Comparison by Spurts

New and old developments in aviation technology.
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sprstdlyscottsmn

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Unread post19 Feb 2020, 15:07

Hey all, my OG thread on this ended up locked. I wanted to say that I made a few updates to the missiles and I did something I normally don't do... I lifted the CFT AA stores carriage limit on the F-15SA. While I have no evidence of this actually happening the F-15SA/QA/EX seem to put an emphasis on AA work more than the Mudhen did, and as such I am making the assumption that the stores envelope was expanded. I realized I had done something similar with the Su-35S in removing it's max G shift through the trans-sonic and into the super sonic. No evidence, I am just assuming new improved versions also improve known weaknesses where reasonable.
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sprstdlyscottsmn

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Unread post20 Feb 2020, 18:52

Here is the comparison currently. I am working on the F-16 model now.

Strike Fighters 2025_4.pdf
(1.74 MiB) Downloaded 351 times
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garrya

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Unread post20 Feb 2020, 19:40

sprstdlyscottsmn wrote:Hey all, my OG thread on this ended up locked. I wanted to say that I made a few updates to the missiles and I did something I normally don't do... I lifted the CFT AA stores carriage limit on the F-15SA. While I have no evidence of this actually happening the F-15SA/QA/EX seem to put an emphasis on AA work more than the Mudhen did, and as such I am making the assumption that the stores envelope was expanded. I realized I had done something similar with the Su-35S in removing it's max G shift through the trans-sonic and into the super sonic. No evidence, I am just assuming new improved versions also improve known weaknesses where reasonable.

Why did it get locked, it is the best thread :(
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garrya

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Unread post20 Feb 2020, 19:43

sprstdlyscottsmn wrote:Here is the comparison currently. I am working on the F-16 model now.

Strike Fighters 2025_4.pdf

Iam very grateful that you took the time in your day to bring us this master piece free of charge
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eloise

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Unread post21 Feb 2020, 08:10

sprstdlyscottsmn wrote:Here is the comparison currently. I am working on the F-16 model now.

The attachment Strike Fighters 2025_4.pdf is no longer available

You are the best.
In the spot area section, do you consider the top view of the aircraft? I think the frontal view is better for comparison because aircraft are rarely viewed from the top
spot.PNG

and what is DPS? is it degree per second? why some missile turn better at longer distance?
dps.PNG

and I don't think SLAM-ER should have smaller RCS than SPEAR, they have similar shape and the later is a fraction the size of the former. SPEAR is in fact smaller than Meteor
Capture.PNG

231495_800.jpg

s_IMG4094-MBDA-Meteor-and-Spear-missiles.jpg
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sprstdlyscottsmn

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Unread post21 Feb 2020, 13:57

eloise wrote:In the spot area section, do you consider the top view of the aircraft? I think the frontal view is better for comparison because aircraft are rarely viewed from the top

when looking at the size of an aircraft the critical issues are length and width. "height" is predominantly a factor of thin little vertical tails and landing gear length.

eloise wrote:and what is DPS? is it degree per second? why some missile turn better at longer distance?

Yes degrees per second. Some missiles appear to turn better at the end of their flight because they are now in denser air and/or are flying slower. A missile flying at twice it's corner velocity is not going to be able to turn as quickly at the same G.

eloise wrote:and I don't think SLAM-ER should have smaller RCS than SPEAR, they have similar shape and the later is a fraction the size of the former. SPEAR is in fact smaller than Meteor

Round nose with exposed seeker vs faceted nose. It boiled down to that.
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eloise

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Unread post21 Feb 2020, 18:43

sprstdlyscottsmn wrote:when looking at the size of an aircraft the critical issues are length and width. "height" is predominantly a factor of thin little vertical tails and landing gear length.

I think length and width can be deceiving because they could have different wing shape and vastly different area
781CCA68-F06C-4390-80BB-6C93A1C59BC1.jpeg

sprstdlyscottsmn wrote:Round nose with exposed seeker vs faceted nose. It boiled down to that.

But SPEAR is very small, smaller than a short range air to air missile. And a short range air to air missile only has RCS about 0.03 m2 frontally
3F38801C-16E7-4575-A720-200A08B22357.jpeg

564688D1-CBD5-4237-8E94-65269AF62BB9.png

And SPEAR uses 3 tail fins instead of 4 tail fins like SLAM-ER. 4 fins design make right angle corners
0136BF52-A1CC-44C3-8215-5B10E5A904C2.jpeg
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sprstdlyscottsmn

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Unread post21 Feb 2020, 18:53

eloise wrote:I think length and width can be deceiving because they could have different wing shape and vastly different area

That is the entire point of that section, to show how densely packed something is inside its Spot Area (a term used by the Navy for describing the actual amount of space a plane takes in the hangar deck).

eloise wrote:But SPEAR is very small, smaller than a short range air to air missile. And a short range air to air missile only has RCS about 0.03 m2 frontally

if you want to make a general argument that SPEAR should be lower than 0.1 I will listen, but length has little to do with RCS. SPEAR is 7in across, the same size as an AMRAAM and wider than a Sidewinder, and has a large rounded glass nose. The overall design of SPEAR shows no LO considerations. I see no reason for SPEAR to not have the highest RCS betwen itself, the SLAM-ER, and AAMs.

**EDIT** so a perfect circular reflector, which I am assuming the nose of SPEAR is, 7in across is 0.025m^2. I would think total RCS would be no less than twice this to account for edge refractions and surface creep, etc. With this in mind, I am inclined to reduce the RCS or SLAM-ER as it displays LO considerations in its design.
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mozza

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Unread post21 Feb 2020, 23:20

sprstdlyscottsmn wrote:Here is the comparison currently. I am working on the F-16 model now.

Strike Fighters 2025_4.pdf


Rafale don't use Damocles pod anymore, he use the Talios pod.

https://www.thalesgroup.com/sites/defau ... S-GB_0.pdf
Last edited by mozza on 21 Feb 2020, 23:23, edited 1 time in total.
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wrightwing

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Unread post21 Feb 2020, 23:22

eloise wrote:


But SPEAR is very small, smaller than a short range air to air missile. And a short range air to air missile only has RCS about 0.03 m2 frontally

RCS isn't based upon physical size. The shape is the more important factor.
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sprstdlyscottsmn

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Unread post22 Feb 2020, 00:46

mozza wrote:
sprstdlyscottsmn wrote:Here is the comparison currently. I am working on the F-16 model now.

Strike Fighters 2025_4.pdf


Rafale don't use Damocles pod anymore, he use the Talios pod.

https://www.thalesgroup.com/sites/defau ... S-GB_0.pdf

Thanks!
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madrat

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Unread post22 Feb 2020, 01:01

I don't think Talios is decommissioned. Damocles supplanted - not eliminates - the Talios, just as Talios did the same to the first generation pod.
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marsavian

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Unread post22 Feb 2020, 04:40

Originating thread

viewtopic.php?f=55&t=25735
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eloise

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Unread post22 Feb 2020, 05:10

sprstdlyscottsmn wrote:if you want to make a general argument that SPEAR should be lower than 0.1 I will listen, but length has little to do with RCS. SPEAR is 7in across, the same size as an AMRAAM and wider than a Sidewinder, and has a large rounded glass nose. The overall design of SPEAR shows no LO considerations. I see no reason for SPEAR to not have the highest RCS betwen itself, the SLAM-ER, and AAMs.
**EDIT** so a perfect circular reflector, which I am assuming the nose of SPEAR is, 7in across is 0.025m^2. I would think total RCS would be no less than twice this to account for edge refractions and surface creep, etc. With this in mind, I am inclined to reduce the RCS or SLAM-ER as it displays LO considerations in its design.

Except for faceted window, there are two problems with SLAM-ER
Saudi Arabia f-15s e   AGM-84H Standoff Land Attack Missiles-Expanded Response (SLAM-ER), 973 AGM-154C Joint Stand Off Weapons (JSOW), 400 AGM-84L Harpoon Block II missiles, 1000 GBU-39B Small Diameter Bomb.jpg

Firstly, the missile body is a pure cylinder, that is the perfect condition for creeping wave return. True VLO missiles such as Jassm, Jsow, Nsm never have pure cylinder body
Image
Secondly, it has four big tail fins, so they made up 4 right angle reflectors. On VLO missile such as Jsow the corner is acute and on Jassm, the horizontal fin is very small
Capture.PNG


Spear isn't fully cylindrical and the 3 small tail fins made obtuse angles
spear-1.006-640x360.jpg
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sprstdlyscottsmn

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Unread post22 Feb 2020, 15:05

I see what you are saying. Per my previous post about the SPEAR window, I can't justify it going lower that 0.05, but you have a decent argument that SLAM-ER should be in the same class, not half the size.
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