REGARDING David Coggins letter 'Low Flying Plane Was in Airport Stack' (LET, January 28). His report was very good.

As a retired microlight pilot I have more than a passing interest in aviation and air traffic in the Blackburn region airspace and I have to say that the 747 Jumbo that was flying over Blackburn on that Saturday was to me, a matter of concern.

It was the only 747 on the circuit at that time. It was well below the regulation 10,000 feet, more like 3,500 and it was circling for more than 40 minutes, an extraordinary long time, that indicated to me that there was something wrong either at Manchester Airport or in the 747 itself.

The problem turned out to be freezing fog over the airport area. I am not in any way suggesting that death and destruction is about to fall from the skies over Blackburn or anywhere else, but with frequent terror alerts and cancelled flights affecting several airlines, we should be concerned and vigilant.

EDDIE DUXBURY, Arthur Way, Blackburn.