Actually SIRIUS is not a radar, it’s an IRST. Thales proposed SMART-S Mk2 to the FELEX by the way.

Cheers,
Sunho

Below is from Aerospace Power Journal – Summer 2002.

http://www.airpower.au.af.mil/airchronicles/apj/apj02/sum02/lambeth.html

The F-117 Shootdown

It did not take long for the problems connected with the air war’s SEAD effort to register their first toll. On the fourth night of air operations, an apparent barrage of SA-3s downed an F-117 at approximately 2045 over hilly terrain near Budanovci, about 28 miles northwest of Belgrade – marking the first combat loss ever of a stealth aircraft. Fortunately, the pilot ejected safely and, against formidable odds, was recovered before dawn the next day by a combat search and rescue team using MH-53 Pave Low and MH-60 Pave Hawk helicopters led by a flight of A-10s.

Afterward, this unexpected event occasioned a flurry of speculation regarding how it might have taken place. Experts at Lockheed Martin Corporation, the aircraft’s manufacturer, reported that – unlike earlier instances of F-117 combat operations – the missions flown over Yugoslavia required the aircraft to operate in ways that may have compromised its stealthy characteristics. By way of example, they noted that even a standard turning maneuver could increase the aircraft’s radar cross section by a factor of 100 or more. Such turns were unavoidable in the constricted airspace within which the F-117s had to fly.15 Another unconfirmed report suggested that the RC-135 Rivet Joint aircraft monitoring enemy SAM activity may have failed to locate the SA-3 battery thought to have downed the F-117 and may not have relayed timely indications of enemy SAM activity to the appropriate C2 authorities. Lending credence to that interpretation, Gen Richard Hawley, commander of Air Combat Command at the time, commented that “when you have a lot of unlocated threats, you are at risk even in a stealth airplane.”16

Although the Air Force has remained understandably silent about the confluence of events it believes occasioned the F-117’s downing, according to press reports, Air Force assessors concluded, after conducting a formal postmortem, that a lucky combination of low-technology tactics, rapid learning, and astute improvisation had converged in one fleeting instant to enable an SA-3 not operating in its normal, radar-guided mode to down the aircraft. Undoubtedly, enemy spotters in Italy reported the aircraft’s takeoff from Aviano, and IADS operators in Serbia, as well as those in Bosnia and along the Montenegrin coast, could have assembled enough glimpses of its position en route to its target from scattered radars to cue a SAM battery near Belgrade to fire at the appropriate moment. The aircraft had already dropped one laser-guided bomb (LGB) near Belgrade, offering the now-alerted air defenders yet another clue. (The Air Force is said to have ruled out theories hinging on a stuck weapons-bay door, a descent to below 15,000 feet, or a hit by AAA.)17

Allegedly, at least three procedural errors contributed to the downing.18 First, ELINT collectors reportedly could not track the changing location of the three or four offending SAM batteries. Three low-frequency Serb radars that could have detected the F-117’s presence, at least theoretically, were not neutralized because US strike aircraft had earlier bombed the wrong aiming points within the radar complexes. Also, F-16CJs carrying HARMs and operating in adjacent airspace could have deterred the SA-3 battery from emitting, but those aircraft had been recalled before the F-117 shootdown.

The second alleged procedural error entailed an EA-6B support jammer that was operating too far away from the F-117 (80 to 100 miles) to offer much protection. Furthermore, it was out of proper alignment with the offending threat radars, resulting in inefficient jamming.

Last, F-117s operating out of Aviano had previously flown along more or less the same transit routes for four nights in a row (because of SACEUR’s ban on overflight of Bosnia) to avoid jeopardizing the Dayton Accords. That would have made their approach pattern into Yugoslav airspace predictable. Knowing the direction the F-117s would take, Serb air defenders could have employed low-frequency radars for the best chance of getting a snap look at the aircraft. Former F-117 pilots and several industry experts acknowledged that the aircraft is detectable by such radars when viewed from the side or directly below. US officials also suggested that the Serbs may have gotten brief, nightly radar hits while the aircraft’s weapons bay doors opened fleetingly.

