Table of Contents

Aerodynamics Series

2018년 5월 23일 수요일

Small Note for Short Range Air-to-Air missiles of Major Countries and their Futures

Short range air-to-air missiles are the most lethal weapon to intercept air-vehicles in current air-warfare, and they represent pinnacle of missile technology for guidance and radical maneuverability. This article tries to review the most advanced SRAAMs to obtain insights of air-warfare, and predict future trend, competing with other advanced weapons such as DEW, MDSM, or SACM. 

 Below Table 1 summarizes specification of few missiles developed by France, UK, German, Russia, Israel, and US. Other countries like China, Japan, South Africa, Brazil, and South Korea developed or will develop their own SRAAM however, concept of their country are still not as matured as conventional super powers. 

Table 1 Summary of specification of SRAAM of major countries

1) Development Background

French previously operated heavy Super 530D targeted MiG-25 which demand Mirage 2000 series to give up usage of external fuel tank. Indeed, as a successor of 530D, French tried to integrate radar and IR homing missiles in one small package to increase magazine of the missiles in their small fighters, Mirages and Rafale; it resulted mid-sized MICA-EM and IR series. Also, French smartly thought their possibility of export for foreign countries which demands multi-seeker missiles in similar size. Development direction of MICA made itself as a one of the lethal missiles in the world in mid-short range however it resulted reduction of efficiency in longer range for radar homing missile. Because of the size of MICA, French should finally develop Meteor missiles to deal with future threat in longer range. So, now, it is hard to judge whether size decision on MICA series is good or bad; anyway, aerial combat inventory of French is proliferated by MICA and Meteor un-intentionally. 

Reason of Anglo’s ASRAAM was very obvious because UK always focused their eye on northern threat of long range fighter-bombers. As ASRAAM obtain relatively longer range than other SRAAMs, it is the only non-TVC missile even with smaller control surfaces. It is the radical contrast of Python series. It gave another aspect of difference when ASRAAM is modified for naval purpose, sea-ceptor. While MICA-VL or ground-based IRIS-T uses its own motor for launch via TVC, sea-ceptor added cold launch method with side array nozzle to control initial direction. Un-intended advantage of the ASRAAM is relatively compact configuration of the missile which takes smaller volume in the internal weapon bays. 

Compared to UK or France, purpose of Israel, German, US, and Russia is simple, maximization of lethality in standard range of SRAAMs. Actually, development direction of the IRIS-T and AIM-9X was triggered by advent of R-73 series, and it is natural that those three missiles become similar. Difference of them could be configured when we watched aspect of cost. Although AIM-9X has advanced performance with TVC and sensor technologies, part of the missile still depends on AIM-9L/M technology to reduce the cost. Because of this limitation, AIM-9X takes position of lightest, smallest, lowest, most-short-ranged of the all candidates. IRIS-T, developed by German, seems to follow mid-position of all missiles, modest range, maneuverability, sensors, range, speed, and warheads; this leads IRIS-T to most exported SRAAMs in the argued competitors. 

Russian’s R-73 is replacement of R-60; R-60 was light-weight air-to-air missile for multiple load and versatile usage of fighter and helicopters. R-73 turn design concept from small-versatility to maximized lethality at that time; R-73 firstly introduced TVC, and HMS with IRST combination in 80’s. In order to integrate these, R-73 could not avoid heavy weight body than competitors. Now R-73 will be replaced by R-74 because some part of R-73 is outdated and western counterpart finished development of new missiles against advent of R-73. 

As described in ASRAAM paragraph, IAF also fully focused on lethality in close combat; short ranged circumstance of the Israel naturally leads that kind of directions. Because of the combat range of IAF, they required fully out-performing missile than R-73. In their scenario, fully air-to-ground armed F-15 or F-16 should do self-defense against R-73, and their Python 5 should be better for maneuverability with reasonable range. Because this higher goal, they could achieve longer range with the best maneuverability via sacrifice of heavy weight, drag, and large sized fin. 

