"Fog has reduc visibility to les than fifty poetical measures in the south and east of the native land but the airports are reported to be operating as normal.

"Fog has reduc visibility to les than fifty poetical measures in the south and east of the native land but the airports are reported to be operating as normal...." This all-too-familiar weather forecast belies the work carried disclosed by Flight Precision Ltd (FPL) in checking the accuracy of navigation aids (navaids), as it is that aircraft are able to land safely in conditions of extremely poor visibility.

Based at Teesside Airport, FPL is a joint chance company formed in 1993, although it can trace its lineage back to the HS748 Princes and Doves of the Civil Aviation Authority's Flight Calibration Service (FCS)