In the immediate aftermath of the shootdown, heated arguments arose in Washington and elsewhere over whether US European Command had erred in not acting aggressively to destroy the wreckage of the downed F-117 in order to keep its valuable technology out of unfriendly hands and eliminate its propaganda value, which the Serbs made every effort to exploit.19 Said Gen John M. Loh, USAF, retired, former commander of Tactical Air Command, “I’m surprised we didn’t bomb it, because the standing procedure has always been that when you lose something of real or perceived value- in this case real technology, stealth- you destroy it.”20 Paul Kaminski, the Pentagon’s former acquisition chief and the Air Force’s first F-117 program manager during the 1970s, bolstered the case for at least trying to deny the enemy the wreckage. He noted that, although the F-117 had been operational for 15 years, “there are things in that airplane, while they may not be leading technologies today in the United States, [that] are certainly ahead of what some potential adversaries have.” Kaminski added that the main concern was not that any exploitation of the F-117’s low-observable technology would enable an enemy to put the F-117 at greater risk but that it could help him eventually develop his own stealth technology in due course.21 Reports indicated that military officials had at first considered attempting to destroy the wreckage but opted in the end not to follow through because they could not have located it before civilians and the media surrounded it.22 Those issues aside, whatever the precise explanation for the downing, it meant not only the loss of a key US combat aircraft, but also the dimming of the F-117’s former aura of invincibility, which for years had carried incalculable psychological value.

Have no idea about F22, nothing was said about it. Though i would think the most optimization talk in general would be about RAM, as composition and thickness of that influences the amount of return youd generate from certain wavelengths.

I would actually think that f22 should be optimized for fighter radars more so than f35. after all, f35 is the designated mud mover, designed to somewhat penetrate air defense networks which work in longer wavelength bands. Then the question might be, shouldn’t shorter wavelengths also be covered by design made to counter longer wavelengths too?

Which is all confronting the only official report, claiming jsf gives out golfball sized RCS, compared to raptor’s marble sized one. Though they didn’t say in what conditions, against what kind of radar.

Well, fire-control radars of almost all SAM systems tend to operate in X-band as well. For example the Russian SA-10 “Grumble” system uses an X-band fire-control radar which NATO calls “Flap Lid”.

I read somewhere that in Kosovo 1999 the Serb’s low-frequency early-warning radar detected the F-117A but higher-frequency target acquisition/fire-control radars couldn’t lock on it. So the Serbs resorted to fire unguided SA-3 SAMs in barrage or guide them by optical means.

Cheers,
Sunho

Not to my knowledge. Longer wavelength bands also require larger radars. Sort of hard to pull off on a small aircraft.

Then what’s the point of the criticism that the F-35’s “Inlet VLO geometry X-band optimised” when every fighter radar operates in X-band?

How about the F-22’s inlet? Is it X-band optimised as well?

Cheers,
Sunho

From F-16.net:

http://www.f-16.net/f-16_users_article7.html

Do you mean the first F-16A was delivered as modified in 1980?

When those modifications were made to the F-16A/B?

Cheers,
Sunho

For the past three years, the Ministry of Defense has been negotiating with the Pentagon over procurement of the F-35. However, during the negotiations it became apparent that the Pentagon would not allow the IAF access to the computers that will be installed in the F-35. Access is necessary to upgrade the computers and integrate them with new ordinance, communications, and electronic warfare systems. The Pentagon previously allowed the IAF’s access to computers of the F-15 and F-16.

Snir said, “The interpretation given to the US refusal, making out that this is a great crisis, is utter rubbish.” He said the US rejected similar requests from other air forces interested in procuring the F-35. Even the UK, which is investing $2 billion in the program, was denied access, and only after last week’s meeting between US President George W. Bush and UK Prime Minister Tony Blair did the Pentagon allow the RAF access to the F-35 computer.

Snir adds, “It should be remembered that Israel has invested only $35 million in the F-35, whereas Italy and the Netherlands have invested almost $1 billion each.” He says the US is refusing to grant access to the F-35 computer because its architecture is different. He stressed that Israel obtained access to the F-15 and F-16 computers only after their development was completed. He said there was no dispute with the US that IAF F-35s would include Israeli communications and electronic warfare technologies and missiles developed by Rafael Armament Development Authority Ltd.

The IAF received its first F-16A in 1980 and the first F-16I with extensive Israeli components arrived in Israel 24 years later. Would it be similar for the F-35?

Cheers,
Sunho

Well, certainly the Singapore F-16s have Israeli ‘spines’, and I suspect there are other Israeli-equipped F-16s out there, though details may well be somewhat restricted (it is not common for countries to list the specific equipment used in their fighters, for obvious reasons).

I think the issue with the radar was not entirely credit related, I have a feeling it was partly due to not wanting the bad advert of your best customer refusing to use your own radar…

Chilean F-16s can fire Python 4 and their D models have the Israeli spine.

Cheers,
Sunho