CBZT references the registration number of a Pegasus Quick aircraft on July 6, 2013:
https://assets.publishing.service.gov.uk/media/5422f1e340f0b613460003ef/Pegasus_Quik__G-CBZT_10-13.pdf
Weird.
re. the helicopter crash, the article says:
"Both aircraft had taken off from Wycombe Air Park, 23 miles away near High Wycombe, where a Notice to Airmen was previously issued to warn pilots the air field's air traffic control services would be closed during three 30-minute periods on selected days between November 7-30 due to a "staff shortage".
The crash occurred around half an hour after the latest closure was due to end."
http://www.telegraph.co.uk/news/2017/11/18/aviation-student-killed-mid-air-crash-loved/