Table of Contents Aircraft... 4

Transcription

1 Strike Fighters

2 Table of Contents Aircraft... 4 Compared Statistics... 4 Mission Performances... 5 Size... 6 Load... 7 Fuel... 7 Systems... 8 Weapons... 9 AIM-9X... 9 AIM-7M... 9 AIM-54C AIM-120D M61A M61A GAU GAU GAU Physical Factors Stability Drag Area Lift Area Mission Performance Interception F-15C vs F-22A:... 17

3 F-16C vs F-35A: AV-8B vs F-35B: F-14D vs F/A-18E: F/A-18C vs F-35C: CAP F-15C vs F-22A: F-16C vs F-35A: AV-8B vs F-35B: F-14D vs F/A-18E: F/A-18C vs F-35C: Escort F-15C vs F-22A: F-16C vs F-35A: AV-8B vs F-35B: F-14D vs F/A-18E: F/A-18C vs F-35C:... 43

4 Aircraft This study will investigate the classic Teen-Series of fighters as well as the aircraft that have or will replace them. The following aircraft will be investigated in depth. Air aircrafts performance data will come from the source listed below. All Aircraft will be evaluated at a year 2020 standard with the exception of the F-14 which is the only aircraft never qualified for AMRAAM carriage and as such will be a 2004 standard to utilize the AIM-54C. F-15C Eagle data taken directly from F-15C -1 using F100-PW-220 data, A-A only F-15E Mudhen data taken directly from F-15E -1 using F100-PW-229 data, A-G only F-22A Raptor data estimated from stated performance and engineering analysis F-16C Viper data taken directly from HAF -1 using F110-GE-129 data A-10C Hog Data taken directly from A-10A -1, A-G only F-35A Stubby data estimated from stated performance and engineering analysis AV-8B Harrier data derived from partial NATOPS and engineering analysis F-35B Bee data estimated from stated performance and engineering analysis F-14D Tomcat data derived from partial NATOPS and engineering analysis. F/A-18E Rhino data taken directly/derived from NATOPS and engineering analysis F/A-18C Hornet data taken directly/derived from NATOPS and engineering analysis F-35C Reaper data estimated from stated performance and engineering analysis Compared Statistics Size Box volume Density Load Fuel Common systems Weapons Physical Factors Stability Drag Lifting surfaces

5 Mission Performances Data Reviewed Fuel usage Speed and Altitudes Acceleration Turning Missile Flight Air to Air Interception 200nm Deep Strike Escort Air to Ground Not Available at this time CAS for 1hr Deep Strike

6 Size Strike and fighter aircraft come in a wide variety of sizes. As with any engineering endeavor there are tradeoffs to be made in deciding how large of a fighter aircraft to design and it is largely based on the primary role of the aircraft. If one lists the pros and cons of large aircraft size the following is seen. Pros: Cons: more fuel higher fuel burn more weapons greater basing restrictions more room for systems reduced agility Aircraft size can be measures many ways such as length (from 72.8ft for the Su-35S to 46.3ft for the AV-8B), span (from 64ft for the F-14D to 30.3ft for the AV-8B), wing area (from 667ft 2 for the Su-35S to 243ft 2 for the AV-8B), or empty weight (from 43,735lb for the F-14D to 13,968lb for the AV-8B). For our purposes we will use box volume (length times span times height) and density (empty weight divided by box volume). A larger box volume will indicate greater size for the pro-con list above and a greater density will indicate how tightly packaged everything is. All figures listed will be relative to the smallest/least dense aircraft. Box Volume: Density AV-8B 1 A-10C - 1 F-35A/B 1.53 F-15C 1.05 F-16C 1.58 F-14D unswept 1.23 F/A-18C 1.86 F/A-18E 1.35 F-35C 1.89 F/A-18C 1.36 F-14D swept 2.33 F-15E 1.38 F/A-18E 2.62 F-16C 1.42 A-10C 2.75 AV-8B 1.54 F-22A 2.81 F-22A 1.70 F-15C/E 3.08 F-35C 2.03 F-14D unswept 3.92 F-14D swept 2.07 F-35A 2.09 F-35B 2.32 From this we can see a few interesting date points. The Eagles are extremely large, second only to the Tomcat, but very light. The F-35 family is extremely dense as it has many things internally that most aircraft have externally.

7 Load The public often only sees fighter aircraft at airshows flying with clean wings for maximum performance. A warplane is no good without a warload however so we will look at the fuel load, systems, and both the air-to-air loadings and air-to-ground loading potentials of each aircraft. Loads are carried on one of five types of stations; light (L), heavy (H), heavy/wet (H-W), wet (W), TGP. Light stations typically carry only air to air missiles however Russian ECM systems typically go on the wingtip light stations and the Hornet series carries TGP on them. Heavy stations are typically rated to carry bombs, missiles (both air-to-air and air-to-surface), TGP, or ECM pods. Heavy/Wet stations gain the ability to carry external fuel tanks but often lose the ability to carry air-to-air missiles. Wet stations are dedicated to drop tanks only and are only found on the Tomcat. TGP stations are used exclusively to carry additional targeting and navigation equipment. These dedicated stations are only found on the F- 16C and the F-15E. Fuel Fuel is carried both internally and externally for most fighters. External fuel is carried in drop tanks mounted to either a heavy/wet station or a dedicated wet station. The trade-off of external fuel tanks is that while they are being carried they add significantly to drag and while they can be dropped they are not very cheap. Below we will look at each aircrafts internal, external, and total fuel loads as well as the number of external stations used for carrying said external fuel load. The aircraft will be sorted based on total fuel weight Aircraft Internal External Total H-W W AV-8B 7,500 4,080 11, F-35B 13, , F-16C 7,162 7,072 14, F/A-18C 10,810 4,480 17, F-35A 18, , F-35C 19, , F-14D 16,200 3,630 19, A-10C 11,000 12,240 23, F/A-18E 14,400 9,792 24, F-15C 13,850 12,261 26, F-22A 18,000 16,320 34, F-15E 22,300 12,240 34, Here we see that the F-35 family chose to forgo external tanks for combat loadings altogether while the F-15C, F-16C, and F-22A roughly double their fuel loads with them. The F-22A, however, only uses four external tanks for ferry missions. The F-15C and F-22A are essentially dedicated air-to-air platforms in practice so they do not sacrifice load carrying capability with fuel tanks while the F-14 uses dedicated fuel stations and the A-10 has stations to spare (11 in theory).

