The (as yet) unexplained destruction of two 65 ft wind turbine blades coupled with sightings of strange lights and noises in the night sky has fuelled widespread speculation about a UFO strike, possibly, according to the more imaginative reports, by a craft not of this earth.

A wind turbine at a wind farm near Conisholme, Lincolnshire, UK, has been badly damaged, hit, say local reports, by an unidentified flying object. The damage is believed to have occurred on the night of 4 January, when according to witnesses among local residents a loud bang was heard following sightings of strange lights streaking across the sky.

Owner Ecotricity is currently investigating the wreckage to try and determine how the turbine, which has one of its three blades missing from the hub and one twisted out of shape, was so severely damaged. It is one of 20 at the Fen Farm site, but none of the others was affected.

Speculation about UFOs from space heightened after it was stated by The Sun that one of the 65 ft blades had disappeared, but this turned out to be an exaggeration. In fact the torn off blade had only disappeared as far as the ground nearby, where it was found. Ecotricity engineers said on 8 January that lightning had been ruled out as a cause and, as there was no significantly windy weather on the night in question no evidential cause immediately suggested itself. However, the investigation continues and engineers are confident of finding the cause within a few days. But if catastrophic materials failure is also ruled out, then it will likely turn out that the turbine had been hit by a heavy object. At this stage, says Ecotricity, with its tongue firmly in its cheek, a UFO impact is the best explanation available.

A major flaw in the UFO-from-space theory however is that the reports of strange lights seen hovering in the sky on 4 January were separated by some hours from the loud bang, suggesting a collision or explosive failure, heard by some residents later. This includes one report from a witness who saw unexplained lights streaking towards the turbine and actually striking it, but inexplicably the noise of the smash was not heard until some hours later at about 4 am, when several residents reported hearing the noise.

One interesting speculation suggests a strike by a conventional aircraft, possibly a heavily armoured plane such as the US air force A10 Thunderbolt, which is designed for low-flying, low speed, tank-busting operations. Such a craft could conceivably cause this kind of damage without being brought down by the collision, and they do operate out of airbases in the area. But no report of any such flight has come from either air force or from aviation authorities.

Turbine blade failures (from terrestrial causes) are not particularly uncommon. Usually the cause is high winds or, occasionally, materials failure. To give just a few examples, in 2002 a rotor blade was destroyed by lightning strike at the Blyth, UK, offshore farm; in April 2005 one 40m blade of a turbine at a wind farm in Berwickshire, Scotland suddenly shattered, the failure being blamed on strong winds and icy weather conditions; in November 2006 the tip of the rotor blade of a turbine in Oldenburg, Germany was torn off following a sudden gust of wind, throwing it into a field 200m away; in January 2007 a family in Belfast narrowly avoided tragedy when a 16 ft blade spun off a wind turbine and crashed through the roof of their home; in July 2008 a giant wind turbine near Sheffield, UK, was shut down and dismantled (‘controlled deconstruction’) after cracks in the blades appeared; and in December 2008 lumps of ice were catapulted from an 80 m high turbine in Peterborough, UK, causing some concern among local residents. Several incidents were reported during 2007 and early 2008 in Denmark where turbines made by the world’s largest manufacturer, Vestas, literally exploded after running out of control in high winds following brake failure, and in Scotland where high winds had caused wind turbine towers to collapse.