2) Reach of Arm 

As a function of propulsion (speed, kinetic energy), weight, and aerodynamic layout (lift and drag), range of the missile could be determined. Heavier weight with lower drag missiles could maintain its kinetic energy in longer range while heavier weight act as burden for maneuverability and acceleration. From this point of view, MICA-IR take top position among these missiles because MICA was designed as semi-mid-range missile rather than pure SRAAM. MICA-IR could achieve fastest speed (~M4) with its heaviest weight and reasonable drag level. UK’s ASRAAM secure similar range with limited weight via sacrifice of TVC, and control surfaces. Although ASRAAM’s weight is limited in the level of IRIS-T or AIM-9X, bigger diameter of rocket motor is used. 

Python 5 could reach similar top speed of MICA with similar weight however, a lot of number of control surfaces providing more lethality make drag limiting the range of the Python. Russian’s R-73 or 74 series also adopted big rocket motor and heavy weight to achieve 40km+ level of maximum range; it is interestingly noted that top speed of Russian is still in M2.5 level. Probably, we could expect that motor of Vympel’s has longer burn time via sacrifice of peak thrust. As a summary, MICA-IR and R-74 enjoys top level of kinetic energy via decision of missile sizing while ASRAAM and Python optimize their performance for range and maneuverability respectively. IRIS-T, AIM-9X series limited its physical size and only concentrated short-range performance which originally SRAAMs intended for. 

3) Maneuverability

After shock of R-73, most SRAAMs secure TVC for few ten times of G maneuverability, so now, most experts argue that manned jet fighter could not evade advanced SRAAMs in lethal range. Most candidate in table 1 reach at least 50G in their peak turn. Only ASRAAM is lack of TVC which means peak maneuverability could be performed after few seconds of launch. Python 5 and IRIS-T performs little-bit better performance in maneuverability because they could fully focus in that area without limitation of cost (AIM-9X), or range (ASRAAM, MICA)

4) Sensor

ASRAAM, IRIS-T, AIM-9X share almost same sensor, array of IR sensors for better image, because they are based on the ASRAAM project. MICA is also expected to have same class of IR image sensor; Rafale simultaneously linked sensor data as IRST. Python 5 are known for larger array of IR sensors and expected to give better angular resolution than the other candidates. R-73 is the oldest missile of them, and Russian will be expected to give better sensor for R-74. As a summary, Python 5 is known for largest IR array sensors than others while Russians are still in behind in the age of 80’s. 

5) Size, Adaptability and Further Development

As we discussed in the development background, French MICA is largest one; Russian and Israel consist second group; US, UK, and German are in third group. However, the difference in weight do not significantly impact on the physical size of the missile, diameter and length. Except, ASRAAM, extremely minimized configuration as SRAAM, and Python 5, having largest sized fins, other candidates take similar internal space of planform. If proper size of booster is attached behind of the SRAAMs, they could become lethal mid-range SAM or new type of AAM. French, Israel, and German already presented ground or naval based version of their SRAAM without heavy modification. 

6) Overall

Overall comparison between these advanced missiles is not easy because they developed in different time, purpose, cost, and concept. Technological level of the major powers is similar, and no one can judge easily which one is the best among them. If fight between the fight occurs in fair condition, MICA-IR, and ASRAAM provides trigger-initiative for their pilot. MICA is also top-speed runner among them which provides short shot-to-kill time for best convenience. When we consider MICA also contain TVC for close maneuverability, MICA could cover wider range of aerial combat from semi-mid to short range effectively. Indeed, I could set MICA-IR as top performance missile among candidates. In a close range, Python 5 has large sensor part and high maneuverability with high speed which could be at top position in lethality. Except those heavier ones, MICA and Python 5, IRIS-T and ASRAAM could compete for 2nd place of the missile. While ASRAAM has advantage in range and speed, IRIS-T attached TVC and fins to give better lethality than ASRAAM in close range. Russian and US seems to be little behind due to the age (R-73), and cost concept (AIM-9X). 

7) Compatibility with Future Weapons like DEW, MDSM, or SACM – Conclusion

In the future aerial fights, these missiles still in place however, DEW, MDSM and SACM will push their own position. DEW obviously has advantage over missiles for its magazine, promising un-limited shot, and it could be used as CIWS of fighters in future. Laser generally requires massive power for fighters, and it is expected that large 6th generation fighter only enjoys that magazine advantage overcoming power usage. If current 4.5 or 5th generation fighter uses DEW, range or simultaneous usage of DEW could be not enough for engagement of multiple targets. 

