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Gloster Javelin

Started by Archibald, January 02, 2008, 12:52:12 AM

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jcf

#45
Quote from: rickshaw on January 22, 2013, 04:10:44 PMI think you'll find its related to wing loading and wing area.  Large area wings tend to have high gust response.  If coupled with low wing loading, it means every time the wing hits even a slight difference in pressure, gusts of wind, etc., it moves easily.  A small wing with high wing loading doesn't. Fighter designers usually aim for as low a wing loading with as great a wing area as possible to ensure manoeuvrability.  Strike aircraft designers usually aim for the reverse.  One reason why the F-104 was successful as a strike aircraft but lousy as a fighter, while the Mirage wasn't much good low down.

That means that the Bristol 217 would have been the pre-eminent low-level strike aircraft
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... as long as you were only carrying a single weapon. ;D

Apologies for the thread drift.  ;)

PR19_Kit

Quote from: The Rat on January 22, 2013, 02:12:18 PM
More than just large wings. The Hunter was hell on pilots at low level, the Swift was rock steady, but they were a comparable size.

What rickshaw said applies, the Swift had a smaller wing area for a similar weight so the wing loading was higher and the gust response was better.

The Javelin had over 900 sq. ft wing area and weighed 31500 lbs auw, whereas the Buccaneer had around half that wing area and weighed about TWICE as much. So the Javelin had around a 1/4 of the wing loading of the Bucc, and the gust response at low level would probably have been appalling!
Kit's Rule 1 ) Any aircraft can be improved by fitting longer wings, and/or a longer fuselage
Kit's Rule 2) The backstory can always be changed to suit the model

...and I'm not a closeted 'Take That' fan, I'm a REAL fan! :)

Regards
Kit

Weaver

If you're modifying your strike Javelin, there's a lot of empty space in the airframe that could be filled with more fuel, giving you more range and a higher wing loading. On a quick perusal of a cutaway, I'd say the entire outer wings and fin are available, as are the gun/ammo bays (if you dump the guns, of course) and the area around the front end of the air intakes.
"Things need not have happened to be true. Tales and dreams are the shadow-truths that will endure when mere facts are dust and ashes, and forgot."
 - Sandman: A Midsummer Night's Dream, by Neil Gaiman

"I dunno, I'm making this up as I go."
 - Indiana Jones

rickshaw

Quote from: joncarrfarrelly on January 22, 2013, 10:58:25 PM
Quote from: rickshaw on January 22, 2013, 04:10:44 PM
I think you'll find its related to wing loading and wing area.  Large area wings tend to have high gust response.  If coupled with low wing loading, it means every time the wing hits even a slight difference in pressure, gusts of wind, etc., it moves easily.  A small wing with high wing loading doesn't. Fighter designers usually aim for as low a wing loading with as great a wing area as possible to ensure manoeuvrability.  Strike aircraft designers usually aim for the reverse.  One reason why the F-104 was successful as a strike aircraft but lousy as a fighter, while the Mirage wasn't much good low down.

That means that the Bristol 217 would have been the pre-eminent low-level strike aircraft


... as long as you were only carrying a single weapon. ;D

Apologies for the thread drift.  ;)

I would suggest, to paraphrase someone or other, "that lady is not for turning!"  It'd go bloody fast in a straight line but be nearly impossible to execute any tight turns.   Perhaps it's intention was to VIFF to change direction?
How to reduce carbon emissions - Tip #1 - Walk to the Bar for drinks.

The Rat

Quote from: joncarrfarrelly on January 22, 2013, 10:58:25 PM

Makes the F-104 look like a U-2. I think I've got a coffee table bigger than those wings.
"My mind is a raging torrent, flooded with rivulets of thought, cascading into a waterfall of creative alternatives." Hedley Lamarr, Blazing Saddles

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Daryl J.

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jcf

#51
Not a Jav, but if one wanted to cut one up.

;D

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Weaver

Had to share this graphic of a Javelin maintenance procedure:



From here: https://www.researchgate.net/publication/278782607_Evaluation_of_Aircraft_Maintainability_and_Aircraft_Maintenance



Quote from: joncarrfarrelly on January 02, 2008, 01:42:22 PM
Bomber and recce versions.



jon

The bomber version interests me because it reflects an idea I came up with independently: a Canadian Javelin (CF-100 was cancelled) with weapons in the conformal packs, fuel in place of the wing guns and big slipper tanks in place of the guns. Early versions would have retractable FFAR launchers in the belly packs, later ones would have two Falcons in each pack with the option of Genies on the outer wing pylons.

The recce version looks a natural for an aircraft with a low wing loading. Kit, are you looking?  :wacko:
"Things need not have happened to be true. Tales and dreams are the shadow-truths that will endure when mere facts are dust and ashes, and forgot."
 - Sandman: A Midsummer Night's Dream, by Neil Gaiman

"I dunno, I'm making this up as I go."
 - Indiana Jones

PR19_Kit

Quote from: Weaver on March 09, 2018, 05:03:19 AM

The recce version looks a natural for an aircraft with a low wing loading. Kit, are you looking?  :wacko:


You better believe it, and I like the look of that extended wing too. Thanks for the link.  :thumbsup:

I've had a few thoughts about PR Javelins before, but that's much better than any of my ideas. I have three Javelin kits as well, maybe four, a mix of Airfix Heller and Frog types.
Kit's Rule 1 ) Any aircraft can be improved by fitting longer wings, and/or a longer fuselage
Kit's Rule 2) The backstory can always be changed to suit the model

...and I'm not a closeted 'Take That' fan, I'm a REAL fan! :)

Regards
Kit

Weaver

Quote from: PR19_Kit on March 09, 2018, 10:32:42 AM
Quote from: Weaver on March 09, 2018, 05:03:19 AM

The recce version looks a natural for an aircraft with a low wing loading. Kit, are you looking?  :wacko:


You better believe it, and I like the look of that extended wing too. Thanks for the link.  :thumbsup:

I've had a few thoughts about PR Javelins before, but that's much better than any of my ideas. I have three Javelin kits as well, maybe four, a mix of Airfix Heller and Frog types.

