MBU-19/ HGU-55 NBC HEADGEAR COMBO
During the early 90's, Swiss AF evaluated a number of Chemical/ Biological Warfare (CBW) pilot protective systems.
The main evaluation criteria the chem/bio protection effectiveness and the compatibility/ integration with Swiss AF aircrew and aircraft operations.
Among the systems taken into consideration were British AR-5 and CLARE (at the time under development); US made PIHM (Protective Integrated Hood Mask) and TAERS (Tactical Air Eye Respiratory System).
Although not included in the tests, the MBU-13/P full-face mask - CRU-80 /P filter combo was considered as an "off the shelf" option in order to have comparative parameters.
As usual, implementation of a number of equipment and aircraft modifications were foreseen, such as replacing breathing regulator and ejection seat hoses with "chemically hardened" ones and replace the NBC hood original ones with Swiss made filter canisters.
Here in picture a PIHM protective hood MBU-19/P.
The MBU-19 consists of a protective bromobutyl adjustable hood, fitted with a standard MBU-12/P oxygen mask and drinking facilities.
Its breathing manifold allows the selection between the aircraft oxygen system and ambient air through a (standard issue) C2A1 NBC filter cartridge.
(Not shown here) - An electrically operated blower (CQU-7/P), provides filtered air when the crew is not connected to the aircraft oxygen system; when connected, the blower ensure positive pressure condition in the hood. A dedicated unit (MXU-835/P) permits communication with ground crew. For both units (not surprisingly...) looks Swiss AF tested also alternate devices.
Photographs of the time show the MBU-19 worn underneath an HGU-55 on board a Mirage III.
Because of the test results, most likely also for technical, logistical and financial reasons, none of the evaluated systems was put into service.