Accident Analysis

Reducing The Risk In Flying After Dark

Flying at night is undoubtedly a more risky proposition than flying during the day. According to the AOPA Air Safety Foundation's 1999 Nall Report, which covers accident trends and factors for 1998, night flights account for only about 11 percent of all general aviation flying. Yet roughly 24 percent of all the approach phase accidents - those that occur after entering the pattern to land or during the final phase of an instrument approach - happen at night. Furthermore, accidents that occur at night in visual meteorological conditions (VMC) are more than twice as likely to be fatal as day VMC accidents. Numerous factors play into the night flight risk, but fortunately, most of these are within our control on some level.

The prospect of a night flight when we're unprepared can be daunting, and attempting such a flight can be dangerous. Even the psychological pressure of impending darkness, along with the shifting shadows of twilight, can conspire against us. Such was the case of the pilot of a Piper Cherokee (PA-28-181) who had departed Pawtucket, Rhode Island, with two passengers on a short hop to Richmond, Rhode Island. The weather was VFR, but darkness was fast approaching as the pilot entered the pattern for Runway 29, a 2,130-foot by 30-foot paved runway with a 135-foot dis- placed threshold because of trees on the approach end.

As the pilot wrote in his accident report, he had arrived at the airport at about 8 p.m. local time. "By this time it was almost dark. I made about four or five passes, being high on each pass. Trees at the approach end of the runway made it difficult as I couldn't see the tops of the trees to judge my height relative to the end of the runway. On the last pass, I dropped it in almost half way down the runway. It became obvious I was not going to stop in time, and it was too late for a wave-off."

The pilot knew that there was a steep downslope at the end of the runway, so he veered left in hopes that the soft ground would slow him down. The pilot lost control and ran into the trees. Neither the pilot nor his passengers were injured, but the aircraft sustained substantial damage.

If you prefer not to fly in darkness, give yourself plenty of cushion in your flight planning. Winds aloft and other delays can quickly erode our time margin and force us into a tricky twilight situation. If you do fly at night, learn to use new visual cues when making an approach at night. If a visual aid such as a visual approach slope indicator (VASI) or precision approach slope in-dicator (PAPI) is unavailable, the spot landing technique, with careful attention to airspeed, can be used to ensure that you fly a proper approach path.

Just as dangerous as impending darkness is the rush to gain night currency, especially when an extended gap exists in your night flight experience. And more important than the legal currency - three takeoffs and landings to a full stop required within the previous 90 days for a night flight with passengers - is the preparation needed for a safe flight into the night sky.

A 135-hour private pilot arrived at Ocean City Municipal Airport in Maryland and set out to establish his legally required night currency before taking two passengers on a night cross-country in a Cessna 172. It had been more than a year and a half since the non-instrument-rated pilot had logged his last night flight - a flight that lasted only 30 minutes.

Had he obtained a weather briefing, he may might have learned that conditions were ripe for fog formation, and that low instrument meteorological conditions (IMC) were forecast. At the time of his departure, the weather at Cape May, New Jersey, to the north, had included a 100-foot ceiling in overcast conditions with one-mile visibility. At Salisbury, Maryland, 20 miles inland, the sky was clear, and visibility was one-and-one-half miles in mist with a temperature of 75 degrees Fahrenheit and a dewpoint of 70 F. The pilot performed a preflight and then departed.

"After [the pilot] took off," one witness reported, "I could see this wall of fog rolling in. It was coming off the ocean and coming in. When the fog came in, you couldn't see anything, anything at all. I believe [he] was coming in to land on [Runway] 14 and couldn't find the airport."

According to other witness accounts in the NTSB report, the pilot made a low pass over the hangars and then went around. Moments later, the aircraft slammed into the ground near the intersection of Runways 20 and 14. The aircraft was destroyed and the pilot killed.

A thorough weather briefing is often more critical at night than during the day. Adverse weather is difficult if not impossible to see, and numerous phenomena in the night sky and underlying terrain can induce disorienting vertigo and countless visual illusions. These same factors can also come into play for experienced night flyers. Case in point: the pilot of a Cessna 182 on a night cross-country flight from Coleman Municipal Airport in Coleman, Texas, to San Geronimo Airport near San Antonio.

The pilot had finished work around 9 p.m. and was planning to fly to San Geronimo that night. A private pilot with nearly 1,200 hours, he had logged more than 55 hours of night flying experience and just over nine hours of simulated instrument flight. He had started training for his instrument rating, and he had passed the written exam. The previous month he had completed a biennial flight review.

A little more than an hour after departing Coleman, the aircraft was seen flying low toward the southeast in the vicinity of Blanco, Texas. Weather observations suggested an 800-foot ceiling in the area with light drizzle reducing the visibility. Witnesses saw the aircraft turn south, then disappear behind a hill. An impact was heard, then the witnesses saw a fire erupt. No preimpact failures of the engine or airframe were revealed in the course of the investigation. An autopsy revealed the presence of allergy medication, which the pilot's wife indicated the pilot was taking at night before going to sleep. These medications are known to cause drowsiness.

