for example); this is also the form preferred by most Welsh writers, among others. Many authoritative works, from other study groups, also use the Welsh form. The Welsh personal name Llywelyn, from which the mountain's name is derived, is always spelt thus in the Welsh language, although the forms Llewelyn and Llewellyn are found in older English-language sources. Plane crash On 14 March 1950 a number of Royal Air Force, Avro Lincoln's from No. 230 Operational Conversion Unit RAF took off from RAF Scampton bound for RAF Hemswell, England on a night-time cross-country exercise. In the early hours of 15 March a controller at RAF Barton Hall instructed three of the Lincolns to divert to RAF Valley, Anglesey, Wales due to bad weather at RAF Scampton. It was at 2:55am GMT that one of the Avro Lincoln's (RF511) had gone missing and the other two aircraft landed safely five minutes later. The wreckage of RF511 was found at 5:20 GMT on Carnedd Llewelyn and it was confirmed that all six crew had died. The subsequent Court of Inquiry determined that the likely cause of the crash was pilot error; the crew had turned onto a southeasterly course over Anglesey instead of the reciprocal out to sea. The pilot misheard the instruction to "turn 180 degrees" as "turn 80 degrees", resulting in a controlled flight into terrain. The wreckage of RF511 remains on the mountain, and in 2002 a memorial plaque was placed at the crash site. Cultural references The mountain features in Welsh poetry and literature; the earliest known work is a poem by Rhys Goch Eryri, Carnedd Llywelyn, composed c. 1400. Notes Further reading External links Carnedd Llewelyn is at coordinates Walking Routes, photos and GPS files for Carnedd Llewelyn Walk Eryri www.geograph.co.uk : photos of Carnedd Llewelyn Hewitts of Wales Marilyns of Wales Mountains and hills of Snowdonia Nuttalls Mountains and hills of Conwy County Borough Mountains and hills of Gwynedd Climbing areas of Wales Landmarks in Wales Furths Llanllechid Caerhun Capel Curig One-thousanders of Wales Aviation accidents and incidents locations in Wales