TWO pilots who died when their light aircraft hit electricity pylons on a Gwent mountaintop may have seen the structures too late to save themselves, a crash report says.

Their aeronautical chart would not have shown the pylons - atop Mynydd Maen, above Cwmbran - because they were less than 300 feet tall and so not required to be marked.

A post-accident investigation revealed that the pylons were hard to see against their background.

Gerald Prangley, aged 52, from Bridgend, and Kevin Mansbridge, aged 50, from Barry, died on Easter Monday, April 1. Qualified pilots and members of Cardiff (Wales) Flying Club, they were flying a Piper PA38 Tomahawk from Cardiff Airport to Shobdon, Herefordshire, when they encountered worsening weather.

An inquiry by the Department of Transport's Air Accident Investigation Branch (AAIB) found the aircraft had turned north over Cwmbran towards high ground, several miles before a planned turning point, but could not discover a reason.

"A turn back towards Car-diff, where the weather was known, would have been the more logical choice. Why they turned left towards the high ground could not be determined," says the AAIB report.

"It may have been that the weather looked brighter in that direction, or the turn kept them closer to their planned route. In turning, however, they found themselves flying in and out of the cloudbase, making it difficult to navigate and maintain visual contact with the ground.

"Although their chart showed the height of the ground ahead, it did not show the pylons. Being less than 300 feet high, (these) are not required to be depicted on the aeronautical chart and the pilots may have been unaware of their presence.

"It is possible they maintained level flight throughout this period for they hit the pylon at approximately 1,500 feet (above sea level), their planned altitude for the route.

"The ground that rose rapidly beneath them was relatively featureless and there would have been few visual cues.

"On their track the pylons contrasted very poorly with the background. The fact that the impact was in straight and level flight suggests neither of the pilots had any significant warning of their presence."

The report considers the pair may have, in poor visibility, mistaken Risca for Cwmbran and turned earlier than they intended, but concludes that navigational error was "a less likely scenario."

* Pictured, the Gwent mountain where two pilots were killed when their light aircraft crashed