The number of U.S. business jet accidents appears to be going down based on the 2013 returns, but landing accidents continue to be a problem and have helped spur an increase in fatal accidents, according to preliminary data from safety expert Robert E. Breiling Associates.

Through the first nine months of this year, U.S. business jets were involved in seven accidents, compared with 13 in the first three quarters of 2012. But four of those accidents this year were fatal, resulting in 13 fatalities. This is up by one in both the number of fatal accidents and fatalities over the totals from the first three quarters of 2012, Breiling reports.

Two of the fatal accidents involved Beech Premier aircraft that crashed during abandoned approaches in visual meteorological conditions. They combined for seven fatalities. Another involved the late September crash of a Cessna 525 business jet, which veered off the runway after landing at Santa Monica Airport in California, killing four. That accident stirred up ongoing opposition to the airport, with community activists and at least one lawmaker calling for a review of the airport. The fourth was the crash of a U.S.-registered Learjet 60 on approach in Venezuela.

These accidents continued a recent growing trend of landing crashes, Breiling says. Landing accidents have accounted for 45% of all crashes over the past 10 years, but 58% this year and 54% last year. Surprisingly, Breiling says, only 8% occurred on runways of less than 4,000 ft., while 76% occurred on runways of 5,000 ft. or longer. Despite runway length, Breiling notes approach speeds continue to be a worry.

U.S.-registered turboprops accidents increased in 2013 to 23, compared with 20 through the first nine months of 2012. Of the 2013 crashes, 10 were fatal resulting in 27 fatalities, compared with three fatal accidents a year earlier resulting in eight fatalities. The majority of the turboprops in accidents – 15 – were flown either by business owners or privately (non-professionally), while two involved corporate aircraft and six were operated under Part 135. Breiling notes that these differentiations are particularly important to highlight where the accidents are concentrated.

Non-U.S.-registered business jets, meanwhile, were involved in six accidents, two fewer than a year earlier, and one fatal accident that resulted in two fatalities. Similarly, non-U.S.-registered turboprops were involved in two fewer accidents, with 26 so far this year. But of those, 13 were fatal, resulting in 48 fatalities.