EmergencyLight – Phantom Menace
Winter flying in real, cold continental climate is hard on pilots, aeroplanes and controllers alike. The somewhat lower traffic volume is frequently offset by the delays resulting from snow and ice on the runway, or the occasional broken-down snow-sweeper…
As you will see, cold winter air has a number of its own tricks up its sleeve. Darkness had fallen some hours earlier when the last departure of the day, a cargo 707 roared into the air, leaving a flurry of snow swirling above the frozen runway long after the plane was gone. Alone in the air, they climbed swiftly in the thick, cold air and it looked like another routine end to the day.
In no time at all, however, departure control was shaken out of its peaceful reverie when the pilot of the Boeing announced in a shaken voice that he was taking avoiding action due to another large aircraft maintence sighted immediately below their own. A quick look at the flight progress board confirmed what controllers knew already, namely that there was no other aircraft within a hundred miles. Radar seemed to bear out the same, with only the cargo machine’s blip inching along on the screen, albeit on a heading almost 90 degrees away from its original course. They were making an avoiding action, all right.
On being told about the empty air around them, the crew sounded incredulous, but nevertheless they accepted the series of radar vectors that brought them back on course. No sooner were they back on track, however, when with a frightened “Here it comes again” cry on the radio, they once again veered off to the right.
Not knowing what to make of it all, the controller again brought them back onto the airway, all the time assuring the crew that there just could not be another aircraft operations anywhere nearby. By now a different voice, obviously the captain, was responding from the plane, indicating in a no nonsense manner that he wished to file an airmiss report. He also made it plain he thought the controllers’ insistence on their being alone was nothing but a poor attempt at covering something up.
The bewildered controller jotted down what he had to say and handing over the sector to his relief man, he went away to write his own report. He also had the good sense of getting confirmation from the military that they, too, had nothing flying in that area at that particular time.
A few days later, when the official complaint arrived at the safety inspectorate, the experts got together in an attempt to find out what had actually happened. To put it mildly, the reports were somewhat conflicting. The captain insisted that they had, on two consecutive occasions, sighted a big, four engine aircraft, approaching their own from directly below and the collision had been avoided solely by his sharp turn away from the other plane. They claimed to have clearly seen the other aircraft’s navigation lights as well as its blinking anti-collision beacon. The controller’s report at the same time asserted that there had been no other aerospace operations visible on radar and in fact none was expected for several hours. The transcript of the tape recording routinely made of all radio and telephone conversations also had no indication of the possible presence of another aircraft.
The investigators could only assume that both reports contained the truth, but then what could the crew of the Boeing have seen? As the weeks passed and no progress was being made, someone jokingly suggested that they had seen a mirror image of themselves. A meteorological expert was brought in at that stage and he carefully went through the high altitude data collected on the night of the incident. What he finally revealed turned out to be nothing short of spectacular. Although there had been no clouds reported, there was a marked temperature inversion around 30000 feet and he also suggested the possible presence, just above this inversion, of a thin layer of almost invisible ice crystals.
With a full moon shining, those ice crystals acted like a Venetian mirror leading the 707 crew into believing that they were about to collide – with themselves!