MDSM and SACM, half size of conventional SRAAM, could be another alternative for DEW and current SRAAMs. They appeal double magazine than the conventional one because internal weapon bays suffers limited load of the missiles. These choose hit-to-kill method, side nozzle, and optimum trajectory to reduce size and maximize range in their limited size. No one could expect that these could replace current SRAAM completely. Before SACM and MDSM are fully matured, SRAAM probably has advantage for range slightly and mix of SRAAM and SACM could be used for a while. In that reason, AIM-9X and IRIS-T, having little advantage in range, could be phased out easily via advent of SACM. Already US pilot preferred AIM-120 in close combat than AIM-9X having longer minimum range than mid-range missiles. This is the possible reason that US only slightly upgraded AIM-9X without heavy investment on advanced SRAAM. 

French, UK, and Russia could discriminate their missiles over SACM class for its relatively longer range; also, French and UK will not hesitate to use MICA and ASRAAM as semi-mid-range missile, having radar-homing variant as MICA-EM and Sea-ceptor (although it is naval use) respectively. So, temporary, distinction between medium and short range missile become unclear as many classes of missiles are in inventory. It is no doubt that DEW expands their effective kill range as time goes on. Among the class of missiles, shortest ranged one will loses their role as DEW shows its full potential. Surprisingly, in that situation, effectiveness of SACM or MDSM is reduced rapidly; advantage of number of missile is easily neutralized by few shot of DEW. I expect that inventory of air-warfare could be shortlisted as DEW, MICA or ASRAAM class, and Medium range missiles. 

Someone could argue that it is same as the gun-SRAAM-AMRAAM combination in the current age; only difference is each component, DEW, MICA and Med. Missiles, has longer range, more magazine, and better angular tracking capability. Development of SACM and MDSM class missile can be just contemporary weapon for F-35 and F-22 having small internal weapon bays. Their legacy, hit-to-kill technology and miniaturization of components, will be survived for new medium range missiles which will be consists of booster and SRAAM. 

2018년 5월 19일 토요일

Project Lavi

Image result for lavi jet

Israel's old project, Lavi, is development of light weight jet fighter using F404 engine, similar size of FA-50 or F-20. Linked paper presented initial sizing study of Lavi while vid. shows effort of development. 

There was a rumor that effort of Lavi design was delivered to China's J-10; both aircraft have similar planform configuration except size of engine (F404 vs AL31F).

2018년 5월 10일 목요일

Small Note for [1... : 1.3.1] : Current Technical Difficulties in Hypersonic MIRV Air to Air Missile

Full Article of [1. High AoA Aerodynamics for Combat Aircraft : 1.3.1]

As I argue future air-warfare of 2030 age in [1. High AoA Aerodynamics for Combat Aircraft : 1.3.1], age of the successor of 5th generation fighters, I had proposed hypersonic MIRV Air to Air missile to overcome the layered defense line of 6-5th generation fighters. 

Although, numerous past and recent studies of hypersonic vehicles extended our understanding of hypersonic and propulsion device, scramjet engine, a lot of inherited difficulties related to hypersonic MIRV Air to Air missiles. I shortlisted possible technical difficulties for the realization of the concepts. 

1. Flight of Heat Shield and MIRV Warhead Parts

Heat shield provides protection and drag reduction effect for MIRVs before they enter the terminal phase of guidance. However, it is easy to expect that precise flight control between separated head shield and MIRV warheads. it requires high level of understanding of aerodynamic characteristics of hypersonic, specifically, interference between the numbers of object in one big shock, naturally inducing complex structure of shocks. 

2. Sensor Technology for Hypersonic MIRV

In the hot flow of hypersonic condition, embedding sensor on the nose of the missile could be challenge task for missile designers. This problem is already serious for hypersonic ammunition which are currently developing; this could be severe for smaller and faster air to air missile requiring more precise guidance information. 

3. Precise Guide & Control of Hypersonic MIRV against 6th Generation Fighters

As described in #2, sensor technology is huge burden for the hypersonic ammunitions. not only acquiring information from sensors, but also guidance and control of the hypersonic object for the maneuverable jet fighter is very challenge task. Similar problem was emerged when hit-to-kill style interceptor for ICBM. Now target jet fighter is much slower but it could show much unpredictable avoid maneuver than ICBMs. 

