report included the helmet
> visual cueing which is seriously affected by design issues and airframe
> buffet in the heart of the combat envelope. Also, all F-35 variants suffer
> from paper-thin weight margins, unsafe fuel dumping, flight restrictions on
> diving, speed and proximity to lightning hazards to name a few. And, it can
> only be flown during the daytime.
>
> An August 2011 DOD F-35 program briefing revealed that the engineers will
> have to be reorganized because they were not getting access to all the
> information/data they needed for design nor, it would appear, were organized
> and structured in an environment that was being properly managed and
> transparent. This reorganization should complete in 2012.
>
> The program's pilot training program was supposed to start at Eglin Air
> Force Base, Florida in 2011 after previous delays. With the design issues
> mentioned above, pilot training is effectively grounded due to safety
> concerns. There is no known date when pilot training can start. This along
> with the aircraft's engineering defects strongly suggest that it will be a
> long time until military services see any F-35 variant in a go-to-war
> configuration.
>
> Related articles:
> DOD report - F-35 problems will take years to fix (2011-12-13)
> Warning signs to watch with the F-35 program (2011-11-14)
> Carrier version of F-35 cleared for production (2007-06-23)
> Other F-35 Lightning II News
> News archive for January 2012


/Thomas Adamsson

Re: Problemen med JAS 39 kontra F-35

Postat: 18 jan 2012, 01:01
av Karl Persson
Operational Assessment
The JSF Operational Test Team completed an operational
assessment of the F-35 program and determined that it is
not on track to meet operational effectiveness or operational
suitability requirements.
The JSF Operational Test Team
assessed the program based on measured and predicted
performance against requirements from the JSF Operational
Requirements Document, which was re-validated in 2009.
The primary operational effectiveness deficiencies include
poor performance in the human systems integration
(e.g.
helmet-mounted display, night vision capability) and aircraft
handling characteristics
, as well as shortfalls in maneuvering
performance
(e.g. F-35A combat radius, which is a KPP, and
F-35C acceleration).
• The driving operational suitability deficiencies include an
inadequate Autonomic Logistics Information System (ALIS)
for deployed operations, excessive time for low observable
maintenance repair and restoration capability, low reliability
and poor maintainability performance, and deficient crypto
key management and interface compatibility.
• The assessment was completed prior to release of an updated
program integrated master schedule. While additional
time and resources in development may aid the program
in resolving some deficiencies, several requirements are
not going to be met given current, known program plans.
After the new master schedule is available, along with
documentation of the application of the additional resources
applied to SDD plans, an updated operational assessment
may be provided.
http://www.dote.osd.mil/pub/reports/FY2 ... f35jsf.pdf

Re: Problemen med JAS 39 kontra F-35

Postat: 18 jan 2012, 12:01
av Åba
Oj oj oj, vad ska man säga?
Det ena magplasket efter det andra...

"it can only be flown during the daytime."

Ehh..ok


"The distance from the hook to the main landing gear is so short that it is unlikely the aircraft will catch the landing wires on a ship's deck."

Ajdå

Re: Problemen med JAS 39 kontra F-35

Postat: 19 jan 2012, 15:21
av Emil Lindberg
Man bör ha i åtanke att många militära flygplansystem sannolikt levereras med en hel del brister, restriktioner, avsteg, m.m. Så även i Sverige. Pö om pö åtgärdas eller avskrivs dessa - förhoppningsvis.

"it can only be flown during the daytime." skulle lika gärna kunna betyda att systemet för tillfället är belagt med restriktioner eller förbud som inte medger flygning i mörker.

Re: Problemen med JAS 39 kontra F-35

Postat: 19 jan 2012, 21:10
av Karl Persson
Japp restriktioner drabbar alla flygplan vad jag vet.

Jag tror det finns en förståelse för att det sker utvecklingssvårigheter i program som dessa men det finns också en irritation som grundar sig i att programkontoret och Lockheed Martin sålt in en glädjebild samtidigt som det hela tiden kommer fram nya problem, förseningar och ökade kostnader. Just nu en knapp 8-årig försening för USAF IOC och minst en fördubbling på priset samtidigt som man i dagsläget ligger under delar av kravspec på systemet. Men nog brukar problem ordnas upp med tiden och man skapar en operativ förmåga utifrån de systemförmågor som faktiskt levereras.

Det värsta som jag ser det är att väst-vänliga flygvapen ytterligare tvingas reducera sina flottor för att ha råd med JSF och det är verkligen inget att skratta om. Förseningar är ett problem också. Har ett land väl valt JSF (ist för Gripen tex) så tycker jag vi får hoppas på att det går bra med anskaffning och flygplan.

Re: Problemen med JAS 39 kontra F-35

Postat: 20 jan 2012, 09:59
av Åba
Emil Lindberg skrev:Man bör ha i åtanke att många militära flygplansystem sannolikt levereras med en hel del brister, restriktioner, avsteg, m.m. Så även i Sverige. Pö om pö åtgärdas eller avskrivs dessa - förhoppningsvis.

"it can only be flown during the daytime." skulle lika gärna kunna betyda att systemet för tillfället är belagt med restriktioner eller förbud som inte medger flygning i mörker.
Jo, jag vet att det tar tid att få en produkt helt färdig.
Jobbar själv med utveckling.

I Just JSF-fallet så känns det dock som att förseningarna och missarna har dragit iväg och blivit helt absurda och bisarra.
Sen har jag alltid undrat lite över behovet av ett sådant flygsystem. Behövs det verkligen, eller är det ett sätt för industrin att berättiga sin egen existens?

Re: Problemen med JAS 39 kontra F-35

Postat: 21 jan 2012, 12:54
av Tommy Johansson - ToJ
Talar man om trollen...

Första mörker/natt flygningen skedde den 19 januari, men detta var en F-35A från Edwards AFB.

Tommy

Re: Problemen med JAS 39 kontra F-35

Postat: 24 jan 2012, 01:46
av Fredrik Astlid
Jag vet inte riktigt vad artikeln om problem med att få F-35 sjöduglig och godkänd för "Arresting Hook landning" har med Gripen att göra?

Surt sa Räven.

Re: Problemen med JAS 39 kontra F-35

Postat: 24 jan 2012, 02:25
av Karl Persson
Prisförändringar och omgjorda leveransplaner för en JSF variant påverkar de andra 2 varianterna. Det var nog ett inlägg om bilden av hur ett program fortlöper som avsågs... eller nå't.