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RF-101C auxiliary tanks


quangster

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13 hours ago, quangster said:

Aha, I will be watching your build closely. Is it already on the forum?

 

Quang

 

@quangster no, mate, and I don't think I will as construction will be identical to 60119 that I posted recently. It will be the camouflage scheme that will be different, of course. 

 

Martin

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7 hours ago, quangster said:

 

What do you fellas think?

cheers

Quang

 

Great work on the tail lamp and fuselage vent Quang, and the RHAWS.

The RF-101C Mod 1181 jets all had the ventral vents AFAIK

I might draw decals for mine.

 

Tony 

 

 

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8 hours ago, quangster said:

@Keith T

KH provided 4 extra parts to correct the intakes: 2 (upper and lower) for the right intake and 2 for the left intake.

Here’s how they must be located on the right intake. Note the flare on the lower lip.

Note that contrary to what have been published on the internet, the kit intakes need to be extended and not shortened.

 

cheers,

Quang

Please provide your evidence for this. The technical data on the development of the type IIIc intake states the intake was enlarged and the ramp extended.

How does 'enlarged and extended' for the B model make for a longer intake on the A/C model? The intake was modified not only for the difference in airflow to the J57-P-53 engine, but also to allow for the airflow around the fences adjacent to the rotary weapons door. Measurements to scale reveal the KH intake for the A/C variant to be 1/3 too long from the lip to the leading edge of the wing. (In scale it is 20mm whereas it should be 15mm) Adding the extra parts exacerbates the problem, not corrects it.

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My own take on the inlets is that the kit wing parts need to be ground back to the same depth (across, at an angle) commensurate with the thinner, inside depth of the inlet add-ons. I would also be inclined to grind back the add-ons so as to create flat mating surfaces. I think this makes a 17mm or so distance which might still be inaccurate, but is an acceptable compromise.

 

The kit still, at the very least, requires decals to represent the ventral vents and exposure meter unit nearer the nose. 

 

I have the D-Mold nose with its trigonal camera representation and it's very helpful. By 1967 the RF-101Cs were using Hycon KS-72s (same as RF-4C before the CAI KS-87 auto-exposure framing cameras became available to the Phantom and RF-101G/H).

 

A great kit overall and soooo cool we finally have it in 1/48. 

 

Tony 

 

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Hi Quang, a point of accuracy - the RF-101A never flew operationally over Vietnam. These early machines flew from Thailand to Laos and Cambodia. Regarding the long tanks, these were all about speed and given their role its not unexpected that it was so.

 

I'm happy to be proved wrong, though!

 

Martin

Edited by RidgeRunner
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@bentwaters81tfw It's a well-known fact that there is no reliable plans for the F-101 single -seat variants. So what's left is existing photographs and our trusty Mark One eyeball.

 

Take a good side view photograph, taken from some distance with a long lens and you get yourself a document you can trust. Enlarge it to 1/48 scale on your computer screen – diameter of the fuselage should be 40 mm at the intake level – and measure the distance between the intake lip and the wing root. You get 22 mm.

 

Mc-Donnell-RF-101-A-25-MC-SN-54-1502-060

 

As for the two photos you've posted, the official McDonnel drawing is clearly destined to the factory painters. Its first priority is not the accuracy of the aircraft outline but rather the exact location of the stencils, walkway, etc… Using such a document is as reliable as using an automobile instruction book to model a car.

 

The second photograph is part of a series of walkaround pics of a RF-101C in Pima. Like most walkaround pictures, it was taken at close-up using a wide-angle lens and as such presented a certain amount of deformation. One cannot use wide-angle pictures to depict accurate shape and proportions. On the other hand, they're great for details – that's what walkarounds are for, aren't they?

 

@tony.t Looks like I'd have to build the ventral inlets after all 😩

 

@RidgeRunner I don't know whether RF-101A were operational in Vietnam, let's say it served in the Vietnam conflict – that would include Laos, Cambodia and Thailand as well.

Speed was the only the Voodoo could defend itself against AA and SAMs. So the use of speedy, slimmer tanks does make sense.

 

Thank you gents for your input.

Quang

 

 

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20 hours ago, quangster said:

Here’s how they must be located on the right intake. Note the flare on the lower lip.

Note that contrary to what have been published on the internet, the kit intakes need to be extended and not shortened.

No. The kit intakes has a furrow inside and needs to be cutted there, then glue the lips parts on. That’s not mentioned in instructions, but that’s how it designed to be. There’s not a simple way I think - so I recommend just to cut and shape it along with a splitter plate. Anyway, all the drawings (except the @bentwaters81tfw‘s MDD original one) is completely off, so the angle between an intake and the fuselage must be 90 degrees, even if it’s not so evident on some pictures (just because of the shooting angle, as you correctly stated before).

 

On 10/03/2019 at 11:56, quangster said:

During my research, I noticed that Voodoo of that theater often carry a different kind of aux tanks, slimmer and longer than their European counterparts.

As Craig Baldwin said on an ARC Discussion Forums: «The F/CF-101's used two different styles of external tanks Streamlines and Stubby as we called them. Those of course pictured are the Streamline while Monogram and KH provide the Stubbies. As maintenance we hated the Streamlines, awkward to install and work around.»

 

On 20/03/2019 at 10:50, RidgeRunner said:

How did I miss this thread!?

Same thing, Martin! 😶

 

Cheers! 😎

Edited by Nikolay Polyakov
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So, firstly I am confused over this intake issue. What's it all about? I guess I should know but I donT :(

 

And secondly can F-84F tanks be used to represent the slimmer Voodoo tanks?