4. Miniaturization of MIRV Warhead containing SCRAMJET, Sensor, and Fuel

Similar hit-to-kill intercept missile for ICBM is very huge ordnance than hypersonic MIRV missiles, so things described above should be contained in much smaller volume of the warhead parts. Adopting of scramjet for maintaining kinetic energy in horizontal flight could reduce weight of oxidizer compare to rockets however it requires delicate design of air-breathing part. 

5. Material Problem for Producing Cheap MIRV Warheads

All of this should could be done high temperature, pressure (compare to exo-atmospheric interceptor) condition; development of light-weight material capable of operating in that condition is required. 

2018년 5월 9일 수요일

Chinese New Stealth Bomber?

Short Video of Chinese Stealth Bomber

As short video from China, they released very similar aircraft to US' B-21; even angle of shot for veiled aircraft is almost same. Chinese already showed their attempt to develop such a aircraft, however, it is first time to show specific intent. Still, there is no specific details of the aircraft, so, I could not judge any of this new bomber. 

2018년 5월 4일 금요일

1. High AoA Aerodynamics for Combat Aircraft : 1.3.1

3. Future sight of high AoA

3.1 High AoA capability become useless in future air-warfare? (laser, stealth, hypersonic, etc)

PART A. Future Air-warfare plan of US' 2030

Before we argue about future usage of high AoA on air-warfare, we have to figure out or expect what is going on future air-warfare. Actually, before 2008, full-scale emerge of China and Russia, research or development of future air-war was sluggish due to “War on Terror” against Afghanistan and Iraq. Weapon development had focused reduction of causalities for this war; naturally it leads to emphasize precision rather than speed, stealth, range, altitude, agility, and destruction. 
Advent of J-20, and Pak-Fa, symbol of new-style Cold-war, changed everything around 2008; power of Moskva and Beijing now well prepare for challenge against USAF and USN after long break of collapse of Soviet. In this article, I do not want discuss about geo-political stuff around high powers of the world near 10 years; only what I want to emphasize is that development for preparation of “After F-22” was triggered by the Chinese-and-Russian-made-new-challengers. 

Importance of high AoA or maneuverability was peaked at 70~80’s due to the lessons of the Vietnam war, described in chap. 1 of this article, and emphasizing on this lesson still alive design of F-22, J-20, and Pak-Fa. All those 5th generation fighters have well designed OML to obtain high AoA stability with TVC although long-range missiles, sensors, and stealth also took their pies. Now numerous articles released expectation for future air-warfare which will be performed by 6th generation fighter, after F-22 generation, with new fancy weapons such as laser and hypersonic guided missiles. Noticed things in these articles are that high maneuverability is not ‘1st priority’ performance factor anymore. 

Future fighters described in the articles become bigger and bigger like end age of warships before WWII, and engine manufactures already emphasize obtaining more power from engine turbine in limited fuel usage. Future air-warfare system of US consists of stealth aircraft, DEW, UCAV, Swarm of small UAV, SDB, EMP ( Advent of SACM, and DEW presents why maneuverability is not 1st priority option for jet fighter performance; US has confidence about close combat intercept could be done by DEW, MDSM, SACM acting like CIWS, RAM, and ESSM on recent warships as shown in Fig. 3.1. If these ideas of US become true in the future, US could complete multi-layered air-superiority strategy as shown in Fig. 3.2. 

Fig. 3.1. DEW, SACM, MDSM could act like CIWS, RAM, and ESSM?

Fig. 3.2. US’ 2030 strategy for air-superiority (top), possible requirement for 6th generation fighter (bottom)

EMP cruise missile could be spearhead of the possible US’ 2030 strategy air-warfare; which malfunctions enemy electronic devices commanding, sensing, and tracking US assets. It cannot guarantee downing every enemy device however, at least, it could degrade enemy capability of seamless operation. After strike of EMP missiles, remained enemy AD assets try to suppress US’ advance. Information of this kinds of activities are collected by numerous sensors including multi-spectral sensors of satellites, HALE, swarm of small UAVs launched from transport at low altitude, highly stealth 5th and 6th generation fighters. These ‘many hunters’ provides large amount of information for the commanding center or 6th generation fighter if the 6th generation fighter could be capable of taking command center role. 
Killer role is also done by multi-number of platforms like ammunitions from UCAV, 5th, 6th generation fighters or long range conventional missile from 4.5th generation fighters if they still stand for front line. Prior or danger enemy assets like fighters, and radars are primary target of AIM-120D or its replacement, hypersonic ammunition, SACM, MDSM, and DEW pod of UCAV. Enlarged 6th generation fighters usually released hypersonic weapons expected to be too huge for IWB of the conventional 5th generation fighters. These hypersonic cruise missiles target most emergency high value assets for which response time is important. 

