역사 1999년 - EA-6B가 없었던 것이 F-117 격추의 원인 중 하나

[위종민]

https://theaviationgeekclub.com/usaf-aerospace-engineer-explains-how-serbs-were-able-to-shoot-down-an-f-117-stealth-fighter-during-operation-allied-force/

익히 알려진 동일한 비행경로를 여러 번 재사용한 실수에 더해, 원래 EA-6B가 전자전 지원을 제공하는 것이 표준 작전절차인데 그 날은 날씨 문제로 EA-6B가 비행하지 못했다고 합니다. 또한 세르비아는 민간 소식통을 포함한 이탈리아의 각종 정찰자산을 이용해 EA-6B 지원 없이 F-117이 공습을 실시할 거란 사실을 알고 있었다고 하네요.

또한 S-125는 보통은 고정식으로 운용되지만 세르비아군은 훈련을 거듭해 4연장 발사기에 2발만 미사일을 장착해 90분만에 미사일 시스템을 재배치할 수 있었다고 합니다. 나토가 침투경로에 사전에 미사일이 없었다는 걸 확인하더라도 세르비아군이 몇 시간 뒤에 S-125를 매복시킬 수 있었다고. 

대공방어 시스템은 P-18 조기경보레이더와 P-15 표적획득레이더, SNR-125 사격통제레이더, PRV-11 고도측정레이더로 구성됐으며, P-18은 F-117을 잡기 위해 가장 낮은 주파수와 최대 대역폭으로 작동시켜도 F-117에 대해 15마일  이내에서 말 그대로 조기경보만 가능했다고 합니다.  그래도 비행하는 경로를 알고만 있다면 다른 시스템에 접근 정보를 알려주기엔 충분했다고 하네요. 

C대역 표적획득레이더인 P-15는 F-117이 머리 위로 지나가도 탐지하지 못해 쓸모가 없었다고 합니다. 따라서 P-18이 F-117 접근 경보를 올리면 SNR-125를 제한된 시간 동안 F-117의 예상 접근위치로 비췄다고 합니다. 격추 전에도 F-117 격추를 위 해 두 번 매복을 시도했다고 하네요. 격추 당시에도 SNR-125를 처음 켰을 땐 F-117을 못 찾았지만, EA-6B가 없다는 사실을 알고 있기 때문에 일정시간 뒤에 SNR-125를 또 가동시켰고 때마침 폭탄창을 연 F-117을 탐지했다고 합니다. 

USAF Aerospace Engineer explains how Serbs Were Able to Shoot Down An F-117 Stealth Fighter during Operation Allied Force - The Aviation Geek Club

Dario Leone

10-13 minutes

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‘Unfortunately, on the day Vega 31 would be taken out of the sky, the [EA-6B] Prowlers were grounded due to weather. The decision was made for the F-117s to fly their strike mission unsupported,’ Chris Morehouse, USAF Aerospace Engineer.

The F-117 Nighthawk was developed in response to the urgent national need for a jet fighter that could operate completely undetected by the enemy. In true Skunk Works fashion (Skunk Works is Lockheed Advanced Development Projects in Burbank, California) it was developed rapidly and in complete secrecy.

The F-117A production decision was made in 1978 with a contract awarded to the “Skunk Works.” The first flight over the Nevada test ranges was on Jun. 18, 1981, only 31 months after the full-scale development decision.

Streamlined management by Aeronautical Systems Center, Wright-Patterson Air Force Base (AFB), Ohio, combined breakthrough stealth technology with concurrent development and production to rapidly field the aircraft.

The first F-117A was delivered in 1982, and the last delivery was in the summer of 1990. Air Combat Command’s only F-117A unit, the 4450th Tactical Group (later 49th Fighter Wing at Holloman Air Force Base, N.M.), achieved operational capability in October 1983.

During Operation Desert Storm in 1991, F-117A’s flew approximately 1,300 sorties and scored direct hits on 1,600 high-value targets in Iraq. It was the only U.S. or coalition aircraft to strike targets in downtown Baghdad.