The onset of darkness affects human performance in a number of significant ways. Our alertness decreases as the stresses of the day accumulate to create fatigue, and our cognitive abilities diminish. Combined with the subdued lighting in the cockpit, a pilot's situational awareness may be impaired. We may not see a bad situation developing as quickly as we would during the day, and if our preflight preparations and planning are not adequate, the yoke in our hands may, in fact, be the short end of the proverbial stick.

The instrument-rated pilot of a Beech V35A Bonanza departed Jackson, Tennessee, just after 10 p.m. carrying one passenger on a flight to Baton Rouge, Louisiana. Although VMC prevailed, it was a dark night and the pilot was operating on an IFR flight plan.

Problems developed approximately one hour and forty-five minutes into the flight in the vicinity of Clinton, Louisiana, about 30 miles north of Baton Rouge. According to the pilot's report, he was descending through 6,500 feet msl and the fuel selector was on the right tank, which indicated one-quarter full, when the engine lost power. He switched to the left tank, which indicated one-third full, and attempted several restarts as the aircraft descended in the darkness. The engine did not restart, and the pilot made a forced landing in a "timbered field." Both the pilot and his passenger were seriously injured.

The NTSB report states that excessive plug gaps were noted on all spark plugs, which may have contributed to the failed restart attempts. However, the accident investigation also revealed that the right tank was empty, and the left tank contained only nine gallons, or about 45 minutes of fuel. Perhaps the accident could have been avoided with more attention to flight planning and more substantial fuel reserves.

Our final accident report provides an important reminder regarding professionalism in flight instruction. Instructors must serve as role models and provide a safe learning environment for their students. Seeing an instructor continue a flight in adverse conditions and flagrantly disregard federal aviation regulations undermines the development of student judgment and decision making.

Before departing on a night cross-country training flight from Lafayette to Reserve, Louisiana, in late February, the student pilot received a weather briefing and filed a VFR flight plan. The student and instructor departed at 5:20 p.m. local time.

Along the route of flight, in the vicinity of Plaquemine, Louisiana, power lines stretch across the Mississippi River. The power lines are suspended from towers that stand 425 feet high on either side of the river. It was here at about 6:30 p.m. that seven witnesses saw the Cessna 152 flying low over the river beneath low clouds. According to their reports, the aircraft was in cruise flight when it struck the power lines. The aircraft momentarily hung up in the power lines, then dropped into the water and sank in about 10 seconds. Both the student and the instructor were killed.

Although instrument meteorological conditions prevailed throughout the area, the student and instructor were receiving VFR flight following from Baton Rouge Approach Control. They had communicated with the controller approximately five minutes before the accident but had reported no problems. No preimpact anomalies were identified in the course of the investigation.

Night flight may impose a number of additional challenges and represent a higher level of risk than daytime flights, but those risks can be mitigated. Night flights can be made safe and enjoyable as long as proper training, preparation, planning, and judgment are part of the flight plan.

Night Flight Safety Tips

1. Never attempt a night flight if you don't feel up to par. Fatigue can seriously degrade your judgment and decision making abilities. To make matters worse, the combination of darkness and dim cockpit lighting can add to feelings of tiredness.
2. Set conservative weather minimums, and always get a thorough weather briefing. Continually monitor changes in the weather through flight watch (122.0 MHz), air traffic control, and weather recordings from airports along your route.
3. Plan a route that keeps you over well-lighted terrain and plan to fly at altitudes higher than those you might use on day flights. The extra altitude increases your safety margins for terrain and obstacle clearance, gives you more time to find an appropriate landing site in the event of an emergency, and improves communications reception.
4. Take advantage of navaids such as VORs, NDBs, and DME (as well as loran and GPS) to cross-check your navigation.
5. Perform a thorough preflight, and be certain to carry plenty of extra fuel. The 45-minute regulatory fuel reserve is an absolute minimum, not a target for planning purposes.
6. Know your airplane, especially the electrical system and the location and operation of cockpit lighting. Turn the lights on before it gets dark and carry two spare flashlights-just in case.
7. Cockpit organization is critical. Be sure to have all the necessary flight information within easy reach.
8. Whenever possible, bring along another pilot or instructor to share the workload.
9. Use flight following if it's available. Air traffic controllers can be an invaluable resource, especially if a problem develops.
10. Besides staying current for night flight, practice your instrument skills and be prepared to transition to instruments at any time during a night flight. Clouds and fog can be difficult to see at night until you enter them. If this happens, vertigo and disorientation become a significant hazard unless you fly by the instruments. If you aren't instrument-rated, make sure that you can perform a potentially life-saving 180-degree turn on the gauges.