PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Military Aviation (https://www.pprune.org/military-aviation-57/)
-   -   No cats and flaps ...... back to F35B? (https://www.pprune.org/military-aviation/478767-no-cats-flaps-back-f35b.html)

Willard Whyte 19th May 2012 11:55

longer ron, -B can vector rear thrust and use the lift fan to achieve STOVL*, it was demonstrated last October. Whether this is practical for every sortie is another matter, given the wear on the clutch mechanism for example.

*Or VTO for that matter, albeit with ~1/2 fuel and just a couple of Sidewinders.

longer ron 19th May 2012 12:35

Yes WW thanks I know it can but I was asking specifically about ski jumping,on another forum I am sure some poster said that it was planned to ski jump with fan door closed and nozzle aft.
AFAIK the B has not as yet done a ski jump ...

rgds LR

LowObservable 19th May 2012 12:41

First, having taken some time off to cool down, a considered response to Evalu8r:

ENOUGH WITH :mad:ING GUADALCANAL, ALREADY!

At the time of the "Navy bug-out", the Navy had built a total of eight carriers since CV-1 Langley in 1922 and three had been sunk, leaving five for two oceanic wars. Carriers had been shown to be both lethal and vulnerable (see Midway) and two more CVs - the brand new Wasp and Hornet - would be sunk in the months after Guadalcanal.

Only two new fleet carriers (Essex and Yorktown) were commissioned and operational in the 12 months after Guadalcanal, along with a few much less capable CVLs.

The US Navy Aircraft Carriers List

The US could not afford to play attrition warfare with CVs. Nevertheless, Marine mythology has continued to depict Guadalcanal as the betrayal of the brave Marines by the milquetoast Navy. Rubbish.

GK - Congress did, eventually, legislate a single JSF program, true enough. However. the "Congress made me do it" excuse still does not apply. The notion that one basic design could cover CV, CTOL and STOVL emerged from industry and DARPA studies and was adopted by the Aspin/Perry DoD as a way to plan for TacAir recapitalization, punt the major costs into the lap of the 2000 election winner, and force industry to consolidate.

Trifecta? They damn well did and the rest of us too.

It's very true that a standalone Harrier replacement would have been hard to get funded. An RN-USMC ASTOVL-only program might have worked, but the US threw a huge spanner in the works in the late 1980s by driving towards stealth, which not only drove weight up but for some time froze cooperation.

Engines: Thanks as usual. Just a few points:

The fuselage is not short, it's just really, really broad, under the wing. It's effective wing area is actually very large.

So why does the F-35C need almost 40 per cent more gross area than the Super Hornet (670 vs 500 ft2)? Seems to me that the projected wing area over the body is not as efficient or effective than the bits sticking out of the side.

Where the LM team did come unstuck was in not having the right weight estimation tools to cope with an airframe that had large holes and bays in it. On top of that, some of the detailed structural design was, well, uninspired to say the least.

I would add that they came unstuck on production cost estimation as well, see this: Root Cause Analyses of Nunn-McCurdy Breaches, Volume 1: <em>Zumwalt</em>-Class Destroyer, Joint Strike Fighter, Longbow Apache, and Wideband Global Satellite | RAND

I still think that the single engine was more driven by STOVL than affordability - after all, JSF or SSF/ASTOVL before it was never envisaged as F-16-sized. It started as F-18 Classic and grew to F-18 Super.

USMC F-35B CONOPS do envisage forward strips, I think the strip length is 1200 ft. (Could be 1500, not sure).

I have never seen a KPP for land-based STO. However, as a practical matter the Marines never talk these days about less than 3,000 feet (it was 4,000 feet in their latest talking points to Congress). I suspect that has to do with getting KC-130s in and out.

Occasional Aviator 19th May 2012 13:42


Quote:
Why, if we could live with Invincible Class sized carriers for the Harrier, do we need something as big as the Queen Elizabeth Class for yet another VSTOL?

Simple....sortie generation rate with max load of 36 JSF. INV class simply too small, always was.
But now the max load will be 12.....

Obi Wan Russell 19th May 2012 13:47

No. The minimum load will be 12 F-35s, plus six Merlin HMA2 for ASW, plus whatever mix of helos is deemed necessary for the current mission. The CHF will be aboard regularly. The MAX load will include another 24 F-35s when required, and/or a Commando brigade when in LPH mode.

draken55 19th May 2012 16:46

ICBM

Agreed!

I saw an American film called "Speed and Angels" covering the training of US Navy aviators. Have a look for it on U Tube and watch Part 4 from about 8 minutes in then think if we really would want the C!

