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Gloster Javelin intakes


Selwyn

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Building a frog Javelin as a FAW 8 at the moment and consequently have been reading up on the subject. 

I have come across a couple of mentions in passing that the intakes were increased in size for the second generation Javs (FAW 7,8,9,) with the Armstrong Siddeley Sapphire Sa.7 engine variants. I have not heard of this before.  I have looked a some images, but the jury is out on this as I can't find anything definitive, best pics I can find are these;

 

FAW 1

FAW 9

 

Anybody have anything definitive on this?

 

Selwyn

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Hello Selwyn,

 

I have a couple of technical manuals for Javelins covering several variants. They don't give any dimensions for the intakes. If I remember correctly, at least some of the earlier marks had wooden intake lips and metal was used from FAW.7 on. They might have been slightly different in shape giving the illusion of smaller (or wider) intake.

(and of course you know that FAW.9s and FAW.9/Rs were actually upgraded FAW.7s and FAW.8 was the last "new" variant with new cambered wing leading edge. These wings and re-heated engines of FAW.8 were attached to FAW.7 fuselage to create an FAW.9).

 

I also have a small collection of Javelin books and if there is something definitive available it is most likely in "Javelin from the cockpit" or in Maurice Allward's "Gloster Javelin". I'll have a look.

 

Cheers,

Antti

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1 hour ago, Selwyn said:

Building a frog Javelin as a FAW 8 at the moment and consequently have been reading up on the subject. 

I have come across a couple of mentions in passing that the intakes were increased in size for the second generation Javs (FAW 7,8,9,) with the Armstrong Siddeley Sapphire Sa.7 engine variants. I have not heard of this before.  I have looked a some images, but the jury is out on this as I can't find anything definitive, best pics I can find are these;

 

FAW 1

FAW 9

 

Anybody have anything definitive on this?

 

Selwyn

 

Hi Selwyn,

The late Roger Lindsay mentioned it in the second volume of his "Service history of the Gloster Javelin Marks 7 to 9R", but does not give any dimensions

A couple of shots to illustrate the difference, the top one from Gloster's, the bottom shot I took in Malta whilst the aircraft, Mk.9R XH891, was on delivery to 29Sqdn 

 

Early Javelin Mk.1 :-

spacer.png

 

Javelin F(AW) Mk.9R :-

spacer.png

 

HTH

Dennis

 

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Going by the photos in Slogin57's reply, it looks as if the intakes on the Javelin F(AW) Mk.9R are indeed larger than the early Javelin Mk.1 delivery photo.  It may be just me, but if you set aside the actual dimensions of the nacelles, etc., the illusion(?) of a larger intake may be caused by the reduced thickness of the intake lips.  Those on the F(AW) Mk.9R do appear to be much thinner than intake lips of the early Mk.1

 

Scott

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15 hours ago, Scott Hemsley said:

Going by the photos in Slogin57's reply, it looks as if the intakes on the Javelin F(AW) Mk.9R are indeed larger than the early Javelin Mk.1 delivery photo.  It may be just me, but if you set aside the actual dimensions of the nacelles, etc., the illusion(?) of a larger intake may be caused by the reduced thickness of the intake lips.  Those on the F(AW) Mk.9R do appear to be much thinner than intake lips of the early Mk.1

 

Scott

I understand the change occurred  between the FAW6 (Armstrong Siddeley Sapphire Sa.6 engines), and FAW7 (Armstrong Siddeley Sapphire Sa.7  or Sa.7R for FAW8&9)  engines.

 

Selwyn 

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Makes me want to weep!  I am planning on converting one of my ‘FAW 9’s’ to a FAW 6 - 29(F) Sqn being one of only 3? Sqns that were equipped with them.

