Flight Crew Air Transport Pilot (ATP)
Confusion; Distraction
Aircraft Equipment Problem Less Severe
Flight Crew Overcame Equipment Problem; General Maintenance Action
Aircraft; Human Factors; Environment - Non Weather Related
In Cruise approaching the descent phase into ZZZ; the FO inadvertently discharged the forward fire bottle by rotating his sun visor. He immediately pointed out that he did this when the warning chime went off. I canceled the CDC; and we briefly spoke about what happened. I then contacted dispatch and maintenance for a conference call as to what had happened and what our intentions should be. At this point we had started our descent phase into ZZZ. As we were positive about the inadvertent triggering of the fire bottle; we decided that ZZZ would be the landing point; and maintenance would meet us there to deal with the situation. We then advise the ZZZ station as to the situation. We landed in ZZZ without further incident and parked at the gate.At this point we again looked at the sun visors on both the first officers and Captain side. We carefully rotated the shades to close proximity to the overhead panel to see which switches they could actually come in contact with. Obviously; on the first officer side this was the forward fire bottle red guarded switch. Then on the captain side; the sunshade when rotated and upwards comes in contact with the RAT (Ram Air Turbine) deployment red guarding switch. Because these two red guarded switches have the hinges at the upper side (12 o'clock position); the sunshade is capable of lifting the red guards; moving underneath and manipulating the buttons. Both of these guarded switches are protected from rotation but I'm about to buy other non-emergency switches or knobs. We both view this as a situation that could possibly occur again and with greater consequence. I believe both of these red guarded lift to push guards could be inverted so that the hinges were on the 6 o'clock position which would guard them from manipulation by the sunshades.
An A319 flight crew reported the inadvertent discharge of the forward cargo fire bottle. This was due to the rotation of the First Officer's sun visor in such a manner that it triggered the fire bottle discharge switch. The flight crew expressed concern that this event could be repeated.