December 8, 2016

Night Flying Primer: More Things To Consider


Night Flying Primer: More Things To Consider

Donald Anders Talleur


Last month I touched on the issues of night flying in terms of night vision, illusions, and pilot and aircraft equipment. This month the focus is on nighttime considerations for specific phases of flight.

Night flight planning is not significantly different than for daytime flights, with the exception that VFR flights need to take into consideration that fewer visual references are available. Specifically, landmarks that might be used to identify a daytime flight path may not be visible at night.

Similar sized towns that are distinguishable during the day may be easily confused at night.Terrain features may not be visible at all. However, some features that are very useful for position fixing include airport rotating beacons, highways, prominently lit obstructions and large cities.

Once a desirable flight path is picked, the line drawn on the map should be wide enough and dark enough to be easily seen in the ambient light conditions expected for the flight. Bear in mind that certain colors will not show up well if the cockpit is lit with the same color light (e.g. red lines will not show up prominently, and some times not at all under red cockpit lighting).

Extra fuel reserves are also a good idea (and the nature of your mission may require it by regulation!) For night flight. While a daytime divert may provide multiple airport options, night time diverts may be dependent on the existence of airports with runway lights.Even so, if the reason for the divert is a complete electrical failure, you’ll likely need to pick an airport that has lights that stay on all the time; as opposed to airports with pilot controlled lighting.

Determine the type and status of airport lighting prior to flight by checking airport directory information and NOTAMs.However, even a lit runway may still be tricky to land on without an operating landing light, so a thorough preflight of the aircraft’s exterior lights should be made prior to each night flight.As an aside, if you’ve never landed at night without a landing light, you should find a qualified instructor and go try it (don’t pick a moonlit night; that’s cheating!).

Maneuvering on the airport surface at night requires more vigilance than daytime since surface conditions are not as easy to see. Taxi slow and keep your eyes open! If it’s been awhile since you’ve flown at night, re-familiarize yourself with airport lighting standards.

At tower controlled airports, if in doubt about where you’re at, or where you’re going, ask for progressive taxi instructions.

In general, use whatever lights you want during taxi (in addition to the anticollision and navigation lights) but as a courtesy, turn off your landing/taxi lights holding short of a runway if other aircraft might be passing by. Likewise, unless your strobe lights are the only anti-collision lights installed, it’s recommended that these also be turned off until taking the runway.

Takeoff at night requires a little extra care in that tracking the centerline of the runway is sometimes difficult on a dark runway. The best way to assure a safe takeoff is to have the cockpit lights turned down to the minimum level necessary to see the instruments, thus allowing for better vision of the sparse cues outside.

Centerline alignment after the takeoff roll has begun is accomplished by keeping the airplane centered between the runway edge lights. Take care to look far enough down the center of the runway during takeoff. Looking towards one side or another will lead to a drift towards that side.

Once flying airspeed is reached, smoothly lift off and establish the normal climb attitude using the attitude indicator and available outside cues.

Frequent use of the attitude indicator during climb will help verify that the correct pitch attitude and heading are maintained.

During the climb, once collision avoidance is no longer an issue, the landing/taxi lights may be turned off. Continued use of recognition lights (if installed) is recommended for the entire flight.

During cruise flight, navigation is carried out the same way as during daytime, with the exception that you may need to rely more heavily on ground or satellite navigation facilities than on pilotage.

Frequent cross checks with NAVAIDs or GPS for position should be made to assure correct flight path alignment. Also be sure to keep track of altitude so that proper terrain clearance is maintained.

Keep in mind that when flying over large, poorly lit areas (large bodies of water as well), depth perception and orientation are difficult. Reliance on instrument indications and navigation equipment will adequately supplement a lack of visual cues in these circumstances.

Arriving at an airport at night is sometimes difficult and sometimes easy. It really depends on how the airport and runways are situated relative to your arrival flight path, and whether the airport is buried within a sea of lights from other buildings or obstructions.

I find the best way to approach at night is to head straight for the rotating beacon until airport surface features can be identified via the lighting arrangement. Another good way to positively identify your airport and runway is to tune in and track an ILS or other approach course for the runway of intended landing.

ILSs and LPV GPS approaches are especially useful in that they also provide vertical guidance (clear of terrain) to the runway environment. In any event, know whether the runway of intended landing has any sort of visual slope indications such as VASIs or PAPIs and stay at or above the normal approach path until adequate visual references are in sight, or until necessary to make a safe landing.

Realize that without visual slope indications the runway edge lights may be the only source of information as to your height and approach angle.Remember that if the runway starts to look flat, you are approaching from a shallow angle.

Pilots should approach uncontrolled airports at night with great caution.Be prepared to reactivate pilot controlled lighting prior to reaching the final approach so that you don’t get any surprises right before touchdown (I once found it quite disturbing when the runway edge lights turned off during the flare to touchdown!).

In general, touchdown is made the same way at night as for day, but with the scarce visual references it may be helpful to reference the landing light (assuming it’s properly focused).As the light from the landing light starts to reflect off the surface and the runway is visible, the roundout can be started with a smooth gradual reduction of throttle to idle as the airplane touches down.

Without landing lights, the pilot can reference the runway edge lights at the far end, and when they appear to rise above the nose of the aircraft, the roundout and landing flare should be started. Slight adjustments in pitch and power may be Necessary to “feel” for the runway so that it settles gently to the ground. This type of night landing is difficult, so I’d recommend getting some practice with an instructor prior to trying it solo for the first time.

Night time emergencies are perhaps the most dreaded of all.An engine failure or adverse weather situation at night and a subsequent emergency landing Are hard enough to deal with, but at night you may have to simply guess about what’s below since the ground may not be visible until the very last second.

Generally, if a forced landing is inevitable, and terrain is known, heading towards unlit areas is wisest since lit areas generally present more obstructions to avoid.

One exception to this rule is for mountainous areas. In this case, lit areas may actually provide larger flatter open areas than the darker hilly terrain. In either case, landing should be made at the slowest possible airspeed.If an appropriate landing area with nearby public access can be reached that would also be desirable.

During the approach to landing, don’t forget to turn on the Landing light (if possible) as you may be able to make some minor adjustments to the flight path just before touchdown if you see an obstacle, or even swerve to avoid ground obstacles after landing. After landing, shutdown the aircraft, grab your flashlight and move away from the aircraft until you’re sure that fire is not imminent.

Night flying can indeed be a rewarding experience.However, proper preparation and inflight decisionmaking are key to making the night flight a safe experience.Before night flight consider your body, your equipment, the airplane’s equipment, airport lighting, and technique for the specific phases of flight.Also consider the possible night-time visual illusions and review emergency procedures.And remember, flying at night does not require the pilot to be in the “dark” about safety!

This month’s Pilot Primer is written by Donald Anders Talleur, an Assistant Chief Flight Instructor at the University of Illinois, Institute of Aviation. He holds a joint appointment with the Professional Pilot Division and Human Factors Division.He has been flying since 1984 and in addition to flight instructing since 1990, has worked on numerous research contracts for the FAA, Air Force, Navy, NASA, and Army. He has authored or co-authored over 200 aviation related papers and articles and has an M.S. degree in Engineering Psychology, specializing in Aviation Human Factors.