Sirena alert System for the MiG-15Bis (Radar Warning Receiver for the AN/APG-30 radar)

July 26

Hello guys! Want to know how the Sirena system works in the MiG-15 and detect those AN/APG-30 emissions? How to beat the detection system too in a Sabre? This is for you!

Cockpit Appearance

When the Sirena system is installed, two additional components are fitted to the cockpit:

1. Visual Warning System

An SM-30 warning light with a red filter, mounted in an SLT-45 housing bearing the inscription "Enemy on the Tail". It is installed on the front-right side of the cockpit

2. Control Unit

A standard housing fitted with a rotary knob and a toggle switch.

Rotary knob: Adjusts the warning tone volume (counter-clockwise = lower volume, clockwise = higher volume).

Toggle switch: Turns the entire Sirena system ON or OFF (left = OFF, right = ON).

How It Works

Sirena does a simple job: detect emissions from the AN/APG-30 radar. It remained effective for years, even against aircraft such as the F-100 Super Sabre, which used the same radar.

The system has an effective detection range of approximately 8 km, down to just a few metres, within the rear hemisphere. The receiving antennas are located near the tail navigation light, in the vertical fin.

Note: Sirena does not measure the distance to the attacking aircraft. It simply detects the radar emissions from the AN/APG-30. As the received signal becomes stronger, the warning tone increases in volume/tone, indicating that the emitting aircraft is likely getting closer or pointing its radar more directly at the MiG.

Limitations and Advantages

The Sirena also has some important limitations. Its lower rear coverage is very limited, meaning that if the pilot lowers the nose, the system may lose coverage of targets flying at the same altitude behind the aircraft. Likewise, if an aircraft equipped with an AN/APG-30 approaches from below, the system may not detect it.

Lateral coverage is also restricted, with an effective detection angle of around 20° to either side of the rear hemisphere. However, Sirena also offers a major advantage. The AN/APG-30 only begins providing an accurate firing solution at around 2 km, whereas Sirena can detect its emissions from up to 8 km away.

Since the radar transmits continuously while operating, the MiG pilot can receive an early warning that an aircraft is behind them—unless the attacking aircraft switches its radar off.

How does it warn the pilot?

The system generates an audible warning tone. As the received AN/APG-30 signal increases rapidly in strength—typically at around 4 km, as the attacker approaches weapon range—the warning becomes louder, and in IL-2 Korea the tone also becomes deeper. This provides the pilot with a clear indication that the attacker is closing in and is approaching firing range.

https://www.youtube.com/watch?v=Y3kzJsqNc1Y

More information:
https://militera.lib.ru/memo/russian/matskevich_vv/index.html (It's own author)

Adoption and trials in Korea

The following month, the 64th IAK received 18 Sirena radar warning system (SWS) kits for combat testing. Fifteen kits were installed on aircraft from the 133rd and 216th IADs. After testing the Sirena in combat, the pilots spoke highly of it and demanded that it be installed on all of the Corps' MiGs

In April-May 1953, all MiG-15bis of the 64th Corps were equipped with SPO, and in June, new ejection seats with improved armor protection were installed. In the last month of the Korean War, MiGs began to be modified to accept PPK-1 anti-G suits. Also, by the end of the war, TS-27 periscopes were installed on the sliding canopy sections of the Corps' aircraft, improving rearward visibility.

*Taken from Honza an Kongo users.