The S-11 SD-SYSTEM (SELF-DESTRUCTION-SYSTEM) is device stored in the skirt armor of all TSFs, expected to undertake Hive infiltration missions. Generally used as suicide devices in case a pilot or their TSF is critically damaged in battle while still surrounded by BETA, as a means to a painless death, and to destroy as many BETA as possible.
Essentially, the most powerful explosive humanity has without resorting to things such as nuclear weaponry or G Bombs. Each device has an explosive yield similar to that of a tactical nuclear warhead.
An S-11 also has a handle on it, in the event that it can't be used by the TSF it is stored in, it can be taken out and used by another TSF as a thrown explosive such as in the operation to seize the Kashgar Hive in Muv-Luv Alternative, or in some cases, carried to a location and detonated there such as in the last battle of Muv-Luv Unlimited The Day After Episode 01 and during the Refugee Liberation Front's attack on Yukon Base when the US took advantage of the chaos to hinder the Soviet Union.