8 Systems One of the most common systems associated with tactical aircraft is the radar. Radar uses, in a most simplified form, radio waves transmitted through an antenna in the nose and then received through the same antenna. Radar has evolved greatly over the ages and continues to evolve. Early firecontrol radars need to lock a target in order to get accurate enough azimuth, elevation, range, heading, and velocity data to guide a missile. If the enemy aircraft was equipped with a Radar Warning Receiver (RWR) then the RWR was able to distinguish this difference in pulse pattern and could warn the pilot that he was being engaged. Once RWRs became common a new way of surprising your enemy was needed. This lead to Track-While-Scan (TWS) technology in which the radar transmitted a normal sweeping scan while noting the delta of a targets location on each pass and using that information to derive all the needed data for a weapons lock. A more recent advancement is that of the Active Electronically Scanned Array (EASA) radar with Low Probability of Intercept (LPI) in which the radar does not have a single large transmitter but hundreds of individual Transmit-Receive (TR) modules. These TR modules allow a radar to have as big or small of an antenna as needed for a given task by working in groups. Each group can transmit in unique directions and on separate frequencies. They also will change the frequency transmitted, and power of the transmission, a thousand times a second. By doing this the AESA radar can mask it s transmissions as noise and can likely only be detected by a system of equivalent sophistication. This is supported by numerous statements made about teen-series aircraft engaging in BVR training with F-22s (the first LPI AESA equipped fighter) in which none of their systems, radar or RWR, ever detected the F-22. For Very Low Observable (VLO) aircraft this is an important ability as it minimizes the chances of an enemy knowing even the direction from which the VLO aircraft are attacking. The following will list the specified aircrafts radar systems and if they are LPI. Aircraft Radar LPI F-15C AN/APG-63(V)3? F-15E AN/APG-70? F-16C AN/APG-68 No A-10C none - AV-8B AN/APG-65 No F-14D AN/APG-71 No F/A-18C AN/APG-73 No F/A-18E AN/APG-79? F-22A AN/APG-77 Yes F-35A/B/C AN/APG-81 Yes Other common systems carried by strike fighters are ECM for protection from enemy aircraft and ground threats as well as EO/IR systems for air-to-air and/or air-to-surface targeting work. Before

9 the Fifth Generation aircraft these systems were very large and were often carried externally in selfcontained pods. The below list gives the systems used by the selected aircraft and, if externally carried, what type of station is used to carry it in parentheses. Aircraft ECM EO/IR F-15C AN/ALQ-128 None F-15E AN/ALQ-128 LANTIRN/Sniper XR/LITENING (TGP) F-16C AN/ALQ-131 (H-W) LANTIRN/Sniper XR/LITENING (TGP) A-10C AN/ALQ-131 (H) LITENING (H) AV-8B AN/ALQ-131 (H-W) LITENING (H-W) F-14D AN/ALQ-165 AN/AAS-42 F/A-18C AN/ALQ-131 (H-W) LANTIRN/Nighthawk/ATFLIR (L) F/A-18E AN/ALE-214 LANTIRN/Nighthawk/ATFLIR (L) F-22A none listed none F-35A/B/C AN/ASQ-239 EOTS and EODAS Weapons All the above items are to enable the aircraft to deploy their weapons effectively. Weapons will fall into two major categories: Air to Air and Air to Ground. Air to Air weapons again fall into the categories of missiles and cannon. Missiles are typically judged by their speed, range, and turning ability. However, all three of these parameters will vary greatly based on many factors. For now we will just discuss the missiles employed by these aircraft. Missile AIM-9X The current standard of short range missile is the AIM-9X which has become, arguably, one of the best Infrared missiles in the world. With an Imaging InfraRed seeker it is very resistant to traditional flares and it possesses a high off-boresight (HOBS) capability to lock a target up to 90 degrees off it s nose and a Thrust-Vectoring Control (TVC). It has smaller fins than previous versions of the Sidewinder giving it greatly improved rated range of 19nm. The AIM-9M carried by the Tomcat only had a rated range of 14nm, a 45 degree field of regard, and no TVC. AIM-7M The Sparrow missile is no longer in service due to the prevalence of the AIM-120. It will be used on the F-14D only as it was never operationally cleared for the AMRAAM. In Viet Nam the AIM-7 proved an agile missile in a dogfight once its control laws were altered. With a warhead four times that of the Sidewinder it s lethal blast radius was twice as large. The M model has a rated range of 27nm.

