English: Pictured is the Bristol Type 138 High Altitude Monoplane, K4879. Completed in early 1936, the aircraft was routinely capable of achieving 50,000ft and could also carry an observer when necessary.

The Bristol Type 138 High Altitude Monoplane was a British high-altitude research aircraft developed and produced by the Bristol Aeroplane Company during the 1930s. It holds the distinction of setting nine separate altitude world records, the ultimate of these happened during a 2¼-hour flight flown by Flight Lieutenant M.J. Adam, in which he achieved a record altitude, which was later homologated by the Fédération Aéronautique Internationale as having attained a maximum altitude of 53,937 ft (16,440 m).

• Some of these images have had some dodging and burning done and have been retouched to remove detritus and dust and scratch marks only*
• Organization: RAF
• Object Name: H-1387
• Category: MOD
• Supplemental Categories: Aircraft, Equipment, People, Historic
• Keywords: K4879, Royal Aircraft Factory S.E.5, Historic Aircraft, RAF, Royal Air Force, Historic, Equipment, Aircraft, B&W, Black and White, Monoplane, High Altitude, Bristol Type 138, Research Aircraft, Inter War Years, RAF 100
• Country: UK