It’ll fly in certain instances:
http://www.sbcmag.info/article/2012/single-top-plate-wood-stud-wall
The 2012 International Residential Code (IRC) allows for the use of a single top plate in a wood stud wall if the design meets specific requirements. IRC Section R602.3.2 outlines the top plate requirements, and then the exception lists the qualifications for using a single top plate. The 2012 IRC Commentary further explains the requirements for a single top plate in Figure R602.3.2 (see Figure R602.3.2).
To summarize, in order to use a single top plate per the IRC’s prescriptive requirements:
• Plate must be tied at the joints, corners and intersecting walls.
• Minimum 3" x 6" x 0.036" galvanized steel plate must be fastened to each wall or segment by six 8d nails.
• Trusses, rafters or joists must be centered over the studs with a tolerance of not more than 1".
The minimum connector and fastener schedule, along with the 1" tolerance, provide the strength needed to transfer loads from member to member when less wood is used in the wall. When trusses are used on a project, the stud spacing can be increased to 24" o.c., which removes more lumber, improves energy efficiency and still allows a continuous load path.