 

Martin

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I'm nearly done modifying the intakes but am still deciding about their length –the distance between the intake lips and the wing root–. On some photos, it appeared longer, on others it's shorter. Now don't tell me there were two different types of intake on the A/C. :please:

I'll use the Monogram F-84F tanks to represent the streamlined tanks.

 

Quang

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On 3/20/2019 at 6:58 PM, TBC said:

From IPMS Canada Vol.16 No.4

 

 

flXriI.jpg

I compared the figures quoted with Monogram's Voodoo and Thunderstreak tanks, and they match well, except for the 35" diameter for the 'stubby', I think that number should be 30".

 

Rob

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@Rob de Bie According manufacturer Sargent-Fletcher , the stubby is 29" in dia. (15,3 mm in 1/48 . The KH tank is 15,8 mm which is acceptable in my book.

The Monogram 1/48 streamline at 14,2 mm dia. and 145 mm long is spot-on. 

 

@canberra kid The fuel data table is very helpful. Thanks!

 

Cheers,

Quang

 

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4 hours ago, quangster said:

I'm nearly done modifying the intakes but am still deciding about their length –the distance between the intake lips and the wing root–. On some photos, it appeared longer, on others it's shorter. Now don't tell me there were two different types of intake on the A/C. :please:

I'll use the Monogram F-84F tanks to represent the streamlined tanks.

 

Quang

Using your rule of thumb, I took a ruler to your photo. Without bothering to allow for scale the ratio between the fuselage diameter and the distance between the leading edge of the wing and the intake lip is 2.5:1 Assuming the fuselage diameter of the kit is 40mm, this makes the intake 16mm. in length.

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@bentwaters81tfw According to the view on my screen, the intake is 22 mm long for a fuselage diameter of 42 mm. Will need to check again.

Anyhow the lips on my intakes are nearly done. It's just a matter of adjusting the length.

Thank you for your comment.

 

Cheers,

Quang

 

 

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21 hours ago, quangster said:

Will need to check again.

Please, check the post #113 of my build here:

 

You don’t need to cut more than showed in that thread.

 

Put the hinge on a cutted splitter plate close to an intake lip (with about an 1 mm distance), and the forward edge of the splitter plate must be in the middle of the fuselage section behind the cockpit:

x56-085+RF-101C-65-MC+Georgia+Peach+III+

 

Cheers! 😎

Edited by Nikolay Polyakov
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Hello Nikolay,

I read your build thread some time ago. It's a very inspiring thread which demonstrated that the KH was quite buildable after all. 

Nevertheless I persist to believe that the real-life A/C intakes are longer. As a  proof, I took the photo you just posted, enlarged it on my computer screen to 1/48 scale, measured the intake and got roughly the same result as with my other photo.

 

intake-dimensions.jpg

 

Cheers,

Quang

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40 minutes ago, quangster said:

Hello Nikolay,

I read your build thread some time ago. It's a very inspiring thread which demonstrated that the KH was quite buildable after all.

Thanks for this kind of words, Quang!

 

40 minutes ago, quangster said:

Nevertheless I persist to believe that the real-life A/C intakes are longer. As a  proof, I took the photo you just posted, enlarged it on my computer screen to 1/48 scale, measured the intake and got roughly the same result as with my other photo.

On this photo you can see an F-101A starboard intake (notice the shorter splitter plate):

F-101A_Voodoo.jpg

 

And on my Voodoo:45056058515_43823a6738_k.jpg

 

As for me, the difference in intake lengths is not so noticeable, and building designed by manufacturer kit is always a compromise.

 

Cheers! 😎

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On some photos like the one you just posted, the intakes appear to be shorter. That makes me wonder whether there were two different types of intake. 

Here's another shot where the intakes look longer.

 

RF-101-C-FP.jpg

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1 hour ago, quangster said:

On some photos like the one you just posted, the intakes appear to be shorter. That makes me wonder whether there were two different types of intake.

According to the Ronald Easley’s book, there was some difference between the different production Blocks: «The intakes of the Block 5 aircraft had remained the same as the initial Block 1 configuration. These came to be known as the Type I ducts. Beginning in the subsequent Block 10 aircraft the inlet duct was modified, most notably by addition of a larger boundary layer splitter, but the duct itself was also extended forward by eleven inches. As with the earlier production blocks, there was no boundary layer bleed sub-inlet present inboard of splitter plate. While this improved pressure recovery over the earlier examples of the F-101A, compressor surge remained a serious problem in many flight regimes. Also, the critical Mach number was reduced from Mach 1.554 for the original Type I duct to Mach 1.448 for the new Type II duct.»

 

Some NASA drawing:

40491997723_33bd5e7715_k.jpg

 

So, I think we’re sorted out (nearly) all the Voodoo intake nuances, and with an addition to the aforementioned information by @bentwaters81tfw, I must say that’s all these millimeters matters if you’re modelling the particular aircraft from the particular production block only. For this kit, I recommend you to cut an intakes my way and save your time and(!) mojo.

 

But it would be interesting to see how the new kit parts (an intake lips) will comes together... 😋

 

Cheers! 😎

Edited by Nikolay Polyakov
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1 hour ago, canberra kid said:

I don't know if these add anything?

Thanks, John! Sure thing, but it’s a «B»-model related data. 👍 It’s always interesting to see an original plans.

 

Cheers! 🙂

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