Lockheed Martin F-22 Raptor

[uk 75]

I did not include Canada or Australia in my list for the same reason- they didnt get F15s - like the UK come to that.
Only the Israelis and the Japanese have the money or need to afford F22s. I threw Saudi into the mix for the same reason it got F15- Washington and Riyadh have common enemies

 

[icyplanetnhc (Steve)]

Interesting set of pictures of F-22s returning from a Middle East deployment.

FF and TY F22s at Moron AFB, Spain

June 2019 Serials FF/09-4174 FF/08-4167 FF/04-4082 Marked “149FS” FF/10-4192 Marked “192FW” FF/08-4163 FF/08-4157 FF/04-4067 FF/09-4173 FF/08-4165 FF09-4189 TY/05-4100 TY/05-4089

www.flickr.com

I think this is the first time that I've noticed that the 600 gal external tanks are actually toed in slightly (in stark contrast to the F/A-18E/F pylons...). I suppose this may have the benefit of reducing drag in supersonic flight due to conical flow.

https://flic.kr/p/2gkJHY5

 

[BDF]

Went down the rabbit hole on a google excursion and came across a website that sells desktop avionic trainers. They had one for the F-22. It represents unclassified symbology and displays but I've see these displays before in the cockpit trainer Lockheed used to give demonstrations to media etc. Anyway I was wondering if anyone knew what the symbol is on the PMFD shown by the orange arrow? I'm assuming its the radar footprint but it seems strange to me that the wider coverage portion stops at the 20nm ring then a much longer footprint that extends out to what appears to be +/- 10 off of centerline out to . I believe that AESA radars have reduced performance the further off boresight you get, especially as you approach scan limits. This strikes me as a drastic drop. I've also attached an interesting concept for SAR mapping image. Note that on this one the PMFD in the middle has two green football shapes emanated off to the sides of the radar footprint. Any ideas on what those are?

website where I found these: http://www.zedasoft.com/products/f22.jsp

 

[Foo Fighter]

Is it a realistic idea to adapt the F-22 airframe to the F-35 systems and modern engines with the radar absorbing coatings etc to produce a sidekick aircraft with complementary abilities? Obviously they have different roles and capabilities so could the hybrid be a useful addition to the fleet instead of modernising 4th gen aircraft while hoping they can do the job? I know this is as old as the hills but with all the talk of F-15X and F-16 that I thought I would see if I could get a single answer or just differentiated opinion. Rock on.

 

[TomcatViP]

@BDF : IMOHO the radar is in TWS mode* and the larger cone in the 20 first nm reflects enhanced capabilities to keep your SA level. TWS have traditionally a narrow scan band (steerable) that is here markedly alleviated by this increase coverage cone (proximity awareness).


*TWS: Track While Scan

 

[icyplanetnhc (Steve)]

Is it a realistic idea to adapt the F-22 airframe to the F-35 systems and modern engines with the radar absorbing coatings etc to produce a sidekick aircraft with complementary abilities? Obviously they have different roles and capabilities so could the hybrid be a useful addition to the fleet instead of modernising 4th gen aircraft while hoping they can do the job? I know this is as old as the hills but with all the talk of F-15X and F-16 that I thought I would see if I could get a single answer or just differentiated opinion. Rock on.

When it comes to adapting the F-22 airframe with F-35-like systems, the technical feasibility shouldn't in question, although you may need to add more electrical power generation. In fact, I believe that a mid-life upgrade in the 2020s is aiming to adapt a lot of the F-35's additional air-to-air capabilities into the F-22, such as DAS, cockpit upgrade, hardware refresh, sensor enhancements (some of this is being funded in FY2021, I think), etc. If you're talking about producing upgraded F-22 aircraft, I think the main problem is cost and schedule, since the production line is gone so any new F-22s production restart would need some pretty substantial non-recurring costs, on the order of $10 billion over nearly a decade. I think the USAF would rather invest those funds on a fresh NGAD design that would offer far greater capabilities for the money. It's a shame that we don't have more F-22s, but that is well behind us now.