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My suspicion is that the Airfix 1/72 model has the ‘small intakes’ of the T3 Heller original.  It does look as though there is enough plastic to be open them out though.  Unless anyone does so in the mean time, I will add that to the measurements I need to take when I meet with ‘theplasticsurgeon’ at Jet Age Museum.  If any one has easy access to an earlier mark somewhere ……?

spacer.pngspacer.png

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1 hour ago, TeeELL said:

My suspicion is that the Airfix 1/72 model has the ‘small intakes’ of the T3 Heller original.  It does look as though there is enough plastic to be open them out though.  Unless anyone does so in the mean time, I will add that to the measurements I need to take when I meet with ‘theplasticsurgeon’ at Jet Age Museum.  If any one has easy access to an earlier mark somewhere ……?

spacer.pngspacer.png

Doesn't the Jet age museum have a FAW9 and a FAW4  (Ex leeming gate guard ) now?

https://jetagemuseum.org/faw-4/

Selwyn

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45 minutes ago, Selwyn said:

Doesn't the Jet age museum have a FAW9 and a FAW4  (Ex leeming gate guard ) now?

https://jetagemuseum.org/faw-4/

Selwyn

Yes.  but the the FAW4 is not on display, in a non-public area, risk assessed as hazardous.  I'll try to get photos to scale from.

I'm not sure I can reach the intakes on our display FAW9, but I've just measured the parts in the Airfix 1/48 Javelin kit - Airfix measured our FAW9. 

Internal diameter 27 inches.

 

The exhaust measurements were at exactly the right height.

Fuselage-Width74inches.jpg

 

 


 

 

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I guess I can ‘dry my tears, mate’ with regard to the FAW6 conversion - oh!  that doesn't work for the FAW9 :(  I think a compromise will be needed and the intakes enlarged ‘a bit’.

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On 8/18/2022 at 9:56 AM, TeeELL said:

I have just measured the Airfix intake at between 8.35 and 8.5mm, 27” is 9.35mm

My frog kit intakes measure out at between 9.6 /9.8mm

 

Selwyn

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Checking in Maurice Allward's book on the Javelin, there is no mention of changes to intake dimensions.  For the Mk7, it is stated that changes associated with the new engines involved the extended rear fuselage and angled jet pipe nozzles.  It seems very likely that any change in overall intake dimension would have been mentioned. 

 

I agree with Scott Hemsley that the blunter more rounded intake lips of the prototypes certainly make the intake front look smaller. That is probably a visual illusion, made more evident by the dark painting of many later intakes.

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On 8/18/2022 at 8:35 AM, Selwyn said:

Doesn't the Jet age museum have a FAW9 and a FAW4  (Ex leeming gate guard ) now?

https://jetagemuseum.org/faw-4/

Selwyn

I have measured the intakes today.

Here's the FAW4, not on public display.

FAW4-P.jpg

Intake diameter 22.5 inches.

FAW4-Intake22-5.jpg

 

And the FAW9

FAW9-S.jpg

Intake diameter 26 inches.

FAW9-Intake.jpg

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29 minutes ago, theplasticsurgeon said:

I have measured the intakes today.

Here's the FAW4, not on public display.

FAW4-P.jpg

Intake diameter 22.5 inches.

FAW4-Intake22-5.jpg

 

And the FAW9

FAW9-S.jpg

Intake diameter 26 inches.

FAW9-Intake.jpg

So 3 1/2" inch wider, that's quite  an increase in airflow!  Strange that it hasn't been really noticed before, especially if you look closely at the differences on the intake lip profile.

 

That works out to 7.94mm dia for FAW1 to 6 in 1/72

9,2 mm for FAW 7 to 9.

the 1/72 Airfix kit intakes are measured at  8.35 and 8.5mm  the Frog at  9.6 /9.8m (both are slightly oval in the kit!)

 

Selwyn

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2 hours ago, Graham Boak said:

Did Airfix change the intakes from the Heller T Mk.3 that their kit was modified from?

Tee Ell is building a Airfix FAW 9  (see pics above) and measured the intakes at   between 8.35 and 8.5mm which is closer to the smaller intake and he suggests in his post that the intakes were not changed from the T3.

 

Selwyn

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1 hour ago, Selwyn said:

Tee Ell is building a Airfix FAW 9  (see pics above) and measured the intakes at   between 8.35 and 8.5mm which is closer to the smaller intake and he suggests in his post that the intakes were not changed from the T3.

 

Selwyn

 

Interesting to compare the T-Bird and the 9 on the same day and virtually the same angle.  

Personally I never found any difference in diameter when crawling down them for compressor checks ( I was a lot slimmer, younger and dafter in those days !!) 

Both photos by me.

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HTH ?

Dennis

 

 

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Currently sat in Frankfurt airport en-route to Cuba.  At home I have an Airfix/Heller T3 Javelin so on my return I will be able to check the measurements,  unless someone else has the T3?

