A KLM Lockheed L-049 Constellation airliner (named Nijmegen and registered PH-TEN) crashed into high ground near Glasgow Prestwick Airport, Scotland, on 20 October 1948; all 40 aboard died.

The weather forecast Parmentier had been given by the Royal Dutch Meteorological Institute at Schiphol had told him that there was some slight cloud at Prestwick, but that it would likely dissipate by the time the Nijmegen arrived.

However, KLM pilot guidelines, drafted by Parmentier himself, forbade a landing at Prestwick in low cloud on the alternative runway.

Three miles (4.8 km) inland ran a series of electricity pylons and high-tension cables, the main national grid line for South Scotland, carrying 132,000 volts.

[8] At this point the Nijmegen was headed directly for the power cables at 450 feet (140 m), which the crew believed to be substantially lower.

[8] Parmentier realised the 'isolated fog' he had run into was getting denser, but due to his belief that they would have visual contact with the ground the crew had not attempted to time their flight downwind of the runway.

[8] Before he could abort the attempt, the plane crashed into the electricity cables, hitting the main phase conductor line.

However, the faulty charts led them to crash into high ground five miles east-north-east of the airfield[12] at about 23:32 UTC.