The entire reason for buying the F-15EX is to rapidly get more fighter aircraft for the USAF as the F-15C fleet is nearing the end of its structural life, and relatively affordably since the production line is still active from export orders (Saudi Arabia and Qatar). Although, I have to admit that the justification is a bit shaky given that the apparent unit cost of the F-15EX doesn't seem to be particularly different from an F-35A, but I suppose it can fulfill a different set of missions or perhaps niche roles; USAF and Israeli Air Force at least found it compelling enough. I suspect that industrial considerations to support Boeing's St. Louis division might also be a motivating factor.

 

[Foo Fighter]

Somewhere in this thread or the F3 thread is a comment that the tooling is still extant in storage and if the Japanese are going to go for the hybrid F22/35 it may just make enough financial sense to see of the enhanced gen 4 aircraft. Might just end up with a better aircraft.

 

[TomcatViP]

The representation we were given to see point to a larger design that no traditional F-22 airframe is going to cover.
Then we can discuss about the longer range versions proposed by LM. But since none were built to my knowledge, the cost of re-opening the 22 line is not relevant to the discussion anymore (although the variants I am talking about were re-using F-22's fuselage sections).

 

[BDF]

@BDF : IMOHO the radar is in TWS mode* and the larger cone in the 20 first nm reflects enhanced capabilities to keep your SA level. TWS have traditionally a narrow scan band (steerable) that is here markedly alleviated by this increase coverage cone (proximity awareness).


*TWS: Track While Scan

Hmmmm not sure that makes sense. AESA radars can scan the entire field of view quickly and interleave modes as they operate. BTW- my memory failed me, it's AESA's beam width that increases as it approaches scan limits, not so much as power drop. So a TWS limited scan volume doesn't make sense. For mechanical radars, you limit scan volumes to increase update rates for accurate target tracking and weapons support but AESAs don't have that limitation. In fact they don't even scan in a traditional raster type scan that mechanical arrays do, instead employing pseudo-random scan patterns.

It does make sense that high priority target mode (HPT) would include targets closer to the aircraft as those are the most threatening but it doesn't to me make much sense to demark that scan volume at such a short range. I could see the longer range scan cone (for lack of a better phrase) representing some sort of long range search volume. In any case whatever that display represents I'm sure doesn't represent the real capability.

 

[sferrin]

Interesting set of pictures of F-22s returning from a Middle East deployment.

FF and TY F22s at Moron AFB, Spain

June 2019 Serials FF/09-4174 FF/08-4167 FF/04-4082 Marked “149FS” FF/10-4192 Marked “192FW” FF/08-4163 FF/08-4157 FF/04-4067 FF/09-4173 FF/08-4165 FF09-4189 TY/05-4100 TY/05-4089

www.flickr.com

I think this is the first time that I've noticed that the 600 gal external tanks are actually toed in slightly (in stark contrast to the F/A-18E/F pylons...). I suppose this may have the benefit of reducing drag in supersonic flight due to conical flow.

https://flic.kr/p/2gkJHY5

I think it may be more a result of perspective.

 

[sferrin]

The representation we were given to see point to a larger design that no traditional F-22 airframe is going to cover.
Then we can discuss about the longer range versions proposed by LM. But since none were built to my knowledge, the cost of re-opening the 22 line is not relevant to the discussion anymore (although the variants I am talking about were re-using F-22's fuselage sections).

My favorite was always FB-22-1

 

[aonestudio]

https://twitter.com/x/status/1243255876200341511

 

[Foo Fighter]

Bloody marvelous. Thank you.

 

[jsport]

The representation we were given to see point to a larger design that no traditional F-22 airframe is going to cover.
Then we can discuss about the longer range versions proposed by LM. But since none were built to my knowledge, the cost of re-opening the 22 line is not relevant to the discussion anymore (although the variants I am talking about were re-using F-22's fuselage sections).

