UK MOD in a muddle over F-35C

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by SpudmanWP » 24 May 2012, 16:17

They could solve the problem by learning to read....

That and learn to use Google.
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by stobiewan » 24 May 2012, 16:39

SpudmanWP wrote:They could solve the problem by learning to read....

That and learn to use Google.


The paper in question is a fairly hideous rag and shouldn't be confused with a serious newspaper :)


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by spazsinbad » 25 May 2012, 05:21

The THERMIONites have a sense of humour:

http://www.thermioninc.com/nonskid.php

"...Lawsuit Resistant..." :roll:


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by popcorn » 25 May 2012, 11:36

spazsinbad wrote:The THERMIONites have a sense of humour:

http://www.thermioninc.com/nonskid.php

"...Lawsuit Resistant..." :roll:


If it provides corrosion protection for 10 years, I say coat the entire,ship and spare sailors from paint duty :D


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by spazsinbad » 25 May 2012, 12:52

Yeah - If it don't move - paint it! :D

And GodSpeed with the jumpin' at Pax River Ski Jump Championships soonish....

JSF ski jump tests due in 2011 Jane's Defence Weekly Jul 08, 2010

http://articles.janes.com/articles/Jane ... -2011.html

“'Ski jump' trials of the Lockheed Martin F-35B Lightning II Joint Strike Fighter are expected to take place in 18 months' time at US Naval Air Station (NAS) Patuxent River in Maryland.

The tests will see if the F-35B can fly from the take-off ramps to be fitted to the UK Royal Navy's two new Queen Elizabeth-class future aircraft carriers (CVF), but BAE Systems F-35 test pilot Graham Tomlinson told Jane's that he expects such take-offs to be far more straightforward than those from flat deck aircraft carriers.


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by spazsinbad » 25 May 2012, 14:10

http://www.defense-aerospace.com/articl ... decks.html

"...(EDITOR’S NOTE: This is the first official acknowledgement that the F-35’s very hot exhausts can damage carrier decks, which has been previously reported.)"

A 'beatup' begets a 'beatup' which confirms the first 'beatup' which in turn spawns another 'beatup' and I GIVE UP! :twisted:


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by popcorn » 25 May 2012, 16:06

spazsinbad wrote:Yeah - If it don't move - paint it! :D

And GodSpeed with the jumpin' at Pax River Ski Jump Championships soonish....

JSF ski jump tests due in 2011 Jane's Defence Weekly Jul 08, 2010

http://articles.janes.com/articles/Jane ... -2011.html

“'Ski jump' trials of the Lockheed Martin F-35B Lightning II Joint Strike Fighter are expected to take place in 18 months' time at US Naval Air Station (NAS) Patuxent River in Maryland.
The tests will see if the F-35B can fly from the take-off ramps to be fitted to the UK Royal Navy's two new Queen Elizabeth-class future aircraft carriers (CVF), but BAE Systems F-35 test pilot Graham Tomlinson told Jane's that he expects such take-offs to be far more straightforward than those from flat deck aircraft carriers.


So, will the UK's B jets be able to do a STO carrying a heavier payload courtesy of the ramp compared to their USMC counterparts flying off a LHA?


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by spazsinbad » 25 May 2012, 21:50

That has been said all along especially in the 'very long thread'. UhOh. [This is the very long thread: http://www.f-16.net/f-16_forum_viewtopic-t-12631.html ] :D And here is another quote for ye:

Lockheed Martin rebuts F-35 critics on cost, progress by Chris Pocock | July 15, 2010

http://www.ainonline.com/taxonomy/term/ ... node/25359

“...When asked how the F-35B compared to the Harrier in terms of ease of takeoff/landing, Tomlinson replied: “It’s chalk and cheese–and so it should be! This is a single-button operation with no special controls–much easier than the Harrier. For short takeoffs you just power up; the system takes care of everything else. On the ski-jump, for instance, the system detects the change in deck angle and doesn’t apply any rotation as it would on a flat deck.”...”

If the KPP for the same load is/was 550 feet [changed to 600] on a flat deck but 450 [now changed to 450+ equivalent] on CVF then the ski jump does impart some extra oomph. :D However there is likely some maximum groundspeed that the aircraft can attain before/on the ramp limit but I don't know what that is. And don't someone say 'Google is my friend'. If it is I could find it but likely NATOPS will know and yet I don't have a copy. :-(
_______________

This info is repeated on the verylongthread but I'll insert it here for good reference...

Preparing for take-off: UK ramps up JSF carrier integration effort 11-Dec-2008 International Defence Review

http://militarynuts.com/index.php?showtopic=1507&st=120

"...A NEW ANGLE: OPTIMISING THE SKI-JUMP PROFILE FOR CVF
The origin of the ski-jump ramp now widely fitted to aircraft carriers undertaking fixed-wing STOVL air operations at sea is widely credited to Lieutenant Commander Doug Taylor RN. His thesis, written while studying for a PhD at the University of Southampton in the early 1970s, identified the substantial gains in payload radius achieved if an aircraft performing a short takeoff — such as the Harrier with thrust vectoring — was launched upwards on a semi-ballistic trajectory.