After, AD commanding center or radars are destroyed by EMP and hypersonic missiles, remained enemy fighter, unfortunately unorganized, will be hunted by front-line 5th generation and UCAV fighters. If some stealth enemy fighters have fortune to close range between US and enemy ones, DEW and CUDA like missiles, SACM and MDSM, could provide overwhelmed magazine and self-defense tools for friendly assets. While numerous platforms from space to airborne spot location of enemy, 2nd swarm of UAV provides missing spot information of enemy stealth platforms. These swarmed UAV sometimes will be used as ‘Kamikaze’ style attack when situation is in urgency. US thinks this multi-layered defense and attack could handle any kind of non-nuclear AD threat; it seems that air-warfare evolves as naval-warfare without aircraft-carrier. Each 6th, 5th generation and UCAV corresponds to cruiser, frigate, and destroyer while performance of the fight is determined by what they carry. 

It is why US’ commercial for future warfare did not emphasize maneuverability of platform itself. Finding, tracking, hunting, and even evading could be done by sensors and ammunitions launched from the fighters. Fighters do not have to show their extreme turning performance because kill or killed will be decided by magazine of DEW and MDSM. Someone could argue that this is revival of ‘missile fantasy’ of 60’s before break of Vietnam war; difference is completeness of technologies underneath of the missiles and DEW is much higher than the past one. So, now high maneuverability enters the technology of the past? Like big-gun technologies of WWII battleship? When we limit our discussion about future air-warfare in 2030, it looks correct. However, from Part B, I will present counter-technologies of US’ 2030, and possible revival of high maneuverability in future air-warfare. 

PART B. How to counter Air-warfare plan of US' 2030

US’ strategy described in Part A reminds us multi-layered defense tactics like air-defense system of WWII warship without carriers or big-box formation of WWII bombers believed to provide perfect coverage for all directions and enough depth. One of the strategy to follow this one is just build better or bigger than any other; building bigger, stealthier, and more fighters than enemy. However, that kinds of strategy already seem to arrive in final destination as shown in F-35 case; many countries feel too much burden on building or buying F-35s. How many countries buying enough number of 6th generation fighters having lots of functions proportional to the cost? It is very probable that divergence of cost and function of the next generation jet fighter limit the number of production itself. Because of this reason, similar to fate of big battle ships of WWII, only limited number of countries like US, USSR, Chinese, Japan, and EU is capable of having limited number of 6th generation fighters. 

 Counter method of this vicious circle is combination of relatively cheap method from the un-expected directions; asymmetric power method was usually used as weaker side. One of the famous example of the asymmetric power is usage of U-boat developed and well-used by Kreigsmarine in WWII; Nazi German tried to compensate advantage of Royal Navy by using the highly stealth weapon at its time. Lessons from the famous history is well reflected in the current US’ strategy that US want to use stealthier fighter and invest their assets on ‘finding-enemy’ very generously. Indeed, asymmetric approach should be come from other than stealth method which US has most confidence about. Possible approaches for the asymmetric method are aggressive usage of ‘Hypersonic’, and ‘EMP’ missiles. Hypersonic and EMP concept are also adopted by US already as one their teeth, however, as shown in the U-boat case, submarine itself was not first invented or used by Germans, similarly. 

 How to use hypersonic and EMP missiles more aggressive than US’? Fig. 3.3~3.5 summarize usage of Hypersonic MIRV ballistic and conventional EMP missiles for air-to-air combat. The missile consists of one big booster, delivering MIRV warheads to semi-orbital altitude, heat shield, protecting MIRV from strong shock of hypersonic, and MIRV warheads having small scramjet engine to preserve kinematic energy and maneuverability to kill enemy fighters. In a similar altitude of air-to-air combat against US’ strategy is not easy task as described above; solution should be coming from vertical advantages. If threats were coming from horizontally, US’ strategy, multi-layered and deep magazines of missiles and DEW, works well. Hypersonic ballistic missile could break this by reduction of response time via speed, direction, and multi-warhead while EMP cruise missile intrudes in horizontal direction to divide situation-awareness resources and down the UCAV power of US. 

