This is a repost from our WhatsApp group but it is worth archiving here

It has come to my attention that there was a rather spirited conversation in the office the other day on an old topic: the interpretation of the long commercial cross country flight and whether it can be done VFR or IFR.

It is true that FAR 61.129 does not specify VFR or IFR for the long cross country. It doesn’t even specify day or night. However, and this is a big HOWEVER, the ACS is what the DPE will use to measure the applicants skill, knowledge, and risk management. The ACS specifies often that the skills being evaluated for a commercial pilot are for VFR flight. Our local DPEs have specifically mentioned that doing any of the commercial cross country flights as instrument flights would defeat the purpose of the commercial pilot requirements and that they would not consider a flight logged under IFR valid as prerequisite for any cross country in 61.129. I agree. 

With respect to the cross country training, the logic is that commercial applicants are further developing their skills at the commercial pilot level - not instrument pilot level. Among many other areas, this includes greater accuracy and precision with pilotage (requires VFR) and dead reckoning (VFR when using visual landmarks) as they apply to cross country piloting. The syllabus also incorporates this into the cross country training for commercial pilots. Thus, we will continue to have our applicants complete this requirement daytime VFR. The interpretation of the regulations only begins with the FAR. We are not the legal experts but, believe me, there is a lot of time invested here seeking interpretation and guidance on the regulations. Always feel free to ask for help with interpretation.