lying an instrument approach procedure shouldnt be all that challenging. After all, its basically a managed descent to a specified altitude, along a predetermined heading, to a point at which one either lands the airplane or initiates a climb for the missed approach. Yet, pilots of every stripe botch approaches with great regularity. In reality, its all a bit more complicated than that, of course, but still should be manageable, especially for a two-pilot crew: One guy flies while the other monitors the first guy. Simple, right? Done it hundreds of times. Yet, two-pilot crews-and a few trios-find ways to place themselves and their passengers in the weeds from time to time. Often, the ultimate cause of such an accident isnt some sinister new development never before contemplated by the industry-even if the airline and government bureaucracies believe they must find something never before identified as a cause of an aviation accident. Instead, it turns out to be something long ago recognized, trained for and thought resolved. For example, night flying can pose specific challenges, mainly involving certain well-understood limitations of the human eye, optical illusions like autokinesis and lack of depth perception. The cockpit procedures necessary for a professional crew to set up for and fly a non-precision approach should be well-ingrained after a few sim sessions or a couple of months flying the line. And the need to maintain a sterile cockpit and a focus on the tasks at hand during critical stages of flight should be something every primary student understands and accepts. So, how can a crew flying a scheduled passenger flight under FAR Part 121 allow things to get so far out of whack that they end up short of the runway? And what lessons can GA pilots learn from their mistakes? Background/Investigation On October 19, 2004, at about 1937 Central time, a BAE Systems BAE-J3201 (Jetstream 32 twin turboprop) operating as Corporate Airlines Flight 5966 struck trees on final approach and crashed short of Runway 36 at the Kirksville (Mo.) Regional Airport (IRK). The operation was a scheduled passenger flight from the Lambert-St. Louis International Airport to IRK. The captain, first officer and 11 of the 13 passengers were fatally injured; two passengers received serious injuries. The airplane was destroyed by impact and a post-impact fire. Night instrument conditions prevailed. The NTSBs report makes it clear the en route portion of the flight was routine. Prior to beginning the Localizer/DME Runway 36 approach at IRK, the captain thoroughly briefed it, including the minimum descent altitude (MDA) and missed approach procedures. As the approach continued, however, the crew failed to follow standard company procedures for non-precision approaches, including callouts. Meanwhile, as the flight continued to descend, the captains statements captured by the cockpit voice recorder make clear that, contrary to company procedures, he was looking for visual references. That should be the nonflying pilots job. When the airplane reached the MDA, the crew should have leveled off and remained there until those cues came into sight or until the airplane reached the missed approach point. The first officer failed to provide required callouts, including those related to arriving at the MDA. Instead, both pilots ended up looking for the runway; no one was monitoring the descent. The airplane was still descending at about 1200 fpm passing through about 100 feet agl. As the NTSB drily put it, “The captains failure to stop or slow the airplanes descent indicates that he was not aware of the airplanes excessive descent rate and/or significantly misjudged its proximity to the ground.” The first evidence of ground impact was found about 1.3 miles south of Runway 36s threshold. The airplane had impacted trees at about 50 feet agl (about 996 feet msl). The main wreckage, which was almost totally consumed by fire, was located some 775 feet north. Probable Cause The NTSB determined the accidents probable cause to include “the pilots failure to follow established procedures and properly conduct a non-precision instrument approach at night in IMC, including their descent below the minimum descent altitude (MDA) before required visual cues were available (which continued unmoderated until the airplane struck the trees) and their failure to adhere to the established division of duties between the flying and non-flying (monitoring) pilot.” The Boards report, which runs to 110 pages, focused on numerous other factors, including operational and human factors issues, the pilots professionalism and sterile cockpit procedures, non-precision instrument approach procedures, flight and duty time regulations, fatigue and flight data/image recorder requirements. But at the end of the day, the ultimate reason for this accident involves something very simple and which every instrument student understands: One doesnt descend below the MDA until and unless the airplane is in a position from which a normal landing can be made. In this instance, the crew continued their descent well below the MDA and into the trees more than a mile from the threshold. All the crew-resource training, all the speculation about fatigue, all the concern about company-specific cockpit procedures and all the recommendations that cockpit voice and flight data recorders be upgraded really doesnt change the fundamental reason this airplane crashed: The crew blew a nighttime, straight-in non-precision approach, something which should have been a walk in the park. Its often hard for the non-flying public to accept that pilots are human. As humans, we tend to make the same kinds of mistakes as other humans again and again, perhaps believing “it cant happen to us.” So, investigators, perhaps under political pressure, go to great lengths to find something new and different on which to blame the accident. In this instance, however, a professional flight crew flew a perfectly good airplane into the ground on a night instrument approach. The real question investigators should ask is why the crew didnt understand what was about to happen.
