|
Print friendly version of this article (text only)
This article appeared in the January 2001 issue of Code One Magazine.
New era for air-to-air
By Lt. Col. David Nelson
 Lt. Col. David "Doc" Nelson, the first operational test pilot for the F-22, is participating in the developmental test flights of the Raptor. He is a graduate of both the USAF Fighter Weapons School (F-15) and the USAF Test Pilot School. His more recent F-22 flights have included high angle-of-attack and departure resistance testing. He also fired the first AIM-120 AMRAAM from the F-22 in October 2000. Nelson has accumulated more than 2,400 hours in the F-15 and another 1,000 hours in more than forty aircraft types, including the F-86, Mirage 2000, F-18F, F-16, and F-22.
Leading a four-ship of F-22s to a merge will be a very different experience than it is in today’s fighters. Radio calls will be minimized because fused sensors and datalinks will help pilots digest and share information much more easily. Cruising to the merge at supersonic speeds without afterburner will increase lethality, reduce vulnerability, and shorten enemy reaction time. Under the cloak of stealth, every pilot in the four-ship will be unthreatened beyond visual range. And if some lucky bandit survives to the merge, he will be overwhelmed by the Raptor’s ability to turn quickly and shoot. Stealth, supercruise, integrated avionics, and agility set the F-22 apart from any other fighter flying today. While each of these characteristics complements the others, stealth stands out as the real enabler.
Stealth
Stealth enhances every other combat capability of the F-22. Other stealth airplanes in the US Air Force fleet have demonstrated the difficulty for an enemy fighter to detect and target them. However, the Raptor incorporates these same advantages into a fighter with some real air-to-air talons. An opposing pilot searching around to engage an F-22 is analogous to a blind soldier tapping around the battlefield with a white cane—he sticks out like a sore thumb. His odds of finding something before getting shot are low. Roaming the battlespace without being detected allows a freedom of maneuver unprecedented for an air-to-air fighter. Stealth, combined with the Raptor’s offensive punch, makes the job of opposing the F-22 in air combat truly miserable. Stealth combined with all of the other revolutionary characteristics of the F-22 forms the foundation of air dominance.
Stealth Plus Integrated Avionics
Fighter pilots who have flown with the Joint Tactical Information Distribution System, or JTIDS, understand how advanced avionics can be a force multiplier. JTIDS allows fighters to share information via a secure electronic datalink with airborne warning and control aircraft. It takes target information derived from AWACS and displays it in the fighter cockpit. At a glance, a pilot can see not only his own targets but also the targets identified by his wingmen and the other targets identified by AWACS. He can see who in his flight has targeted properly, and he can see the state of his wingmen’s targets, the general layout of the fight, and the identity of the various contacts. JTIDS significantly reduces the amount of radio communication needed to complete a mission. It also increases situational awareness by an order of magnitude. By building an overall picture of the fight and sensibly displaying it in the cockpit, JTIDS frees the pilot to select and execute the optimum tactics. The avionics increase lethality and lower vulnerability.
The centerpiece of the F-22 avionics suite, the active electronically scanned array radar, is just as revolutionary as this datalink capability. Track quality throughout the entire field of regard of this radar is better than the weapon quality track-while-scan volumes of current weapons. The agile electronically steered beam tracks multiple and widely spaced targets simultaneously and accurately. This radar bolsters AMRAAM’s multi-targeting capability.
The F-22 avionics suite collects information from multiple sensors, both active and passive, and fuses that information onto one large color situation display. Three other mid-sized color displays can be used for attack, defense, stores management, and other functions. Color and shape identify each target. The large plan position indicator format of the situation display shows the true relation from the F-22 to each target and the true relation from target to target. Ground sites and navigation aids are also displayed in their proper relation. Attack steering, shoot cues, threat status, weapon fly out, and a host of other time-critical information are funneled into the pilot’s brain, effortlessly. Luckily, the intuitive layout of the displays eliminates the need for an advanced degree in symbology.
The F-22’s information gathering and sharing capability contrasts with its ability to deny information to enemy pilots through stealth. Its powerful sensors pull in lots of battlespace information. Its datalink pulls in lots of information from other aircraft in the formation. It also knows what the AWACS knows. Paradoxically, enemy pilots give up information to the F-22 by merely using their sensors to search for it. While the information streams into the F-22 cockpit, the opponent’s search is rejected by the Raptor’s cloak.
