A Boeing study noted that 16 LOCI commercial jet accidents from 2004 to 2013 resulted in 1,576 fatalities, which is nearly twice the number in the next highest category.
The NTSB targets the issue on its 2015 “Most Wanted” list of safety improvements, citing its linkage in over forty percent of fixed-wing general aviation accidents from 2001 to 2011. Business aviation LOCI accidents are a subset of those across the broader GA spectrum, and the alarming consistency of catastrophic outcomes in this type of accident compels an effort to better understand and control LOCI risks.
Business aviation encompasses a wide range of aircraft types and operational paradigms, which works against any single solution for reducing LOCI incidents. Single-pilot and owner-flown aircraft are often lighter and less automated than their business jet counterparts.
Their pilots are particularly exposed to the threats of wake turbulence when operating amidst heavier aircraft and task saturation during high workload periods (a potential precursor to spatial disorientation and monitoring breakdowns, which can lead to upsets).
They often have less exposure to robust and recurrent training compared to members of full-time charter or corporate flight departments. In addition to facing these threats in varying degrees, business jet operators also confront high altitude maneuvering, relatively low roll inertia in many business jet designs, and increasing levels of automation complexity rivaling those of modern commercial transports.
Many business aviation pilots operate more than one type of aircraft, elevating the threats of confusion or negative habit transfer in managing different automation and flight characteristics.
A study of business jet LOCI accidents from 1991 to 2010 noted unintentional stalls occurred in 31 of 71 accidents examined (Source: presentation by P.R. Veillette at ISASI 2011).
Automation mismanagement, flight control anomalies and wind shear or turbulence-induced upsets rounded out the list, but no cause was nearly as prevalent as unintentional aerodynamic stalls.
Two-thirds of the studied accidents occurred during takeoff, approach or landing with the aircraft below 1,000 feet AGL, affording those crews precious little recovery margin. Twelve of the 31 stall events occurred while banking during a circling approach, implying that this maneuver, performed more frequently in business compared to scheduled carrier operations, deserves attention.
Nine of the stall accidents involved degraded aerodynamic efficiency due to in-flight icing and/or inappropriate adjustment to airspeed for such conditions. Ice-induced binding was also implicated in a number of the flight control anomalies, underscoring that icing and LOCI are frequent associates.
A review of NASA ASRS and FAA reports of near-LOCI events was generally consistent with the accident study, with wake turbulence, automation mismanagement, near-stalls at low altitude, atmospheric turbulence and high altitude maneuvering as precursors to the reported incidents.
The lethality of LOCI coupled with an overriding sense that its occurrence can be reduced through improved prevention, recognition and recovery skills make this a targeted issue for safety improvement by the NBAA Safety Committee.