Aftermath: A Flight in Total Darkness Ends in a Fatal Crash

A pilot flying VFR gets the leans after taking off in an area without ground lights or a visible horizon.

Aftermath Artwork
Accident analysis that goes behind and beyond the NTSB report.Flying

In August of last year, a 125-hour pilot rented a Piper Arrow in Palm Beach, Florida. The rental agreement the pilot signed included a proviso that “there are not to be any night flights to or from the Bahamas or Florida Keys before sunrise or after sunset.”

Notwithstanding the advice of one’s parents, one may sign many things without reading them carefully, and so the pilot may not have taken note of that restriction, which was merely one of dozens of conditions and codicils that occupied three single-spaced pages of the rental agreement. Or he may have consciously chosen to ignore it. In any case, security cameras at Marathon Airport, which is in those very Florida Keys, recorded the airplane taking off shortly after midnight. It was a warm, calm night with clear skies and unlimited visibility, but the moon was on the other side of Earth. The only light over the Florida Bay was starshine, and the southern tip of Florida, across the bay, is an unpeopled wilderness. The airport cameras recorded, along with the receding lights of the Arrow as it climbed out from Runway 25 and turned north, the fact that there was no visible horizon.

The pilot, who did not have an instrument rating, had filed a VFR flight plan to West Palm Beach. The Arrow had traveled only a mile and a half, however, when it collided with the water, disintegrated and sank. Two night-fishermen witnessed the crash and retrieved the pilot’s body from the sea.

Warnings about the dangers of night flying in areas without ground lights or a visible horizon are part of every pilot’s education. So is the art of using the attitude indicator to keep an airplane right-side up. What cannot be taught, but must be discovered by experience, is the difficulty of overcoming the spatial disorientation, or vertigo, that sometimes materializes like an evil spirit, without warning, out of the darkness.

One form of disorientation, most likely the one that caused this accident, is known by the innocuous-sounding nickname “the leans.” You get the leans when you have been in a banked turn long enough for the balancing machinery in your inner ear to become accustomed to it, and then you roll out. When you roll level, your brain believes you are banking the other way.

In visual flight, either the eye or the body’s sense of the gravity vector corrects the information the brain receives from the position sensors in the inner ear. But when there is no horizon and insufficient ground lighting to produce a sense of one, the brain falls back on the ear, which is both easily deceived and extremely persuasive. The instrument panel, which is always level with respect to the pilot, masquerades as the true horizon; the vector sum of gravity and the centrifugal force of a turn impersonates the true vertical.

Turning from the runway at Marathon to a direct track to West Palm would have involved changing heading by about 130 degrees. The pilot would have had ample time to create the conditions that might produce a case of the leans. Relatively inexperienced, he may never before have flown over water on a black night; perhaps he found his physical sensations so persuasive that he did not consult the attitude indicator to verify them.

A similar accident occurred a year earlier in Texas when a Lancair 550 took off from a private strip on a ranch in desolate country about 80 miles west of Fort Worth. It was a dark, moonless night. A number of airplanes, many with professional pilots, were leaving an event at the ranch in succession. Several pilots who were interviewed by the National Transportation Safety Board’s investigator described the conditions as “extremely dark” or “like a black hole.”

The Lancair, with three aboard, took off after a Cessna Citation. How much separation there was between the two departures was unclear; observers on the ground estimated several minutes, while ATC radar put the airplanes 57 seconds and — somewhat implausibly — 5.5 nautical miles apart.

Onlookers saw the Lancair break ground at midfield, begin to climb and initiate a right turn. Its bank angle slowly increased until the navigation lights were vertically aligned, and then the airplane descended out of sight. It crashed less than half a mile from the departure end of the runway, killing all aboard. The highest altitude reported by its transponder was 250 feet.

The pilot in this case had an instrument rating and nearly 500 hours, but he had logged only 2.4 hours at night in the Lancair. His most recent night flight had been more than a year earlier, and that had been with an instructor. Furthermore, his night-flying experience, the Board suggested, may have been confined to areas with ample ground lighting. He was not current for night flight with passengers under the FARs, which require three night takeoffs and landings within the preceding 90 days.

Not being legal does not prevent using an attitude indicator, however, and it is not immediately obvious why an instrument-rated pilot would have any difficulty transitioning to instruments when he found no external references. But investigators found a clue in photos recovered from a couple of iPhones found in the wreckage. They showed an iPad mounted at the right side of the instrument panel displaying navigational data.

Like the Arrow’s departure from Marathon, the Lancair’s takeoff, in this case from Runway 35, would probably have been followed by a right turn toward his home airport in Grandbury, 40 miles to the east. The Board’s theory of the accident is that the pilot looked to his right to consult the iPad map and unconsciously overbanked as he did so.

The Board’s discussion refers generically to spatial disorientation, but there is a special category of disorientation that can come into play with a powerful airplane, like the Lancair 550. Forward acceleration may be interpreted by the brain as a backward tilt of the pilot’s seat, causing him to believe that he is climbing steeply when, in fact, he may be level or even descending, and prompting him to nudge the nose downward.

Pilots who take off over populated areas, pass over unlighted wilderness en route, and then land in populated areas again may never experience the disorienting quality of total darkness. The seconds following takeoff over dark terrain are particularly hazardous because lights in the middle distance have not yet come into view, attitude and speed are changing, and the usual evidence of positive climb rate, the rapid recession of the surrounding environment, is missing.

At very low altitude, the time needed to recognize an unusual attitude or the lack of a horizon, interpret the attitude indicator, and finally take corrective action may be longer than the time it takes the airplane to return to the ground.