In 1999, 24 F-117A’s deployed to Aviano Air Base, Italy, and Spangdahlem AB, Germany, to support NATO’s Operation Allied Force. The aircraft led the first Allied air strike against Yugoslavia on Mar. 24, 1999.

Three days later, on Mar. 27, one F-117A (AF ser. no. 82-0806) was lost to enemy action.

How were the Serbs able to shoot down an F-117 stealth aircraft?

‘Through a combination of Complacency, Strategy and Luck,’ Chris Morehouse, US Air Force Aerospace Engineer, said on Quora.

‘First the Complacency. This was on the part of the US Air Force, and joint allied forces. The routes used by the F-117s during the shoot down had been flown previously multiple times. This contrary to the F-117 operations in the 91 war where they flew into Baghdad, never repeating the same inbound track consecutively.

‘Perhaps this was due to over confidence in their equipment, and air superiority. During Operation Allied Force, the NATO air campaign, it was standard operating procedure (SOP) for all strike missions to be accompanied by electronic warfare aircraft [EA-6B Prowlers]. These aircraft flew with strike missions to detect, jam, and destroy enemy radar installations. Because of these aircraft, it was difficult for the Yugoslavian anti air forces to operating their radars and get target quality tracks on even conventional military aircraft. Keep in mind, during the 78 days of Operation Allied Forces we flew 38,004 air sorties and lost only 2 aircraft to enemy fire. The Prowlers were a big part of that unprecedented record.

‘Unfortunately, on the day Vega 31 would be taken out of the sky, the Prowlers were grounded due to weather. The decision was made for the F-117s to fly their strike mission unsupported.

‘Worse yet, the Yugoslavian anti air forces knew that the Prowlers were grounded, and knew that the F-117s were going to fly a strike mission anyway. How did they know? Because the Serbs had spotters and human intelligence assets in Italy, where the strike missions were flying from. They had also compromised NATO communications in the area, and had civilian source in Italy feeding them intelligence who had access to operational information. In short, the NATO forces had a massive failure in operation security, OPSEC, that was feeding valuable data to the enemy. The Serbs knew the strike was coming, knew the general route, and knew the F-117s would be flying without electronic warfare support.

‘It is important to note that the F-117A is a very lean aircraft. It has no radar of its own. When flying for penetration all of its antennas are retracted. It had a single system that could function as a radar warning receiver, but the antennas are not exposed during a strike mission. As such it has no way of detecting search and track radar on its own. Simply put, operating alone, it is effectively blind.’

This print is available in multiple sizes from AircraftProfilePrints.com – CLICK HERE TO GET YOURS. F-117A Nighthawk (Stealth) 49th OG, 8th FS “The Black Sheep Squadron”, HO/88-843, Holoman AFB, NM – 2008

Morehouse continues;

‘Now let’s discuss the Strategy.

‘The Serbs were leaning every available advantage they could to accomplish a shoot down of American aircraft. They knew war was not a popular option for the US civilian population, and it was perceived that if they could shoot down some American aircraft, they could turn public opinion against the air war. A particularly valued prize would of course be one of the coveted “Stealth Fighters”. As such, they worked diligently to set up anti-air ambushes for NATO aircraft, particularly hunting for the F-117As. How did they do this?

‘For these ambushes they employed two radar systems. First the P-18 “Spoon Rest D” early warning radar. This radar is a Soviet Union radar system that operates in the VHF frequency. Typical it can detect a fighter aircraft out to 200 nautical miles. The Serb’s discovered that by setting it to its absolute lowest frequency, and thus largest bandwidth, they could detect the F-117As. However, at these settings the radar cannot provide very good information on the F-117s, and the “early warning” radar could only detect them withing 15 miles. This is a very poor detection range indeed, however if you just so happen to know the route your enemy is flying, it is enough to let you know when they are getting within range of your other systems.

‘Even when the P-18 is operating at optimal performance (not at the absolutely lowest frequency) and against a conventional aircraft, it can still not produce a precision track of a quality to guide a weapon on anything more than a kilometer or so away. That is why these systems are considered ‘early warning’ radar. They are not meant to guide weapons. This brings us to the next system the Serbs used.