Thank Jon: he posted it back in 2008. :thumbsup:

The nice thing is that you can use all the 'pretty' (i.e. not actively ugly) Javelin parts: the long T.3 nose, the pen nib engine fairing, and a nice elegant solid cockpit faring instead of the lumpy two-seater canopy.

After I'd posted I offered up a pair of Eastern Express (Frogspawn, I presume) Sea Vixen outer wings to a Javelin. They're a tad too narrow in chord to just bolt on, although you could do it by stealing a slice of the original outer wings to make an adapter.
"Things need not have happened to be true. Tales and dreams are the shadow-truths that will endure when mere facts are dust and ashes, and forgot."
 - Sandman: A Midsummer Night's Dream, by Neil Gaiman

"I dunno, I'm making this up as I go."
 - Indiana Jones

Weaver

#55
The Javelin's wing is really weird. The inboard trailing edge section, which you'd imagine to be a control surface, is actually fixed, and contains two fence-type airbrakes that open upwards and downward. The actual flap is the panel in front of that one on the underside of the wing, and it extends behind the guns which means the cartridge ejection chutes have to be long tubes that run over it and eject from slots in the fixed trailing edge section.

I presume they went for this setup because they wanted upper and lower air brakes to avoid pitch-up when they were deployed, and they didn't want the wake from them impinging on the flaps, so they put them behind the flaps. It does mean though, that there's remarkably little fuel in that big wing.

My suggestion would be to replace the trailing edge sections with normal flaps, fill the flap bays with  fuel cells, and add left and right area-rule bulges on the rear fuselage which open like the halves of a Buccaneer tail to provide air brakes.

Having done that, the next thing I'd do is replace the guns and ammo tanks with more fuel. Moving the flaps back to the trailing edge would then allow you to carry big drop tanks or slipper tanks immediately outboard of the undercarriage. You could then fit Harrier-style gunpods or tanks to the fuselage stations. It might be possible to fit a pair of Firestreaks or Red Tops on the wingtips too. Alternatively, use the front part of the gunbays (where the barrels are) to house the missile cooling bottles and control black boxes, thereby getting them out of the area around the intakes. Then fit two ADENs in the lower intake walls (there's LOADS of space between the duct and the outer skin in this area), with curved ammo boxes running up around the ducts.
"Things need not have happened to be true. Tales and dreams are the shadow-truths that will endure when mere facts are dust and ashes, and forgot."
 - Sandman: A Midsummer Night's Dream, by Neil Gaiman

"I dunno, I'm making this up as I go."
 - Indiana Jones

PR19_Kit

The other weird thing about a Javelin's wings is the thickness of the trailing edge, it's about 1-2" thick and it cuts off vertically, there's no taper at all, it just stops.



Courtesy of Flankerman on Britmodeller.
Kit's Rule 1 ) Any aircraft can be improved by fitting longer wings, and/or a longer fuselage
Kit's Rule 2) The backstory can always be changed to suit the model

...and I'm not a closeted 'Take That' fan, I'm a REAL fan! :)

Regards
Kit

kitnut617

It's actually an aerodynamic fix Kit, I've read about it and it's supposed to keep the airflow attached to the wing surface ----
If I'm not building models, I'm out riding my dirtbike

Weaver

#58
Quote from: kitnut617 on March 09, 2018, 05:15:54 PM
It's actually an aerodynamic fix Kit, I've read about it and it's supposed to keep the airflow attached to the wing surface ----

I can see how that would work in it's own terms: the cut-off trailing edge would generate a low pressure area behind it that would suck the airflow coming over the wing flat until it 'fell' into it. It would be like having a suction slot right at the back. However, having base drag across the entire wing.... :o

Also, look at the size of those vortex generators! They're like table mats! The equivalent generators on the Harrier wing are so small that they're barely bigger than rivets in 1/72nd scale. If Sword ever do a Javelin, what's the betting all the vortex generators will be separate bits of photo-etch? :banghead:

On the subject of vortex generators, here's a great picture from 'billybookcase' on Britmodeller who found out that the ones on the 1/48th Airfix model work when you're washing it:



Original post here: http://www.britmodeller.com/forums/index.php?/topic/234954956-another-airfix-148-gloster-javelin/
"Things need not have happened to be true. Tales and dreams are the shadow-truths that will endure when mere facts are dust and ashes, and forgot."
 - Sandman: A Midsummer Night's Dream, by Neil Gaiman

"I dunno, I'm making this up as I go."
 - Indiana Jones

rickshaw



A Javelin in an unusual pose...
How to reduce carbon emissions - Tip #1 - Walk to the Bar for drinks.