So Things Don’t Go Bump in the Night

Avoiding Terrain While Flying Night VFR

By Paul Cianciolo
Source: FAA Safety Briefing Nov/Dec 2020

“They had been flying for a half-hour when John Hicks noticed that the Cessna’s airspeed had dipped, so he mentioned it to the flight instructor. His teacher, sitting next to him in the cramped cockpit, pushed in the throttle, accelerating the aircraft with such power that Hicks’ head was rocked back. It was then that he lifted his eyes, peered out the windshield and saw what was directly before them in the darkness enveloping the George Washington National Forest: a mountain.

At more than 120 mph, the 2,500-pound plane sliced through a cluster of Appalachian hardwoods in a remote corner of northwestern Virginia. The tip of the left wing snapped off and the right wing struck a tree so hard that it streaked the trunk with red paint. Hicks heard metal rip, glass shatter, tree limbs break, the engine scream. And yet the Cessna 172, he realized, hadn’t stopped moving.”

This excerpt is from a 2016 narrative by John Woodrow Cox, an enterprise reporter at The Washington Post. It’s an all-too-common example of controlled flight into terrain — or CFIT as we call it, which is third on the list of causal factors of general aviation fatal accidents.

The flight instructor in this story did not survive; the learner did. He was also my soon-to-be flight instructor, who was a friend and fellow auxiliary airman. Don’t think this can’t happen to you. With nearly 6,000 flight hours; an airline transport pilot certificate for airplane single-engine land, multiengine land, and helicopter ratings; a commercial pilot certificate for airplane single-engine sea, airplane multiengine sea, and glider ratings; a flight instructor certificate for airplane single-engine, multiengine, and instrument, and glider; and a first-class medical certificate, the instructor still missed something as large as a mountain while flying under visual flight rules (VFR) on a clear night.

The NTSB determined that the probable cause of this accident was “the flight instructor’s decision to conduct a night training flight in mountainous terrain without conducting or allowing the student to conduct appropriate preflight planning and his lack of situational awareness of the surrounding terrain altitude, which resulted in controlled flight into terrain.”

Off by 300 Feet

Most pilots involved in CFIT accidents are not instrument-rated, so we’ll start by going back to basics. Avoiding terrain at night is easier if you use the altitudes shown on VFR charts as part of your preflight planning.

Review the maximum elevation figures (MEF) shown in quadrangles bounded by ticked lines of latitude and longitude and represented in thousands and hundreds of feet above mean sea level (MSL). MEFs are determined by rounding the highest known elevation in the quadrangle, including terrain and obstructions (trees, towers, antennas, etc.) up to the next 100 foot level. These altitudes are then adjusted upward between 100 to 300 feet. Pilots should be aware that while the MEF is based on the best information available, the figures are not verified by actual field surveys.

If you need a refresher on chart symbology or the depiction of information and/or symbols on visual chart-ing products, download the FAA Aeronautical Chart Users’ Guide at bit.ly/FAAChartGuide.

In the case described earlier, the flight instructor, who was instrument rated, was conducting a demonstration of the autopilot with an altitude hold set for 3,000 feet. The airplane impacted the side of the mountain at 3,100 feet MSL, which was approximately 300 feet below the top of the ridgeline. A review of the intended flight path on the sectional chart would have provided a better baseline altitude for the autopilot hold.

Automation Bias

Another key precursor for CFIT is a pilot’s overreliance on automation. This can lead to pilot complacency and degraded hand-flying competence and confidence. That’s why this is a safety enhancement topic identified by the General Aviation Joint Steering Committee (GAJSC).

Automation is by no means a bad thing; today’s autopilots with associated navigation equipment can greatly reduce cockpit workload and help pilots fly with greater precision and accuracy. However, you must be keenly aware of an automation system’s capabilities and limitations. That means understanding when your system is operating normally, and when a failure requires you to step in and fly manually.

Many GA autopilots also lack the ability to integrate aircraft position and terrain information, which was part of the issue that led to the accident in the example. The aircraft that was originally scheduled for use in this training flight was equipped with a Garmin G1000 glass cockpit with terrain awareness capability. However, a last minute change in aircraft to an old-school cockpit eliminated the technology the instructor may have counted on using.

Transition training, also a safety enhancement topic identified by the GAJSC, is important whenever you’re operating an unfamiliar aircraft or avionics system. This includes stepping from a glass cockpit with all the bells and whistles to traditional analog dials and gauges.