‘For their anti-aircraft weapon system, they had the S-125, or SA-3 Goa to NATO. The S-125 had three radar systems; The P-15 Flat Face, SNR-125 Low Blow and PRV-11 Side Net.

‘The P-15 was a C-band target acquisition radar. Nominally it had a detection range for a fighter aircraft out to 150 miles. Against the F-117s it was completely worthless. It could not detect them, even flying overhead.

‘The SNR-125 was the fire control radar, intended to guide the missiles onto their targets. This had two modes of operation for detecting aircraft, essential two different radar bands. Nominal it could detect and track a fighter aircraft between 25–50 miles out, depending on the mode of operation and conditions.

S-125 air defense system

‘The PRV-11 was used as a ‘height finder’ to get an accurate read on a targets altitude.

‘All these radars were paired with a quad missile launcher carrying the V-600 missile. A two-stage solid fueled surface to air missile with a max range of about 15 miles and a minimum engagement range of a little more than a mile.

‘This SAM system is not usually considered a mobile missile system. But the Serbs had trained diligently, and by only arming their quad missile launchers with two missiles each they were able to relocate the missile system in 90 minutes. Doing so meant they could set up ambush positions with this missile system, and then take down and relocate. So, if a route was flown one day and there were no missile systems detected in the area, the Serbs could be operating in that area just hours later.

‘The Serb had attempted to set up ambushes in this way for the F-117s two times previous to the actual shoot down. They would get an indication of a pending strike mission, and move their missile batteries into place to intercept the suspected routes. The P-18 would be able to detect the F-117As when they got within 15 miles, as was mentioned before. Even with the Prowlers flying, the P-18 did not register on their systems as a radar system when operating at their lowest frequency.

‘With the P-18 indicating the F-117s were in the area, they would time for a possible intercept and when they believed the F-117s were close enough, activate the SNR-125 radar trained in the direction of the incoming F-117s. They limited the amount of time they kept the SNR-125s active due to the risk of being detected by the EW aircraft and then hit with Anti-Radar missiles. On both previous attempts the SNR-125 was unable to detect or track the F-117s. This brings us the last bit.

‘Luck.’

Morehouse explains:

‘On the day of the shoot down, as has been mentioned, the Serbs got intelligence that the F-117s would be flying a strike mission without the support of the Prowlers. Being well drilled in setting up these ambushes, they positioned their S-125 missile system into position on the F-117s suspected approach.

F-117 canopy (Museum of Aviation, Belgrade)

‘The P-18 radar detected the F-117As when they were about 15 miles out. The Serbs activated their SNR-125 radar and detected…… nothing. Looks like they were going to miss out again.

‘Except for the fact that they knew no Prowlers were in the air. That being the case, they decided to try again. They activated their SNR-125 radars another time.

‘Meanwhile, aboard Vega 31 the Air Force pilot [Lt. Col. Dale Zelko] was preparing to drop his ordnance. His weapon bay doors opened, exposing his very radar reflective bomb bay interior.

‘The SNR-125 radar detected the F-117A five miles distant. We should point out that this strike mission had 3 F-117s in it, and they only were able to target one of them. This reinforces the fact that they were ONLY able to do so because at that time Vega 31’s weapons bays were open.

‘The Serbs fired at least 2 missiles at Vega 31. The F-117A had no indication it was being painted by a targeting radar, but the pilot did visually acquire two missiles that were launched against him. The first missile flew right by the aircraft, passing it overhead. A close miss. The missiles passing buffeted the stealth fighter but it did not detonate, its proximity trigger likely not detecting the F-117 to initiate detonation. The second missile that approached also failed to hit the F-117 but it DID detonate in close proximity.

‘The F-117 took blast and fragment damage. Flight control was lost, and the pilot was forced to eject.

‘Complacency, Strategy and Luck.’

Photo credit: U.S. Air Force, Srđan Popović via Wikipedia and Petar Milošević via Wikipedia