I've been a bit curious about this and spent some time yesterday tracking down the history.
At this point, there are two styles of manual computer, the E6B (which has a slide that fits into the main body of the computer) and the CR, which is circular and has no slide.
Philip Dalton, a pilot with the U.S. Naval Reserve, invented and patented the E6B, and his 1936 patent application can be read via a search on Google Patents. On the marketing side, he worked with Philip Weems, whose name will be familiar to mariners here as one half of Weems and Plath.
Siegfried Knemeyer, both an active military pilot and head of technical development for aviation for the German Reich, invented the predecessor of the CR for use by the Luftwaffe. In 1955, a pilot named Harold Raymond Lahr, together with his employer, United Airlines, patented a version of Kneyemeyer's computer and assigned the patent to Jeppesen. The Lahr/United Airlines patent can also be read via a search on Google Patents.
The main difference between the E6B and the CR is that the latter takes a more mathematical, trigonometric approach to solving wind triangles. One result is that the CR is more compact (indeed, this is stressed in the patent application), but perhaps a bit harder to grasp.
Philip Dalton died when his plane crashed while instructing a new Naval aviator. After the War, the U.S. decided to "invite" Knemeyer, along with von Braun and other prominent German scientists, to become a U.S. citizen. Lahr went on to become the principal spokesman for the argument that TWA Flight 800, which in 1996 crashed off Long Island with major loss of life, was shot down by a missile, and that the U.S. Government, including the NTSB, the CIA and the FBI, have engaged in a massive coverup ever since. Ray Lahr, or people associated with him, continue to maintain a web site in his name dedicated to the cause, most recently updated two years ago.
The Patents on both styles of flight computer have long since lapsed. The Pooley's CRP computers (dominant in the U.K.) are based on the E6B. There are several companies making copies of the CR. The "new" ASA E6B Circular Flight Computer, released in 2014, is not an E6B at all. It is a copy of the Jeppesen CR. I guess that ASA thought that the name "Circular E6B" would sell better.
If you look at instruction manuals from 30 years ago, they stress the wind functions and treat the rest as secondary. Newer manuals stress such useful features as converting liters and U.S. gallons to Imperial Gallons. Hey, there are apparently a couple of Caribbean islands that continue to use the latter, and wind computations are a bit harder
Yes, I have too much time on my hands
At this point, there are two styles of manual computer, the E6B (which has a slide that fits into the main body of the computer) and the CR, which is circular and has no slide.
Philip Dalton, a pilot with the U.S. Naval Reserve, invented and patented the E6B, and his 1936 patent application can be read via a search on Google Patents. On the marketing side, he worked with Philip Weems, whose name will be familiar to mariners here as one half of Weems and Plath.
Siegfried Knemeyer, both an active military pilot and head of technical development for aviation for the German Reich, invented the predecessor of the CR for use by the Luftwaffe. In 1955, a pilot named Harold Raymond Lahr, together with his employer, United Airlines, patented a version of Kneyemeyer's computer and assigned the patent to Jeppesen. The Lahr/United Airlines patent can also be read via a search on Google Patents.
The main difference between the E6B and the CR is that the latter takes a more mathematical, trigonometric approach to solving wind triangles. One result is that the CR is more compact (indeed, this is stressed in the patent application), but perhaps a bit harder to grasp.
Philip Dalton died when his plane crashed while instructing a new Naval aviator. After the War, the U.S. decided to "invite" Knemeyer, along with von Braun and other prominent German scientists, to become a U.S. citizen. Lahr went on to become the principal spokesman for the argument that TWA Flight 800, which in 1996 crashed off Long Island with major loss of life, was shot down by a missile, and that the U.S. Government, including the NTSB, the CIA and the FBI, have engaged in a massive coverup ever since. Ray Lahr, or people associated with him, continue to maintain a web site in his name dedicated to the cause, most recently updated two years ago.
The Patents on both styles of flight computer have long since lapsed. The Pooley's CRP computers (dominant in the U.K.) are based on the E6B. There are several companies making copies of the CR. The "new" ASA E6B Circular Flight Computer, released in 2014, is not an E6B at all. It is a copy of the Jeppesen CR. I guess that ASA thought that the name "Circular E6B" would sell better.
If you look at instruction manuals from 30 years ago, they stress the wind functions and treat the rest as secondary. Newer manuals stress such useful features as converting liters and U.S. gallons to Imperial Gallons. Hey, there are apparently a couple of Caribbean islands that continue to use the latter, and wind computations are a bit harder
Yes, I have too much time on my hands
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