You are in an FAA approved training and proficency program for your air carrier, you are not acting as a pilot in command you are therefore legal to fly in the 121 operation, but if you are flying outside the air carrier, like owning a C-172 or something, you will need to log your inst time and apporaches to act as PIC in inst condtions
Please post supporting references for your post. I have perused the FAR 121 regs and can't find anything that says an FO must be "instrument current" to act as SIC. My old POI at Lakes said the PIC was the only one required to be "instrument current". If it was required, I would imagine the FAA would have to come down on almost every airline. From what I can tell, it seems the 3 takeoffs and landing in the previous 90 days is all that applies. I just looked back through my logs and I never had a time when I was not "instrument current". I was flying out of ORD most of that time though. The guys down in Florida and out of DEN must lose currency all the time. My last month in DEN I never really saw a cloud. I am a sponge, soak me with knowledge.
PS. FAR 61.55 (d)
This section does not apply to a person who is:
(1) designated as the SIC under 121,125, or 135 of this chapter, in that specific type of aircraft.
Disregard. The passage that leapt to mind off the top of my head was actually Part 135, rather than Part 121. Upon reference (not having one's books is hell), I find it is 135.245(a), and reads:
§ 135.245 Second in command qualifications.
(a) Except as provided in paragraph (b), no certificate holder may use any person, nor may any person serve, as second in command of an aircraft unless that person holds at least a commercial pilot certificate with appropriate category and class ratings and an instrument rating. For flight under IFR, that person must meet the recent instrument experience requirements of Part 61 of this chapter.
This refers to Part 61, specifically 61.57(c), (d), & (e). (c) is the reference for instrument currency, and is required of a SIC under Part 135 (not 121; my error), regardless of the annual checkflight. It is up to the SIC to maintain currency.
While the following passage is entitled "Recent flight experience: Pilot in command," it also refers to required experience of the SIC, due to the specific referenced requirement under 135.245(a). Thus, without a rendering of both passages, one may be lead to believe that 61.57 applies strictly to someone acting as pilot in command, when it does not. 61.57 does spell out requirements without which one cannot act as PIC, but these requirements also apply to the SIC under Part 135.
§ 61.57 Recent flight experience: Pilot in command.
(c) Instrument experience. Except as provided in paragraph (e) of this section, no person may act as pilot in command under IFR or in weather conditions less than the minimums prescribed for VFR, unless within the preceding 6 calendar months, that person has:
(1) For the purpose of obtaining instrument experience in an aircraft (other than a glider), performed and logged under actual or simulated instrument conditions, either in flight in the appropriate category of aircraft for the instrument privileges sought or in a flight simulator or flight training device that is representative of the aircraft category for the instrument privileges sought -
(i) At least six instrument approaches;
(ii) Holding procedures; and
(iii) Intercepting and tracking courses through the use of navigation systems.