My favorite was always FB-22-1
View attachment 628523

If 6th G is going to be another decde of PPT we had better get back on the F22,

 

[Josh_TN]

Is it a realistic idea to adapt the F-22 airframe to the F-35 systems and modern engines with the radar absorbing coatings etc to produce a sidekick aircraft with complementary abilities? Obviously they have different roles and capabilities so could the hybrid be a useful addition to the fleet instead of modernising 4th gen aircraft while hoping they can do the job? I know this is as old as the hills but with all the talk of F-15X and F-16 that I thought I would see if I could get a single answer or just differentiated opinion. Rock on.

When it comes to adapting the F-22 airframe with F-35-like systems, the technical feasibility shouldn't in question, although you may need to add more electrical power generation. In fact, I believe that a mid-life upgrade in the 2020s is aiming to adapt a lot of the F-35's additional air-to-air capabilities into the F-22, such as DAS, cockpit upgrade, hardware refresh, sensor enhancements (some of this is being funded in FY2021, I think), etc. If you're talking about producing upgraded F-22 aircraft, I think the main problem is cost and schedule, since the production line is gone so any new F-22s production restart would need some pretty substantial non-recurring costs, on the order of $10 billion over nearly a decade. I think the USAF would rather invest those funds on a fresh NGAD design that would offer far greater capabilities for the money. It's a shame that we don't have more F-22s, but that is well behind us now.

The entire reason for buying the F-15EX is to rapidly get more fighter aircraft for the USAF as the F-15C fleet is nearing the end of its structural life, and relatively affordably since the production line is still active from export orders (Saudi Arabia and Qatar). Although, I have to admit that the justification is a bit shaky given that the apparent unit cost of the F-15EX doesn't seem to be particularly different from an F-35A, but I suppose it can fulfill a different set of missions or perhaps niche roles; USAF and Israeli Air Force at least found it compelling enough. I suspect that industrial considerations to support Boeing's St. Louis division might also be a motivating factor.

I think the main motivation for F-15 over F-35 is that it is an entirely different line. The F-35 line is quite spoken for; if you want more aircraft you have to go somewhere else. Additionally I think there is a desire to have a two engined heavyweight fighter than potentially can lug around a large hypersonic piece of ordnance on the center station. The F-15 likely has a larger war load and more known tolerances for outsided ordnance than other craft.

 

[jsport]

An article in AW&ST this week claimed LM and the JPO confirmed 35s will replace 15Es by 2035. Es currently number 228. That is not a one to one replacement by any means. A mix of 15EXs and new 22s would sure be the better way not to lose payload delivery capacity much like the 21 would reduce payload delivery capacity w/ the potential hasty but necessary retirement of many of the Bones.

 

[In_A_Dream]

If the US wanted to re-open the Raptor production line because Congress felt the threat from China was significant enough, they would. Right now, that specific threat isn't large enough, which means they think they can get a good 6th gen platform fielded in time to stay a generation ahead of the Chinese.

 

[TAOG]

An article in AW&ST this week claimed LM and the JPO confirmed 35s will replace 15Es by 2035. Es currently number 228. That is not a one to one replacement by any means. A mix of 15EXs and new 22s would sure be the better way not to lose payload delivery capacity much like the 21 would reduce payload delivery capacity w/ the potential hasty but necessary retirement of many of the Bones.

Can you provide the AW&ST article link? Thx

 

[Grey Havoc]

If the US wanted to re-open the Raptor production line because Congress felt the threat from China was significant enough, they would.

Unfortunately it's not that simple. For example, much of the equipment and materials set aside for such a contingency was (illegally) used by Lockheed Martin over the years to prop up F-35 production.

 

[jsport]

An article in AW&ST this week claimed LM and the JPO confirmed 35s will replace 15Es by 2035. Es currently number 228. That is not a one to one replacement by any means. A mix of 15EXs and new 22s would sure be the better way not to lose payload delivery capacity much like the 21 would reduce payload delivery capacity w/ the potential hasty but necessary retirement of many of the Bones.

