FMU-139 Fuze and FZU-48 Initiator for MK-80 / BLU bombs
I am creating my project related to the Mk80 / BLU series of bombs.
This part is dedicated to - FMU-139 Fuze and FZU-48 Initiator
The FMU-139 series electronic bomb fuzes are an electronic impact or impact-delay fuze. The fuzes are solid state, micro-computer, multi-option tail or nose fuze used in the Mk 80/BLU 100 series general-purpose bombs. The fuzes are joint service (Navy and Air Force) with multiple settings. The arming times are in-flight selectable and the functioning delay must be set during weapon assembly. The fuze has two basic operational modes. One mode is the pulse power employment mode, FFCS power or Navy mode. The other mode is the continuous power employment mode, FZU power mode or Air Force mode. The FZU-48 generates and supplies power to arm the fuze during the Continuous power employment mode and is activated at release by the Lanyard. The Lanyard is pulled as the weapon separates from the aircraft pulling the ram air turbine into the air stream.
This is part of the Mk-84.
Link for 3D model:
https://www.cgtrader.com/3d-models/military/other/mk-84-bomb
The system consists of FMU-139C/B, FZU-48/B and two connectors.
This is part of the Mk-84.
Link for 3D model:
https://www.cgtrader.com/3d-models/military/other/mk-84-bomb
The most recent modification and fuze currently entering production is FMU-139C/B.
If the safing pin is removed from the FMU-139 and the red-and-black striping is visible on the gag rod sleeve, the fuze is enabled and could be armed.
In the end of the fuze located the plastic shipping plug and the flag.
If a FZU-48/B is used, then electrical connector is installed.
The FMU-139 fuze is inserted into tail fuze well and the closure ring is twisted.
If operational requirements dictate the use of a FZU-48, the M70 series cable is removed and set aside while the FZU’s power cable is routed through the bomb body.
FZU-48/B
The second connector is pulled through the body of the bomb by the ring, which is then removed and it is connected to one of the connectors located at the bottom of the FZU-48/B.
The cover assembly has an arrow to indicate proper orientation when installed in the bomb and has a flexible lanyard with a swivel break link that attaches to the bomb rack.
When bomb moves away from bomb rack at release, lanyard pulls on cover. Once cover is open, a minimum of 250 Knots Calibrated Airspeed is required for FZU-48/B turbine alternator to generate sufficient power to arm fuze.