page_title: Chiltern Air Support Unit
section_title: History
hierarchical_section_title: Chiltern Air Support Unit / History
caption_attribution_description: English: Police Helicopter of the Chiltern Air Support Unit after it had taken off from the A505 at Offley Grange after attending a scene of a Road Traffic Collision involving a police vehicle
context_page_description: The Chiltern Air Support Unit was a police helicopter unit that operated under a consortium agreement between Bedfordshire Police, Thames Valley Police and Hertfordshire Police until 1 October 2012, when it merged into the National Police Air Service.
context_section_description: Before 1980, Thames Valley Police occasionally used helicopters at special events.
  In 1963, Oxford City Police experimented using a Brantley helicopter with a dog basket attached to the skids.
  In 1980, an aircraft was used on twenty separate days at various events, with further use taking place during 1981. It was not until June 1982 that the first formally contracted flights took place.
  During the next four years the helicopter was used more frequently. A single engine Aerospatiale A350 Squirrel helicopter designated G-JORR was hired for day-time operations for each weekday of 1985. This aircraft was based at Oxford Airport and used exclusively by the Thames Valley Police. Seven sergeants were drawn from the Traffic and Operations Departments as part-time observers.
  During April 1986, the Thames Valley Police Air Support Unit, as it had become known, was relocated to RAF Abingdon. Providing daylight cover only, the Unit was allocated a budget of 650 flying hours, but was still crewed by sergeant observers on an ad hoc basis. It was recognised that the specialist skills required could no longer be met by part-time observers, and in 1988 the decision was taken to recruit and train dedicated observers.
  The unit was renamed to the Chiltern Air Support Unit in 1996.
  Chiltern Air Support's Luton helicopter (EC135T2 CPDS) moved from London Luton Airport to RAF Henlow,  near Hitchin and Shillington. The helicopter was upgraded in 2001, and reached 10,000 hours of flying in September 2011. It operated using the call-sign XA99.
  Chiltern's other helicopter (EC135T1CDS) is based at RAF Benson near Wallingford in Oxfordshire. An order was made to replace the current helicopter due to changes in the law. It is now a requirement that the aircraft should have an Autopilot to make operations safer. In October 2010, the helicopter was exchanged with another Eurocopter EC135P2+ registered G-TVHB. It operated using the call-sign XA97.
caption: G-CPSH attending at scene of RTC on the A505 at Offley Grange
exif: {"Image Make": "FUJIFILM", "Image Model": "FinePix A610", "Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Digital Camera FinePix A610    Ver1.00", "Image DateTime": "2010:05:17 21:39:46", "Image YCbCrPositioning": "Co-sited", "Image Copyright": "", "Image ExifOffset": "294", "Image PrintIM": "[80, 114, 105, 110, 116, 73, 77, 0, 48, 50, 53, 48, 0, 0, 2, 0, 2, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0]", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail Orientation": "Horizontal (normal)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "1350", "Thumbnail JPEGInterchangeFormatLength": "9728", "Thumbnail YCbCrPositioning": "Co-sited", "EXIF ExposureTime": "1/640", "EXIF FNumber": "27/5", "EXIF ExposureProgram": "Program Normal", "EXIF ISOSpeedRatings": "100", "EXIF ExifVersion": "0220", "EXIF DateTimeOriginal": "2010:05:17 21:39:46", "EXIF DateTimeDigitized": "2010:05:17 21:39:46", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "2", "EXIF ShutterSpeedValue": "233/25", "EXIF ApertureValue": "49/10", "EXIF BrightnessValue": "967/100", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "16/5", "EXIF MeteringMode": "Pattern", "EXIF LightSource": "Unknown", "EXIF Flash": "Flash did not fire, auto mode", "EXIF FocalLength": "99/5", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "2848", "EXIF ExifImageLength": "2136", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "EXIF InteroperabilityOffset": "1202", "EXIF FocalPlaneXResolution": "4853", "EXIF FocalPlaneYResolution": "4853", "EXIF FocalPlaneResolutionUnit": "3", "EXIF SensingMethod": "One-chip color area", "EXIF FileSource": "Digital Camera", "EXIF SceneType": "Directly Photographed", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF SceneCaptureType": "Standard", "EXIF Sharpness": "Normal", "EXIF SubjectDistanceRange": "0"}