Can you provide the AW&ST article link? Thx

As USAF Feet Plans Evolve, can the F-35A progrm survive intact. Mar 23 Apr 5 AWST p38

 

[jsport]

If the US wanted to re-open the Raptor production line because Congress felt the threat from China was significant enough, they would. Right now, that specific threat isn't large enough, which means they think they can get a good 6th gen platform fielded in time to stay a generation ahead of the Chinese.

IMHO you are just factually incorrect about the PLAAF.

 

[critter]

I worked on and helped install the Circulator Automated Assembly and Test System referred to here.

Keller Technology Honored for Cutting F-22 Avionics Costs

Boeing and Northrop Grumman on Friday presented the Keller Technology Corp. with an award of excellence for its outstanding efforts to reduceF-22 avionics costs and cycle time. Keller Technology...

boeing.mediaroom.com

 

[In_A_Dream]

IMHO you are just factually incorrect about the PLAAF.

From my perspective, I haven't seen anything that points to the J-20 being in FRP and there isn't anything available in the PLAAF inventory to significantly challenge our F-22s. On an existential level, yes the CCP is America's largest threat (and vice versa) and I'm by no means downplaying their military/industrial potential but specifically in regards to an Air Dominance fighter, the threat isn't there yet to justify a 5th gen (new or updated F-22 model) stop gap in Air Dominance. Once we see FRP begin for the J-20, I think Congress will consider options for the future.

 

[AN/AWW-14(V)]

some ANG future efforts
Multispectral sensors, advanced expendables and etc (read pdf)

https://www.ang.af.mil/Portals/77/documents/Resources/2019%20Mod%20Book%20v2.pdf?ver=2019-05-30-122634-043

 

[Ronny]

some ANG future efforts
Multispectral sensors, advanced expendables and etc (read pdf)

https://www.ang.af.mil/Portals/77/documents/Resources/2019%20Mod%20Book%20v2.pdf?ver=2019-05-30-122634-043

So IRST and towed decoy basically

 

[BDF]

Is there any program of record for the active duty Raptors to get these updates? Glad to see that IRST and HMD are tops of the list.

 

[bring_it_on]

???

Infrared search and track sensor (IRST) systems are considered a high-value asset to the United States Air Force. Current systems can search, track and target enemy aircraft and discriminate between multiple aircraft at intermediate to long ranges better than many traditional radar systems fielded today. The unique capabilities of IRST technology is now driving the demand to provide the same capabilities for a variety of different tactical aircraft by improving performance and reducing size, weight, and power (SWaP). A key element to this approach is to move from a steered, small focal lane array (FPA) to a staring, large-format FPA. By eliminating the requirement for bulky mechanical stabilization and pointing hardware, a high-performance, low-SWaP, flexible IRST system can be realized. The challenge to developing such a system is in performing image stabilization in the presence of full aircraft kinematic movement. Toyon in partnership with Lockheed Martin Santa Barbara Focalplane, proposes a solution that uses IMU-based stabilization and innovative infrared search and threat identification algorithms to exploit the rich capabilities of LM-SBFs latest nBn sensors. The proposed system will result in a low-SWaP, wide-field-of-view (WFOV) staring IRST capable of long-range detection and tracking of targets in cluttered environments.; BENEFIT: At the end of the Phase I effort Toyon will have developed an approach for providing non-mechanical image stabilization for a staring WFOV IRST sensor. The Phase II work will lead to the development of a prototype staring IRST sensor based on the design approach established within the Phase I effort. Such a system will result in a high-performance, low-SWaP, WFOV IRST sensor with the flexibility to be installed on a variety of different tactical aircraft. In addition to being deployed in Air Force tactical networks, the main commercial prospect is in the field of commercial surveillance.