 Stealth Plus Supercruise
The Raptor supercruises very nicely, and I’m not referring to speeds of only 1.0 or 1.2 Mach. For the sake of security, let’s just say only that the aircraft can achieve in excess of 1.5 Mach in military power. Of course, we won’t be raging around supersonic in the cap or up initial, but we’ll have speed when we need it—enroute to a merge, running “out” if you’re not sure where everyone is, or running down that Flogger you really need to nail. The airplane supercruises at essentially any altitude.
Some of the advantages of supersonic flight are obvious and generally understood, like the extra energy imparted to a missile launch, the speed to get somewhere quick, and the ability to reduce enemy reaction time. These advantages are magnified if high-speed flight can be prolonged. The F-22 can significantly prolong supersonic flight, making it a tactical practicality by sustaining it without a gas-guzzling afterburner.
Supercruise can also act as a countermeasure— another advantage not as clearly understood. In conjunction with stealth, supercruise significantly limits the number of enemy shot opportunities. Any pilot who has flown a high fast intercept on an SR-71 or on a Foxbat in the simulator knows what I mean. A high-speed Foxbat making a ten-degree check turn can ruin an interceptor’s day. Similarly, a supercruising F-22 kinematically challenges any missile fired at its stern or aft quadrant. Beam quadrant shots are challenged with kinematic and seeker gimbal limitations as well as with clutter. Pure head-on shots at the F-22, on the other hand, may appear to be enhanced by the high speed, but stealth limits this effect by minimizing the threat’s acquisition range.
A subsonic airplane is easily targeted by fighters from the stern, aft quadrant, beam, and front. Attackers approaching from the stern have a relatively good stand-off capability since their missiles don’t need to go so fast to run down a subsonic fighter. As the targeted airplane pushes past the Mach, however, it greatly reduces any stern firing opportunities. Similarly, aft quadrant shots are denied because they lack the energy to complete the flyout. Beam shots fail because missile seekers exceed gimbal limits when they attempt to pull the proper amount of lead for an intercept.Front quarter shots are limited because of the higher line-of-sight rates created by a high-speed target. All of these shots are complicated by thin air at high altitude, where the F-22 flies comfortably. Adding stealth to these situations significantly reduces the vulnerable area, even at subsonic speeds.
Agility
The features of the F-22 highlight the Air Force’s commitment to agility for its next air-superiority fighter: big engines, a huge wing, thrust vectoring nozzles, leading edge flaps, giant stabilators, flaperons, and ailerons. The F-22 routinely flies to stabilized angles of attack twice as great as current USAF fighters. The aircraft has no angle-of-attack limiters in its normal combat configuration. It has flown maneuvers specially designed to put it out of control, reaching well over plus-or-minus sixty degrees angle of attack and more than forty degrees of sideslip. The airplane has never departed controlled flight. The throttles have been slammed from stop to stop above 50,000 feet and at slow speed. The engines never missed a beat. The design goal to allow pilots carefree maneuvering has been our experience.
A clean F-16 impresses in acceleration and turning performance—almost as good as an F-22. But add eight missiles to both airplanes and the performance difference expands significantly. Because of its internal weapon bays, the F-22 performs essentially the same with eight missiles as it does clean.
Ironically, the F-22’s dominant performance in beyond visual range may greatly reduce or eliminate the need to exercise this investment in maneuverability in actual combat. But the capability is there when needed.
Final Thoughts
Air-superiority pilots aren’t looking for a fair fight. Success in the air-superiority mission demands a fighter that performs better than its most capable potential adversary. The F-22 can sustain speeds and maneuver to angles so far unknown to operational fighters. The mission also demands sensors and displays that provide more information in a convenient format. Such avionics will soon be demonstrated in the fourth flying F-22. Finally, the air-superiority mission will be greatly enhanced by the F-22’s cloak of stealth, which makes it essentially invisible to other fighters. By design, the attributes combined in the F-22 will provide the unfair advantage the Air Force desires to maintain for the next era in air to air.
|