10 AIM-54C The Phoenix missile was only carried by the F-14 and was retired before the Tomcat was iteself. It will be used for the F-14D only as it was never operationally cleared for the AMRAAM. While the AIM-54 is a heavy missile and not agile enough for most anti fighter work it carries a warhead over six times as large as the Sidewinder for a lethal blast radius nearly two and a half times larger. The AIM-54C had a rated range of 100nm. AIM-120D The AIM-120D is the latest version of the AMRAAM line which combined advanced datalinking, optimized trajectory and guidance, and improved HOBS while maintaining a small package in both weight and diameter. A warhead only 81% larger than the Sidewinder gives a lethal blast radius increase of 34.5%. The AIM-120D has a rated range of 97nm, nearly equaling the much larger Phoenix. Cannon M61A1 The six-barreled Vulcan cannon was designed in 1946 and was first used on the F-104 and has been used on nearly every US fighter aircraft up to the F-22. At 248 pounds and nearly 72 inches in length it is a rather compact weapon system. It fires a 20x102mm cartridge at a rate of 6,000 rounds per minute and a velocity of 3,450 feet per second (fps). The projectiles weigh 102.4g with a 10g bursting charge. This gives a Weight of Fire (WoF) of 10.24kg/s raw and 1kg/s burst. M61A2 The six-barreled Vulcan cannon was lightened for the F-22. This model weighs 202 pounds and is also 72 inches in length. It fires a 20x102mm cartridge at a rate of 6,600 rounds per minute and a velocity of 3,450 feet per second (fps). The projectiles weigh 102.4g with a 10g bursting charge. This gives a Weight of Fire (WoF) of 11.22kg/s raw and 1.1kg/s burst. GAU-8 The seven-barreled Avenger was built for destroying tanks and armored vehicles in the Cold War and was the starting point of the A-10 design. The gun is 620lb and over 112in long, but the system is almost 20ft long and weighs 5,000lbs fully armed. It fires a 30x173mm cartridge at a rate of 3,900 rounds per minute and a velocity of roughly 3,500fps. The projectiles weigh 367g for HEI. While the heavier API round is the most famous, the use of Depleted Uranium is now highly frowned upon. If we assume a similar percentage of charge weight between the HEI for the Avenger and the round used in the Vulcan this gives a WoF of 23.86kg/s raw and 2.33kg/s burst for HEI. GAU-12 The five-barreled Equalizer is based on the much larger Avenger cannon that has been scaled down for use on the AV-8B. The system is 270lb and over 83in long, but the external case gives a total weight of

11 1,230lb. It fires a 25x137mm cartridge at a rate of 3,600 rounds per minute and a velocity of roughly 3,350fps. The projectiles weigh 184g for HEI and 215g for API. If we assume a similar percentage of charge weight between the HEI for the Equalizer and the round used in the Vulcan this gives a WoF of 11.04kg/s raw and 1.08kg/s burst. GAU-22 The GAU-22 is a version of the Equalizer that uses four barrels instead of five for use in the F-35. The internal system weighs 416lb while the external system weighs 735lb. The rate of fire is slightly reduced to 3,300 rounds per minute. While the GAU-8 and GAU-12 had two distinct types of ammunition the GAU-22 uses a combined APEX projectile. The 223g projectile with a similar burst charge percentage as the Vulcan ammunition would give a 21.8g burst charge. This would give a WoF of 12.27kg/s raw and 1.2kg/s burst.

12 Physical Factors There are many factors that determine the performance of a combat aircraft. The most commonly used metrics are Wing Loading (W/S) and Thrust to Weight (T/W). These two parameters are often used by those who do not grasp the complexities of aircraft performance and below we will look at why these can be very misleading. Wing Loading is a measure of aircraft weight per unit area of wing and is often used to determine instantaneous turn capability. This value can be very misleading as different wing planforms allow for different maximum lift coefficients (C Lmax), lift curve slopes, load limits, and only takes into account the reference wing area. While many people recognize that the bodies of many fighter aircraft generate a sizable portion of lift they often fail to recognize that a sizable portion of the reference area is also inside the body of the aircraft. A prime example of this is the F-15, one of which famously lost almost an entire wing and flew home on body lift. While essentially the entire right wing was missing, that only accounts for roughly 25% of the wing area. The pilot was also using left roll input that generated positive lift on the right side with the horizontal tails. While a single horizontal tail only equals 8% of the wing area it can be deflected to a greater degree relative to the local airflow (given the medium speed and low maneuver environment of the remainder of the flight) to allow it to make up the lost lift. Tail area is not accounted for in the wing area and its effects vary with stability. We will look at this shortly. Thrust to Weight is a measure of the combined engines uninstalled sea-level static thrust divided by the weight and is often used to determine straight line speed, acceleration, climb, and sustained turn capability. The first problem is that no aircraft ever operated with uninstalled engines and are almost never at zero airspeed at sea level. Installing an engine in the aircraft reduces thrust available in two ways. The intake reduces the airflow through surface friction and flow distortion. Think of breathing in through a curved straw compared to without. The equipment gearbox allows the turbine section of the engine to power all the systems onboard an aircraft. To help visualize this reduction in power think of pedaling a bicycle with the back tire off the ground. The tire can easily be spun up to almost any speed with a hand. Once the tire presses onto the road however work is being done by the system and the energy required to rotate the tire at a given rate increases. The summation of these effects on sea-level static thrust is typically about 25% of the military thrust rating based on data of installed thrust ratings for various aircraft. Thrust will then change drastically with speed and altitude increase, generally increasing with speed to the inlet/airflow limit and decreasing with altitude as density drops. Lastly, all the above performance parameters are dependent on excess thrust, or thrust remaining after drag has been subtracted. Stability Stability is the tendency of an aircraft s nose to pitch down under normal flight conditions. The cause of this is the center of mass of the aircraft being in front of the center of lift. Think of a paper airplane on a string representing the lifting force. If the string is behind the center of mass the nose will point down.

13 This has traditionally been countered using negative lift on the tails, a string on the back pulling the tail down and the nose up. This has two negative effects. The first is that the lifting surfaces, the main string if you will, now have to pull that much harder to balance the total force. This means that at any given time a stable aircraft is using less than 100% of the lift being generated by the wing/body to maintain flight or turn. The second is that there is now an increase in the induced drag. There is induced drag on the tail and an increase in induced drag on the wing/body. This is called trim drag. These effects were mitigated by trying to minimize the stability margin. Starting with the F-16 there was a new option. Fly-by-Wire (FBW) controls allowed for an unstable aircraft s disturbances to be monitored and corrected dozens to hundreds of times a second. In an unstable paper aircraft the nose points up when hanging from the string. A second string is then added to the tail to lift that up as well. This reverses the drawbacks mentioned in the previous paragraph. The aircraft not only gets all of the lift generated by the wing/body, but also that of the tail. As a result of this level flight is maintained with a lower C L. This reduces the induced drag by a second order. We will now analyze stability estimates of our aircraft. Estimated were determined by looking at the Idle Descent charts and measuring L/D to determine total drag and thus find the induced drag which gives us the absolute value of the total C L and comparing that to the C L required to maintain flight, in effect measuring the trim drag. When that was not available the author used experimental values to find the point at which the benchmark specifications were met. It is important to note that stability changes with fuel burn and weapon load, it is not static. This is most notable in the F/A-18E which has a 15% range which goes from the neutral end of stable to unstable. In contrast the F-15E only has a range of around 4%. Stability listed is the percentage of the main wing/body lift that the tail is producing as downforce. Aircraft Stability F-15C 4.7% F-15E 3.3% F-16C -11.0% A-10C 10.6% AV-8B 12.0% F-14D 17.0% F/A-18C 3.0% F/A-18E 2.0% F-22A -10.0% F-35A/B/C -8.0%

14 Drag Area So just as we have seen how stability can have positive or negative impacts on aircraft performance we shall now also look at airframe drag. Drag always has a negative impact. The primary factors for drag are the raw surface area and shaping. More surface gives more skin friction but this is mitigated on aircraft designed for large degrees of radar stealth as the required surface tolerances result in a dramatically smoother surface. Shaping based drag can be intersections between surfaces or antennae sticking up from the surface and even the angle at which a surface meets the airflow. Again, airframe drag is found using the Idle Descent charts where available, elsewise found with wind tunnel data or experimentally matching the benchmark specifications. Drag Area will be the Zero-Lift Drag Coefficient multiplied by the reference wing area and represents the flat plate area in square feet of the clean aircraft. Lift Area Aircraft Drag Area F-15C F-15E F-22A F-16C 8.92 A-10C F-35A 9.75 AV-8B 7.48 F-35B F-14D F/A-18E F/A-18C 9.76 F-35C Just as there is a Drag Area there is also a maximum Lift Area representing the total C Lmax of the aircraft multiplied by the reference wing area. Lift Areas are calculated either using stall speeds from flight manuals, where available, and otherwise are found using either a CFT analysis or a formula to approximate the lift curve slope based on wing thickness, aspect ratio, taper ratio, sweep, stability, and high lift devices. The formula was first tested against known aircraft for validation. The F-16 is the anomaly here in that it reduces its max angle of attack as speed increases and as such it s maximum value of C Lmax changes. This study shows the difference of the values for 25 degrees (1G max AoA) and 15 degrees (9G max AoA) angle of attack. All stability corrections are already made at this point and this number would be a better reference than traditional wing loading to examine turning ability below corner velocity. At the lowest speeds of course there are controllability issues but that is outside the scope of this review. Weight for wing loading will be clean plus a 20% fuel fraction as a reference only

15 Aircraft Wing Area Wing Loading Lift Area Lift Loading F-15C F-15E F-22A F-16C A-10C F-35A AV-8B F-35B F-14D F/A-18E F/A-18C F-35C Note: C Lmax values for F-35 series taken as 1.85 despite data implying values of 1.91 and 2.1 for the A/B and C respectively based on calculations of lift enhancing effects. A value of 2.0 was used for the F-22A based on an analysis of the Low Speed Pass procedure and the amount of thrust available under said circumstance.

16 Mission Performance All of the previous reviews and data only serve to get help one understand some of the factors that impact mission performance. Several different mission types will be reviewed and they will be reviewed in stages of flight for the mission. Interception The basis of this mission is that the early warning systems have detected incoming hostile aircraft and the strike fighters are being launched to engage. Each fighter will have missiles for four BVR shots and will have at least two missiles in reserve for a potential close in fight. Any External Fuel Tanks (EFT) will be jettisoned as soon as they are empty. The flight profile being used is maximum power take off followed by acceleration to maximum thrust climb profile speed. The maximum thrust climb profile will be followed until the aircraft reaches an altitude at which it can accelerate to its maximum physical speed. If the maximum forward speed is drag limited then the aircraft will continue at maximum thrust for the dash stage. If the maximum speed is a placard limit and the aircraft has excess thrust then it will climb at its maximum speed until the rate of climb falls below 500ft/min or the aircraft reaches a critical fuel state. Each aircraft will then be assumed to be in a turning engagement, which for planning purposes is the fuel required for three full circle turns at max power while flying at 0.8M and 20,000ft. After the combat phase they will perform a military power climb to their optimum cruise altitude and perform an idle maximum range descent back to base/ship with a 14% internal fuel reserve unless another load is explicitly given in the manuals. 14% was chosen as in several manuals where reserve fuel is specified it averages to be 14% of the internal fuel capacity. The simplified metrics that would often be used to determine Intercept performance would be T/W and fuel fraction, the percentage of total weight that is made of fuel. This study will also look at Drag Area, which will impact tope speed; Wing Loading, which will not have any real impact; and Lift Loading, which will impact turning capabilities. Using the minizap missile calculator I found that the rated range for the AIM-120B in the program was matched by using default launch conditions of 32,808ft, launching from 1.02M at a target flying at the same altitude head on at 0.83M. The parameters of the missile were altered until the rated range of the AIM-120D were matched. A higher launch speed and/or altitude allow the missile to carry more energy into the top of its flight profile. This serves to greatly extend the range of the missile. This study will look at the flight distance of the missile that can be achieved while still holding a speed of Mach 1.88 or better. This is not indicative of launch range as that varies by the vector of the target.

17 F-15C vs F-22A: Aircraft # of EFT # of AIM- 120D # of AIM-9X Sec of cannon fire F-15C F-22A Figure 1 - F-15C vs F-22A Payload Aircraft T/W Fuel Fraction Drag Area Wing Loading Lift Loading F-15C F-22A Figure 2 - F-15C vs F-22A Physical Characteristics In terms of loadout the F-15C and F-22A are quite comparable. The F-15C has quite a bit of cannon ammo and can be outfitted with an identical missile load for almost no change in overall performance. The physical characteristics are mostly all in the F-22A s favor. The fuel graph shows how much fuel the F-22A can carry but it does not explain why it has nearly three times the range of the F-15C. Both fighters are flying a bit over Mach 2 on these intercepts and they both should be burning fuel at a prodigious rate. The overwhelming thrust of the F-22A allows it to finish its initial climb at 60,000 feet having already accelerated to Mach 1.5. Around this same distance the F-15C is accelerating through Mach 1.5 at 36,000 feet. Looking at the speed chart past 50nm it is easy to see that the F-15C is accelerating faster than the F-22A after they both level off despite the F-22A having a much more favorable rated T/W after dropping the external tanks of 1.16 to the F-15C This is due to the difference in altitude.

18 While the F-15C has a more effective inlet design for supersonic pressure recovery the F119 of the F-22 is designed for high dynamic thrust at altitude. The F-15C is thrust limited in this mission as it is at full throttle until to needs to decend for the combat portion. The F-22A on the other hand is still pulling power to not exceed its maximum design speed, which when combined with the extreme altitude gives a very low fuel burn. In the missile launch chart we can see the positional advantage of the F-22A over the F-15C. Accelerating during the climb pushes it further out in front and causes the missile engagement envelope to expand rapidly. We can also readily see the advantage of launching the AIM- 120D from 23,000ft higher at essentially the same speed. The F- 15C can get an AIM-120D out 150nm from the airfield in 13.2 minutes while the F-22A can do so in a remarkable 11.2 minutes.

19 We can see from the turn performance data that the F-15C is essentially at corner velocity at 0.8M for this weight and that the 0.8M performance varies a realitvely small amount compared to their respective corner velocity performance. The superior Lift Loading of the F-22A gives a much lower corner velocity which give improve rate and radius for a given G. Aircraft F-15C F-22A 0.8M@FL200 Avail G IT Rate, deg/s IT Radius, ft Sust G ST Rate, deg/s ST Radius, ft Corner V M Avail G IT Rate, deg/s IT Radius, ft P S, ft/s Decel, G Sust G ST Rate, deg/s ST Radius, ft Figure 3 - F-15C vs F-22A turn performance

20 F-16C vs F-35A: Aircraft # of EFT # of AIM- 120D # of AIM-9X Sec of cannon fire F-16C F-35A Figure 4 - F-16C vs F-35A Payload Aircraft T/W Fuel Fraction Drag Area Wing Loading Lift Loading F-16C F-35A In terms of loadout the F-16C can mimic the missile load of the F-35A for almost no penalty and it has more cannon fire. In terms of the physical characteristics the F-16C shows minor superiority in basic T/W and Wing Loading but it is inferior in the other three. Figure 5 - F-16C vs F-35A Physical Characteristics In the Fuel chart the first thing that should become apparent is that even when carrying a centerline gas tank the F-16C has half the fuel capacity of the F-35A on internal fuel. The Speed chart highlights some common criticisms of the F-35 program. It is out climbed, out accelerated, and has a lower top speed than the intercept configured F-16C. It completely outranges the smaller F-16C due in no small part to the higher fuel fraction.

21 The Altitude chart shows that while the F-16C has to stay at 37,000 feet to maintain the best forward speed we see that the F-35A has enough reserve thrust at its placard speed limit that it can climb to 50,000 feet while at 1.6M. Being able to climb to such a high altitude helps give it a vastly improved range by keeping the fuel burn rate down in the same manner that the F-22A did. The missile launch chart shows how the acceleration and speed of the F- 16C give it an edge in getting a missile downrange initially. Once the F-35A gains some altitude it gains a farther cast. The F-16C can get an AIM-120D out 150nm from the airfield in 12.9 minutes while the F- 35A takes 14.0 minutes to do so.

22 The turning data for this pair also reveals one of the common criticisms of the F-35 program, Sustained G. With a lower corner velocity, the F-35 can make up some of its 0.8M FL200 sustained disadvantage and generate fantastically quick and tight turns. Due to the unique FLCS of the F-16 it has a corner plateau instead of a corner velocity. This shifts its best speed to the right and while it picks up improvements to turn rate in both instant and sustained turns it widens the turn radii for both. Aircraft F-16C F-35A 0.8M@FL200 Avail G IT Rate, deg/s IT Radius, ft Sust G ST Rate, deg/s ST Radius, ft Corner V M Avail G IT Rate, deg/s IT Radius, ft P S, ft/s Decel, G Sust G ST Rate, deg/s ST Radius, ft Figure 6 - F-16C vs F-35A turn performance

23 AV-8B vs F-35B: Aircraft # of EFT # of AIM- 120D # of AIM-9X Sec of cannon fire AV-8B F-35B Figure 7 AV-8B vs F-35B Payload Aircraft T/W Fuel Fraction Drag Area Wing Loading Lift Loading AV-8B F-35B In terms of loadout the AV-8B and F- 35B are quite comparable. The lack of cannon pod on the F-35B gives a notional advantage to the AV-8B however the AV-8B may never get within range to use it. The physical characteristics tend to favor the F- 35B. The fuel graph shows that while the F-35B has a signifficantly greater fuel load it also burns fuel at a much faster rate due to the lack of afterburner on the AV-8B. While this gives the AV-8B a great range advantage on a full-throttle mission an intercept really is time sensitive so much of that added range is wasted. Looking at the speed graph we can see the greatest physical advantage the F-35B has over the older AV-8B. The F-35B does have a very short range in this profile as it has a small fuel load concidering the output of the engine. In the altitude graph we see that the F-35B climbs to a higher altitude in Figure 8 AV-8B vs F-35B Physical Characteristics

24 less distance than the AV-8B. The missile launch graph helps to shiow the combined effect of the performance gap between these two aircraft. In the time it takes for the AV-8B to reach 32,000ft at 0.82M the F-35B is already at 36,000ft and has accelerated to 1.5M and could potentially already be in a position to get a missile 150nm from the LHA. The AV-8B needs an astounding 19.4 minutes to get an AIM-120D 150nm from the LHA due to its low speed and altitude while the F-35B shaves five full minutes off of that time and can do the same task in 14.4 minutes. This shows that while the AV-8B has been equipped with a BVR radar and missile it is by no means an interceptor.

25 We can see from the turn performance data that the AV-8B and F-35B are very similar in what the airframes can generate at 0.8M at FL200 but the sustained performance is worlds apart due to the lack of afterburner on the AV-8B. The corner velocity data shows that the F-35B is superior in every way. Aircraft AV-8B F-35B Avail G IT Rate, deg/s IT Radius, ft Sust G ST Rate, deg/s ST Radius, ft Corner V M Avail G IT Rate, deg/s IT Radius, ft P S, ft/s Decel, G Sust G ST Rate, deg/s ST Radius, ft Figure 9 AV-8B vs F-35B turn performance

26 F-14D vs F/A-18E: Aircraft # of EFT # of AIM- 120D # of AIM- 54C # of AIM-7M # of AIM-9X Sec of cannon fire F-14D (-9M) 6.8 F/A-18E Figure 10 F-14D vs F/A-18E Payload Aircraft T/W Fuel Fraction Drag Area Wing Loading Lift Loading F-14D F/A-18E The loadouts for the F-14D and F/A- 18E are very different due to the F-14 never being operationally cleared for AIM-120 use. As the F-14D has two BVR missile type we will look at both of them here. While the physical performance of the F/A-18E was highly criticized when it was being introduced we can see here that it actually comes out ahead in many of the traditional physical characteristics. The fuel graph shows that while the F/A-18E has a signifficantly better fuel fraction and lower theoretical drag area it has a comparitively poor dash range. This is due to the F/A- 18E having greatly comprimised wave drag characteristics. Looking at the speed graph we can see many of the criticisms of the Super Hornet come out in a slower acceleration to a lower top speed. In the altitude graph we see both of these aircraft have similar altitude profiles until they are returning to Figure 11 F-14D vs F/A-18E Physical Characteristics

27 the ship in which case the F/A-18E is able to cruise at a much higher altitude. The missile launch graph shows that while there is a remarkable performance gap between these two planes the missile technology advancements very nearly close the gap. Importantly the AIM-7M, while a medium range missile, lacks the speed over most of it s flight profile to gain much separation from the launching aircraft. The AIM-54C uses a high loft profile that the AIM-7M lacks to extend it s range. The F-14D can get an AIM-54C 150nm from the Carrier in 13.8 minutes, the AIM-7M will never get 150n from the carrier in this profile. The F/A-18E takes 15 mintues to get an AIM-120D the sme distance, but this means the Super Hornet has 4 missiles it can launch at range while the Tomcat actually only has two. While the F-14D can be fitted with as many as six of the Phoenix missiles their weight and drag would reduce the range and speed to the point where the F/A- 18E would actually outperform it.

28 The turn performance at 0.8M and FL200 heavily favors the F/A-18E but things mostly even out once both aircraft are at their corner velocities with the Super Hornet still holding a small edge in turn rate. Important to note however is the difference in G-limits. The F-14 series is unique in that the manufacturers G limit was not observed by the user. The NATOPS had imposed a wartime G limit of 6.5G at 57,000lb weight to the F-14D (used in analysis), while Grumman had recommended a G limit of 9.5G at 57,000lb and had tested the plane out past 12G. Under the Grumman recommended guidelines the F-14D corner velocity moves up to 0.75M, 9.5G, 22.3 ITR, 2005ft radius, and P S(-2.1G). Service pilots would go over the NATOPS limit on occasion and at least one has pulled the plane to 12G without damage. All of a sudden it s Guns on Hoser. At Guns I yanked that poor Tomcat into a break that topped out at 12Gs Grumman checked that bird over when we recovered. Not a hair out of place. Joe Hoser Satrapa Snort (Dale Snodgrass) would bring in a bird from a cross-country you d start looking closer. Over-G d. Leaking fluids. Rocky Riley Aircraft F-14D F/A-18E 0.8M@FL200 Avail G IT Rate, deg/s IT Radius, ft Sust G ST Rate, deg/s ST Radius, ft Corner V M Avail G IT Rate, deg/s IT Radius, ft P S, ft/s Decel, G Sust G ST Rate, deg/s ST Radius, ft Figure 12 F-14D vs F/A-18E Turn Performance