Electronic Image Stabilization for Staring Infrared Search and Track (IRST) Sensors | SBIR.gov

www.sbir.gov

Successful implementation of an offensive staring infrared search and track (IRST) system can potentially yield significant benefits when incorporated into a fighter aircraft fire control system. It is anticipated that this type of passive sensor will yield higher performance in a more compact, lighter weight design with greater installation flexibility. Advancements in large format two-dimensional FPAs and readout integrated circuits offer potential advantages in clutter rejection, more frequent updates, longer integration times, multi-frame detection techniques, and image stabilization. It is expected that by exploiting these advantages, an IRST can be developed that supports long range detection and tracking of targets in cluttered environments with a low false alarm rate over a large field-of-view (FOV).

By leveraging advancements in the development of large format two-dimensional FPAs for wide FOV search and track to maximize aircraft installation flexibility and yield the highest performance in the most compact and light weight design, it is preferable to eliminate all mechanical pointing and line of sight stabilization components. This is especially critical for embedded/conformal sensors on highly dynamic aircraft. It is expected that successful implementation of electronic image stabilization and exploitation of other advantages of large format arrays will result in a novel and innovative IRST. It is envisioned that such a system can be developed to support long range detection and tracking of targets along clear atmospheric paths and in cluttered environments with low false alarm rates while staring over the system FOV.

The technical focus of this topic is to explore novel techniques and sensor chip assembly design concepts that can provide rapid control of the field of view from the subpixel level to a substantial fraction of the field of view to enable fine line-of-sight stabilization in addition to image motion compensation during aircraft maneuvering. The sensor wavelength bands of interest are midwave (3.0 to 5.0 microns) and longwave (8.0 to 12.0 microns). Stabilization must occur during the integration time of the FPA and requires an appropriate bandwidth input source.

Non-mechanical stabilization techniques such as those implemented in the FPA/readout integrated circuits of the sensor are of primary interest, but other techniques shall be considered. Mechanical and non-mechanical beam steering approaches are specifically excluded from this solicitation.

Teaming/collaborating with prime contractors to develop transition approaches is encouraged.

PHASE I: Investigate component-level concepts and techniques. Perform initial component prototype development and experiments to validate concepts. Establish system design implementation and provide technical analysis that supports the proposed design and quantify expected performance. Develop business case analysis and transition plan.

PHASE II: Based on Phase I results, construct and test a prototype imaging sensor to demonstrate and evaluate the design concept. Identify and reduce the risk of the component technologies needed to perfect the design and demonstrate the approaches needed for commercialization of a flight-capable instrument. Refine business case and transition plan.

PHASE III DUAL USE APPLICATIONS: Transition the newly demonstrated design to DoD industry partners. There may be some commercial applications that could benefit from the proposed approach.

Electronic Image Stabilization for Staring Infrared Search and Track (IRST) Sensors | SBIR.gov

www.sbir.gov

 

[Ronny]

F-22 EW system includes jamming antennae?

 

[riggerrob]

Canada could never afford F-15 or F-22.
The RCAF struggles to keep their CF-18A fleet in the air with expensive avionics upgrades and fatiguing airframes. They recently bought a batch of C-18A from the Royal Australian Air Force. Political meddling prevented the RCAF from buying F-35 … something about a trade war with Boeing over Dash-8 sales ....

 

[Purpletrouble]

IRST would be an obvious upgrade to help with confrontations with other g5 stealth fighters, and probably also the biggest bang for the buck.


Cheek radars would be lower priority so long as the US would likely retain a preponderance in both surveillance assets and networking in likely battlefield. But if it become necessary to keep assets like AWACS from battlefields due to presence of such adversaries as j-20, it might be advantageous to fit the cheek radars that f-22 was designed for.


HMS would probably be a low priority because with only 187 f-22s, it should be the American strategy to make the maximum use of the f-22 stealth and speed, and avoid at all cost dog fighting with f-22.


My own feeling is f-35 really won't cut it against j-20 and t-50, and there will be a 10 year period between 2020 and 2030 when the US would wish it had a larger force of f-22s.

Sorry, but that is nearly all wrong.

