Night IFR Operations
Operating after dark can leave you in the dark. Extra vigilance is required to overcome the higher risk factors.
Most instrument rated pilots log about 10 percent of their flight time in IMC. That same percentage holds true for night operations. When you combine the two, encountering IMC at night is a rare occurrence for many. Most of us recognize that night IMC presents a high risk environment (statistically five-times more so than day operations) that should be undertaken only after carefully contemplating all the factors. I consider all night flights to be IFR operations to alert my psyche to the task at hand—especially because I operate primarily single pilot in mountainous terrain.
Weather is an obvious consideration, particularly when each season is measured for its specialties—icing in the winter and embedded thunderstorms in the summer. Terrain, MEAs and endurance, of both the plane and its occupants, are also of primary importance.
A rundown of the numbers for a recent year shows that 28 percent of GA accidents occur at night, of which 74 percent are by IFR rated pilots. Most accidents occur on dark nights—those when little or no moon is present. Winter typically has worse weather and presents 40 percent less daylight hours, thus more opportunity to be aloft at night.
Definitions Of Night
A quick review of the legalities of night operations reveals there are four considerations—lights, logging, landings and liquids. Each is covered in a different part of the FARs and more easily remembered in the sunset sequence.
Lights are required from sunset to sunrise (FAR 91.209). You may turn-off the anti-collision lights when in precip (91.209).
Logging can be made for flights after evening civil twilight—about 30 minute after sunset (FAR 1.1); one of the many uses of AirNav.com.
Landings are required one hour after sunset when used to record night currency for PIC operations with passengers (FAR 61.57(b)). As for liquids, FAR 91.151 requires that you have a 45 minute fuel reserve—the prudent pilot will make that one hour.
My son, an experienced commercial/instrument rated pilot, recently flew a solo IFR night trip from Scottsdale to Albuquerque in a Cirrus SR-22TN. As I usually do, I followed my boy’s trip on FlightAware (OK, so he is 45, but he will always be my boy) and noticed that he went north out of KSDL to about Winslow before turning east. An area of noticeable precipitation occupied the direct route and, as it was early April, I suspected that icing was forecast. He had his first encounter with icing only a few weeks earlier on a trip to Kansas—and I thought this might be a factor. As he is always eager to log actual, I knew something had influenced his decision.
The next morning I emailed to inquire about his trip, noting the radar returns for the weather he had skirted. I was pleased by the wisdom exhibited when he indicated that the routing was in response to the desolate and hostile terrain on a direct track. The path he has taken assured him of a major highway close to his route, located conveniently by the G1000.
Obviously, ensuring the destination airport has appropriate lighting is essential. On a flight from Los Alamos NM, to San Diego CA, I launched later in the afternoon than planned and encountered higher than forecast winds requiring an unplanned night refueling short of my destination. I diverted to Blythe, but discovered the lighting had been NOTAMed as out-of–service, a detail I had not anticipated. For those who know the area, there aren’t many options. Always keep your backdoor open.
Mitigating Electrical Failure
While a power failure is a remote possibility, at night it is a major player in flight planning. An electrical problem, such as a failed alternator, also can rear its ugly head. Although the battery may last up to 30 minutes, that time will slip by quickly, so have airports with IAPs at frequent intervals. A more catastrophic failure can happen without notice.
Planning for various types of electrical failures should be in your playbook. Scan engine and electrical systems more often. I’ve lost alternators twice at night and an immediate response is needed. Review the procedures before the flight for discharge or overcharge indications. Know the location of all electrical switches and breakers. If you are in IMC it is an emergency—so don’t hesitate to declare and request a vector and altitude change to VFR conditions.
Shed power—get rid of nav lights and beacon and consider a complete power down. Advise ATC if you need to go off-the-air for periods as radio transmission and the transponder are power hungry devices. Consider ded-reckoning for stretches of navigation. Save the battery for the IAP, everything else is a luxury. When you use the “E” word, ATC will be most accommodating.
We know that a flashlight is a place to store dead batteries and that the flight bag must have two within arm’s reach. But have you ever tried to fly an approach with one stuck under your arm or clinched in your teeth? Invest in a small LED unit with a head band, and practice a few approaches with no cockpit lighting. It’s a revelation.
With respect to landing lights, if you are in snow, they are almost useless in flight because of the visual effect akin to achieving warp speed in a starship—with thousands of horizontal white streaks mesmerizing you—consider doing without. When was the last time you landed at night without a landing light? That is another interesting operation where you might want to have a CFI in the right seat.
Making an approach to a non-towered airport, there are other considerations. I recall one with an instrument student to such an airport that, although not down to minimums, it was low. As we came out of the overcast at the MDA, we had good visibility and could plainly see lighted buildings and streets, but the runway was nowhere in sight. I let him hunt a bit until I could tell from the higher vocal notes he was achieving in his declaratives that he was concerned. Almost before I could complete the phrase “pilot controlled-lighting” he was clicking the mic button with enthusiasm. The display was a welcome sight. Add PCL to your check list at the FAF.
Not only are some IAPs not available at night because there may be no one to provide an altimeter setting (most now have automated sensor suites-ASOS/AWOS) but some may not serve as alternates for a variety of reasons. Where a nearby substitute altimeter setting is used, the minimums are often noticeably higher—Santa Fe NM, RWY 33 for example, goes from an MDA of 6720 (416) to 7620 (1316).
Visibility is another consideration—one mile visibility at night is more restrictive than the same value during the day. You may not be able to see cloud bases or tops and precipitation will appear as a haloing effect around any visible ground lights. Of course, all is not sinister in the world of night IFR if you ever have the privilege of experiencing being on-top or over a snow covered landscape during a full moon.
Special VFR (one mile and clear of clouds) takes on a new dimension at night as only IFR rated and current pilots may request, and the aircraft must be instrument capable. This can be a very high risk operation so use it only when you are sure of the environment.
Follow The Yellow Brick Road
After landing, stay on the runway centerline so that you can pick up the taxiway lead-in markings. Remember, the taxiway sign is placed before the exit point—which can be a challenge to find at night. Missing the turn-off with a 737 on your heals will not make any friends in the tower or with the crew in the cockpit that has to execute a miss while you fumble for the turn-off.
The physiology of night IFR could fill several articles, but keep in mind fatigue inducing stress, visual illusions and the impact of hypoxia on night vision—even at lower altitudes.
In summary, thorough preflight planning and the methodical use of the check list is the key to reducing risk and stress levels. The ability to fly IFR night operations brings added flexibility to our piloting privileges but requires a higher degree of diligence and responsibility.
Ted Spitzmiller, who has been flying IFR for over 40 years, appreciates and respects night flight.