DCS MiG-29: Introduction to Soviet/Russian Air-to-Ground Bombs and Fuzes (2/2)
Now that you understand the vocabulary and logic of Soviet/Russian aviation bombs, we can get a look at the second pillar of the weapon system: the fuzes. Even if following the previous general articles about Western fuzes you should be familiar with most of the following concepts, you will still certainly discover peculiarities linked to the Soviet technical approach. Before we look at the individual fuze models and their settings, we will examine their general underlying principles.
II. Terminology of Soviet/Russian Fuzes
Before examining individual models, it is interesting to establish the vocabulary used in Soviet and Russian documentation. The terminology slightly differs from Western usage.
II.1 - Vocabulary
II.1.1 - "Fuze" in Russian
The English word fuze corresponds primarily to two Russian terms:
Взрыватель (vzryvatel’): “(detonating) fuze”
This is the official technical term used in Soviet documentation for aerial bombs. It designates the entire fuze unit, equivalent to the Western M-904 or FMU-139.
Взрывательное устройство (vzryvatel'noe ustroystvo): “fuzing device” / “detonating device”
This term is equivalent to the previous term, but is used in various circumstances instead of the shorter version, for example in expressions like "встроенное взрывательное устройство" (internal fusing system, or ВУ - VU).
That particular term VU is used when the fuze is built into the bomb body rather than being installed separately. In practice, a VU performs the same role as a fuze but is integrated into the bomb’s structure.
II.1.2 - "Arming" in Russian
That terms взведение (vzvedéniye) - “arming” appears consistently: it designates the activation of the fuze from safe to armed condition. It occurs after release, typically based on airflow (mechanical fuzes), rod extraction, timed mechanisms, or acceleration sequences.
In particular, it's used in a device called "механизм дальнего взведения" (long-range arming mechanism, or MVD - МДВ). This device is installed when the bomb must not arm too close to the aircraft (e.g., low-level bombing). It is not a fuze, but an intermediary system that extends or ensures the arming delay. MDV appears frequently in BETAB and OFAB documentation.
On certain types of devices, the MDV is a pyrotechnical system that burns after release, and that lets free the fuze's windmill after a given delay. This type of additional arming device is only used with older fuzes, like the AV-1. With more modern fuzes, the MDV is integrated within the fuze itself, as for Western fuzes.
II.2 - Bomb Fuze Categories
The Soviet/Russian engineers used to categorize fuzes very similarly to their Western counterparts. Let's try to identify all the various way to distinguish them.
II.2.1 - Mechanical vs Electrical Fuzes
The most fundamental distinction is between mechanical (механические) and electrical or electromechanical fuzes (электрические / электромеханические). This is exactly the same difference as for Western fuzes (eg M-904 vs FMU-139).
Mechanical fuzes constituted the backbone of Soviet general-purpose aviation. They rely purely on mechanical safing and firing logic: airflow impellers that spin once the bomb separates, inertia blocks that shift under deceleration, or mechanical locks that only disengage after a safe number of rotations. All energy required to fire the detonator comes from springs and striker pins, not from electrical circuits.
Electrical and electromechanical fuzes appeared later, either on dedicated devices like for KAB guided bombs, or through upgrade of existing fuzes. For example, the E in AVU-E fuze designates the "electrical" version of the original AVU fuze. These fuzes contain electrical detonators, powered safing chains, timed circuits, or proximity sensors. They offer greater precision and reliability, and more complex logic than mechanical fuzes.
II.2.1 - Impact, Time-Delay, and Proximity Functioning
A second standard way to classify the fuzes is by considering the mode of detonation: impact, timed, or proximity detonation.
Impact fuzes (контактные) trigger when the bomb physically strikes the target or the ground. Their sensing mechanisms may be based on deforming nose caps or inertia elements. Nearly all conventional Soviet bombs rely on this logic. AVU-E, AVT-E, and AV-139E all fall into this category and can incorporate adjustable explosion delays (from immediate action to several hundred milliseconds).
Time-delay fuzes (дистанционные) initiate detonation after a preset time interval, regardless of impact. They are used commonly in cluster bombs, and with some special bombs like illumination or leaflet bombs. That delay is generally set on the ground.
Proximity fuzes (неконтактные, or NV - НВ) trigger based on distance to the surface or to a target, using radar or other sensors. Their sensor can be active or passive. Depending on the type of energy used to determine the moment of detonation, NV are classified as radar, optical, magnetic, etc... BNV-1E and BRV-2 are examples of NV fuzes used with OFAB-250-270.
III.2.3 - Arming Delay: Short, Medium, and Long
Soviet fuze practice places considerable emphasis on arming times, defined as either short (короткое взведение), medium (среднее), and long (дальнее). These delays ensure that the fuze arms only after the bomb has reached a safe distance from the aircraft.
Long arming is adequate for medium or high-altitude bombing where separation time is naturally sufficient. Medium arming is supposed to be used with dive deliveries while short arming is reserved for low-altitude, high-speed releases.
To achieve longer-arming distances, Soviet bombs may use the MVD (that we have already seen above) or the VDV (which are additional arming extensions inserted between the fuze and the bomb body).
For example, the AVU-E fuze has 3 arming delay windows:
short arming delay: 2.2 to 3.2 seconds;
medium arming delay: 4 to 5.5 seconds;
long arming delay: 10 to 12 seconds.
