WEACLRS

If the flight is a ferry flight, aircraft flight test, or evaluation flight of an aircraft's equipment, and is not carrying any person or property on board the aircraft (61.55 (g)), then a commercial certificate with multiengine rating or an ATP would be adequate as long as the pilot within the preceding 12 months meets 61.55 (b)(1) - ie, familiar with operational procedures, performance, normal, abnormal, and emergency procedures, flight manual, placards, etc. This would need to be documented ground training. He would not need to meet 61.55 (b)(2) which requires three t/o and landings to a full stop, engine out procedures and maneuvering, and CRM.

If he was just a private pilot with a multiengine rating the he would need to meet both 61.55 (b)(1) and (2).

An instrument rating and instrument currency would only be needed if the flight was conducted under IFR conditions.

An actual SIC type does require documented training. A trainer or qualified management official must make an endorsement in the applicant's logbook, and the applicant's flight experience and/or training records, if in electronic form, must be presented at the FSDO or to an examiner/APD. Also the person who provided the ground and flight training, or the management official, must sign the back of the 8710-1. There is no practical test. (61.55(d)(2), (3), and (5), and 61.55(e)(2), (3), and (5)).