IRST is much overhyped, hardly ever used. The F35 level yes, but that is basically a Laser Designator Pod embedded. The LDP is the thing pilots want because it is cued to the radar and has definition (and ongoing development, much easier to swap out and improve) orders of magnitude over IRSTs.

Cheek radar, yes low, as the radar fit is good, although ageing, software being the key issue and the inability of hardware to take modern software.

HMS, helmet mounted sight - the one thing they desperately do want. The advantages of this are beyond just short range dogfighting and relate to vastly improved SA (and we're not talking F35 look through here, just Euro HMS style) in all missions and flights at all ranges.

F35 doesn't need to "cut it", (a) there's hordes of them vs. serviceable J-20/t-50s, (b) working as a team is what all air combat is about anyway - there is a reason they fly 4-ships all the time, and if they have to, accept a pair! Pretty much nothing would stand a 4 ship of F35s with the sharing of info in terms of ease, reliability and speed that they can.

This whole F35 thing is like looking at HMS Tiger of the 1950s and saying "what, 4 x 6" barrels, that is awwwwwful vs. the 1930s Town class with 12". Ignoring the sensors and fire control system which makes the former worth multiple of the latter (let's just ignore reliability though!).

 

[BDF]

F-22 EW system includes jamming antennae?

View attachment 630940View attachment 630941

Very interesting stuff. What document is this from? If this is accurate its interesting, beyond the ECCM stuff highlighted, is that the ALR-94 covers down to the C Band but can not cover the A and B bands; i.e. VHF and UHF frequencies. I wonder if the F-35 has the same limitations? I also wounder what the Cooperative Engagement Capability arrays are? 64 element AESA arrays. I wonder if they support missile data links?

 

[Ronny]

Very interesting stuff. What document is this from? If this is accurate its interesting, beyond the ECCM stuff highlighted, is that the ALR-94 covers down to the C Band but can not cover the A and B bands; i.e. VHF and UHF frequencies. I wonder if the F-35 has the same limitations? I also wounder what the Cooperative Engagement Capability arrays are? 64 element AESA arrays. I wonder if they support missile data links?

It came from this book


F-35 EW can go down to band 2, so it won't has the same limitations

 

[stealthflanker]

I'm curious tho if the Band 2 is really used for Emitter locating, as in F-22 antenna of similar place are listed in as Navigation, Identification and Others. It probably an IFF Interrogator.

 

[Josh_TN]

I wish I understood the various band nomenclatures more accurately. That said, isn't IFF interrogation done in around the save wavelength as common datalinks like 16? L band, to use the lettered system? I'd be surprised if a single fighter sized aircraft could resolve angle outside of a cardinal direction in that range, but given a flight of aircraft with differentiation of time of arrival, they possibly could geolocate very accurately by sharing information over the MADL.

 

[Ronny]

I'm curious tho if the Band 2 is really used for Emitter locating, as in F-22 antenna of similar place are listed in as Navigation, Identification and Others. It probably an IFF Interrogator.

According to what I know, Band 2 on F-22 is used for CNI but on F-35 it is used for EW function as well.

 

[Richard N]

MIT Private Pilot Ground School 2019, F-22 Flight Controls

 

[Sundog]

For all of his degrees, he really doesn't know much about aircraft design. The fact is, most of the aerospace companies said designing for stealth actually aided the aerodynamic design of their vehicles. For the record, stealth does not make an airplane unstable. One can design stable stealthy stable aircraft (See the Scaled Composites Model 401 for reference). What makes an aircraft stable or unstable, if I reduce it to it's most simplistic explanation, is the position of the wing relative to it's position on the fuselage (The over all center of mass to the aerodynamic center). Also, launching a missile isn't a huge change, although the flight controls, indeed, must compensate. The empty weight of the raptor is around 43,400 lbs, so it is going to weigh more in combat when it launches the missile. An AMRAAM weighs about 335 lbs. That's .7% of the F-22's empty aircraft. The C.M. isn't moving that much. In fact, opening the missile launch doors and the trapeze ejecting the missile probably cause a greater FCS response than the missile weight change.

