{"product_id":"raf-navigational-computor-mk-iii-h-air-ministry-6b-250-1953","title":"Vintage RAF Aviation Navigation Computer with Original Carry Case | Circa 1953","description":"\u003cp\u003e\u003cstrong\u003eHistorical Context \u0026amp; Origin\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eRegion:\u003c\/strong\u003e Great Britain\u003cbr\u003e\u003cstrong\u003eMaterial:\u003c\/strong\u003e Metal, Bakelite, printed celluloid\/plastic navigation scales, canvas\u003cbr\u003e\u003cstrong\u003ePeriod:\u003c\/strong\u003e Early Post-War RAF, WWII-era design\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDescription\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThis Royal Air Force navigational computer is an original \u003cstrong\u003eNavigational Computor Mk. III H*\u003c\/strong\u003e, Air Ministry reference 6B\/250, manufactured by L.N.P. for use by British military aircrew.\u003c\/p\u003e\n\u003cp\u003eThe front plate is clearly marked:\u003c\/p\u003e\n\u003cp\u003eNAVIGATIONAL COMPUTOR MK. III H*\u003cbr\u003eREF. NO. 6B\/250\u003cbr\u003eL.N.P.\u003cbr\u003eLNP\/R\/8\/53\u003c\/p\u003e\n\u003cp\u003ealongside the British military broad-arrow property mark.\u003c\/p\u003e\n\u003cp\u003eDeveloped from the mechanical flight computers employed by RAF navigators during the Second World War, this sophisticated analogue instrument allowed aircrew to rapidly calculate and compensate for variables including true course, wind drift, airspeed, altitude, distance and estimated flight time. Comparable RAF navigational computers were specifically designed to solve wind-triangle and ground-speed calculations during flight.\u003c\/p\u003e\n\u003cp\u003eThe front incorporates a large circular 360-degree course and drift scale surrounding a movable red-and-white plotting grid. A side-mounted adjustment knob controls the internal plotting mechanism, while an integral pencil channel retains an accompanying British H.B. Morris “Falcon” Royal Sovereign pencil.\u003c\/p\u003e\n\u003cp\u003eThe reverse carries a second circular calculating assembly marked I.C.A.N. Calibration, providing scales for indicated and true airspeed, altitude, temperature, distance and time calculations. I.C.A.N. refers to the International Commission\/Convention for Air Navigation calibration system employed in aviation before the modern ICAO framework.\u003c\/p\u003e\n\u003cp\u003eEspecially noteworthy is the original green canvas carrying pouch accompanying the computer. Period handwritten markings appear to read G. E. Hunt, Flt\/Eng, No. 230 Sqn, suggesting association with a Flight Engineer serving with RAF No. 230 Squadron. The squadron had a long maritime aviation history and operated Short Sunderland flying boats, including extensive wartime operations in the Mediterranean and Far East.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFeatures\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e- British military broad-arrow property marking\u003c\/p\u003e\n\u003cp\u003e- I.C.A.N. calibration computer to reverse\u003c\/p\u003e\n\u003cp\u003e- 360-degree true-course and drift scale\u003c\/p\u003e\n\u003cp\u003e- Adjustable internal navigation plotting grid\u003c\/p\u003e\n\u003cp\u003e- Airspeed, altitude, distance and time calculation scales\u003c\/p\u003e\n\u003cp\u003e- Original-style integral pencil holder\u003c\/p\u003e\n\u003cp\u003e- Accompanied by H.B. Morris “Falcon” Royal Sovereign British pencil\u003c\/p\u003e\n\u003cp\u003e- Original green canvas carrying pouch\u003c\/p\u003e\n\u003cp\u003e- Period handwritten RAF personnel and squadron markings to pouch\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCultural Significance\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eMechanical navigational computers were essential tools of mid-20th-century military aviation. Before electronic flight-management systems and digital navigation equipment, RAF pilots and navigators relied upon instruments such as this to manually resolve the mathematical relationship between heading, wind direction, drift, airspeed and ground speed.\u003c\/p\u003e\n\u003cp\u003eThe Mk. III series descended directly from navigational equipment developed for wartime flying and represents an important transitional technology between traditional plotting methods and increasingly sophisticated electronic aircraft-navigation systems.\u003c\/p\u003e\n\u003cp\u003eThe apparent association of this example with No. 230 Squadron RAF adds particular historical interest. No. 230 Squadron served as a maritime reconnaissance and flying-boat unit and operated the Short Sunderland during both the Second World War and the early post-war period.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCondition\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eGood vintage military condition with expected age-related surface wear, light scratching, oxidation, staining and handling marks consistent with service and storage. Printed scales and markings remain clearly legible. The internal plotting grid and rear calculation scales are present.\u003c\/p\u003e\n\u003cp\u003eThe accompanying canvas carrying pouch displays age-related staining, discoloration and wear while retaining its drawcord and period handwritten markings. The pencil shows expected wear from age and use.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDimensions (Approximate)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eHeight: 6.25 in\u003cbr\u003eWidth: 5.5 in\u003cbr\u003eDepth: 1 in\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAge (Approximate)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e73 years old (as of the year of listing, 2026)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eProvenance\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eFrom a private collection in Newcastle, United Kingdom, formed with a focus on military artifacts and militaria.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eLearn More\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eCompare this instrument with a Navigational Computor Mk. III H* catalogued by the \u003cstrong\u003e\u003ca href=\"https:\/\/www.iwm.org.uk\/collections\/item\/object\/30000185\" title=\"Navigational Computor Mk. III H* – Imperial War Museums\"\u003eImperial War Museums\u003c\/a\u003e\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003cp\u003eDiscover more through our \u003cstrong\u003e\u003ca href=\"https:\/\/relicandrarity.com\/collections\/wwi-and-wwii-military-artifacts\" title=\"WWI and WWII Military Artifacts – Relic \u0026amp; Rarity\"\u003eCollection of WWI and WWII Military Artifacts\u003c\/a\u003e\u003c\/strong\u003e.\u003c\/p\u003e","brand":"Relic \u0026 Rarity","offers":[{"title":"Default Title","offer_id":55906268283202,"sku":null,"price":350.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0955\/1803\/2194\/files\/First_photo_design_-_2026-08-22T185515.738.png?v=1787456489","url":"https:\/\/relicandrarity.com\/products\/raf-navigational-computor-mk-iii-h-air-ministry-6b-250-1953","provider":"Relic \u0026 Rarity","version":"1.0","type":"link"}