I believe that if the operations manual (issued in accordance with JAR-OPS 1) states that the aircraft is to be operated with 2 crew members, then the JAA should accept it as being valid for ATPL issue.
I have had several conversations recently, one with a B200 operator and the other with the operator of a Citation Bravo (both under 5700kg). They said that if they send you along to the CAA with 1500 hours, 500 multi crew, 100 night (etc etc) and a letter stating that the time logged in their aircraft is multi crew, this is no bar to getting the ATPL issued.
Either JAR-FCL has been changed, or the CAA's interpretation of JAR-FCL has changed. Multi crew time originally had very strict caveats: a/c over 5700kg, at least one cabin crew member. These have now been relaxed I believe.
Which leads me nicely to the following question:
An aircraft, operated in accordance with the company's operations manual, is operated by two pilots. The operations manual isn't issued in accordance with JAR-OPS 1 because it doesn't need to be (the operator doesn't need an AOC). The aircraft is a PA31-350 (MAUW 3175kg). Can that be counted as multi crew time do you think?
Bear in mind that both pilots are appropriate qualified to command the aircraft, having as they do MEP ratings. However their IRs (which might or might not be used) are Single Pilot Aeroplane IRs.