Also, if you bank right, the left aileron goes down, causing the wing to go up and the right aileron goes up, causing the wing to go down. Also, the flight controls as air brakes they got from the YF-23 (Not that that matters). Just saying.

Also, like he said, fighters are easy to fly. There is a fighter pilot podcast on test pilots and the test pilot that is the guest normally flew C-130's. When she went to test pilot school and finally flew a fighter she couldn't believe how easy they were to fly.

The "G-Limit Mode" was interesting. It sounds like he's talking about neutral stability, which is really cool. I also like how they use the ailerons to unload the wing while pulling Gs as well.

 

[Purpletrouble]

Hmmm having actually designed for stealth, it does not aid aerodynamics unless you are starting with a corrugated shed surface and the improved smoothing does aid both! The reason for actual comparable aircraft designs it is difficult relates to apertures (inlets/outlets being very inefficient to avoid large electromagnetic returns) and the angles of curvature. We saw the 80s where Aerodynamics was king in getting superlative performing platforms (F22, Typhoon, F16, F15 etc). Vs the 2000s of electro magnetics telling us “this is the shape it has to be, make it fly ok”. It’s one reason I eventually left.

There is mass confusion on stability. It is nothing more than if you disturb something, do the changes prompted by that disturbance return it to the original condition (stable) or exacerbate the disturbance (nstable).


Wing positon is true but a bit clunky - it is simply the position of the aircraft’s Centre of Gravity (CG) vs Aerodynamic Centre (AC, point at which aerodynamic forces can be reduced to acting through). This is for longitudinal stability - lateral would be the wingspan direction offset off the two.

If the AC is in front, a disturbance (eg gust) will create more lift and pitch the aircraft up about the CG, creating yet more lift and pitch = unstable. If behind, that extra lift pitches it back down = stable.
Generally you want stable, as trying to put countering control inputs in quick enough is beyond a human/most control system responses to avoid making it worse/being ineffective. Computers and fast responding high power controls overcome that. The advantage of instability is freedom of design and for fighters, the option to reduce supersonic drag by placing the AC ahead of the CG so that when it (AC) naturally migrates rearward in supersonic flight (about the only time it moves) it actually reduces control surface deflections required to trim (especially vice the opposite) - thus significantly reducing supersonic drag and enabling supercruise on dry thrust which gives you more supersonic range and critically for operational effectiveness, the ability to make more slashing in/out attacks per sortie.

Clearly too far away makes control difficult in that your control surfaces would need to generate huge lift/moment to change direction, leading to excess drag when you do.

Most aircraft have a box in which the CG is permitted to be based on weighs, the exact point being bespoke to that airframe. Payloads and stores have additional limits in clearing them generally heavy inboard . For example Harrier couldn’t ever carry Storm Shadow because it couldn’t handle the lateral stability impact of just having one (if one fired and the other didn’t) which would lead to loss of aircraft. It also couldn’t VL with SS fitted due to the required flap setting fouling the missile but that could be avoided by land based use and RVL.


Payloads are thus best at or near the CG (lat and long) for minimal impact when dropped or not present. Weapon launched the biggest concern is where it goes due to the complex aerodynamics interacting betwen store and aircraft. This was an entire area of specialism in my firm. There is youtube footage of an F111 dropping a drop tank, it goes down, pitches up, gains lift going upwards, pitching more up gains drag goes “backwards”, taking the wing with it.

Hence why stores are forcibly pushed away from the aircraft using gas powered piston ejectors and extending frames (internal/surface mounted). Rail launched are better in that they take themselves away but then you have the fear of hang up plus they seem to come off more easily on (very) heavy landings.
Sorry rather long post!

 

[bring_it_on]

631054[/ATTACH]

Any idea what "Non-MADL EA Mech" refers to?

 

[Josh_TN]

The above reminded me of one of my favorite old timy youtube videos. Its not just dogs that have separation issues: