Fight flights are some of my favorites. The air usually is smooth, what traffic is sharing the sky can be spotted easily, theres less chatter on ATC frequencies and-when conditions are right-the beauty is unmatched. But flying at night also brings with it some additional challenges, at least when compared with the same mission during the daytime. The root problem, of course, is lack of illumination. More than a few aircraft have smacked into hillsides at night and in good weather. Even more insidious is dealing with the odd emergency, especially if we have to put down in a remote, unlit area. Paying attention to your location, along with that of any nearby obstacles, helps resolve the first issue while good maintenance and some operational precautions address the second one. The additional risks flying at night poses are manageable and worth it, at least to me. Those additional risks involve the ways lack of illumination can play tricks with our vision and our piloting skills, making some fixed, lighted objects appear to move, for example, and drastically altering our depth perception. I, for one, need to constantly remind myself Im usually a bit lower during a night landing than the view out the windshield leads me to believe. But thats not the only night-related visual illusion with which pilots must contend. Among other FAA publications, the agencys Airplane Flying Handbook, FAA-H-8083-3A, contains a lot of good material on night flying and these various illusions. Heres an excerpt summarizing their cumulative effect: “Night flying requires that pilots be aware of, and operate within, their abilities and limitations. Although careful planning of any flight is essential, night flying demands more attention to the details of preflight preparation and planning…Night flying is very different from day flying and demands more attention of the pilot. The most noticeable difference is the limited availability of outside visual references. Therefore, flight instruments should be used to a greater degree in controlling the airplane…Under no circumstances should a VFR night-flight be made during poor or marginal weather conditions unless both the pilot and aircraft are certificated and equipped for flight under…IFR….” Background On September 23, 2009, at 2025 Central time, a Cessna T210N impacted trees and an unoccupied home while attempting a go-around at the Hilltop Lakes Airport (0TE4) in Hilltop Lakes, Texas. The airplane was destroyed, and the pilot was fatally injured. Dark night visual conditions prevailed. The accident flight was the pilots third of the day, which began at 0830 Eastern time in Vermont. Runway lights at 0TE4 were inoperative, One witness positioned his car to illuminate the runway; the pilot acknowledged seeing the lights on the CTAF. Several witnesses said the pilots approach was not aligned with the runway and appeared too high to land. They said the airplane was approximately 50 to 150 feet agl when the pilot transmitted he was going around. The airplane almost immediately started a descent, struck trees on the right side of the runway and impacted an unoccupied home. There was an immediate post-impact fire. Investigation The accident site was located in a rural residential neighborhood. The first point of impact was a damaged pine tree approximately 40 feet tall, in which was lodged the airplanes right horizontal stabilizer. The debris path was approximately 320 feet long. The flap and elevator trim actuators, landing gear, engine, propeller and several avionics boxes were found in the main wreckage. The flap jack screw extension measured 3.75 inches, which corresponds to a flap setting of between zero and five degrees. The elevator trim actuator measured 1.4 inches, which corresponds to approximately six degrees tab down. Several primary flight control cables were found in the wreckage, but continuity and identification could not be determined. No avionics components with non-volatile memory were recovered from the wreckage. All portions of the wreckage exhibited extensive thermal damage. No pre-impact anomalies of the airframe were observed that would have precluded normal operations. No pre-impact anomalies of the engine were observed. Three witnesses were instrument-rated professional pilots. They all estimated weather at the time of the accident included visibility of three to five miles in drizzle or light rain, with an overcast at between 1000 and 2000 feet agl. Probable Cause The NTSB determined this accidents probable cause to include: “The loss of control of the airplane in dark night light conditions due to the pilots spatial disorientation.” Its difficult to imagine how a pilot attempting a go-around could manage to lower his airplanes nose when thats basically the last thing he should want to do. However, there are visual illusions explaining the behavior, which are summarized in the sidebar on the opposite page. There are two other possible factors in this accident, one of which involves transitioning from visual flight-looking out the window while trying to land-back to instruments. According to FAA Advisory Circular AC 60-4A, Pilots Spatial Disorientation, studies indicate “it can take as long as 35 seconds to establish full control by instruments after a loss of visual reference of the earths surface.” The dark, moonless night and unlit neighborhood surrounding the intended runway in this accident makes a transition from visual flight to instruments mandatory. Fatigue is the other possible factor, perhaps in combination with the pilot having spent most of his day at altitude and becoming mildly hypoxic. Anyone who has spent much time flying at night with oxygen knows the greatly enhanced visual acuity using it can provide. The NTSBs report on this accident is silent on whether oxygen equipment was aboard the airplane, or the altitudes at which the pilot flew his earlier legs. Ultimately, going around was the right thing for this pilot to do, possibly followed by a diversion to a nearby facility with working runway lights. Well never know the real reasons he lost control when initiating the go-around maneuver, but there are plenty of choices.