The ski-jump ramp works by imparting an upward vertical velocity and ballistic profile to the aircraft, providing additional time to accelerate to flying speed whilst ensuring it is on a safe trajectory. This additional time is manifested either in a reduced take-off length for a given weight, or increased launch weight (fuel and/or ordnance) for a fixed take-off distance.

This additional performance does not come for free, however, with a significant increase in landing gear loads above those of a standard take off, which are very low compared to a landing. The increase represents the energy transferred to the aircraft as it translates up the ramp; and if the angle and curvature of the ramp are increased to obtain greater performance benefit, so are the loads.

An essential first step for optimising the ski-ramp profile for CVF was to define key performance and load cases (in terms of aircraft configurations and environmental condition thresholds). Other ground rules such as take-off distances, maximum ramp length and height constraints, wind over deck speeds and ship motion factors were also generated prior to the main analysis which was based on legacy experience with Harrier analysis, Team JSF ‘best practice’, sensitivity studies of performance and loads to identify sensible values and ranges.

Based on predicted F-35B performance and landing gear loads data, the CVF ski-jump was defined as a 12.5 degrees angled ramp, with the profile achieved by combining a nominal profile based on a quartic fit to an optimum cubic transition plus circular arc, a rounded step lead in and an elliptic let down. Analyses have also confirmed that fatigue impact as a result of cyclical loading was significantly less than that for the legacy Invincible-class ramp; and that minimum weapons physical clearance limits were met even in worst cases (combinations of flat tyres and compressed struts)...."
Last edited by spazsinbad on 25 May 2012, 23:32, edited 1 time in total.


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by SpudmanWP » 25 May 2012, 22:30

Does that mean if the LHD hits a REALLY BIG swell just as an F-35B takes off, that it will detect the increased angle and not rotate? ;)
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by spazsinbad » 25 May 2012, 23:45

NavAvvers are used to dealing with 'REALLY BIG swell' - the sweller the better - for launching / catapulting aircraft. Probably an RBS will have a regular up and down motion which can be anticipated. The time taken for exiting the ski jump / catapult from 'Launch Officer Signal' is known and he will signal such so that the aircraft is at least at the end of launch on a rising bow or close to the top of that UP part if good enough. Yes sometimes the LO gets it wrong and chaps skim the greenie coming over the bow! :D

I think the question has been asked but perhaps on another forum [old NEPLEX] anyhoo here is an old SHAR pilot answer [to similar question]:

“I was TAD from VS-32 to FOF-3 as the S-3 (Viking) Liaison Officer. We didn’t get into Vestfjord, but Airops just outside were quite colorful. Watching a SHAR mis-time his roll and fly through a wave (totally, and I mean totally, submerged) after he jumped off that pointy-end ramp thing-a-majingy was quite an experience. Especially when Wings (their Airboss/CAG equivalent) turned and looked up at me, stogie belching, and remarked:
“Well Yak, that’s gonna f!€k up the bloody corrosion effort!” Old Phantom driver he was.”

http://www.neptunuslex.com/2010/12/15/f ... ent-663784

Old Hairier Driver Retort:
“1) you can't "mis-time" to that extent.
2) a Sea Harrier flying through water is impossible
3) if a Sea Harrier was still on the ski-jump as the wave broke over the bow it might look spectacular, but the aeroplane would still be primarily in the air and going upwards relative to the surface.”
Attachments
CVSskiJumpSwellImpact.jpg


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by popcorn » 25 May 2012, 23:54

Thanks Spaz. I can only hope that some day someone will quantify how much of an advantage in additional payload the ramp provides.
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by popcorn » 25 May 2012, 23:55

Thanks Spaz. I can only hope that some day someone will quantify how much of an advantage in additional payload the ramp provides.
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by spazsinbad » 26 May 2012, 00:12

'popcorn' IMHO the benefit is MASSIVE! Given the benefit of the ski jump to RN Harrier ops but I don't know how that benefit translates to CVF ski jump F-35B ops. Shirley someone will tell us at some point. But first theys have to JUMP! :D


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by quicksilver » 26 May 2012, 01:35

With all other performance elements held constant, the Rule of Thumb for Harrier was roughly a 40% reduction in deck run for ships with ski-jumps. Limiting factor was nose gear compression -- i.e. excessive speed at ramp entry could impart loads to the nose gear in excess of the design limits.


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by popcorn » 26 May 2012, 02:47

I can see how the ramp,would help increase,MTOW vs a STO without a ramp.. yet it appears the performance gain is not compelling enough to install ramps on GATOR ships. Obviously other factors were taken into consideration,as other aircraft would inhabit the deck and not, just B,jets.


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