The F/A-18 family has been a pretty successful program for Naval Aviation, from it’s origins as an inexpensive lightweight fighter, to a replacement for legacy F-4 Phantom and A-7 Corsair II aircraft. It’s evolution into the much larger F/A-18E/F Super Hornet and EF-18G Growler were surprisingly smooth programs.
But the program isn’t without its faults. For instance, the major weakness of the family has always been seen as its relatively low “fuel fraction,” that is, the percentage of the aircrafts weight devoted to fuel. A low fuel fraction leads to relatively short range. External tanks and aerial refueling mitigate this to some extent, but not without penalties in performance, payload, cost, and time.
The Super Hornets also have one other minor issue. A fair amount of attention was paid to reducing the radar cross section of the jet, without having to go full stealth. But when weapon separation tests were conducted on the prototype, it turned out that some loads were not leaving cleanly. The modified wing of the Super Hornet was doing things to airflow that no one had foreseen. Rather than have to redesign the entire wing, the fix turned out to be toeing out the external wing pylons by 4 degrees. Of course, this imposes a healthy bit of drag, both for the pylons themselves, and for any stores on them. It also pretty much shot to hell all the attention to reducing the radar cross section of the jet.
So, with the pylons off, the Super Hornet is pretty sprightly, and has fair low observable characteristics. But it doesn’t have any range, or any weapons.
Boeing is trying to work around that issue. In recent years, other “teen” series fighters, the F-15 and F-16, have used “conformal fuel tanks” fitted to the outside of the airframe to increase “internal” fuel, rather than having to carry drop tanks on pylons. With care, the design can have minimal impact on airframe drag or radar cross section. That goes a long ways toward tacking the range issue. But what about weapons? Boeing is also designing a semi-stealthy pod for the centerline that resembles a drop tank, but is instead a weapons pod.
Jason pointed out this article at The DEW Line showing a mock-up of the configuration that Boeing and the Navy will flight test this summer.
You can see the Conformal Fuel Tanks over the wing root, and the weapons pod on the centerline. Close observation will also show a sensor window under the nose, as opposed to the usual method of mounting a pod on one of the engine bays. Less drag, more stealth.
The concept is to give the Super Hornet fleet some limited ability for “first day of the war” stealth to penetrate enemy air space. My major concern is that the weapons pod right now is only configured (so far as we can tell) to carry four AIM-120 AMRAAM missiles, giving it a fair air-to-air capability. What it really needs is a capability to carry weapons to attack enemy surface to air defense systems. Some way of carrying anti-radiation missiles, or at a minimum, GBU-39 Small Diameter Bombs is going to be critical. I suppose designing an alternative pod shouldn’t be too great an engineering challenge.
Boeing is smart enough to see that its rival Lockheed Martin is struggling to make the F-35C a reality, and is trying to offer a low cost, low risk alternative that will keep the carrier air wing viable through the first half of the 21st Century.