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Forgive me for going ‘off piste’ for a moment!  Sloegin, your photos are particularly useful for me.  As an ex-29(F) Sqn Phantom driver I selected ‘29 as one of my ‘themes’, the FAW9, FAW6 and T3 I am planning will all be marked for that Sqn.  Your comparison photos, notwithstanding the intake differences, also highlight the camouflage differences - wrap around and not.  What is less obvious is the question of high speed silver finish on the  under surface, they both look very ‘light aircraft grey’?  Yep, I realise B&W photo etc, etc, etc.

 

If you have any more 29(F) San specific photos I would very much like to see them.

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Hello,

now the facts are here, just for the record I'd like to mention a book where the larger intakes are mentioned:

 

Roger Lindsay, "Service history of the Gloster Javelin Marks 1 to 6" from around 1975, page 6:

 

"XA560 had the distinction of becoming the prototype for the Javelin 7, fitted with Sapphire A.S.Sa 7 engines, each developing almost 11,000lb. static thrust, and necessitating larger diameter intakes and revised jet pipes. Maiden flight with these engines took place on September 30th 1955, and marked the beginning of a 4-year period of Armstrong-Siddeley engine development for this machine, for most of which it was fitted with Sapphire 7R limited reheat engines later standardised for the Javelin 8 and 9. Mainly based at Bitteswell it became a familiar sight and sound over the Midlands as it "banged" its way through the sky. Interestingly enough '560 was originally scheduled as a test bed for the Rolls-Royce Conway engine."

 

Martin

 

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58 minutes ago, TeeELL said:

Forgive me for going ‘off piste’ for a moment!  Sloegin, your photos are particularly useful for me.  As an ex-29(F) Sqn Phantom driver I selected ‘29 as one of my ‘themes’, the FAW9, FAW6 and T3 I am planning will all be marked for that Sqn.  Your comparison photos, notwithstanding the intake differences, also highlight the camouflage differences - wrap around and not.  What is less obvious is the question of high speed silver finish on the  under surface, they both look very ‘light aircraft grey’?  Yep, I realise B&W photo etc, etc, etc.

 

If you have any more 29(F) San specific photos I would very much like to see them.

There is no question at all about the under surfaces, they were HSS.  Light Aircraft Grey began to be used around 1967/8's when the RAF moved to the polyurethane paint system. For some reason at that time they could not produce a silver polyurethane paint, so  LAG was used instead, as the closest equivalent (lots of questions in the past on BM about this, as in a BW image they are hard to  differentiate, seems to be prevalent on hunter questions!). 29Sqn  got lightnings in 1967, the FAW9 /T3 Javelins would obviously not have been repainted as they went to store/scrap at that time, FAW 6 went long before the change.

I don't think any Jav's were LAG I have never seen a picture of one. If one did exist I would suggest it would have been a 60 Sqn jet in the Far east.

 

Selwyn

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1 hour ago, TeeELL said:

Currently sat in Frankfurt airport en-route to Cuba.  At home I have an Airfix/Heller T3 Javelin so on my return I will be able to check the measurements,  unless someone else has the T3?

Had to giggle at this.

I was reading "The book of heroic failures" by Steven Pyle recently, In the book was; "The most unsuccessful Hijacking of an airliner," when a man entered the cockpit and ordered  the pilot to fly him to Cuba. The pilot answered,  " but we are flying to Cuba anyway!" The man said "Oh!" and went and sat back down in his seat. He was arrested on arrival.

 

Selwyn

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1 hour ago, TeeELL said:

Currently sat in Frankfurt airport en-route to Cuba.  At home I have an Airfix/Heller T3 Javelin so on my return I will be able to check the measurements,  unless someone else has the T3?

Just tryed to find my calipers with out successes but an 8mm steel drill bit can be gently worked in and sit at Wright Angeles to the intake lip

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29 minutes ago, ed-209 said:

Just tryed to find my calipers with out successes but an 8mm steel drill bit can be gently worked in and sit at Wright Angeles to the intake lip

Ooh eer matron!!

It is worth looking at Imperial size drills to get a closer match.  I possess a little technical booklet with mm in steps up to 25 and included are imperial drills ‘to fill in the gaps’.  I know I checked before leaving home and one size was near perfect for the opening the FAW9 intakes.

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