Perils of Perception

Another nighttime peril is vulnerability to any of the many kinds of illusions. Especially at night, the flight environment creates sensory conflicts that make it difficult to determine spatial orientation. Statistics show that approximately 10-percent of all GA accidents can be attributed to spatial disorientation.

Another illusion is the black hole effect, which occurs when you land from over water or non-lighted terrain and runway lights are the only source of light. Without peripheral visual cues to help, it is challenging to maintain orientation. Any downsloping or upsloping terrain will make the runway seem out of position. Bright runway and approach lighting systems with few lights illuminating the surrounding terrain may create the illusion of less distance to the runway. If you believe this illusion, you may lower the slope of your approach and impact terrain before reaching the runway.

You can prevent illusions of motion and position by maintaining a reliable visual reference to fixed points on the ground or, when the ground is not visible, to flight instruments. At night, your outside visual references on the ground may cause illusions when you see those references from different altitudes.

Tips for Avoiding CFIT

An NTSB safety alert about CFIT in visual conditions explains that nighttime visual flight operations are resulting in avoidable accidents. They give the following tips to avoid becoming involved in a similar accident:

• CFIT accidents are best avoided through proper pre-flight planning.
• Terrain familiarization is critical to safe visual operations at night. Use sectional charts or other topographic references to ensure that your altitude will safely clear terrainand obstructions all along your route.
• In remote areas, especially in overcast or moonless conditions, be aware that darkness may render visual avoidance of high terrain nearly impossible and that the absence of ground lights may result in loss of horizon reference.
• When planning a nighttime VFR flight, follow IFR practices such as climbing on a known safe course until wellabove surrounding terrain. Choose a cruising altitude that provides terrain separation similar to IFR flights(2,000 feet AGL in mountainous areas and 1,000 feetAGL in other areas).
• When receiving radar services, do not depend onair traffic controllers to warn you of terrain hazards. Although controllers will try to warn pilots if they notice a hazardous situation, they may not always beable to recognize that a particular VFR aircraft is dangerously close to terrain.
• When issued a heading along with an instruction to “maintain VFR,” be aware that the heading may not provide adequate terrain clearance. If you have any doubt about your ability to visually avoid terrain and obstacles, advise air traffic control (ATC) immediately and take action to reach a safe altitude if necessary.
• ATC radar software can provide limited prediction and warning of terrain hazards, but the warning system is configured to protect IFR flights and is normally suppressed for VFR aircraft. Controllers can activate the warning system for VFR flights upon pilot request, but it may produce numerous false alarms for aircraft operating below the minimum instrument altitude — especially in en route center airspace.
• For improved night vision, the FAA recommends the use of supplemental oxygen for flights above 5,000 feet.
• If you fly at night, especially in remote or unlit areas, consider whether a GPS-based terrain awareness unit would improve your safety of flight.

Hindsight is 20/20

One more fact about the accident described here is that there was a survivor. Survival itself is another safety enhancement topic identified by the GAJSC. Every pilot needs to prepare for the unexpected. Accidents can happen quickly so being prepared is key. Three factors will impact your ability to survive: knowledge, discipline, and planning. Don’t panic. Calm, thoughtful action is what will help you survive the time until you’re rescued. Most importantly, have the will to survive!

The survivor of this accident could not access a cell phone nor did he have a working handheld radio. Though the emergency locator beacon (ELT) was pinging, it was an older 121.5 MHz ELT. Aircraft reported hearing an automated distress tone just after sunset on a cold Saturday night, but nobody started looking until family members reported an overdue aircraft the next morning.

It is not required by regulation, but you still might consider upgrading to a 406 ELT for added safety and a quicker response time.

Learn More

NTSB Safety Alert – CFIT in Visual Conditions - ntsb.gov/safety/safety-alerts/Documents/SA_013.pdf

FAA Advisory Circular 61-134, GA CFIT Awareness - https://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/22907

For more about flying at night, check out our Nov/Dec 2015 N.I.G.H.T. issue of FAA Safety Briefing - bit.ly/FAASB-Arc

Paul Cianciolo is an associate editor and the social media lead for FAA Safety Briefing. He is a U.S. Air Force veteran, and an auxiliary airman with Civil Air Patrol.