The March crash of an Antonov AN-24 near Naryan-Mar in the Nenets autonomous region along Russia's Arctic coast shocked witnesses and initially puzzled officials by its apparent inexplicability. After a normal approach in near perfect conditions of limitless visibility and a gentle breeze, the plane suddenly banked and veered at low altitude, missing the landing strip and ploughing into the snow, nose-down and one wing first. Twenty-nine of the 53 oil-workers on board died, including the commander and navigator.

Initially it was thought that the crew must have had a sudden low altitude engine failure or runaway prop. However, qualified observers nearest to the crash site heard no such irregularity. Officials could think of no technical malfunction that would have caused the violent maneuvering seen on short finals to the Lukoil strip in the village of Varandei, short of flap asymmetry or detachment on one side. (Lukoil is Russia's largest oil producer.) However, the flaps had been already set for landing when the aircraft departed controlled flight. The next thing that sprang to mind was illegal interference or perhaps pilot incapacitation. The survivors suffered severe burns and other injuries, though some of them had revealing stories to tell about what they had seen at that final fatal moment.

The AN-24 belonged to the Kemorovo-based Regional Airlines and Flight 9288 was a charter run for the Perm-based company "Aviol." It usually carried only Naryanmarneftegaz oil company employees who work in the oil and gas wells at Varandei for two-week shifts. It had left Ufa airport at about 10:30 a.m. Moscow time on March 16 on a pickup run via Perm and Usinsk (Komi Republic) to Varandei. Departing Ufa there were the seven crew members on board.

The captain, Viktor Popov, was an experienced AN-24 pilot with more than 14,000 hours logged. His crew consisted of a navigator, the co-pilot trainee, a stewardess, a flight engineer and two technicians. Their layover at Ufa had been for 24 hours so the crew was well rested. At Perm, 41 passengers boarded and another five joined them at Usinsk. En route, the pilots communicated with Air Traffic Control at Archangel, and the aircraft was duly handed off to Varandei as it began its descent. Weather conditions were ideal, with limitless visibility under a static high pressure system overlaying the entire area. It was frosty and a little under minus-20 degrees F but the air was crystal clear.

The breeze was only a few knots from the East and the aircraft was landing more or less into the wind, into the Northeast. Eyewitnesses had picked up the aircraft visually while it was still a good 20 kilometers out. At 1357L the aircraft was configured for landing and only 5 kilometers away, so it was arriving a few minutes earlier than its 1403 estimate. It appeared to be in its normal approach configuration already with gear and flaps down at 1,000 feet above ground level and flying at around its normal approach speed of 135 knots. The Varandei controller heard a few VHF clicks (unmodulated carrier waves or sidetone only) and immediately thereafter the aircraft banked left and, still rolling rapidly, dove into the ground.

The left wing, undercarriage, and tail tore off and were destroyed, and the fuselage was smashed like an egg shell. The waiting company employees instantly became rescuers and dashed the 5 kilometers across the frozen snow-covered tundra and started extricating the survivors from the mounds of scattered and burning wreckage.

Varandei is a very remote and lonely outpost located within the Arctic Circle on the shores of the Northern Ocean. Varandei ATC contacted Naryan-Mar some 250 kilometers away, and Archangel more than a 1,000 kilometers away, by sat-phone for aid in extracting the injured to hospitals in Archangel. The death toll of 29 could rise given the many victims of severe burns. They were choppered out to Naryan-Mar.

The interstate aviation committee representative flew in and quickly claimed the flight data recorder and voice recorder. He was initially convinced that they would tell the story that investigators needed to hear. Unfortunately, even though serviceable and readable, they wouldn't. What had happened had occurred so suddenly that the pilots hadn't the time to communicate with each other or the ground. It had nothing to do with aircraft serviceability or systems failure. Nor was it pilot error.

Secrets of the Polar Light

It's no surprise that in polar regions light can become polarized. The phenomenon of ice-blindness is very familiar to seamen who work in high latitudes. Whalers and sealers used to carry sulfate of zinc to combat its insidious effect upon their eyesight. However, ice-blindness is a short- to medium-term phenomenon. Snow-blindness was the term used by Antarctic Explorer Sir Ernest Shackleton. It's unlike the "white-out," another polar trick upon one's eyes (i.e., illusion), that led to Air New Zealand's DC-10 ZK-NZP (Flight 901) that flew into the side of Mt. Erebus in similarly clear conditions. White-out involves the inability to discriminate between snowy earth and white-leaden sky. Neither phenomenon downed this AN-24, but the mechanism was just as, if not more, deadly.

The proliferation of commercially available cheap laser pointers has recently been keeping the FBI and local police forces everywhere busy with reports of pilots being suddenly blinded by an intensely focused (usually green) light. What the pilots of AN-24 Flight 9288 suddenly hit was Nature's laser. This illusory pitfall is a rare but known phenomenon for pilots who fly into Varandei and a few other coastal airports at this particular time of day and year in the higher latitudes. Fellow company pilots provided the explanation for the enigma. It was a visibility paradox that the investigators were unfamiliar with. It was as if the oil-camp pilots had held it close to their chests like a trade secret. It was indeed a genie that had escaped a local bottle, and was only now recaptured because one of their brethren had run into its full force.

