Radar stealth does not work very well against airborne threats for three very simple reasons. First, visual identification is necessary before engagement, which requires fighters to close in to either eyeball or optical sensor range. This means that larger fighter is at disadvantage, and stealth fighters are always larger than comparable non-stealth fighters. Second, pilots will always try to approach enemy or unknow fighter from the rear to maximize time avaliable for identification and minimize possibility of being detected. This requires higher cruise speed than the target, but also that fighter remains silent during the entire intercept. While fighter performing intercept might benefit from greater situational awareness, using onboard radar warns everyone in vicinity and significantly reduces a possibility of successful attack by either intercepting fighter itself or by any friendly fighters – even those not using the radar. Third, stealth assumes that aircraft will use radars but nobody will have competent RWRs.
As a result, radar-based BVR combat is only useful against large aircraft such as transports and AWACS. But even in that case, large radar is a primary value, and stealth aircraft will have smaller radar because of the shaping requirements. Stealth can be useful to hide from AWACS’ powerful signals, but most of the time only frontal stealth is actually necessary. Further, if a stealth fighter carries out any hard maneuvers which force it to bank, it will get detected even by airborne radars.
So why all-aspect stealth?
All stealth aircraft – F-117, B-2, F-22 and F-35 were intended for offensive actions over the Soviet Union. This was a heavily SAM-infested environment, with hostile radar emissions likely from every angle – but only one altitude, as Russian doctrine meant that fighters only used radars (and IRST) for engagement, and were typically led to the combat area by ground radars. Back then, VHF radars could not provide accurate enough tracking for a SAM launch, while IRST systems – especially Russian ones – were short-ranged, unreliable and with high false alarm rates. Consequently, all-aspect stealth was a major survivability benefit.
Low numbers and sortie rate of stealth fighters were not an issue – at least up until the JSF idea floated – as stealth aircraft were intended to take on high-risk missions, eliminating high-value targets deep inside enemy territory, while conventional aircraft would establish air superiority and carry out ground attack missions over frontline areas, as well as behind the enemy lines once air defences have been sufficiently degraded. SAMs themselves were also rather static, allowing small numbers of stealth aircraft to relatively easily find and eliminate them before they could redeploy (this held true even for “mobile” SAMs).
Designers of first stealth aircraft were also acutely aware of their aircrafts’ limitations – namely, vulnerability to optical acquisition and weapons (no matter how an aircraft is painted, it will appear as a black dot against the sky from the ground, and that is not even going into issue of contrails). F-117 was originally to be painted light gray, but it was repainted black so as to prevent “geniuses” within USAF from trying to use it during the day; this was done despite the fact that light gray camouflage is actually more effective than black during either day or night (if it is so dark that black camouflage is truly effective, it is entirely possible to safely paint the aircraft pink or white as it means there is no light at all).
But the Cold War ended, and suddenly stealth aircraft found themselves with no real mission. This was especially true for the F-22 and F-35 programmes. Both were intended for combat deep behind the frontline. In their employment scenario, F-22 would provide air cover while F-35 destroyed command centers, bridges, ammunition and fuel depots, radars and other fixed ground assets. Both aircraft could still perform well in such missions, better than non-stealth platforms, but they were not strictly necessary – especially not in as large numbers. As a result, F-22 production ended at 187 aircraft (195 when prototypes are included).
However, F-35 was to be a far more important project. US defense industry placed huge stakes in it. First, it was to provide huge profits to contractors producing the F-35. Second, it was to eliminate any competition from Europe. For these reasons, F-35 has no alternative in US defense procurement. Consequently, a lot of effort was put into making the F-35 appear both better and cheaper than it is. Its production is subsidized by US tax payers, and costs are shifted around, making it appear artificially far cheaper than it is. Its lack of performance then has to be excused by a truckload of new and old technologies, all of them presented as revolutionary advances when they are nowhere close to being such.
It is important to understand that stealth was not expected to provide survivability benefit on its own. This was clearly shown with the F-117, which flew in Gulf and Kosovo wars. It suffered one loss per 2.520 sorties, while the A-10 suffered one loss per 2.250 sorties and the F-16 suffered one loss per 4.448 sorties. In Kosovo war, 1 F-117 was shot down and one sustained light damage from a near-miss, while 1 F-16 was lost and two A-10s were damaged but none were lost. F-117 was always to be escorted by jammers; in Kosovo shootdown, jammer aircraft was present but incorrectly positioned. B-2 was expected to fly at extremely low altitudes by using its terrain-following radar. F-22 was to use its high altitude supercruise capability as primary survivability strategy, while F-35 was to rely primarily on low-altitude flight and good situational awareness. In all cases, stealth was there simply to improve on aircraft’s primary survivability approach as opposed to being the primary approach itself.