New Radars for Old Jets = F-22 Compensation

23.07.07

Categorie: Air |

The Air Force has been saying for years that it needs 380 F-22 Raptors to fill out its fighter force, but Congress has capped the program at 180 to keep costs around $60 billion. To make up for the shortfall, the Air Force is considering upgrading 180 of its youngest F-15s with new “electronically scanned” APG-63(v)3 radars roughly comparable to the Raptor’s APG-77. What you get is a “Raptor Lite” lacking only the Raptor’s stealth and more powerful engines.

Traditional radars are mechanically steered. In other words, you’ve got one antenna that literally sweeps back and forth, emitting radio waves to detect targets. That creates blind spots. In the new “Active Electronically Scanned Array” radars, by contrast, there are hundreds of individual emitters all packed together, each capable of shooting its beam in a different direction. With an AESA (pronounced “ay-ee-suh”), you can scan a whole lot of airspace with just one jet — and there are all sorts of fringe benefits. AESAs can be focused to jam other radars or even to transmit data.

“Are there any drawbacks to the AESA?” Air Power Australia asks

Two issues are of key importance with this technology. The first item of interest is power dissipation. Due to the behaviour of microwave transistor amplifiers, the power efficiency of a … module transmitter is typically less than 45%. As a result, an AESA will dissipate a lot of heat which must be extracted to prevent the transmitter chips becoming molten pools of Gallium Arsenide. …

Another issue of concern with AESAs is the mass production cost of the … modules. With a fighter radar requiring typically between 1,000 and 1,800 modules, the cost of the AESA skyrockets unless the modules cost hundreds of dollars each. With early module builds yielding unit costs of around USD 2,000, the cost penalty of using an AESA over a conventional design was prohibitive. The good news in this respect is that the ongoing trend has been downward. 

And as AESAs get cheaper, more fighters are being retrofitted or having them installed on the production line, especially in the U.S.

Eighteen Alaska-based F-15s received early-model (v)2 AESAs in the 1990s (these jets are now cascading down to Kadena, Japan, as Alaska get Raptors) and new Super Hornets got APG-79s beginning last year. The Air National Guard is next. The 180 AESA-equipped “Golden Eagles” will equip U.S.-based fighter squadrons, assuming Congress keeps the cash coming. The F-35′s radar will be an AESA, too, of course — and the European Typhoon might get AESA sometime down the line.  

Related:
Inside America’s Pacific outpost
Raptor “shot down” in exercise!
Super Hornets get new radars
Raptor photos

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10 Responses to “New Radars for Old Jets = F-22 Compensation”

  1. [...] David Axe shows why the F-22 is such a waste: not only is stealth not really needed in an air-superiority fighter (we’re decades away from even the possibility of fighting against a technologically comparable foe), but most of the advanced fighter’s advantages are really in its avionics. Which means F-15s can be made stunningly more effective by upgrading their computers… which is what I’ve been saying all along. [...]

  2. [...] David Axe shows why the F-22 is such a waste: not only is stealth not really needed in an air-superiority fighter (we’re decades away from even the possibility of fighting against a technologically comparable foe), but most of the advanced fighter’s advantages are really in its avionics. Which means F-15s can be made stunningly more effective by upgrading their computers… which is what I’ve been saying all along. [...]

  3. Joe Katzman says:

    An F-15 with AESA (like Singapore’s F-15SGs, for instance) is a long, long way from “Raptor Lite.” Stealth and supercruise have very substantial air combat benefits as well as strike benefits, which matters since Russian AA-12 missiles outrange AIM-120 AMRAAMs (stealth means you launch closer and can do “drive by shootings,” supercruise over Mach 1 extends missile range). Not to mention the thrust vectoring that helps the F-22 hold its own in a dogfight against modern opponents with canards and/or thrust vectoring (JAS-39, Eurofighter, Rafale, SU-30MKI/M, MiG-29OVT) for “slew and point” maneuvers, plus “high off-boresight” short range missiles with wide seeker cones (these days, pretty much all of the new ones). Finally, the F-22′s embedded sensors aren’t there, which give the Raptor ELINT/SIGINT interception capabilities.

    The result is an F-15+, NOT F-22 Lite. It’s an aircraft with improved missile launching ability beyond visual range, and better strike capabilities due to the AESA’s ability to do simultaneous air and ground scans. But that’s it.

    if you’re looking to upgrade US teen series fighters to make them better at cruise missile defense, improve strike capabilities against lightly to moderately defended targets, or extend the F-15′s beyond visual range superiority slightly against early SU-27/30 Flanker family aircraft, AESAs are a good option.

    Let’s not pretend they’re anything more than that, however.

  4. Nicholas Weaver says:

    You can’t be stealthy if you have the radar on.

  5. F-22s to Japan: “No, but…”?…

    Report: Japan to develop prototype fighter jet We continually deny the ability to export the F-22 Raptor, and Japan is getting tired of trying to get them: Japan plans to develop a prototype of an advanced fighter jet in the hope it will spur the Unite…

  6. [...] F-22s and delays to the follow-on F-35, the Air Force wants to upgrade 180 F-15Cs to the so-called “Golden Eagle” standard, with new radars and rebuilt structures. That work is being done at Robins. Gilstrap anticipated [...]

  7. [...] Air Force will see more money pour into radar upgrades for the 400-strong F-15 fighter force, giving the venerable jet roughly the same “eyes” as the [...]

  8. [...] Lockheed Martin. Instead, the U.S. military’s main flying branch has turned to an older jet that, with upgrades, could prove to be an even better J-20-killer than the newer, more expensive F-22. That’s right: [...]

  9. Ednonymous says:

    Nothing beats numbers…. just ask any Eastern Front veteran.

    The F-22 is a waste of money: they just can’t survive if face with the number of aircraft that potential enemies can field.

  10. […] Martin. Instead, the U.S. military’s main flying branch has turned to an older jet that, with upgrades, could prove to be an even better J-20-killer than the newer, more expensive F-22. That’s […]

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