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 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 model MBU-13/P full-face mask - CRU-80 /P filter was considered as an "off the shelf" option in order to have comparative parameters.


Together with the MBU-13 / CRU-80 assembly, crew wore an HGU-39/ P helmet. 


The helmet shell is the same as the SPH-4 one, without visors, as the NBC mask prevent their use.


Accordingly, it was possible to install, on the mask assembly, a dark visor provided with velcro fittings. 


Because of the test results, most likely also for technical, logistical and financial reasons, none of the evaluated systems was put into service.