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Harrier strengthening bar


SaintsPhil

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Hi all,

After doing a fair bit of reaserch for my AV8B conversion it was pointed out that the strengthening bar on fuselage just below the rear nozzle was added after fatigue issues were found. It was added retrospectively to those aircraft in service, but external strengthening was added to new aircraft, hence it's not on all jets.

Does anyone know after which serial number it was added internally? Assuming its that simple...

Hopefully this won't be as complicated as LERX!!

Phil

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Hi all,

After doing a fair bit of reaserch for my AV8B conversion it was pointed out that the strengthening bar on fuselage just below the rear nozzle was added after fatigue issues were found. It was added retrospectively to those aircraft in service, but external strengthening was added to new aircraft, hence it's not on all jets.

Does anyone know after which serial number it was added internally? Assuming its that simple...

Hopefully this won't be as complicated as LERX!!

Phil

that sounds like a nightmare to work out, good luck phil

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Ah here in lies the problem! In all photos of the jets I've found you can't see it!! This is due to the shadow cast by the wings!!

Maybe the best way to explain is to look at my build thread here

Second pic in first thread you can see the strip, just below the 'lumps' around the rear nozzle.

I'll see if I can find the walkaround pic I found that first set me off!!

Phil

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That's a mod known as KT510, which I spent quite some time at St Athan incorporating into the fleet.

It is fitted to all UK Harriers and consists of a butt strap, which is the big plate at the bottom, covering the cut line in the skin and a re-inforcing skin, where all those lovely rivets and Hi-Loks are. The skin behind it was cut away and replaced, the frames re-inforced with doublers and additional stringers fitted, as well as the original stringers being doubled.

The doublers were all steel, the additional stringers were aluminium alloy and the overlay was titanium, as I recall. The butt strap was al-al. The whole thing came as an ill-fitting kit, which needed hours of fettling and in some cases, replacement parts making by workshops.

Drilling the overlay skin was a less than straightforward task due to the compound curve of the fuselage and the hardness of the material and when drilling the steel parts one had to be very careful that they didn't move and result in an oval hole in the alloy stringers they covered.

All this had to be done due to fatigue cracking caused by the combination of heat and vibration from the hot nozzles.

Repainting the interior structure was done by the riggers, with very stringy acrylic paint and disposable brushes. The paint, which stank, was often thinned with MEK, which stank more and the resulting fumes were unbelievable.

The heat resistant sealant between the skins was to be as free of voids as possible, to ensure that the expansion of trapped air didn't cause problems and the whole thing was x-ray tested to ensure that voids were within limits. If it failed, it all had to come off, be cleaned and re-fitted with fresh compound, which was keyed to a special plastic mesh.

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In 1:48th scale - careful painting only is what I'd recommend. Even applying 5thou plates with the rivets embossed will look oversize.

From the side of the taxiway at Cottesemore on all the photos I've looked at so far you cannot see them. You really have to be as close as Graham was when taking that photo to see them. Even the rivet and fastener heads visible in Graham's photo are not visible from 'normal viewing distances' of the real aircraft. If you wish to replicate the effect in Graham's photo apply matt black dots then smaller lightened MSG dots in the middle of them would be what I'd do.

Counting from the left: 1, 2, 3, 4, 5.....................................

(Bleepin' rivet counters!)

HTH,

Nick

IMHO the effect on the 1:32nd Eduard PE looks overdone

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I have to agree with you Nick. The main reason I started thinking about it is the detail on the 1/72 Airfix kit, which I now think is over scale, but still a nice touch!

I've ordered some 5 thou brass sheet, I'm going to try and see if I can replicate something but if it looks too much I might try your suggestion, of possibly drops or Mr Surfacer or something under the paint!

Phil - Slowly becoming a rivet counter...

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While looking though the Air Data 3 Harrier AV-8B book today, I found an excellent photo(page 34) showing the plate.

I don't think the Eduard plate will look too heavy on a model, the rivets on the really item are pretty large.

Shaun.

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I think I've got that book Shaun, I'll have a look!

The link I posted above takes you to home page! If you look at first column second and third pic from bottom they are great views.

I had a go last night at creating a representation of the plate and rivets. I'm happy with the plate, that's just a strip of 5 thou brass sheet. The rivets I tried using Mr Surfacer 500 dabbed on with a cocktail stick but they were a bit wonky and varied in size a bit! Beauty of using Mr Surfacer is that I just sanded it off so I can try again.

I'll post a pic when I'm done so you can judge the result!

Phil

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