All pilots know the basics of night flying and much of the literature talks — rightly so — about the need to adapt your eyes for darkness and about the rules and regulations. Most of us can parrot back that to carry passengers at night we need to have made three takeoffs and landings, at least an hour after sunset, to a full stop within the past 90 days. But, like small children who worry about what’s under the bed, do you really know what can reach out and get you on a night flight when you least suspect it? The risks at night are different and higher, but they can be quantified and mitigated by pilots who are cautious and well-versed in techniques for flying safely at night. But there are pitfalls — some of which aren’t adequately addressed in flight training — that continue to claim even high-time pilots in night flying accidents.
Fly at Night …
There are lots of great reasons to fly at night, and pilots who choose to should embrace it and learn more about it. For starters, the views can be truly spectacular. Metropolitan areas are extremely well lit, and the lights sometimes look like jewels spread over the cityscape. A truly unique example is Las Vegas, with its brightly colored lights. Metro areas are probably among the safest places to fly at night since, even on a moonless night, the bright lights from below make it easier to spot adjacent terrain and obstacles. If you want to avoid turbulence, night (and early morning) is one of the best times to fly. Winds die down at night, which reduces mechanical turbulence, particularly over hills and terrain. Thunderstorms also tend to dissipate at night, which enhances safety in regions prone to storms. There’s also far less competing air traffic at night. Less that 5% of GA flying is done at night, so there’s less competition for the airspace, and ATC will have more time to talk with you. Aircraft are also easier to spot at night, though occasionally it’s harder to perceive how to avoid traffic at your altitude.
… Or Don’t Fly at NightMany things are different that make night flight more inconvenient. Some of the differences also make night flight more dangerous, as we’ll see when we discuss accidents. First, we’re not nocturnal creatures, and it’s much harder for us to see at night. Our eyesight is best suited for the daytime, and most everything we do at night just becomes a little harder. This includes pre-flighting the aircraft, finding switches in the cockpit, taxiing, reading maps, spotting terrain and obstructions, and of course, landing the airplane. GA aircraft often have poor cockpit lighting, which also contributes to the problem. There are many other challenges. Navigating becomes more difficult, since checkpoints are harder to identify. Many airports have fuel available only during business hours and have no services at night. In fact, some airports aren’t even lit and so don’t permit night landings. Fatigue is also a factor. Most people are tired at the end of the day and may not have the same judgment and reaction time they have in the daytime. Spatial disorientation, which can lead to loss of control of the aircraft, is also more likely at night, particularly on dark or hazy nights that lack a clear horizon. Inadvertent flight into a cloud is far more likely at night than in the daytime, since clouds are difficult to spot at night under even the best of circumstances. Probably less then 5% of GA flying is at night, yet half of the VFR into IMC accidents occur at night, which suggests that you’re 10 times more likely to have this type of accident at night. In unpopulated areas with little light, it may be impossible to see and avoid clouds. Emergencies are also more difficult to manage at night. An alternator failure leading to a loss of electrical power may be a minor inconvenience in the daytime, but becomes more serious at night. And if you were to have an engine failure at night, selecting an appropriate off-airport landing site is far more difficult than it would be in the daytime. Night flight is challenging and people deal with it in different ways. Some choose to avoid night flight altogether. Others educate themselves on the risks and set their own personal minimums for the conditions under which they’re willing to fly at night. Either way, understanding all of the factors that affect night flight will make you a safer pilot.
Night AccidentsSafety has been a key focus of the FAA and NTSB for years, so there’s a wealth of accident data available. The AOPA Air Safety Foundation’s 2003 Nall Report, which summarizes accidents that occurred in 2002, lists 312 fatal accidents in the U.S. Of these, 204 were categorized as to day or night: 160 were in the daytime, and 44 (21.6%) were at night. The other 108 accidents were not categorized as day or night, presumably because the NTSB report didn’t list this data, so it’s possible that an even greater percentage of accidents occured at night. What’s most striking about the data is the survivability of daytime vs. nighttime accidents. You can calculate this by looking at total accidents, and then determine what percentage of these accidents was fatal. Nationally, there were a total of 1221 accidents identified as day or night and 204 of these (21.2%) were fatal. It’s not uncommon to see the 21% figure in print, but it obscures some large differences between day and night flight. Of the 1072 daytime accidents, 160 (14.9%) were fatal. But of the 149 nighttime accidents, 44 (29.5%) were fatal. Thus, if you have an accident at night, it’s twice as likely to be fatal as a daytime accident. In a prior AVweb article, I described the need to research accidents on a regional basis to identify unique risk factors, since terrain and weather may lead to differences in accident causes within a local region. For example, my research into fatal accidents in the San Francisco Bay Area concluded that night accidents are twice as frequent and VFR into IMC accidents are nearly six times as frequent factors in fatal accidents in this region as compared to national accident data. Looking at the period from 1993-2004, there were 88 fatal accidents of aircraft that either departed a Bay Area airport or were headed to a Bay Area airport. Of these, 38 (43%) occurred at night. And of those 88 crashes, if you looked at just those 33 that actually crashed in the local Bay Area, as opposed to those that crashed outside the immediate area, 18 (54.5%) of these occurred at night! This difference was statistically significant when compared with the 21.6% of fatal accidents that occurred at night in 2002 across the entire United States.
Dark Night is DeadlyIf you’re going to fly at night, than put the odds on your side. While it may seem obvious that flying when the moon is out will help, it will probably surprise you how much it will reduce your chances of an accident. One book, The Pilots Night Flying Handbook, by Buckwalter, cites NTSB statistics that shows the relationship between night flying accidents and flying in “dark night” conditions. Examples of this would be flying during a new moon or below an overcast that obscures the moon. Here are the data cited, where the numbers represent the number of accidents under different lighting conditions:
% of Accident Fatal
More recent NTSB data show that things haven’t changed very much. The bottom line is simple: The darker it is, the more likely you are to have a fatal accident. Often we talk about personal minimums in flying, such as always having more fuel and visibility than is required by the FARs. You may also want to consider the personal minimum that one local CFI has for night flying: He won’t fly unless there is at least a quarter moon.
One Approach: Just Say No to Night!Recently I spoke to our local EAA Chapter 62 about Bay Area accidents. Prior to the presentation, I re-examined my data on homebuilt accidents and was surprised to see that none of them occurred at night. When I asked about this, audience feedback was that some of their planes are not certified for night flight and that many of the members simply avoid night flight. When you take out the homebuilt fatal accidents, the statistics for those of us flying certified aircraft in the Bay Area are even worse. Five of 33 fatal accidents that occurred in the immediate area were homebuilt aircraft, but none of these were at night. Thus of the 28 fatal accidents for certified aircraft, 18 (64%) of the fatal accidents occurred at night! This is more than triple the national statistic, and points to the much greater danger of flying at night in the S.F. Bay Area, probably because of our locally high terrain and the marine cloud layer that forms on most nights.
Advanced Training: The Life You Save May Be Your Own!One of the best ways to reduce night accidents is to get an advanced rating. Paul Craig, author of The Killing Zone, found in his research that for a given number of hours of experience, a pilot with an instrument rating or commercial certificate had significantly fewer accidents than a pilot without one. This relationship held regardless of a pilot’s total flight time. So, statistically, a pilot who spends his hours getting additional ratings has far fewer accidents than the pilot who spends the same number of hours flying around getting $100 hamburgers. Some countries actually require more than the FAA’s minimum of three hours of night training. To fly at night in Canada, a separate night rating — with a minimum of 10 hours of night training including five hours of night solo — is required. Interestingly, the U.S. Commercial certificate requires the same five hours of night solo and an additional night, dual cross-country. Even if you don’t have an advanced rating, conducting night flight in the same fashion that one would conduct an IFR flight enhances safety (unless it puts you into a cloud). Always know the minimum safe altitudes for your route of flight, and make sure that you are above them. Use a VFR sectional chart to identify the minimum elevation figure (MEF) — the large numbers in each quadrangle — add at least 500 feet, and stay above that altitude while flying in that area.
Common Types of Night AccidentsIn her article Into the Night, Phyllis Anne Duncan gives a breakdown on night VFR flying accidents from 1995 though 1997. During this period, 46 of the accidents had a probable cause concerning preflight, 14 occurred during the taxiing or standing phase of flight, 73 occurred during the takeoff and climbing phase, and 223 occurred during the approach and landing phase. Clearly we’re at greatest risk on a night flight during approach and landing phases. But all phases have risks.