Highway and Desert Mirages

We are all familiar with the liquidity of a summer heat-haze in the middle distance on a bitumen highway or the illusion of a pooled water surface upon the desert sands. It is one of Nature's visionary tricks. It can be transitory, fleeting and even hallucinatory. It is all about reflection, refraction and specular diffraction. Sometimes we just don't believe our eyes. Now look at the other end of the visual spectrum when, for instance, a photo-flash bulb goes off before our eyes after we have "dark-adapted" to night vision. The retina is temporarily unable to do its thing and record an image. The photoreceptors (rods and cones) have been flashed into insensitivity and will need to recuperate before normal vision is restored.

Now combine the two phenomena in the cold hard light of day and add persistence - not just to the aftermath effects, but to the sensory phenomenon itself. Sound like a flash from a nuclear fusion blast? Close .... as old Sol is certainly part of the problem. Specular diffraction is a potential nightmare for forward air controllers laser-illuminating a target in the vicinity of friendly troops. A fire-power demonstration in Qatar a few years ago led to B52s dropping laser-guided bombs (LGBs) onto a line of parked U.S. Marine CH- 53 helos in a little-known but deadly friendly fire incident that destroyed two CH-53s and killed a Marine. It was surmised that specular diffraction might have diverted the laser designator beam and warped the LGB's capture envelope, funneling the bombs onto the undesignated target. When it's raining and metal is shiny and wet, specular diffraction can send LGBs anywhere but into their laser-designated capture basket.

In New York, a particular architect has been designing parabolic windows into U.S. skyscrapers for years with the undesired effect of random hotspots that can zap and dazzle pedestrians and explode concrete sidewalks on a hot summer's day. Parabolic reflective solar furnaces are the alternative to photovoltaic cells for capturing solar energy. It has much to do with the power of the sun - and its inclination and elevation. In the polar regions there can be some very strange effects and solar extremes; some even rarer than the aurora borealis.

The Arctic Mirage

The superior mirage, also known in northern polar regions as the arctic mirage - or in Icelandic, the hillingar effect - causes the light from distant objects to be refracted optically downward so that it becomes possible for objects lying beyond the normal horizon to be seen. They even appear, at times, to rise up over the horizon, a condition known to mariners as looming, and look much closer in distance than they are.

The arctic or superior mirage is quite the opposite phenomenon to the desert or inferior mirage, which is familiar to all highway travelers as an apparent pool of water lying on the roadway, disappearing as it is approached. Under conditions favorable for viewing a desert mirage, the light rays from the sky are bent upward in a curve away from the surface by hot, light air near the ground and to the eye of the observer. The arctic mirage, on the other hand, occurs when the light rays are refracted downward by cold, dense air near the earth into an arc bending toward the observer.

The refractive capacity of air, under the right conditions, is great enough to cause the path of light rays to bend in an arc equal to the curvature of the Earth. This curvature can present an observer with the image of a flat horizon receding to infinity. Indeed, under certain circumstances, light ray paths can exceed the curvature of the Earth, and thus the horizon would appear to be raised upward giving the Earth's surface a saucer-shaped appearance. Under this latter condition, images of objects located at or below the normal optical horizon, such as mountains, glaciers, cliffs or sea-ice rise (loom) into the field of vision, overcoming the normal visual restrictions of the curvature of the Earth.

From the Pilot's Eye Viewpoint

All of the above is of course from a surface observer's point of view. There's no great leap of faith involved to reinterpret the phenomenon for a pilot's illusion on approach. It's just another optical illusion, right? When he descends into the inversion layer he'll see a "picture-jump" - one somewhat akin to what we might see if we thump the side of our TV out of sheer frustration. While the Arctic pilots of Kemorovo were possibly used to this phenomena, the one that claimed Flight 9288 was a much rarer exposition of the power of diffracted light. It was much more powerful even than the blinding distraction of landing into a late afternoon sun.

Varandei residents are long familiar with complaints by pilots that on sunny days the undercut coastal edge of the ice cliffs on the shoreline during the approach acts like a giant parabolic mirror and that its piercing glint could fleetingly dazzle pilots, blinding them momentarily. Consider that in the days before SARAH, SARBE and PRC90 pilot rescue beacons and survivor radios, the simple heliograph was the downed pilot's best daytime signaling device. It worked upon the power of even weak sunshine penetrating an overcast sky and was comprised a simple flat mirror with a cross-hair sighting device extended at arms length - with which to focus upon and transfix the cockpit of any search plane sighted in the area. Even though only a small reflective surface, it was a very effective device for locating downed pilots.

Arctic pilots know that the reflective angle of the sun relative to the shoreline can be much worse on certain days of the year and that on those days the momentary glint on approach could suddenly become an annoying dazzle that was far worse during certain periods of the day. What's more, at those times the coverage in elevation was greater, the phenomenon thus more persistent - and it always struck (i.e., its beam flown into on descent) without warning.

In the late finals ice-dazzle that was also noted by Flight 9288's passengers, the effect was much longer-lasting as the cockpit became suffused with brilliant concentrated white light at a dangerously low altitude. In effect, the pilots would have been doubly blind, as switching to instrument flight would also would have been impossible.

Two totally blinded pilots at 500 feet on finals is a recipe for certain disaster. At low altitude, a rapid loss of control due to disorientation might seem wholly inexplicable to a ground observer. However, from the pilot's "point of view," he simply, and suddenly, no longer had one.