133 Squadron was specifically formed in late 1976 to operate the sophisticated F-15A Eagle in the counter-air role. In order to accelerate deliveries, because of political tensions at the time, the initial four F- 15As were refurbished development (pre-production) airframes, the first three arriving on 10th December 1976 at Tel Nof Airbase.

A core of experienced pilots had commenced training on the type in early 1976 in the USA. The first new build aircraft (including a pair of F-15B two seaters), did not arrive until late 1977, with deliveries being completed in 1978.

During March 1978, the squadron's aircraft flew Combat Air Patrols (CAPs) to cover Israeli forces engaged in Operation Litani in southern Lebanon. No enemy aircraft were encountered.

The Eagle squadron scored its first air-to-air kills on 27 June 1979, when a flight of F-15As shot down four Syrian MiG-21s which were trying to intercept IDF/AF aircraft attacking PLO targets in Lebanon. A further seven MiG-21s had been shot down over Lebanon by December 1980.

A much harder target to kill, a Syrian MiG-25 Foxbat, fell to an AIM- 7F fired from an F-15A by the squadron CO on 13 February 1981. A second Foxbat was shot down on 29 July 1981.

On 7 June 1981 a number of F-15A Eagles flew an escort mission, providing top cover for the F-16s attacking the Iraqi Osirak nuclear reactor (see entry for 117 sqn). However, the Eagles did not penetrate Iraqi air space and were not called into action.

From 26 August 1981, the original F-15A/Bs began to be supplemented by second generation F-15C/D models - with improved radar, increased fuel capacity and more reliable F100-PW-220 engines replacing the -100 power units.

Although the F-15C/Ds were scheduled to split off from 133 squadron on 6 June 1982, this didn't actually occur, because the invasion of Lebanon, (Operation Peace For Galilee), was suddenly launched that same day. Throughout the invasion period 6-11 June, the Eagles operated as a single unit flying escort missions for numerous Israeli air strikes, and engaging in intensive dogfights with Syrian AF fighters. In seven days of fighting the IDF/AF claimed to have destroyed no fewer than 80 aircraft and five helicopters. Of these totals the Eagle squadron accounted for 36.5 victories for no loss - most of the remainder falling to F-16 units.

As a result of these air battles, many Eagles now carry 2, 3 or even 4 miniature Syrian Air Force roundels, as kill markings, under the cockpit.

Shortly after the ceasefire with Syria, the F-15C/D squadron was officially established - see 106 squadron for further details. Since the formation of 106 sqn, 133 sqn seems to have retired from the limelight. All IDF/AF Eagle kills since the end of the Lebanon War have been claimed by 106 sqn.

From about 1988, the unit's F-15A/Bs are thought to have been subjected to the USAF Multi-Stage Improvement Program (MSIP). This involves replacing the APG-63 radar with the APG-70, fitting improved digital central computers and CRT cockpit displays, and installation of the -220 engine used on the F-15C/D.

Along with 106 squadron, 133 was brought to full alert following the Iraqi invasion of Kuwait on 2 August 1990. Continuous Combat Air Patrols were being flown by both units by the time the UN deadline expired on 15 January 1991. However, the Iraqi Air Force declined to fight, and the Eagles could do nothing about the Scud missiles, so the continuous CAP's were discontinued by 12 February.