29 F/A-18C vs F-35C: Aircraft # of EFT # of AIM- 120D # of AIM-9X Sec of cannon fire F/A-18C F-35C Figure 13 F/A-18C vs F-35C Payload Aircraft T/W Fuel Fraction Drag Area Wing Loading Lift Loading F/A-18C F-35C The biggest difference in the loadouts is the lack of cannon for the F-35C. The physical characteristics seem to even out with the F/A-18C having a better T/W and drag area and the F- 35C having a better fuel fraction and both wing and lift loadings. The fuel graph shows that while the F- 35C has a greater fuel load it also burns fuel at a faster rate due to the output of its single engine being roughly a third greater than the combined output of the two engines in the F/A-18C. Looking at the speed graph we can see the F/A-18C accelerates much more quickly to the point that having a lower top speed is almost a wash. The large wing of the F-35C gives it the most comprimised wave drag of all the F-35 variants. Important to note is that the Hornet performance here is for the F404-GE-400 engines. The F404-GE-402 engines provide a roughly 13% improvement to rated afterburning thrust but that Figure 14 F/A-18C vs F-35C Physical Characteristics

30 performance is not in the NATOPS. In the altitude graph we see that the altitude performance of both these planes is fairly similar with the exception that once the F-35C reaches 1.6M it can still climb on its excess thrust. The missile launch graph shows just how similar these two aircraft are in the interception role. The F/A-18C can get an AIM-120D 150nm from the Carrier in 14.3 minutes to the F-35Cs 14.7.

31 We can see from the turn performance data that the F/A-18C and F-35C are nearly identical in both instant and sustained performance at 0.8M at FL200. The corner velocity data shows that the F-35C has far better turn performance. Aircraft F/A-18C F-35C Avail G IT Rate, deg/s IT Radius, ft Sust G ST Rate, deg/s ST Radius, ft Corner V M Avail G IT Rate, deg/s IT Radius, ft P S, ft/s Decel, G Sust G ST Rate, deg/s ST Radius, ft Figure 15 F/A-18C vs F-35C Turn Performance

32 CAP The basis of this mission is that as part of a larger military action Combat Air Patrol is needed 200nm out from the base/ship. Each fighter will have missiles for four BVR shots and will have at least two missiles in reserve for a potential close in fight. All available external tanks will be used and will be held for the duration of the mission. Rated military power Thrust to Weight ratio, Fuel Fraction, Drag Area, and Wing Loading will be compared for each legacy aircraft and its replacement. Wing Loading here should reflect optimum altitudes. The flight profile being used is maximum power take off followed by military power acceleration to the military power thrust climb profile speed. The military thrust climb profile will be followed until the aircraft reaches its optimum cruise altitude. Each aircraft will then perform an optimum cruise to a point 200nm from base/ship at which point they will fly at maximum endurance speed and altitude. Each aircraft will then perform a military power climb, as needed, to their optimum cruise altitude and perform an idle maximum range descent back to base/ship with reserves as specified in the Intercept section. The CAP chart will also show how the CAP time available changes with distance pushed and will culminate with a zero-time CAP representing the maximum range each aircraft can fly with the given loadout under an optimum profile.

33 F-15C vs F-22A: AIM-120D AIM-9X EFT F-15C F-22A Figure 16 - F-15C vs F-22A Payload T/W mil FF DA WL F-15C F-22A Figure 17 - F-15C vs F-22A Physical Characteristics Optimum Cruise Alt Optimum Loiter Alt Initial Final Initial Final F-15C 37kft 44kft 25kft 33kft F-22A 40kft 47kft 30kft 34kft Despite the F-15C having a much better fuel fraction than the F-22A the Raptor s larger wing, cleaner design, and more powerful motors allow the F-22A to have higher optimum altitudes allowing for a comparatively lower fuel burn which in turn gives overall comparable endurance and maximum range. Figure 18 - F-15C vs F-22A Mission Altitudes

34 F-16C vs F-35A: AIM-120D AIM-9X EFT F-16C F-35A Figure 19 - F-16C vs F-35A Payload T/W mil FF DA WL F-16C F-35A Figure 20 - F-16C vs F-35A Physical Characteristics Optimum Cruise Alt Optimum Loiter Alt Initial Final Initial Final F-16C 32kft 42kft 20kft 30kft F-35A 36kft 46kft 33kft 34kft With exception of Fuel Fraction, the F-16C is markedly inferior to the F-35A in all physical characteristics and this is reflected in the lower optimum altitudes, lower time on station, and lower maximum range. The difference in range at which they can provide two hours of CAP is nothing short of astounding. Figure 21 - F-16C vs F-35A Mission Altitudes

35 AV-8B vs F-35B: AIM-120D AIM-9X EFT AV-8B F-35B Figure 22 AV-8B vs F-35B Payload T/W mil FF DA WL AV-8B F-35B Figure 23 AV-8B vs F-35B Physical Characteristics Optimum Cruise Alt Optimum Loiter Alt Initial Final Initial Final AV-8B 37kft 42kft 36kft 36kft F-35B 36kft 41kft 36kft 36kft The AV-8B manages to have better performance due primarily to its fuel efficient engine. While it does have inferior Thrust to Weight and Wing Loading it does have lower drag and a higher relative fuel load. Figure 24 AV-8B vs F-35B Mission Altitudes

36 F-14D vs F/A-18E: AIM-120D AIM-9X AIM-54C AIM-7M AIM-9M EFT F-14D F/A-18E Figure 25 F-14D vs F/A-18E Payload T/W mil FF DA WL F-14D F/A-18E Figure 26 F-14D vs F/A-18E Physical Characteristics Optimum Cruise Alt Optimum Loiter Alt Initial Final Initial Final F-14D 33kft 39kft 36kft 36kft F/A-18E 35kft 44kft 25kft 31kft The dynamic nature of the F-14Ds wing means the optimum altitudes will not follow the same trend as a traditional wing since once the optimum speed exceeds 0.7M the wings begin to sweep back and lose their efficiency. In this mission profile the Thrust to Weight, Drag, and Wing Loading are all very similar. In the end the far greater Fuel Fraction gives the F/A-18E the edge. Figure 27 F-14D vs F/A-18E Mission Altitudes

37 F/A-18C vs F-35C: AIM-120D AIM-9X EFT F/A-18C F-35C Figure 28 F/A-18C vs F-35C Payload T/W mil FF DA WL F/A-18C F-35C Figure 29 F/A-18C vs F-35C Physical Characteristics Optimum Cruise Alt Optimum Loiter Alt Initial Final Initial Final F/A-18C 36kft 43kft 28kft 33kft F-35C 36kft 44kft 36kft 36kft The lower drag and the lighter Wing Loading make up for the smaller Fuel Fraction on the F- 35C allowing it to have improved loiter time and range relative to the F/A-18C. Figure 30 F/A-18C vs F-35C Mission Altitudes

38 Escort The basis of this mission is that as part of a larger military action a hard target is being hit behind enemy lines. The strike aircraft will ingress at 0.9M at an altitude of 30,000ft, if able, for 390nm. The Escort plane will match speed, altitude, and distance so that any detection by the enemy will not be able to distinguish between the bombers and the escort. Each fighter will have missiles for four BVR shots and will have at least two missiles in reserve for a potential close in fight. All available external tanks will be used and will be held for the duration of the mission for the non VLO aircraft as they would be reliant on escort jammers. The VLO aircraft would maximize their stealth for this type of mission and as such will not carry any fuel tanks. Fuel Fraction and Thrust Loading (Military Rated Thrust in tons over Drag Area in ft 2 ) will be compared as these two should indicate if a plane can complete the profile as described. The flight profile being used is maximum power take off followed by military power acceleration to the military power thrust climb profile speed. The military thrust climb profile will be followed until the aircraft reaches its optimum cruise altitude. Each aircraft will then perform an optimum cruise to an initial point 390nm from the target. Each aircraft will ingress at the specified profile of 0.9M at 30,000ft (if able). The escort fighters will then have a fuel allowance for three 360-degree sustained turns at 0.8M at 30,000ft at maximum power. The aircraft will then exit the combat area with the same profile they entered with. Each aircraft will then perform a military power climb, as needed, to their optimum cruise altitude and perform an idle maximum range descent back to base/ship with reserves as specified in the Intercept section.

39 F-15C vs F-22A: AIM-120D AIM-9X EFT F-15C F-22A Figure 31 - F-15C vs F-22A Payload FF TL F-15C F-22A Figure 32 - F-15C vs F-22A Physical Characteristics Both the F-15C and the F-22A possess enough fuel and thrust to perform the specified mission profile. Interesting to note is how little the specific range seems to vary for the F-22A on ingress: nm/lb cruising at FL420/0.944M vs nm/lb cruising at FL300/0.900M. Despite having a more efficient fuel flow the F- 22A is outranged in this profile due to the sheer volume of fuel being carried by the F-15C. The F-15C has nearly burned more fuel by the time the combat phase has ended than the F-22A needs for the entire mission and it still has more left than the F-22 uses from engine start through combat phases.

40 F-16C vs F-35A: AIM-120D AIM-9X EFT F-16C F-35A Figure 33 - F-16C vs F-35A Payload FF TL F-16C F-35A Figure 34 - F-16C vs F-35A Physical Characteristics With an identical Fuel Fraction these two aircraft have remarkably similar performance in this profile. Both of these dimensionally small aircraft are able to reach out over 600nm from their base to hit the target, with the F-35A needing 2800lb more fuel to accomplish the mission. Of that extra fuel, 700lb comes from the combat portion. This is interesting as in this case the F- 35A can perform the three 360-degree turns in 3.26 minutes while the F-16C needs 3.71 minutes. The F-16C has the option of dropping the external tanks to lower the drag, which is more significant than the weight at this point. This decreases time needed to turn to 3.21 mintues, saves no fuel in that phase as the turn burns 200lb less fuel but there was still 200lb in the tanks dropped, increases the non-weapon consumables cost of the mission four to six times over*, and puts additional strain on logistics for planning future missions. *Assumes $1/lb JP-8 and $20,000-$30,000 per EFT

41 AV-8B vs F-35B: AIM-120D AIM-9X EFT AV-8B F-35B Figure 35 AV-8B vs F-35B Payload FF TL AV-8B F-35B Figure 36 AV-8B vs F-35B Physical Characteristics Neither of these aircraft possess the ability to complete the specified mission. The AV-8B lacks the thrust to make 0.9M and the F-35B lacks the fuel to maintain that speed and altitude with enough fuel reserve for combat. As such both of these aircraft have their performance plotted for a reduced speed of 0.8M. The F-35 offers improvements in every way except total fuel burned. It can fly from almost 40nm further out to sea. It has far more agility available for the combat phase, needing 3.36min to the AV-8Bs 7.15min to complete three 360-degree turns. All this despite having a landing weight over five tons higher than the AV-8Bs starting weight.

42 F-14D vs F/A-18E: AIM-120D AIM-9X AIM-54C AIM-7M AIM-9M EFT F-14D F/A-18E Figure 37 F-14D vs F/A-18E Payload FF TL F-14D F/A-18E Figure 38 F-14D vs F/A-18E Physical Characteristics Neither of these planes are able to complete the mission within the specified parameters. The F-14D lacks the fuel and the F/A-18E lacks the thrust. Both of these aircraft will have their performance measured as if they flew the mission at 0.8M. The F-14D is so short on fuel that is begins its final decent back to the carrier as soon as it clears the 390nm restriction. The F/A-18E has 4600lb more fuel to carry 9000lb less total weight. This helps drastically with fuel burn when both aircraft have nearly the same drag area.