Business aircraft activity inched up 1.4 percent year-over-year last month in North America, but was hampered by an unexpected downturn in Part 91 flying, according to TraqPak data released on Friday by Argus International. This also fell short of the company’s projected 4.1 percent uptick for December, though Argus analysts remain cautiously optimistic about this month, estimating a 2.7 percent increase.

The Part 135 segment was the only operational category to show a gain last month, soaring 9.5 percent from a year ago and solely sustaining the overall positive outcome. Fractional flying was flat, while Part 91 activity took a 3.6 percent hit.

Large-cabin jets led in activity by aircraft category, climbing 7.2 percent year-over-year last month. This was followed by rises in light- and midsize-jet activity of 2.3 percent and 0.8 percent, respectively, while turboprop flying fell 1.2 percent from a year ago.

According to the Argus data, large-cabin jets also dominated in individual categories, logging the only double-digit gains last month. Part 135 and fractional large-cabin-jet flying jumped 15.6 percent and 16.2 percent, respectively, year-over-year. Part 91 large-cabin-jet activity was the only individual gainer in this operational category, eking out a 0.6 percent increase.

Argus TraqPak data provides “flight-number-specific aircraft arrival and departure information on all IFR flights in the U.S., Canada and the Caribbean.”