Most discussions of preflight for night flying properly emphasize the need to see that all of the legally required lights are working and that you have sufficiently bright light for the preflight inspection. In addition, make sure that you check the cockpit lighting in the plane before you go. Lighting varies considerably, even among airplanes of the same make and model, and you may be in for a surprise if you don’t check this on the ground. In addition, pay particular attention to your electrical system and make sure that the alternator is operating and charging the battery. While a loss of the electrical system in daytime VFR may be a minor annoyance, it can be a full-blown emergency at night if you’re unable to use your radio to activate pilot controlled lighting at your destination. All pilots learn about the need to adapt their eyes to the dark, and the long period required to do this. However, most people probably don’t brief their passengers about the need for the pilot to preserve that adaptation in the air. One local CFI mentioned that while on downwind for a night landing, one of his passengers said “hey look” and then snapped his picture with a flash camera! There’s also at least one accident in the NTSB records where a student, in a dark cockpit after an electrical failure, turned on a flashlight that blinded his instructor just before touchdown.
Taxi or Standing PhaseThe causes of taxi accidents are fairly obvious: Many airports are poorly lit at night, and if you’re not very careful while taxiing, you may strike an object on the ground. Fortunately most of these accidents are not fatal. Standing accidents usually involve being struck by a prop, and many of these are fatal. In Fresno, Calif., a Cessna 182 pilot stated that he was waiting at night in the transient tie-down parking ramp near the terminal for his passengers to arrive. They contacted him by cell phone and told him they were in the terminal parking lot and would be there shortly and to start the engine. After looking at the instruments he looked up and saw one of the intended passengers in front of the wing tip walking toward the engine and the person was killed. The probable cause was the pilot’s decision to allow unescorted passengers to approach the aircraft with the engine running, and the passenger’s failure to see and avoid the propeller. Spinning propellers are hard enough to see in the daytime, and are almost impossible to see at night. The only time I let someone in or out of the plane with a running engine is if it’s me. This usually occurs when I solo a student, but even then I make sure the plane is parked beyond the flight instructor bench so that all of my instincts will be to walk toward the back of the plane to get to where I’m going.
Takeoff or Climbing PhaseTakeoff over unlit ground or water can be particularly dangerous, even to high time pilots, if there are few visual ground references. There are many accidents on record where the departing pilot crashed on takeoff by descending into the ground, usually within the first mile of departing the airport. How could a pilot, much less an experienced one, crash like this? The answer is in the somatogravic illusion, which is discussed in most instrument training classes but is rarely mentioned in night training for private pilots. According to the FAA Instrument Flying Handbook, “… a rapid acceleration, such as experienced during takeoff, stimulates the otolith organs in the same way as tilting the head backwards. This action creates the somatogravic illusion of being in a nose-up attitude, especially in situations without good visual references. The disoriented pilot may push the aircraft into a nose-low or dive attitude. A rapid deceleration by quick reduction of the throttle(s) can have the opposite effect, with the disoriented pilot pulling the aircraft into a nose-up or stall attitude.” So what happens? A pilot taking off at night will experience the acceleration as a climb and release yoke pressure, allowing the airplane to descend into terrain. The same thing occurs often when instrument pilots reach the missed approach point and add full power to do a go-around. They perceive the acceleration as a climb and then — rather than pitch and trim for climb at Vy — continue to fly level at the worst possible time: close to the ground and possibly in IMC conditions. In Bishop, Calif., a Cessna 340A collided with terrain at night after a loss of control in the initial takeoff climb. Witnesses reported watching the airplane accelerate on Runway 12, rotate, and climb to about 200 or 300 feet above ground level with a decrease in climb rate. The airplane was seen to initiate a left turn before descending into terrain. The impact site was east of the airport about 2/3 of a mile. The departure direction was toward the White Mountain Range with sparse population and few ground reference lights.
Cruise PhaseThe cruise phase of flight is generally the safest, but illusions like false horizon can deceive a pilot. This is when a sloping cloud formation, an obscured horizon or certain geometric patterns of ground lights can lead to a pilot misperceiving the true horizon and putting the aircraft into a dangerous attitude. In hazy or dark night conditions, flying with reference to instruments is almost a necessity. If you cannot see the horizon, it’s hard to keep the airplane straight and level without using the instruments. The obvious paradox is that a private pilot may go years without any additional training on instruments, yet is “legally” allowed to fly in dark night conditions. Remember that legal and safe are two separate concepts, and while you may be legal to fly at night, you will want to get whatever additional training is needed to assure that you are also safe. Choosing a non-direct route at night can also enhance safety if you were to have an emergency and needed to land. Plotting a route over airports, and their very comforting rotating beacons, or along freeways can enhance your safety if the unthinkable occurs. Also, it’s a lot easier to inadvertently fly into a cloud at night. If you do fly into a cloud, generally a 180 turn (using your instruments for reference) is the safest way to slowly extricate yourself from that position. Maintaining a safe altitude is also critical. In a recent accident in Southern California an instructor and a newly licensed pilot in a Piper PA-28-181 struck terrain on a dark night. The flight had departed Redlands Municipal Airport about an hour after sunset in visual meteorological conditions for the purpose of making night landings at Redlands and other local airports. The aircraft struck about 100 feet below a ridgeline at the 4,100-foot level in the San Bernardino National Forest about nine miles southeast of Redlands Airport. The instructor had a total of 22 flight hours logged during night conditions, and it was the newly licensed pilot’s first night flight as PIC. Although a probable cause hasn’t been issued, it will probably note that the accident occurred several hours before the moon rose. Under these “dark night” conditions it is very difficult to see and avoid terrain in sparsely lit areas. One way to know whether you will clear a ridgeline at night is to observe the lights on the far side of the ridge. If, as you approach, you see fewer lights beyond the ridge, you are too low and will not clear the ridge! Obviously it’s far better to not have to rely upon this method, as you should always know where you are and what altitude is needed to clear obstacles in that area.
Approach & Landing
Most pilot have heard of “black holes,” where an aircraft crashes short of an airport when approaching to land due to an illusion created when there are few lights on the ground between the aircraft and the airport. Few, however, know of the studies done by Boeing engineers that have proven that, in black-hole conditions, pilots consistently fly below a standard, three-degree glideslope and often crash short of the runway! AVweb’s Linda Pendleton has an article that gives an excellent treatment of this subject. In one fatal crash, a non-instrument rated pilot in a Cessna 172 on approach to Ocean City, Md., crashed short of the runway because of this phenomenon. The airplane was over water, making a night VFR approach, when witnesses observed it suddenly transition from horizontal flight to a vertical descent into the ocean. According to a witness flying in the area at the time, the accident airplane went over a “black hole,” and he saw “strobe over strobe” before it disappeared. The witness also noted that disorientation around the airport at night was common because of the ocean. According to the NTSB, the probable cause was “spatial disorientation, which resulted in subsequent loss of control of the airplane. A factor was the dark night and over-water visual conditions.” One strategy for dealing with black-hole approaches is to use the VASI or ILS glideslope to maintain a safe altitude on approach, though not all airports have these. However, with the wide availability of GPS (or DME when there’s a VOR on the field), you can approximate your own three-degree slope. On a three-degree glideslope, you’ll descend 318 feet for each nautical mile you travel. So while on approach, stay at least this high above the ground for every mile away from the runway. In any case, avoid very long, straight-in approaches at night, particularly if no glideslope guidance is available. You will be much safer flying a regular pattern with a final that’s at most a couple of miles long, rather than flying a long, straight-in approach over many miles.
Have a Plan … Before you LeaveKnow the challenges in your local area and how to navigate your way through them. For example, many San Francisco Bay Area pilots returning at night find that the passes they want to use are obscured by the marine layer moving east through those same passes. To deal with this, it’s important to have a plan before you leave the ground. In the daytime, fly routes and passes that you commonly fly at night and determine the minimum altitude you are willing to use at night. If an overcast prevents you from maintaining that altitude, plan early to make a 180-degree turn and land at another airport still in the clear. Then you can phone a friend to get you, rent a car, or stay in a motel. Always consider alternatives, but remember that “hoping” things will work out is not an alternative! Plan ahead and select an alternative with a guaranteed known outcome.
Taming Night FlightClearly night flight is different and requires more care and planning. It also requires an understanding of the illusions. But knowledge may not be enough. In the Boeing study, even after pilots were aware of the black hole illusion, most of them still continued to fly too low. So develop your own strategies for night flight and enjoy the view!
More articles to help you become a better pilot are available in AVweb’s Airmanship section.