Controlled Flight Into Terrain (CFIT) continues to be an area of concern for aviation safety. The FAA estimates about 17% of general aviation accidents are caused by CFIT. Thanks to safety equipment, such as an autopilot, a radar altimeter, and the ground proximity warning system (GPWS) onboard, it is not a surprise that modern aircraft with two pilots are better equipped to identify and manage terrain threats than a typical single-pilot, small general aviation aircraft.
The threat increases for VFR pilots who attempt to maintain visual conditions in marginal weather. VFR-only pilots are not trained to fly an aircraft solely relying on flight instruments and must understand the limitations posed by the environment in which they are operating. Spatial disorientation and loss of control may result in impacting the terrain, surface, or obstacle while trying to maneuver. In many instances, the aircraft is in perfectly airworthy condition.
Prevention starts with collecting all pertinent weather information prior to flight. Furthermore, pilots must possess knowledge of the minimum safe/sector altitudes and highest terrain in the area. Relying on ATC is not an option, given that the majority of VFR flights are not in contact with ATC. To become aware of the minimum operating altitudes, proper charts and approach plates (valid and current) for the intended flight must be carried onboard. This applies to IFR pilots as well. VFR charts, although not required, should be onboard because they can provide important obstacle and terrain data for an IFR flight.
In this context, mountain flying is a challenge to any pilot without prior experience and is directly correlated to CFIT accidents. It is highly recommended that one find a qualified and certified flight instructor for a local area training check prior to a mountain flight. The terrain in itself poses additional threats such as strong winds, turbulence, and density altitude degradation on aircraft performance. VFR flight operations may be conducted at night in mountainous terrain with the application of sound judgment and common sense. Given the lack of visual contact with the terrain, night mountain flying increases the risk of CFIT. For aircraft equipped with terrain onboard systems, situational awareness can be greatly enhanced if properly utilized. Pilots must carefully follow any airport-specific, obstacle departure procedure (ODP), and utilize all available resources to make the go/no-go decision prior to flight.
Finally, not all obstructions originate from natural terrain. Antennas, buildings, towers—all significantly affect flight safety. Pilots must understand any operation below 2,000 feet above the terrain poses the risk of CFIT. These may be difficult to see even in good daylight VFR conditions with unrestricted visibility. Though antennas and towers are depicted on VFR charts, be aware that new towers may not have been printed on your chart, even if it is valid/current. As with antennae, towers, high voltage/power lines or the supporting structures of these lines may not always be readily visible, and the wires may be virtually impossible to see. To sum it up, not every man-made obstacle may be published on aeronautical charts. In this instance, the “see and avoid rule” becomes critical to prevent CFIT when operating close to the ground. Be aware at night, towers may not be lighted. If you don’t see it, it does not mean it is not there. Light systems could be inoperative and advertised as a NOTAM.
The best approach to prevent CFIT starts on the ground well before the aircraft is airborne. It encompasses sound preparation by the pilot in command and high levels of awareness of the flight path (both vertical and horizontal). Whether VFR or IFR, each flight has critical flight segments. To a great extent, how the flight segments are planned and handled determines the safety of the flight. Know when to fly—the go/no-go decision. Cutting corners and operating in lower than allowed weather conditions is one of the leading causes of CFIT. The importance of gathering a complete weather briefing and being able to correlate pilot skills and training, aircraft capabilities, and operating environment are key to flight safety.