"It's STILL better to stop and land than it is to land and stop"

Backwards PLT 19th May 2012 19:51



No. The minimum load will be 12 F-35s,
No, the minimum load is zero F-35 with even more helos (including AH-64). Things become a lot easier for LitM if you take those pesky FJ off.

Engines 19th May 2012 20:29

LO,

Thanks for coming back, happy to oblige with a reply.

Wing area of the F-35C is driven mainly be the need to recover at high trap weights at an acceptable speed. LO means that many high lift devices are not feasible, so more wing area it is.

The F-35B certainly did have a requirement to be able to conduct a required mission set from a short land base, I think it was about 1200 feet but could well be wrong. That was driving some aspects of the wheel and brake design, I think. The Conops at the time did not envisage getting C-130s in and out, but it's quite possible that they have changed.

Single engine was certainly driven by STOVL, but seen as a desirable move by Pentagon planners. As I've said previously, twin engined aircraft designs have a habit of growing. They were also influenced by the results of a well funded US engine research programme that showed peRformance advantages from a larger single engine.

Hope this helps a little

Engines

Evalu8ter 19th May 2012 20:30

Jesus LO, I'm going to need a bigger boat!! I wasn't making a historical comment but commenting upon a deep-rooted perception within the pysche of nearly every US Marine I've served with..they believe it, and that's why they want organic air (inter alia).

Every service has its shibboleths....

LowObservable 19th May 2012 21:06

Sorry, Eval. I do apologize.

Please try to understand that in a long struggle to get some rationality happening in acquisition, I have found that Guadalcanal is the Godwin's law issue around STOVL. It makes you want to scream...

It may go away sometime. After all, it was only a few days ago that the CNO endorsed a new USAF bomber...

Revolt of the Admirals - Wikipedia, the free encyclopedia

Evalu8ter 20th May 2012 06:03

LO,
No worries; FWIW I've been trying to get rationality into Procurement for the last decade (with varying degrees of success....). As Liddel-Hart said, "The only thing that's harder than getting a new idea into a military mind is getting an old idea out...". Once you work with the deeply entrenched parochial mindset of VSOs it does rather shake your confidence that anything will ever change......

ICBM 20th May 2012 14:23

Fortunately being the least-senior Service does lend itself to being the most forward thinking most of the time

Squirrel 41 20th May 2012 19:00

ICBM,

Which doesn't say much for the other two!

S41

Lowe Flieger 24th May 2012 00:01

Never quite sure who is behind 'news' stories such as this from Flightglobal. The cynic in me suggests it's LM feeding positive copy but then again it just might be that the change of emphasis from selling then testing to testing before selling might be having a favourable impact. Whatever, it's in our interests that the F35 starts making the news for the right reasons. The sooner it's available in good working order the better.

F-35 problems on their way to being fixed

The B version has also taken it's first tentative hops (conventional ones only for the moment) at Eglin too:

USMC F-35B starts local area flights over Eglin AFB - The DEW Line

peter we 24th May 2012 05:53

With enough time and money things get fixed, there shouldn't be surprise or suspicion about.

BTW, the F-35B has performed several hundred vertical landings, already so "first tentative hops" is a bit harsh. I will believe the F-35C tail hook issue has been fixed after a few hundred tests, its going to have to be statistical proven to work.

ICBM 24th May 2012 07:22

I think Lowe meant first tentative hops at Eglin specifically. It's no news to anyone that many flights have been made by all three types over the years. Eglin is important because these are flown by pilots in the initial training centre batch and not the test pilots at Pax or EDW. That IS progress and is worthy of mention.

Lowe Flieger 24th May 2012 09:52


I think Lowe meant first tentative hops at Eglin specifically...
Thank you ICBM, that was my point. Just shows how easy it is to draw unintended meanings from the written word.

Anyway, I was aware of prior vertical landings and have even found pictures on another aviation forum:
Vertical landing fighter. &bull; FighterControl &bull; Military Aviation Forum

LowObservable 24th May 2012 11:07

Made I larf, thanks LF.

ITman 24th May 2012 11:23

Seems like another hidden cost..!
 
http://bit.ly/KNmUF3

kbrockman 24th May 2012 12:17

@ITMAN,

Not that I'm a proponent of the F35 but as problems come to surface, the melting flightdeck is probably not really of any serious concern in the longrun.
I seem to remember that the V22 initially had similar problems which where effectively dealth with, I would make a fair bet that this will also not be a showstopper for the F35B.


All times are GMT. The time now is 07:24.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.