The approach could compensate the reach advantage of US achieved by long range ISR assets and stealth performance of the platforms. Sensors of the platform mostly focus on lower direction than upper one because sensing the high altitude object is very clear task. However, story goes little bit different when object is in the altitude higher than ozone or sub-orbital layer. Ion-object interaction could interrupt object detection, and IR sensor became main method to detect the object. As we know, performance of IR sensor, angular resolution or range estimation, is lower than that of radar in similar condition; more importantly, US asset is not heavily depending on the IR sensors. Indeed, if hypersonic MIRV ballistic missile could achieve higher altitude than US assets, detection capability against missile is significantly reduced due to that only limited assets like satellite and HALE could detect the missile. 

Fig. 3.3 High Alt attack from hypersonic MIRV

Fig. 3.4. high speed + high AoA for unmanned missile or platform

Fig. 3.5. Specific details of hypersonic ballistic MIRV for counter of 6th generation fighter

After, the missiles avoid detections of the US assets (number 1 phase in Fig. 3.3) and enter the enough high altitude, conventional assets could not intercept the missile, except missile used for MD like SM-6, or THAAD. However, usually, launchers of these MD missiles are not coming with aerial platform until now. Even if they carry it, weight of the missiles limits magazine of the missiles. The missiles start to cruise in hypersonic speed with its scramjet engine which maximize range of the missile via weight reduction of oxidizer carried internally in the conventional rocket engine. When the fuel of the scramjet booster is consumed, missile now separates its warhead as shown in Fig. 3.5. Actually, impact of shock wave at re-entry phase is magnificent, and heat shield acts as front-runner to face the shock wave to protect MIRV warheads. MIRV falls to lower altitude where re-entry phase is over, then heat-shield acts as dummy to harass interception system of US assets. Other hidden MIRV parts activates its scramjet thruster to engage 5th or 6th generation fighters from the upper head of them; MIRV could be changed to one unitary EMP warhead to shut down enemy electric assets. 
There are few reasons why I choose way of intercept in this complex method. MIRV could do counter-act against close combat defense of 6th generation fighters, combination of DEW and MSDM. They have high speed and are coming from upper altitude reducing effective range of MSDMs. If MIRV flythrough whole the altitude from the start, cost of material and sensor is increased to sustain the load of high speed. This is why heat shield act as front runner in front of the MIRVs during dive re-entry. Cost of the MIRV is also reduced by choosing free-fall type warheads, however, even small scramjet thruster is required to maintain its maneuverability at terminal phase. Cost of making this kind of missile is expensive compare to conventional one; not expensive than 5th or 6th generation fighters. 
Although these missiles could be operated in any platform which could reach altitude higher than few kilo feet from the sea level, stealth, long-endurance platform is preferred to flexibility of operation. Possible operation platform is suggested as shown in Fig. 3.6; contrary to US’ 2030 one, expensive options like DEW and MSDM could be avoided. Detachable wing-extension and engine pod could be also suggested for flexible operation of speed and altitude in emergency situations. 

Fig. 3.6. Platform of hypersonic ballistic MIRV; 

 After, complete readiness of US’ 2030 is broken, possibility of close combat between aerial platform is increased. Remained air-asset fights like combat-knife style among UCAV, few manned 5th, 6th generation fighters; in this combat, UCAV, SACM, and MSDM are required to have high maneuverability against for each other. Indeed, US’ 2030 strategy try to rule out usage of high maneuverability in combat due to its uncertainty of winning, fatigue on airframe, and pilot; DEW, SACM, MSDM is result of this research. I supposed the idea of spear for this strategy, and core of the idea is hypersonic ballistic MIRV missile which open the narrow path to US assets. 

 In a future aerial combat, high AoA maneuver is probably not done by manned vehicle, maximum of which was already overtaken by missiles since advent of R-73s. However, legacy of Vietnam war lessons was remained until F-22 generation for emergency or perfect preparation; US’ 2030 strategy shows US will out of this trauma. High AoA maneuverability should be performed by missiles like SACM, MSDM, or the supposed hypersonic ballistic MIRV or UCAVs in future combat, and it means high maneuverability should pursue endless goal for more than 9G and could perform its maneuverability in high supersonic or hypersonic speed.