We can note a very interesting safety feature for the short arming delay: when this mode is selected, the explosion delay is automatically set to 12 seconds (it's called P mode), in order to ensure safe separation. The bomb can therefore be dropped from very low altitude (above 50m in level flight, possibly above 25m with lower chances of good arming) and will not explode immediately at impact. This type of release, with a 12 seconds explosion delay, is certainly possible only against "soft" targets, because the bomb might get destroyed at impact against a hardened target.
III.2.3 - Fuze Location: Integrated, Nose, Tail or Both
Fuzes can also be categorized by their location, which can dictate the firing sequence and the bomb’s combat purpose. We can distinguish:
integrated fuzes: they are built-in with the bomb and are not considered as separated devices.
nose fuse (Головной Взрыватель, ГВ - GV): they are located in the nose section of the bomb. It's the most common type for general-purpose (FAB) and fragmentation (OFAB) bombs, primarily for impact detonation.
tail fuze (Донный Взрыватель, ДВ - DV): they are located in the tail of the bomb, often within the stabilizer assembly. They are crucial for penetration/concrete-piercing (BETAB) bombs, as the tail placement ensures the detonation occurs after the bomb’s hardened body has penetrated the target (e.g., concrete or earth) for maximum effectiveness. Tail fuzes also almost always incorporate a time-delay mechanism for this purpose.
universal fuze (Взрыватель Универсальный, ВУ - VU): they are designed to be mechanically configurable for use in both the nose and tail fuze seats of various bombs. It means that you simplify your logistics by using a singe type of fuze where two different duzes were previously needed.
Note: some large bombs, particularly high-explosive and concrete-piercing types, are designed to accept two or more fuzes to ensure maximum reliability and target effectiveness, or to achieve complex effects. A notable configuration is the use of two tail fuzes, such as on the older FAB-1500 and other heavy bombs. This is primarily a reliability measure: if one fuze fails to arm or function, the second, redundant fuze is intended to ensure detonation. Some concrete-piercing bombs, which rely entirely on a tail fuze for sub-surface detonation, also utilize this redundancy.
III.3 - Fuzes Acronyms
Now that you are more familiar with the terminology and types of Soviet/Russian fuzes, we can decipher some of the acronyms that we'll encounter in the various fuze names. It will help us make more sens of their purpose.
AV (АВ - Авиационный Взрыватель or Aviatsionnyy Vzryvatel): Aviation Fuze. It's the base designation for a general-purpose aircraft fuze. E.g. the older mechanical AV-1 or AV-139 models.
AVU (АВУ - АВ Универсальный or AV Universalnyi): Universal Aviation Fuze. It designates a fuze that can be used either as a nose or as a tail fuze. E.g. the AVU-E models.
AVT (АВТ - АВ Тормозной or AV Tormoznoy): Aviation Fuze Retarder - Electrical An electrical fuze designed for retarded/braked bombs (where Tormoznoy means 'braking/retarding'). It controls the arming sequence specific to retarded delivery.
MDV (МДВ - Механизм Дальнего Взведения or Mekhanizm Dalnego Vzvedeniya): Long-Range Arming Mechanism. It's a supplementary device (often external) used solely to add an extra arming delay to the built-in fuze arming delay. E.g. the MDV-5.
VDV (ВДВ - Выносной Дальнего Взведения or Vynosnoy Dalnego Vzvedeniya): Remote Long-Range Arming Device. It is a specific type of MDV, generally using a mechanical windmill device to increase the arming delay.
E (Э - Электропироческий or Elektropirocheskyi): Electro-pyrotechnic. It designates a fuze that uses electrical power to ignite the explosion, by opposition to mechanical energy (spring, intertia, etc...). The letter E designates the EPU electrical pyrotechnic initiator (ЭПУ).
AT (АТ - Авиационная Трубка or Aviatsionnaya Trubka): Aviation Tube. It's a group of time fuzes primarily used in RBK (Cluster Bombs) to disperse submunitions after a set elapsed time.
TM (ТМ - Трубка Механическая or Trubka Mekhanicheskaya): Mechanical Tube. It's also a type of time-dealy fuze with RBK, but this one is purely mechanical. It's generally used with an MDV-4 to increase the arming delay by an additional 3 seconds.
ATM (АТМ - АТ Модернизированная or Modernizirovannaya): Modernized AT fuze.
ATK (АТК - АТ Кинетическая or Kineticheskaya): Thermal-resistant fuze. It's a ATM that can withstand temperatures up to 150°C during 90 minutes: it's the equivalent of our insensitive munitions.
BNV (БНВ - Бомбовый Неконтактный Взрыватель or Bombovyi Nekontaktnyi Vzrivatel): Bombing Proximity Fuze. It uses an optical proximity fuze that determines its height above target. It's very singular because it uses an incandescent lamp that emits its own IR energy to "see" the target.
BRV (БРВ - Бесконтактный Радиолокационный Взрыватель or Bezkontaktnyi Padiolokatsionnyi Vrivatel): Radar Proximity Fuze. As its name implies, it's the equivalent of the DSU-33+FMU-139 kit equipped on Western bombs.
Conclusion
This (too?) detailed analysis concludes the general overview of Soviet/Russian bomb and fuze classifications, terminology, and acronyms. The endeavor to locate, translate, and synthesize the technical sources was challenging, yet highly beneficial in deepening my personal understanding of Russian air-to-ground ordnance systems.
Some future articles will try to go more in-depth and make a more practical analysis focused specifically on the ordnance available for the MiG-29A in DCS World. More importantly, I will provide a practical look at the selectable fuze settings and modes for each combination, in order to give you employment advice to achieve the desired combat effect.
